Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Investigation of mechanical and physical properties of epoxy hybrid composites reinforced with lignocellulosic materials (roselle stem, reed stem, and palm leaf) Investigation of mechanical and physical properties of epoxy hybrid composites reinforced with lignocellulosic materials (roselle stem, reed stem, and palm leaf) 1 19 735472 10.22034/ijwp.2025.2059284.1709 FA Mohammad Arabi Department of wood and paper science,-Faculty of natural resource - University of zabol 0000-0002-2502-9964 Sadegh Sarabi Phd Student, Department of Science and Wood and Paper Industries, Zabol University, Zabol, Iran. Journal Article 2025 05 25 Problem definition and objectives: Currently, due to high prices and non-biodegradability of synthetic fibers, there has been a significant increase in using natural fibers as reinforcement in polymer composites. Natural fibers have been welcomed by engineers and researchers as suitable alternatives to synthetic fibers, considering their unique characteristics such as low density, low production cost, good modulus and strength, abundance, accessibility, renewability, recyclability, biodegradability, and environmental compatibility. The type and proportion of lignocellulosic materials in combination with polymer resins play a crucial role in determining the final properties of these composites and significantly influence their ultimate applications. Therefore, this study aims to explore the possibility of manufacturing and reinforcing polymer composites (epoxy resin) using different proportions of lignocellulosic materials (reed stem, roselle stem, and palm leaf) and analyze their physical and mechanical properties. Materials and Methods: Reed stem, roselle stem, and palm leaf were obtained from the Chahnameh Nursery and Baqiyatallah Educational and Research Complex at Zabol University. The materials were dried in a laboratory oven at 103°C for 24 hours. Epoxy resin (AD-301) and epoxy hardener (HA-12) from Mokarrar Company were used in a 100:10 ratio. The study variables initially included three lignocellulosic materials: roselle stem (TS), reed stem (RS), and palm leaf (PL) at three levels: 10, 30, and 50 percent (weight ratio of lignocellulosic materials to epoxy resin). Lignocellulosic-reinforced epoxy composites were manufactured using a manual layup method with a wooden mold (300 × 300 × 50 mm) under press conditions (80°C and 6.2 MPa pressure for 3 hours). Tensile, flexural, and water absorption tests were conducted according to ASTM D3033, ASTM D790, and ASTM D570 standards, respectively. The best treatment was subsequently alkaline-treated at 5 and 10 percent levels to improve physical and mechanical properties, and the impact of alkaline treatment was evaluated. Results: Epoxy composites reinforced with 10% roselle stem exhibited the lowest tensile strength, flexural strength, and water absorption. Mechanical properties increased with lignocellulosic material proportion up to 30%, with palm leaf composites at 30% showing the highest mechanical properties. Increasing the lignocellulosic material proportion from 30% to 50% resulted in decreased tensile and flexural strength. The highest water absorption was observed in samples with 50% roselle stem, while the lowest was found in samples with 10% palm leaf. The optimal treatment, based on physical and mechanical properties, was identified as 30% palm leaf reinforcement. Alkaline treatment at 3% and 5% improved the mechanical and physical properties of epoxy composites, with flexural strength, flexural modulus, and tensile strength increasing by 11.9%, 12.7%, and 15%, respectively, compared to untreated samples. Conclusion: The study demonstrated that incorporating lignocellulosic materials in epoxy resin enhances the mechanical properties of hybrid epoxy-lignocellulosic composites. Utilizing these renewable resources not only reduces dependence on petroleum-based materials and costs but also contributes to natural resource conservation and environmental pollution reduction. The findings underscore the potential of these composites as lightweight, robust, and environmentally friendly materials in various industries, including automotive, construction, and packaging. Problem definition and objectives: Currently, due to high prices and non-biodegradability of synthetic fibers, there has been a significant increase in using natural fibers as reinforcement in polymer composites. Natural fibers have been welcomed by engineers and researchers as suitable alternatives to synthetic fibers, considering their unique characteristics such as low density, low production cost, good modulus and strength, abundance, accessibility, renewability, recyclability, biodegradability, and environmental compatibility. The type and proportion of lignocellulosic materials in combination with polymer resins play a crucial role in determining the final properties of these composites and significantly influence their ultimate applications. Therefore, this study aims to explore the possibility of manufacturing and reinforcing polymer composites (epoxy resin) using different proportions of lignocellulosic materials (reed stem, roselle stem, and palm leaf) and analyze their physical and mechanical properties. Materials and Methods: Reed stem, roselle stem, and palm leaf were obtained from the Chahnameh Nursery and Baqiyatallah Educational and Research Complex at Zabol University. The materials were dried in a laboratory oven at 103°C for 24 hours. Epoxy resin (AD-301) and epoxy hardener (HA-12) from Mokarrar Company were used in a 100:10 ratio. The study variables initially included three lignocellulosic materials: roselle stem (TS), reed stem (RS), and palm leaf (PL) at three levels: 10, 30, and 50 percent (weight ratio of lignocellulosic materials to epoxy resin). Lignocellulosic-reinforced epoxy composites were manufactured using a manual layup method with a wooden mold (300 × 300 × 50 mm) under press conditions (80°C and 6.2 MPa pressure for 3 hours). Tensile, flexural, and water absorption tests were conducted according to ASTM D3033, ASTM D790, and ASTM D570 standards, respectively. The best treatment was subsequently alkaline-treated at 5 and 10 percent levels to improve physical and mechanical properties, and the impact of alkaline treatment was evaluated. Results: Epoxy composites reinforced with 10% roselle stem exhibited the lowest tensile strength, flexural strength, and water absorption. Mechanical properties increased with lignocellulosic material proportion up to 30%, with palm leaf composites at 30% showing the highest mechanical properties. Increasing the lignocellulosic material proportion from 30% to 50% resulted in decreased tensile and flexural strength. The highest water absorption was observed in samples with 50% roselle stem, while the lowest was found in samples with 10% palm leaf. The optimal treatment, based on physical and mechanical properties, was identified as 30% palm leaf reinforcement. Alkaline treatment at 3% and 5% improved the mechanical and physical properties of epoxy composites, with flexural strength, flexural modulus, and tensile strength increasing by 11.9%, 12.7%, and 15%, respectively, compared to untreated samples. Conclusion: The study demonstrated that incorporating lignocellulosic materials in epoxy resin enhances the mechanical properties of hybrid epoxy-lignocellulosic composites. Utilizing these renewable resources not only reduces dependence on petroleum-based materials and costs but also contributes to natural resource conservation and environmental pollution reduction. The findings underscore the potential of these composites as lightweight, robust, and environmentally friendly materials in various industries, including automotive, construction, and packaging.

https://www.ijwp.ir/article_735472_a6374046cad07f39898c977b1cf3cb96.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Investigation of the effect of wood species on the optical properties of transparent wood composites with polyvinyl alcohol and epoxy polymers Investigation of the effect of wood species on the optical properties of transparent wood composites with polyvinyl alcohol and epoxy polymers 21 33 735473 10.22034/ijwp.2025.2068027.1719 FA Hamideh Abdolzadeh Shahid Rajaee Teacher Training University,Tehran, Iran 0000-0002-5821-2562 Alireza Kangarloo Shahid Rajaee Teacher Training University, Tehran, Iran Seyed Mahmoud Mir Tari Shahid Rajaee Teacher Training University, Tehran, Iran Journal Article 2025 08 06 Problem Statement and Objectives: Wood has long been used as a construction material. In recent years, various wood-based products, with an emphasis on their aesthetic properties, have attracted significant attention from researchers. Transparent wood composite, commonly referred to as transparent wood in the industry, is one such product. Transparent wood is an emerging optical material that combines properties such as haze and high light transmission with construction applications. Transparent wood composites are produced by delignifcation of wood or deactivating the chromophores in lignin and infiltrating it with a polymer that has a refractive index equal to or similar to that of cellulose. This product integrates mechanical performance with optical capabilities, making it a promising candidate for applications such as smart buildings, optical devices, and photonics. This study investigates the preparation methods and optical performance of transparent wood and discusses its potential applications. Methodology: In this study, two wood species, beech and maple, were used to produce transparent wood composites after delignification. Delignification of wood veneers was carried out using sodium chlorite (NaClO₂) at a pH of 4.6. The delignified samples were impregnated with epoxy resin (E) and polyvinyl alcohol (PVA) under vacuum conditions. Polymerization of PVA resin was conducted at 40°C in an oven, while epoxy resin was polymerized at ambient temperature. The transparent wood composites were tested for optical properties according to the ASTM 1003-21 standard. Wood veneers, delignified veneers, and transparent polymers made from pure epoxy and PVA resins were used as control samples for comparison. In this study, light transmission values were examined as the determining factor for the transparency and haze of transparent wood composites. Three replicates were measured for each sample, and the average values were compared. Results: Optical tests conducted on control samples showed that wood veneers did not transmit light and lacked haze. The delignified samples of both species, despite noticeable color changes, also lacked optical transparency. Consequently, no reportable values were obtained due to the lack of complete transparency in these samples. The results indicated that, unlike solid wood and its delignified veneers, the produced transparent wood composite exhibited suitable optical transparency and transmitted light. Optical tests revealed that transparent wood composites not only transmitted light but also had higher haze compared to transparent polymers. The light transmission in transparent wood made from beech species with epoxy resin and polyvinyl alcohol decreased by 43.17% and 7.85%, respectively. The haze of transparent wood from the beech species was more suitable and increased by up to 671%. The light transmission values showed no significant difference between the two species. Samples made with epoxy resin exhibited higher transparency compared to PVA resin. Images from scanning electron microscopy confirmed the filling of cavities and changes in cell walls after delignification. Conclusion: The results demonstrated the feasibility of producing transparent wood composites. The beech species exhibited better light transmission and haze. Transparent wood composites possess suitable opacity characteristics, making them ideal for use in partition spaces or windows, enabling the utilization of sunlight while providing conditions for maintaining privacy. The results from both species were satisfactory, with the composite made from epoxy resin exhibiting superior properties. Problem Statement and Objectives: Wood has long been used as a construction material. In recent years, various wood-based products, with an emphasis on their aesthetic properties, have attracted significant attention from researchers. Transparent wood composite, commonly referred to as transparent wood in the industry, is one such product. Transparent wood is an emerging optical material that combines properties such as haze and high light transmission with construction applications. Transparent wood composites are produced by delignifcation of wood or deactivating the chromophores in lignin and infiltrating it with a polymer that has a refractive index equal to or similar to that of cellulose. This product integrates mechanical performance with optical capabilities, making it a promising candidate for applications such as smart buildings, optical devices, and photonics. This study investigates the preparation methods and optical performance of transparent wood and discusses its potential applications. Methodology: In this study, two wood species, beech and maple, were used to produce transparent wood composites after delignification. Delignification of wood veneers was carried out using sodium chlorite (NaClO₂) at a pH of 4.6. The delignified samples were impregnated with epoxy resin (E) and polyvinyl alcohol (PVA) under vacuum conditions. Polymerization of PVA resin was conducted at 40°C in an oven, while epoxy resin was polymerized at ambient temperature. The transparent wood composites were tested for optical properties according to the ASTM 1003-21 standard. Wood veneers, delignified veneers, and transparent polymers made from pure epoxy and PVA resins were used as control samples for comparison. In this study, light transmission values were examined as the determining factor for the transparency and haze of transparent wood composites. Three replicates were measured for each sample, and the average values were compared. Results: Optical tests conducted on control samples showed that wood veneers did not transmit light and lacked haze. The delignified samples of both species, despite noticeable color changes, also lacked optical transparency. Consequently, no reportable values were obtained due to the lack of complete transparency in these samples. The results indicated that, unlike solid wood and its delignified veneers, the produced transparent wood composite exhibited suitable optical transparency and transmitted light. Optical tests revealed that transparent wood composites not only transmitted light but also had higher haze compared to transparent polymers. The light transmission in transparent wood made from beech species with epoxy resin and polyvinyl alcohol decreased by 43.17% and 7.85%, respectively. The haze of transparent wood from the beech species was more suitable and increased by up to 671%. The light transmission values showed no significant difference between the two species. Samples made with epoxy resin exhibited higher transparency compared to PVA resin. Images from scanning electron microscopy confirmed the filling of cavities and changes in cell walls after delignification. Conclusion: The results demonstrated the feasibility of producing transparent wood composites. The beech species exhibited better light transmission and haze. Transparent wood composites possess suitable opacity characteristics, making them ideal for use in partition spaces or windows, enabling the utilization of sunlight while providing conditions for maintaining privacy. The results from both species were satisfactory, with the composite made from epoxy resin exhibiting superior properties.

https://www.ijwp.ir/article_735473_84689d5f2e034f7edb171e0dae387521.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Preparation of time-based schedule for drying of walnut slab with different width in vacuum/hot-air kilns Preparation of time-based schedule for drying of walnut slab with different width in vacuum/hot-air kilns 35 51 735474 10.22034/ijwp.2025.2072884.1729 FA Asghar Sistani Department of Wood and Paper Science and Technology, Faculty of Natural Resources, College of Agriculture and Natural Resources, University of Tehran, Iran Asghar Tarmian Department of Wood and Paper Science and Technology, Faculty of Natural Resources, College of Agriculture and Natural Resources, University of Tehran, Iran. 0000-0002-0925-7465 Foroogh Dastoorian Department of Wood Engineering and Cellulosic Products, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Iran Journal Article 2025 09 27 Problem definition and objectives: Drying wood is one of the most important stages of its primary processing, which affects the final quality and cost of producing wood products. Drying valuable hardwood slabs such as Persian walnut in a conventional kiln is associated with serious challenges due to their large dimensions, including prolonged drying time, cracking, deformation, and the occurrence of internal stresses. Similar to conventional kilns, for drying wood in a vacuum kiln, an optimal schedule should be developed according to the type of species and its dimensions. In addition, the type of vacuum kiln and its technical specifications, such as the heat transfer system, also affect the optimal schedule. In other words, a separate schedule must be prepared for each type of vacuum kiln. The main objective of this study was to develop a time-based schedule for drying Iranian walnut (Juglans regia L.) slabs in an industrial-scale vacuum/hot air kiln. Methodology: Persian walnut slabs with a nominal thickness of 7 cm and a length of 180 cm, in two width ranges (below and above 400 mm), were dried. Initial moisture content of the slabs ranged from 60% to 70%. An industrial vacuum/hot air kiln with a nominal volume of 12 cubic meters and a hot oil heating system with intermittent vacuum application was used to dry the slabs. Three time-based schedule were used in 9 to 10 steps with a maximum temperature of 70°C and a maximum vacuum of 0.45 bar. In the first, second and third schedule, the temperature of the first step was 45, 40 and 35°C, and the drying time was 152, 167 and 176 hours, respectively. The vacuum and heating time used for each schedule was also different. After the end of drying, the final moisture content, moisture gradient in thickness and width, residual stress (casehardening), cracking and warp intensity were determined. The experiment was based on a Completely Randomized Design and the significance of the mean data was analyzed with Duncan's multiple range test. Results: The final moisture content of the slabs in all drying schedules was in the range of 10–12%, which is suitable for the final use of the material in the production of office and household rustic-style furniture. The highest moisture gradient across the thickness and width of the slabs was observed in schedule 1, whereas schedule 3 showed the lowest gradient. Surface and end checking were significantly more severe in schedule 1 (total check length exceeding 1500 mm in wide slabs), while the length was reduced to less than 200 mm in schedule 3. Case-hardening also decreased significantly in schedule 3. Furthermore, deformation defects such as cupping, bowing, springing, and twisting were minimized in schedule 3, leading to a substantial improvement in the final quality of the slabs. In all schedules, wide slabs (over 400 mm) exhibited greater checking and deformation compared to narrow slabs. Conclusion: Drying schedule strongly determines the final quality of walnut slabs. In the schedule 1, rapid drying of the slabs due to higher temperatures and greater vacuum resulted in severe defects, while schedule 3, with mild drying condition improved moisture uniformity, reduced cracks and deformations, and enhanced overall quality. Therefore, schedule 3 is recommended as the optimal drying schedule for Iranian walnut slabs in vacuum/hot-air kilns. Problem definition and objectives: Drying wood is one of the most important stages of its primary processing, which affects the final quality and cost of producing wood products. Drying valuable hardwood slabs such as Persian walnut in a conventional kiln is associated with serious challenges due to their large dimensions, including prolonged drying time, cracking, deformation, and the occurrence of internal stresses. Similar to conventional kilns, for drying wood in a vacuum kiln, an optimal schedule should be developed according to the type of species and its dimensions. In addition, the type of vacuum kiln and its technical specifications, such as the heat transfer system, also affect the optimal schedule. In other words, a separate schedule must be prepared for each type of vacuum kiln. The main objective of this study was to develop a time-based schedule for drying Iranian walnut (Juglans regia L.) slabs in an industrial-scale vacuum/hot air kiln. Methodology: Persian walnut slabs with a nominal thickness of 7 cm and a length of 180 cm, in two width ranges (below and above 400 mm), were dried. Initial moisture content of the slabs ranged from 60% to 70%. An industrial vacuum/hot air kiln with a nominal volume of 12 cubic meters and a hot oil heating system with intermittent vacuum application was used to dry the slabs. Three time-based schedule were used in 9 to 10 steps with a maximum temperature of 70°C and a maximum vacuum of 0.45 bar. In the first, second and third schedule, the temperature of the first step was 45, 40 and 35°C, and the drying time was 152, 167 and 176 hours, respectively. The vacuum and heating time used for each schedule was also different. After the end of drying, the final moisture content, moisture gradient in thickness and width, residual stress (casehardening), cracking and warp intensity were determined. The experiment was based on a Completely Randomized Design and the significance of the mean data was analyzed with Duncan's multiple range test. Results: The final moisture content of the slabs in all drying schedules was in the range of 10–12%, which is suitable for the final use of the material in the production of office and household rustic-style furniture. The highest moisture gradient across the thickness and width of the slabs was observed in schedule 1, whereas schedule 3 showed the lowest gradient. Surface and end checking were significantly more severe in schedule 1 (total check length exceeding 1500 mm in wide slabs), while the length was reduced to less than 200 mm in schedule 3. Case-hardening also decreased significantly in schedule 3. Furthermore, deformation defects such as cupping, bowing, springing, and twisting were minimized in schedule 3, leading to a substantial improvement in the final quality of the slabs. In all schedules, wide slabs (over 400 mm) exhibited greater checking and deformation compared to narrow slabs. Conclusion: Drying schedule strongly determines the final quality of walnut slabs. In the schedule 1, rapid drying of the slabs due to higher temperatures and greater vacuum resulted in severe defects, while schedule 3, with mild drying condition improved moisture uniformity, reduced cracks and deformations, and enhanced overall quality. Therefore, schedule 3 is recommended as the optimal drying schedule for Iranian walnut slabs in vacuum/hot-air kilns.

https://www.ijwp.ir/article_735474_0ce208a1ab1e7dba6461bb5065b32b54.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Investigation on the relationship between anisotropy and the electrical resistance of Spruce (Picea abies) carbonized wood Investigation on the relationship between anisotropy and the electrical resistance of Spruce (Picea abies) carbonized wood 53 68 735475 10.22034/ijwp.2025.2071104.1727 FA Journal Article 2025 09 09 Problem definition and objectives: Today, there is an increasing effort to find and use biomass fuels as renewable energy sources with the aim of replacing conventional fossil fuels. Biochar is a porous material, very heterogeneous, and carbon rich, which is produced by biomass pyrolysis under an environment with anoxic conditions or limited oxygen. Among the recent applications for this material is its use as an electrode material in supercapacitors with the purpose of energy storage. The electrical conductivity of the electrode material is a very important factor for the efficiency of this tool. In this research, the relationship between the structural anisotropy of spruce wood and the pyrolysis temperature was investigated on the electrical resistance of carbon electrodes derived from it. Methodology: Radial and tangential samples were prepared separately from the sections without defects and knots of the spruce wood. Radial and tangential samples of spruce wood were pyrolyzed at three different temperatures (700, 800 and 900 ﹾC to investigate the effect of pyrolysis temperature on the physical and chemical characteristics of biochar. 4-point probe technique was used to measure electrical resistance. Raman spectroscopy was used to investigate the degree of graphitization and X-ray diffraction (XRD) was used to investigate the effect of pyrolysis temperature on the crystallinity of biochar samples obtained from spruce wood. The surface chemistry and functional groups of the samples were investigated by Fourier transform infrared (FTIR) spectroscopy. Results: The results showed that the pyrolysis temperature had a significant negative effect on the yield and porosity of the prepared biochar and a significant positive effect on its density. Also, the cutting type had no significant effect on the efficiency and density of biochar. According to the results, the shrinkage in three directions followed a similar pattern to that of wood. In all three temperatures in this study, the highest and lowest shrinkage values were belonged to the tangential and axial directions, respectively. Also, the results of SEM images of the cross-sectional surface of the produced spruce biochar samples showed that the anatomical characteristics of wood were preserved in the biochar. The results of the Raman spectroscopy test showed more graphitization with increasing pyrolysis temperature, which led to a decrease in electrical resistance, or in other words, an increase in electrical conductivity. In the case of both types of radial and tangential samples, the electrical resistance decreased significantly (p<0.05) by increasing the temperature. The highest electrical resistance values (5.46 Ω) correspond to the tangent to the wood biochar growth rings obtained from the tangential sample at 700 ⸰C and the lowest of it (0.05 Ω) correspond to the perpendicular to the wood biochar growth rings obtained from the radial sample at the temperature 900 ⸰C. Conclusion: In general, the electrical resistance of spruce wood biochar decreased by increasing the temperature of pyrolysis and more graphitization of wood. Also, the structural anisotropy of the wood had no significant effect on the electrical resistance of its biochar at temperatures higher than 700 ⸰C. Problem definition and objectives: Today, there is an increasing effort to find and use biomass fuels as renewable energy sources with the aim of replacing conventional fossil fuels. Biochar is a porous material, very heterogeneous, and carbon rich, which is produced by biomass pyrolysis under an environment with anoxic conditions or limited oxygen. Among the recent applications for this material is its use as an electrode material in supercapacitors with the purpose of energy storage. The electrical conductivity of the electrode material is a very important factor for the efficiency of this tool. In this research, the relationship between the structural anisotropy of spruce wood and the pyrolysis temperature was investigated on the electrical resistance of carbon electrodes derived from it. Methodology: Radial and tangential samples were prepared separately from the sections without defects and knots of the spruce wood. Radial and tangential samples of spruce wood were pyrolyzed at three different temperatures (700, 800 and 900 ﹾC to investigate the effect of pyrolysis temperature on the physical and chemical characteristics of biochar. 4-point probe technique was used to measure electrical resistance. Raman spectroscopy was used to investigate the degree of graphitization and X-ray diffraction (XRD) was used to investigate the effect of pyrolysis temperature on the crystallinity of biochar samples obtained from spruce wood. The surface chemistry and functional groups of the samples were investigated by Fourier transform infrared (FTIR) spectroscopy. Results: The results showed that the pyrolysis temperature had a significant negative effect on the yield and porosity of the prepared biochar and a significant positive effect on its density. Also, the cutting type had no significant effect on the efficiency and density of biochar. According to the results, the shrinkage in three directions followed a similar pattern to that of wood. In all three temperatures in this study, the highest and lowest shrinkage values were belonged to the tangential and axial directions, respectively. Also, the results of SEM images of the cross-sectional surface of the produced spruce biochar samples showed that the anatomical characteristics of wood were preserved in the biochar. The results of the Raman spectroscopy test showed more graphitization with increasing pyrolysis temperature, which led to a decrease in electrical resistance, or in other words, an increase in electrical conductivity. In the case of both types of radial and tangential samples, the electrical resistance decreased significantly (p<0.05) by increasing the temperature. The highest electrical resistance values (5.46 Ω) correspond to the tangent to the wood biochar growth rings obtained from the tangential sample at 700 ⸰C and the lowest of it (0.05 Ω) correspond to the perpendicular to the wood biochar growth rings obtained from the radial sample at the temperature 900 ⸰C. Conclusion: In general, the electrical resistance of spruce wood biochar decreased by increasing the temperature of pyrolysis and more graphitization of wood. Also, the structural anisotropy of the wood had no significant effect on the electrical resistance of its biochar at temperatures higher than 700 ⸰C.

https://www.ijwp.ir/article_735475_9e075f037ce20aabf5a27829393ab5a3.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Determining an appropriate structure for developing the poplar value chain in Guilan Province Determining an appropriate structure for developing the poplar value chain in Guilan Province 69 83 735476 10.22034/ijwp.2025.2075449.1734 FA AmirHossien MoteshakkerHossieni Department of Agricultural Economics, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran Mohammad Kavoosi-Kalashami Department of Agricultural Economics, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran 0000-0003-1789-4496 Fatemeh Askari Bozayeh Researcher, Economic, Social and Extension Research Department, Gilan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran. Journal Article 2025 10 24 Problem definition and objectives: Due to its suitable climate and fertile soil, Guilan Province is one of the geographical areas prone to the development of poplar cultivation in Iran. Determining the appropriate structure for developing the poplar value chain in this province can improve productivity, job creation, sustainability, enhanced participation of production factors and market actors, improve resilience, chain customer satisfaction, and moderate the impact of market intermediaries. The main goal of this study is to provide an appropriate mechanism for developing the poplar value chain in Guilan Province using expert opinions to create solidarity and synergy between the various pillars and links of the poplar value chain in this province. Methodology: Considering the main objective of the research, two main steps were considered in its implementation. The first step of the study involves designing a comprehensive decision tree of drivers affecting the development of the poplar value chain in Guilan Province. The drivers were determined based on an extensive review of theoretical foundations, research background, and based on the perspectives of 15 selected experts (experts in the agricultural and wood industries of Guilan Province, leading poplar growers, and faculty members from the agricultural and natural resources research and education center of Guilan Province and University of Guilan) in the form of an experts' meeting. After preparing a comprehensive list of factors and drivers for the development of the poplar value chain in Guilan Province using the coding method, categorization of similar opinions, and examination of the frequency of selection of sample experts, the drivers were refined, modified, and finally selected. In the second step, the importance of various drivers of the development of the poplar value chain in Guilan province and the determination of the appropriate business model were determined using the Fuzzy Hierarchy Process (FAHP) and a paired comparison questionnaire. Results: The research findings showed that the economic driver was assigned 51.65% importance among the decision tree criteria. Also, structural, environmental, and socio-cultural criteria are ranked second to fourth in importance. Among the economic drivers, profitability, productivity, and chain financing, with a total relative weight of 66.82 percent, are the top three economic drivers for the development of the poplar value chain in Guilan Province. The most important socio-cultural driver is building trust in people with a relative weight of 33.7 percent. The sub-criterion of preserving water and soil resources, with a relative weight of 40.66 percent, is the most important environmental driver. Also, energy and water supply, contract farming, and chain intelligence, with a total relative weight of 59.08 percent, are considered the three top structural drivers of poplar value chain development in Guilan Province, respectively. Comparisons among four business models - Orchestra, Market Maker, Layered, and Integrated - based on 21 studied drivers showed that the market maker model is the optimal mechanism for developing and creating sustainable interaction between actors and agents of the poplar value chain in Guilan province. Conclusion: The Market Maker model represents the most effective and prioritized structure for developing the poplar value chain in Guilan Province in the current situation. It is suggested that financial resources and capital be directed purposefully to different links in this chain to provide the basis for market regulation and effective support for producers and consumers in the wood market. The creation of a platform or market-making institution by the private sector or the government can play a facilitating role in the wood market. The market maker manages risk on the supply and demand side and reduces price gaps in the market. Other roles that can be envisioned for the market maker include launching an online market for the wholesale and retail sale of poplar wood, providing banking facilities for the development of poplar farming, small and medium-sized processing rings in Guilan Province by guaranteeing and providing market maker collateral, providing financial support to startups, cores, and technology units in the field of wood farming and the poplar value chain, and modernizing the support infrastructure, transportation, and distribution network between the different rings of the poplar value chain in Guilan Province through appropriate financing. Problem definition and objectives: Due to its suitable climate and fertile soil, Guilan Province is one of the geographical areas prone to the development of poplar cultivation in Iran. Determining the appropriate structure for developing the poplar value chain in this province can improve productivity, job creation, sustainability, enhanced participation of production factors and market actors, improve resilience, chain customer satisfaction, and moderate the impact of market intermediaries. The main goal of this study is to provide an appropriate mechanism for developing the poplar value chain in Guilan Province using expert opinions to create solidarity and synergy between the various pillars and links of the poplar value chain in this province. Methodology: Considering the main objective of the research, two main steps were considered in its implementation. The first step of the study involves designing a comprehensive decision tree of drivers affecting the development of the poplar value chain in Guilan Province. The drivers were determined based on an extensive review of theoretical foundations, research background, and based on the perspectives of 15 selected experts (experts in the agricultural and wood industries of Guilan Province, leading poplar growers, and faculty members from the agricultural and natural resources research and education center of Guilan Province and University of Guilan) in the form of an experts' meeting. After preparing a comprehensive list of factors and drivers for the development of the poplar value chain in Guilan Province using the coding method, categorization of similar opinions, and examination of the frequency of selection of sample experts, the drivers were refined, modified, and finally selected. In the second step, the importance of various drivers of the development of the poplar value chain in Guilan province and the determination of the appropriate business model were determined using the Fuzzy Hierarchy Process (FAHP) and a paired comparison questionnaire. Results: The research findings showed that the economic driver was assigned 51.65% importance among the decision tree criteria. Also, structural, environmental, and socio-cultural criteria are ranked second to fourth in importance. Among the economic drivers, profitability, productivity, and chain financing, with a total relative weight of 66.82 percent, are the top three economic drivers for the development of the poplar value chain in Guilan Province. The most important socio-cultural driver is building trust in people with a relative weight of 33.7 percent. The sub-criterion of preserving water and soil resources, with a relative weight of 40.66 percent, is the most important environmental driver. Also, energy and water supply, contract farming, and chain intelligence, with a total relative weight of 59.08 percent, are considered the three top structural drivers of poplar value chain development in Guilan Province, respectively. Comparisons among four business models - Orchestra, Market Maker, Layered, and Integrated - based on 21 studied drivers showed that the market maker model is the optimal mechanism for developing and creating sustainable interaction between actors and agents of the poplar value chain in Guilan province. Conclusion: The Market Maker model represents the most effective and prioritized structure for developing the poplar value chain in Guilan Province in the current situation. It is suggested that financial resources and capital be directed purposefully to different links in this chain to provide the basis for market regulation and effective support for producers and consumers in the wood market. The creation of a platform or market-making institution by the private sector or the government can play a facilitating role in the wood market. The market maker manages risk on the supply and demand side and reduces price gaps in the market. Other roles that can be envisioned for the market maker include launching an online market for the wholesale and retail sale of poplar wood, providing banking facilities for the development of poplar farming, small and medium-sized processing rings in Guilan Province by guaranteeing and providing market maker collateral, providing financial support to startups, cores, and technology units in the field of wood farming and the poplar value chain, and modernizing the support infrastructure, transportation, and distribution network between the different rings of the poplar value chain in Guilan Province through appropriate financing.

https://www.ijwp.ir/article_735476_97ada39badb4d756ae87d6ed4880bac6.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Investigating of the heavy metals accumulation in the bark of woody species planted in green spaces of Isfahan city Investigating of the heavy metals accumulation in the bark of woody species planted in green spaces of Isfahan city 85 99 735477 10.22034/ijwp.2025.2076814.1736 FA Kord Behrouz Department of Green Space Engineering, M.C., Islamic Azad University, Malayer, Iran Sara Pourabbasi Department of Wood Science and Paper Technology, M.C., Islamic Azad University, Malayer, Iran Ahmad Samariha Department of Wood Industry, National University of Skills (NUS), Tehran, Iran. Journal Article 2025 11 14 Problem definition and objectives: Heavy metals are persistent environmental pollutants that are mainly researched for the purpose of biological monitoring and removal from the environment. Today, the ability of plants to absorb, accumulates, and degrades pollutants or biomarkers are used to assess polluted environments. In addition, choosing species that can adapt to polluted environmental conditions is of great importance. The study aimed to investigate the accumulation of heavy metals such as lead, zinc, copper, chromium, nickel, and cadmium in the bark of the Ash (Fraxinus rotundifolia Mill.), Elm tree (Ulmus carpinifolia var umbraculifera Rehd.), Plantain tree (Platanus orientalis L.), Pine (Pinus Eldarica Medw.) and Cypress (Cupressus arizonica Greene.) trees in the green space of Isfahan city. Methodology: For this purpose, Chahar Bagh Street in the city center was considered as a contaminated site and Fadak Forest Park on the outskirts of the city was considered as a control site and Considering the main wind direction , a transect of 1800 meters was selected and tree bark sampling was done in the form of a systematic randomness statistical design in three repetitions. A total of 90 tree bark samples were prepared, which after initial preparation and the concentration of heavy metals in them was measured using the device Inductively Coupled Plasma Mass Spectrometry was measured. Statistical analyses were performed using SPSS version 19 software, and the analysis of variance test was used to investigate the significance of the effect of stations and tree species on heavy metal concentrations, Duncan's test was used to compare means, and Pearson's correlation coefficient was used to determine the relationship between element concentrations in tree bark at a 95% confidence level. Results: The results showed that the concentration of heavy metals in the environment (air and soil) in the contaminated site was higher than in the control site. In addition, the concentration of heavy metals in the bark of trees in the contaminated habitat was significantly higher than in the control site and in order, Elm < Ash < Plantain tree < Cypress < Pine show an increase. Meanwhile, the results of the analysis of variance test showed that the effect of site on the accumulation of heavy metal concentrations in tree bark had a significant difference. Duncan's test also classified the average concentration of heavy metals in tree bark into different groups. In such a way that the concentration of elements is in the order of lead > cadmium > zinc > nickel > copper > chromium and the highest amount of lead metal and the bark of Pine trees in the contaminated site with 95.75 mg/kg and the lowest amount of chromium metal and elm tree bark was in the control site with 0.21 mg/kg. Pearson correlation analysis also indicates that lead and cadmium had the highest correlation among the elements studied. Conclusion: Given that the concentration of heavy metals in the bark of Pine, Cypress, and Plantain tree was significantly higher than that of other trees studied, Therefore, the bark of these trees is a suitable indicator for tracking heavy metals and can be used as a biological indicator of pollution caused by these metals to assess environmental quality. Problem definition and objectives: Heavy metals are persistent environmental pollutants that are mainly researched for the purpose of biological monitoring and removal from the environment. Today, the ability of plants to absorb, accumulates, and degrades pollutants or biomarkers are used to assess polluted environments. In addition, choosing species that can adapt to polluted environmental conditions is of great importance. The study aimed to investigate the accumulation of heavy metals such as lead, zinc, copper, chromium, nickel, and cadmium in the bark of the Ash (Fraxinus rotundifolia Mill.), Elm tree (Ulmus carpinifolia var umbraculifera Rehd.), Plantain tree (Platanus orientalis L.), Pine (Pinus Eldarica Medw.) and Cypress (Cupressus arizonica Greene.) trees in the green space of Isfahan city. Methodology: For this purpose, Chahar Bagh Street in the city center was considered as a contaminated site and Fadak Forest Park on the outskirts of the city was considered as a control site and Considering the main wind direction , a transect of 1800 meters was selected and tree bark sampling was done in the form of a systematic randomness statistical design in three repetitions. A total of 90 tree bark samples were prepared, which after initial preparation and the concentration of heavy metals in them was measured using the device Inductively Coupled Plasma Mass Spectrometry was measured. Statistical analyses were performed using SPSS version 19 software, and the analysis of variance test was used to investigate the significance of the effect of stations and tree species on heavy metal concentrations, Duncan's test was used to compare means, and Pearson's correlation coefficient was used to determine the relationship between element concentrations in tree bark at a 95% confidence level. Results: The results showed that the concentration of heavy metals in the environment (air and soil) in the contaminated site was higher than in the control site. In addition, the concentration of heavy metals in the bark of trees in the contaminated habitat was significantly higher than in the control site and in order, Elm < Ash < Plantain tree < Cypress < Pine show an increase. Meanwhile, the results of the analysis of variance test showed that the effect of site on the accumulation of heavy metal concentrations in tree bark had a significant difference. Duncan's test also classified the average concentration of heavy metals in tree bark into different groups. In such a way that the concentration of elements is in the order of lead > cadmium > zinc > nickel > copper > chromium and the highest amount of lead metal and the bark of Pine trees in the contaminated site with 95.75 mg/kg and the lowest amount of chromium metal and elm tree bark was in the control site with 0.21 mg/kg. Pearson correlation analysis also indicates that lead and cadmium had the highest correlation among the elements studied. Conclusion: Given that the concentration of heavy metals in the bark of Pine, Cypress, and Plantain tree was significantly higher than that of other trees studied, Therefore, the bark of these trees is a suitable indicator for tracking heavy metals and can be used as a biological indicator of pollution caused by these metals to assess environmental quality.

https://www.ijwp.ir/article_735477_9f341ea0a914e01dd79be348e7523fe3.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 The influence of soil physical and chemical characteristics on the biometrical and mechanical properties of Pinus eldarica wood The influence of soil physical and chemical characteristics on the biometrical and mechanical properties of Pinus eldarica wood 100 112 735478 10.22034/ijwp.2025.2072213.1728 FA Majid Kiaei Department of Wood and Paper Science and Technology, Cha. C., Islamic Azad University, Chalus, Iran Journal Article 2025 10 04 Abstract: Problem definition and objectives: Soil is one of the important site factors that affects wood properties. Precise understanding of its influence on wood characteristics is essential for optimizing forestry practices and better utilization of wood resources. The present study aimed to investigate the effect of altitude and the physical and chemical properties of soil on the biometry and mechanical characteristics of eldar pine (Pinus eldarica) wood in the western region of Mazandaran province. Methodology: To this end, 9 healthy trees were selected from three altitude levels of 500, 1200, and 1400 meters, and disc samples were taken at breast height. A soil profile sample was collected from the base of each tree. Wood properties measured included density, modulus of rupture, compression strength parallel to the grain, tracheid length and diameter, and cell wall thickness. Simultaneously, soil characteristics such as texture, pH, macro-and micronutrients, organic matter, lime content, and electrical conductivity were evaluated. Results: The results of analysis of variance showed that altitude had a significant effect on most wood properties, with many mechanical traits, including bending and compression strength, reaching their highest values at 1200 meters, while density and cell wall thickness were highest at 500 meters. Soil properties indicated that the silty-clay texture at 500 meters had a higher capacity for water and nutrient retention but offered limited drainage, whereas the clay-loam texture at 1200 meters, with relatively low acidity and the presence of key elements such as iron, manganese, and copper, provided optimal conditions for wood growth and development. At 1400 meters, an increase in sand content accompanied by decreases in nutrients and calcium led to reduced wood quality. The results of Pearson’s correlation analysis and the multiple regression model showed that wood density had a positive relationship with soil calcium and a negative relationship with sand. The modulus of rupture, bending strength, and tracheid length exhibited positive correlations with clay and copper, while tracheid diameter showed a positive relationship with soil copper, nitrogen, and iron. These findings highlight the key role of soil conditions, especially clay, copper, and calcium, in improving the biometry and mechanical quality of wood. Conclusion: The altitude of 1200 meters, due to balanced soil texture, suitable pH, and micronutrient richness, provides the best growth conditions for eldar pine and can be recommended as the optimal elevation for afforestation of this species. Conclusion: The altitude of 1200 meters, due to balanced soil texture, suitable pH, and micronutrient richness, provides the best growth conditions for eldar pine and can be recommended as the optimal elevation for afforestation of this species. Abstract: Problem definition and objectives: Soil is one of the important site factors that affects wood properties. Precise understanding of its influence on wood characteristics is essential for optimizing forestry practices and better utilization of wood resources. The present study aimed to investigate the effect of altitude and the physical and chemical properties of soil on the biometry and mechanical characteristics of eldar pine (Pinus eldarica) wood in the western region of Mazandaran province. Methodology: To this end, 9 healthy trees were selected from three altitude levels of 500, 1200, and 1400 meters, and disc samples were taken at breast height. A soil profile sample was collected from the base of each tree. Wood properties measured included density, modulus of rupture, compression strength parallel to the grain, tracheid length and diameter, and cell wall thickness. Simultaneously, soil characteristics such as texture, pH, macro-and micronutrients, organic matter, lime content, and electrical conductivity were evaluated. Results: The results of analysis of variance showed that altitude had a significant effect on most wood properties, with many mechanical traits, including bending and compression strength, reaching their highest values at 1200 meters, while density and cell wall thickness were highest at 500 meters. Soil properties indicated that the silty-clay texture at 500 meters had a higher capacity for water and nutrient retention but offered limited drainage, whereas the clay-loam texture at 1200 meters, with relatively low acidity and the presence of key elements such as iron, manganese, and copper, provided optimal conditions for wood growth and development. At 1400 meters, an increase in sand content accompanied by decreases in nutrients and calcium led to reduced wood quality. The results of Pearson’s correlation analysis and the multiple regression model showed that wood density had a positive relationship with soil calcium and a negative relationship with sand. The modulus of rupture, bending strength, and tracheid length exhibited positive correlations with clay and copper, while tracheid diameter showed a positive relationship with soil copper, nitrogen, and iron. These findings highlight the key role of soil conditions, especially clay, copper, and calcium, in improving the biometry and mechanical quality of wood. Conclusion: The altitude of 1200 meters, due to balanced soil texture, suitable pH, and micronutrient richness, provides the best growth conditions for eldar pine and can be recommended as the optimal elevation for afforestation of this species. Conclusion: The altitude of 1200 meters, due to balanced soil texture, suitable pH, and micronutrient richness, provides the best growth conditions for eldar pine and can be recommended as the optimal elevation for afforestation of this species.

https://www.ijwp.ir/article_735478_e074e96096c8892d8a0fc789a460e828.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Evaluation of Physical and Mechanical Properties of Cement-Based Composites Containing Recycled Paper Fibers Evaluation of Physical and Mechanical Properties of Cement-Based Composites Containing Recycled Paper Fibers 113 125 735479 10.22034/ijwp.2025.2075469.1735 FA Valiullah Mousavi Assistance at Department of wood science and paper technology, Calous branch, Islamic Azad University, Calous, Iran. Journal Article 2025 10 28 Problem definition and Objectives: In recent years, construction engineering has increasingly shifted toward the use of lightweight, durable, and environmentally compatible materials. Cement-based composites, as emerging construction materials, offer considerable potential for development depending on the availability of regional raw materials such as wood, cellulosic fibers, and waste paper. Given the limited wood resources and the growing demand for composite products, the use of fibers recovered from recycled printing-paper waste has been suggested as an economical and environmentally sustainable alternative. Accordingly, waste printing-paper fibers were employed in the present study. One of the major challenges in producing such composites is the inherent incompatibility of lignocellulosic fibers with Portland cement, which restricts the formation of strong and stable interfacial bonding within the composite matrix. Previous studies have shown that the incorporation of calcium chloride can enhance cement hydration and improve fiber–cement compatibility. The combined use of recycled cellulosic fibers with additives such as calcium chloride or nanosilica has also been reported to improve durability, phase cohesion, flexural performance, and reduce thickness swelling in wood–cement composites. Therefore, calcium chloride was utilized in this research to improve the setting behavior of cement in the presence of waste paper fibers. The primary objective of this study was to determine the optimum mixing ratio of recycled printing-paper fibers and cement, together with an appropriate dosage of calcium chloride, in order to enhance the physical and mechanical properties of the resulting composite. Methodology: In this study, cellulosic fibers derived from waste printing paper were used as the reinforcing agent, while Type II Portland cement served as the matrix. Calcium chloride powder was employed as a setting accelerator and to improve the fiber–cement interfacial bonding at two levels (3% and 5% by cement weight). The specimens were prepared with three different fiber-to-cement ratios (30:70, 25:75, and 20:80 by weight) and cured for 28 days. Subsequently, they were tested for physical and mechanical properties according to EN standards. The obtained results were analyzed to evaluate the effects of the mixing ratios and calcium chloride content on the performance of the paper fiber–cement composites. Results: The results showed that increasing the cement content from 70 to 80% led to a decrease in water absorption and thickness swelling, as well as an improvement in the density of the samples measured. In contrast, the effects of 3 and 5% calcium chloride on the physical and mechanical properties of the samples were not independently significant observed. The highest mechanical properties, including modulus of rupture, modulus of elasticity, and internal bond strength, were obtained in the 20:80 cement-to-fiber ratio prepared. The use of calcium chloride in limited amounts contributed to the acceleration of setting and the improvement of fiber–cement bonding facilitated. However, at higher contents, a slight reduction in physical properties was observed due to porosity formation and volumetric stresses induced. Overall, optimizing the cement-to-fiber ratio and controlled application of calcium chloride played a crucial role in enhancing the performance of paper fiber–cement composites achieved. Conclusion: The mixing ratio of recycled printing-paper fibers and cement plays a decisive role in improving the physical and mechanical properties of cement-based composites, as demonstrated in this study. An increase in the cement content to 80% led to higher density and enhanced mechanical strength, while water absorption and thickness swelling decreased. In contrast, raising the fiber content to 30% resulted in greater water absorption and thickness swelling, a phenomenon attributable to the porous structure of the fibers that provided additional capillary pathways for moisture penetration. The incorporation of 3% calcium chloride accelerated the hydration process and strengthened the fiber–cement interfacial bonding, whereas increasing its level to 5% caused a relative decline in both physical and mechanical properties because of salt crystallization and increased porosity. A significant interaction effect between cement and calcium chloride was observed only for internal bonding. The optimal performance was obtained in the formulation containing 20% fibers, 80% cement, and 3% calcium chloride. Overall, the use of recycled printing-paper fibers as a sustainable and environmentally compatible substitute has the potential to enhance composite performance and reduce the environmental impacts of building materials. Problem definition and Objectives: In recent years, construction engineering has increasingly shifted toward the use of lightweight, durable, and environmentally compatible materials. Cement-based composites, as emerging construction materials, offer considerable potential for development depending on the availability of regional raw materials such as wood, cellulosic fibers, and waste paper. Given the limited wood resources and the growing demand for composite products, the use of fibers recovered from recycled printing-paper waste has been suggested as an economical and environmentally sustainable alternative. Accordingly, waste printing-paper fibers were employed in the present study. One of the major challenges in producing such composites is the inherent incompatibility of lignocellulosic fibers with Portland cement, which restricts the formation of strong and stable interfacial bonding within the composite matrix. Previous studies have shown that the incorporation of calcium chloride can enhance cement hydration and improve fiber–cement compatibility. The combined use of recycled cellulosic fibers with additives such as calcium chloride or nanosilica has also been reported to improve durability, phase cohesion, flexural performance, and reduce thickness swelling in wood–cement composites. Therefore, calcium chloride was utilized in this research to improve the setting behavior of cement in the presence of waste paper fibers. The primary objective of this study was to determine the optimum mixing ratio of recycled printing-paper fibers and cement, together with an appropriate dosage of calcium chloride, in order to enhance the physical and mechanical properties of the resulting composite. Methodology: In this study, cellulosic fibers derived from waste printing paper were used as the reinforcing agent, while Type II Portland cement served as the matrix. Calcium chloride powder was employed as a setting accelerator and to improve the fiber–cement interfacial bonding at two levels (3% and 5% by cement weight). The specimens were prepared with three different fiber-to-cement ratios (30:70, 25:75, and 20:80 by weight) and cured for 28 days. Subsequently, they were tested for physical and mechanical properties according to EN standards. The obtained results were analyzed to evaluate the effects of the mixing ratios and calcium chloride content on the performance of the paper fiber–cement composites. Results: The results showed that increasing the cement content from 70 to 80% led to a decrease in water absorption and thickness swelling, as well as an improvement in the density of the samples measured. In contrast, the effects of 3 and 5% calcium chloride on the physical and mechanical properties of the samples were not independently significant observed. The highest mechanical properties, including modulus of rupture, modulus of elasticity, and internal bond strength, were obtained in the 20:80 cement-to-fiber ratio prepared. The use of calcium chloride in limited amounts contributed to the acceleration of setting and the improvement of fiber–cement bonding facilitated. However, at higher contents, a slight reduction in physical properties was observed due to porosity formation and volumetric stresses induced. Overall, optimizing the cement-to-fiber ratio and controlled application of calcium chloride played a crucial role in enhancing the performance of paper fiber–cement composites achieved. Conclusion: The mixing ratio of recycled printing-paper fibers and cement plays a decisive role in improving the physical and mechanical properties of cement-based composites, as demonstrated in this study. An increase in the cement content to 80% led to higher density and enhanced mechanical strength, while water absorption and thickness swelling decreased. In contrast, raising the fiber content to 30% resulted in greater water absorption and thickness swelling, a phenomenon attributable to the porous structure of the fibers that provided additional capillary pathways for moisture penetration. The incorporation of 3% calcium chloride accelerated the hydration process and strengthened the fiber–cement interfacial bonding, whereas increasing its level to 5% caused a relative decline in both physical and mechanical properties because of salt crystallization and increased porosity. A significant interaction effect between cement and calcium chloride was observed only for internal bonding. The optimal performance was obtained in the formulation containing 20% fibers, 80% cement, and 3% calcium chloride. Overall, the use of recycled printing-paper fibers as a sustainable and environmentally compatible substitute has the potential to enhance composite performance and reduce the environmental impacts of building materials.

https://www.ijwp.ir/article_735479_4bf85e35cc412582c3ceb5553ad3a5da.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Feasibility Study on the Production of Cellulose Films from Hypochlorite-Bleached Sugarcane Bagasse Pulp Feasibility Study on the Production of Cellulose Films from Hypochlorite-Bleached Sugarcane Bagasse Pulp 127 137 735480 10.22034/ijwp.2025.2074743.1733 FA Seyede Soad Taffakh department of Wood Science and Technology , Faculty of agriculture and natural resources ,University of Mohaghegh Ardabili, Ardabil, Iran Mearaj Sharari Faculty member of University of Mahaghegh Ardabili, Faculty of Agriculture and Natural Resources, Department of Wood Science and Technology 0009-0005-7188-6675 Mohammad Hadi Moradian Wood Science and Technology, Department of Forestry and Cellulosic Industries, Faculty of Natural Resources, Khatam Al-Anbia University of Technology, Behbahan, Iran Bita Moezzipour Wood Science and Technology, department of Wood Science and Technology , Faculty of agriculture and natural resources, University of Mohaghegh Ardabili, Ardabil, Iran. 0000-0001-8769-9528 Journal Article 2025 11 22 Problem Statement and Objective The excessive consumption of synthetic plastics in the packaging industry poses a major global environmental challenge. Due to their limited biodegradability, these materials contribute significantly to waste accumulation and environmental pollution. On the other hand, agricultural waste is an important, available and inexpensive resource for converting it into biodegradable products, helping to prevent its accumulation in nature, and providing appropriate added value for the production of new products. Sugarcane bagasse, a by-product of the sugar industry, is an abundant and low-cost resource in Iran that can serve as a sustainable raw material for producing biodegradable films. This study aims to produce and evaluate cellulose films derived from hypochlorite-bleached bagasse pulp obtained from Pars Paper Company (Haft-Tappeh) and to investigate their physical, mechanical, and chemical properties for potential application in sustainable packaging. Materials and Methods Hypochlorite-bleached bagasse pulp from Pars Paper Company (Haft-Tappeh), with a freeness of 350 CSF, brightness of 71%, and kappa number of 2, was used. The film production process involved alkalization with 20% sodium hydroxide, etherification with monochloroacetic acid, neutralization and washing with ethanol, preparation of a dope solution with a 6% weight concentration, followed by casting and coagulation in a 10% sulfuric acid bath. The produced films were characterized for mechanical properties, gas permeability, water vapor transmission rate, water contact angle, and degree of substitution according to ASTM standards. Results The resulting cellulose film exhibited a tensile strength of 64 MPa and a Young’s modulus of 2.8 GPa, indicating adequate mechanical strength for packaging applications. The water vapor transmission rate was 248 g/m²·day, and the moisture absorption was 7.7%. Gas permeability values for CO₂ and O₂ were 0.05 and 0.4 Barrer, respectively, reflecting low gas transmission. The degree of substitution of carboxyl groups in the dope solution was 1.4 mmol/g, and the percentage of undissolved fibers was 0.5%, confirming the quality and homogeneity of the prepared dope. The droplet contact angle of 72° indicates balanced hydrophilicity of the film surface. Conclusion Cellulose films produced from sugarcane bagasse present a sustainable and eco-friendly alternative to petroleum-based polymer films for packaging applications. The films demonstrated moderate mechanical strength and barrier performance, making them suitable for various packaging uses. To enhance moisture resistance, surface coating or the incorporation of nanomaterials is recommended. Overall, this study highlights the potential of utilizing agricultural residues as renewable raw materials for developing sustainable packaging solutions, contributing to the reduction of environmental pollution caused by conventional plastics. Problem Statement and Objective The excessive consumption of synthetic plastics in the packaging industry poses a major global environmental challenge. Due to their limited biodegradability, these materials contribute significantly to waste accumulation and environmental pollution. On the other hand, agricultural waste is an important, available and inexpensive resource for converting it into biodegradable products, helping to prevent its accumulation in nature, and providing appropriate added value for the production of new products. Sugarcane bagasse, a by-product of the sugar industry, is an abundant and low-cost resource in Iran that can serve as a sustainable raw material for producing biodegradable films. This study aims to produce and evaluate cellulose films derived from hypochlorite-bleached bagasse pulp obtained from Pars Paper Company (Haft-Tappeh) and to investigate their physical, mechanical, and chemical properties for potential application in sustainable packaging. Materials and Methods Hypochlorite-bleached bagasse pulp from Pars Paper Company (Haft-Tappeh), with a freeness of 350 CSF, brightness of 71%, and kappa number of 2, was used. The film production process involved alkalization with 20% sodium hydroxide, etherification with monochloroacetic acid, neutralization and washing with ethanol, preparation of a dope solution with a 6% weight concentration, followed by casting and coagulation in a 10% sulfuric acid bath. The produced films were characterized for mechanical properties, gas permeability, water vapor transmission rate, water contact angle, and degree of substitution according to ASTM standards. Results The resulting cellulose film exhibited a tensile strength of 64 MPa and a Young’s modulus of 2.8 GPa, indicating adequate mechanical strength for packaging applications. The water vapor transmission rate was 248 g/m²·day, and the moisture absorption was 7.7%. Gas permeability values for CO₂ and O₂ were 0.05 and 0.4 Barrer, respectively, reflecting low gas transmission. The degree of substitution of carboxyl groups in the dope solution was 1.4 mmol/g, and the percentage of undissolved fibers was 0.5%, confirming the quality and homogeneity of the prepared dope. The droplet contact angle of 72° indicates balanced hydrophilicity of the film surface. Conclusion Cellulose films produced from sugarcane bagasse present a sustainable and eco-friendly alternative to petroleum-based polymer films for packaging applications. The films demonstrated moderate mechanical strength and barrier performance, making them suitable for various packaging uses. To enhance moisture resistance, surface coating or the incorporation of nanomaterials is recommended. Overall, this study highlights the potential of utilizing agricultural residues as renewable raw materials for developing sustainable packaging solutions, contributing to the reduction of environmental pollution caused by conventional plastics.

https://www.ijwp.ir/article_735480_1d3dc77334ede37bced9eaa4693661c8.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Investigating the Impact of Lignin on the Physicochemical Properties and Biodegradability of a Composite Fabricated via 3D Printing from Polyvinyl Alcohol, Nanocellulose, and Lignin Investigating the Impact of Lignin on the Physicochemical Properties and Biodegradability of a Composite Fabricated via 3D Printing from Polyvinyl Alcohol, Nanocellulose, and Lignin 139 151 735481 10.22034/ijwp.2026.2080598.1749 FA Mahdi Ansari Chaharsoughi Ph.D. Student, Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Karaj, Iran Yahya Hamzeh Professor, Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Karaj, Iran 0000-0001-5237-9866 Mohammad Rafienia Professor, Department of Biomaterials, Nanotechnology and Tissue Engineering, Faculty of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Seyed Ali Poursamar Assistant Professor, Department of Biomaterials, Nanotechnology and Tissue Engineering, Faculty of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Alireza Ashori Professor, Chemical Technologies Research Institute, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran 0000-0003-0946-1965 Journal Article 2025 12 11 Problem definition and objectives: In the past two decades, integrating specialized or stem cells with biodegradable three-dimensional scaffolds and a variety of biochemical, physical, and mechanical cues has opened new avenues for reconstructing the structural and functional properties of impaired tissues. These components exhibit their highest efficacy when incorporated into a coordinated system that closely mimics the physiological microenvironment of native tissue. Among the available fabrication technologies, three-dimensional printing particularly direct ink writing (DIW) has gained significant attention due to its precise control over ink rheology, tunable internal architecture, adjustable porosity and pore orientation, and the ability to combine multiple biomaterials simultaneously. This technology enables the fabrication of scaffolds with complex geometries analogous to native tissues, providing a conducive platform for cell adhesion, proliferation, and differentiation. The selection of appropriate bio-ink constituents is therefore a critical aspect of scaffold development. Nanocellulose, a natural and renewable polymer, offers high mechanical strength, robust three-dimensional network formation, excellent biocompatibility, and tunable surface chemistry, making it an attractive candidate for bio-ink formulation. Complementarily, lignin, an abundant aromatic biopolymer, provides antioxidant activity, moderate hydrophobicity, and reinforcing capability, thereby influencing the rheological behavior, printability, and mechanical performance of printed scaffolds. Polyvinyl alcohol (PVA), with its ability to form stable hydrogels, favorable flexibility, and coherent network structure, further enhances the stability, uniformity, and integrity of the composite scaffold. Given the growing demand for biodegradable and renewable biomaterials in scaffold fabrication, the present study investigates the effect of varying lignin content within nanocellulose/PVA-based systems. The objective is to elucidate how lignin concentration influences structural stability, chemical behavior, water absorption capacity, wettability, and ultimately the biodegradability of the resulting scaffolds. This work aims to identify an optimized material composition capable of producing high-performance scaffolds suitable for both clinical and research-based tissue engineering applications. Methodology: In this study, PVA/nanocellulose/lignin composite scaffolds containing 10%, 20%, and 30% lignin were fabricated via 3D bio-printing. Morphological features were assessed by scanning electron microscopy (SEM), chemical interactions analyzed through Fourier-transform infrared spectroscopy (FTIR), water absorption and long-term hydrophilicity evaluated, and surface wettability measured via contact angle analysis. Biodegradability was monitored in phosphate-buffered saline at 37 °C over three months. Results: SEM images revealed that low lignin content maintained a uniform and stable PVA/nanocellulose network, while 30% lignin induced phase separation and agglomeration, reducing structural coherence. FTIR spectra indicated improved interfacial interactions through hydrogen bonding and partial coating of nanocellulose by lignin. Water absorption decreased and contact angles increased with higher lignin content, reflecting reduced hydrophilicity and enhanced moisture resistance, largely due to lignin’s hydrophobicity and citric-acid-induced esterification. Biodegradation results demonstrated that lignin’s aromatic structure slowed scaffold degradation. Overall, moderate lignin incorporation enhanced matrix cohesion, controlled water affinity, and preserved structural stability, whereas excessive lignin compromised scaffold integrity. Conclusion: These findings highlight that optimizing lignin concentration is critical to achieving desirable morphological, physicochemical, and biodegradation properties in PVA/nanocellulose scaffolds, providing a promising approach for tissue engineering applications. Based on the results, the formulation containing 20% lignin exhibited the best balance between structural stability, water absorption, and biodegradability, and could be proposed as a suitable candidate for the development of bio-scaffolds in tissue engineering. Problem definition and objectives: In the past two decades, integrating specialized or stem cells with biodegradable three-dimensional scaffolds and a variety of biochemical, physical, and mechanical cues has opened new avenues for reconstructing the structural and functional properties of impaired tissues. These components exhibit their highest efficacy when incorporated into a coordinated system that closely mimics the physiological microenvironment of native tissue. Among the available fabrication technologies, three-dimensional printing particularly direct ink writing (DIW) has gained significant attention due to its precise control over ink rheology, tunable internal architecture, adjustable porosity and pore orientation, and the ability to combine multiple biomaterials simultaneously. This technology enables the fabrication of scaffolds with complex geometries analogous to native tissues, providing a conducive platform for cell adhesion, proliferation, and differentiation. The selection of appropriate bio-ink constituents is therefore a critical aspect of scaffold development. Nanocellulose, a natural and renewable polymer, offers high mechanical strength, robust three-dimensional network formation, excellent biocompatibility, and tunable surface chemistry, making it an attractive candidate for bio-ink formulation. Complementarily, lignin, an abundant aromatic biopolymer, provides antioxidant activity, moderate hydrophobicity, and reinforcing capability, thereby influencing the rheological behavior, printability, and mechanical performance of printed scaffolds. Polyvinyl alcohol (PVA), with its ability to form stable hydrogels, favorable flexibility, and coherent network structure, further enhances the stability, uniformity, and integrity of the composite scaffold. Given the growing demand for biodegradable and renewable biomaterials in scaffold fabrication, the present study investigates the effect of varying lignin content within nanocellulose/PVA-based systems. The objective is to elucidate how lignin concentration influences structural stability, chemical behavior, water absorption capacity, wettability, and ultimately the biodegradability of the resulting scaffolds. This work aims to identify an optimized material composition capable of producing high-performance scaffolds suitable for both clinical and research-based tissue engineering applications. Methodology: In this study, PVA/nanocellulose/lignin composite scaffolds containing 10%, 20%, and 30% lignin were fabricated via 3D bio-printing. Morphological features were assessed by scanning electron microscopy (SEM), chemical interactions analyzed through Fourier-transform infrared spectroscopy (FTIR), water absorption and long-term hydrophilicity evaluated, and surface wettability measured via contact angle analysis. Biodegradability was monitored in phosphate-buffered saline at 37 °C over three months. Results: SEM images revealed that low lignin content maintained a uniform and stable PVA/nanocellulose network, while 30% lignin induced phase separation and agglomeration, reducing structural coherence. FTIR spectra indicated improved interfacial interactions through hydrogen bonding and partial coating of nanocellulose by lignin. Water absorption decreased and contact angles increased with higher lignin content, reflecting reduced hydrophilicity and enhanced moisture resistance, largely due to lignin’s hydrophobicity and citric-acid-induced esterification. Biodegradation results demonstrated that lignin’s aromatic structure slowed scaffold degradation. Overall, moderate lignin incorporation enhanced matrix cohesion, controlled water affinity, and preserved structural stability, whereas excessive lignin compromised scaffold integrity. Conclusion: These findings highlight that optimizing lignin concentration is critical to achieving desirable morphological, physicochemical, and biodegradation properties in PVA/nanocellulose scaffolds, providing a promising approach for tissue engineering applications. Based on the results, the formulation containing 20% lignin exhibited the best balance between structural stability, water absorption, and biodegradability, and could be proposed as a suitable candidate for the development of bio-scaffolds in tissue engineering.

https://www.ijwp.ir/article_735481_bc147dee5114bf378c26f14fa4ecc769.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Effect of extrusion and 3D printing methods on morphological characteristics of biocomposite for chair printing Effect of extrusion and 3D printing methods on morphological characteristics of biocomposite for chair printing 153 172 735482 10.22034/ijwp.2026.2082268.1756 FA Behrouz Neyciyani Department of Wood and Paper Science and Technology, Faculty of Natural Resources, Faculties of Agriculture and Natural Resources, University of Tehran, Iran. Mehdi Jonoobi Department of Wood and Paper Science and Technology, Faculty of Natural Resources, Faculties of Agriculture and Natural Resources, University of Tehran, Iran. Payam Moradpour Department of Wood and Paper Science and Technology, Faculty of Natural Resources, Faculties of Agriculture and Natural Resources, University of Tehran, Iran. Mohammad Razavi-Nouri Department of Plastics, Faculty of Polymer Processing, Iran Polymer and Petrochemical Institute, Tehran, Iran. Journal Article 2025 10 29 Abstract: Problem Definitionand and Objectives: Growing concerns about plastic pollution have increased the interest in biopolymers such as polylactic acid (PLA) due to their biodegradability and processability. However, the brittleness of PLA poses limitations in structural applications. Natural reinforcements such as wood flour (WF) and microcrystalline cellulose (MCC) can improve the mechanical properties of PLA, but their uniform dispersion and phase coherence depend on the extrusion method and the type of 3D printing. This study investigates the effect of extrusion repetition and comparison of two 3D printing methods, fused filament (FFF) and fused granulation (FGF), on the morphological and structural properties of PLA-WF-MCC biocomposites to determine the most optimal production conditions for structural applications such as chair printing. Materials and Methods: In this study, PLA granules were used as the main matrix, MCC as the reinforcing phase, and WF as the filler to produce biocomposites. The PLA-WF-MCC blend was passed through a single-stage and two-stage twin-screw extruder to make the composite. After the extrusion process, the biocomposites were divided into four different methods to investigate the effects of the extrusion process repetition and 3D printing methods on their morphological characteristics. 3D printing methods including fused filament (FFF) and fused granule (FGF) were used to make 3D samples. All the setting parameters in the two 3D printing methods included a temperature of 210°C for filament and granule, 60°C for the printing bed, a printing speed of 40 mm/s, a layer thickness of 0.2 mm, and a filler density of 100%. In order to investigate the interphase adhesion, particle dispersion, microstructure, porosity and structural quality, scanning electron microscope (SEM) images of extruded and printed samples were prepared and analyzed. These images were recorded at different magnifications and used to analyze and compare morphological features and structural density. Results: The results of SEM images showed that in the single-extruded samples, uniform and homogeneous dispersion of MCC was observed in the PLA matrix and the adhesion between the phases was well established. Also, in these samples, no clear boundary was observed between the polymer matrix and MCC, indicating good and homogeneous mixing of the materials. In contrast, the double-extruded samples suffered from interphase separation and the formation of micropores in the phase boundary areas. These differences were due to the high thermal sensitivity of PLA and its partial degradation in the two-step extrusion process, which reduced the structural quality and created porosity in the samples. These results indicate that in biocomposites, the number of extrusion steps plays an important role in maintaining the balance between proper mixing and structural integrity. In the 3D printing process, the once-extruded samples were selected for printing due to their uniform dispersion and better morphological properties. Among the two printing methods, the samples fabricated by the granular method had better morphological properties and showed less porosity than the filament samples. In this method, due to the reduction of thermal stresses and improved bonding of the layers, a denser structure was obtained, which is more suitable for printing a chair. Finally, the chair was successfully printed by the granular method. Conclusion: Based on the results of this study, the single-extruded samples had a uniform dispersion of MCC in the PLA matrix, which improved interfacial adhesion and structural integrity. In PLA/WF/MCC biocomposites, the double-extrusion process caused interfacial separation and voids, which is related to the high thermal sensitivity of PLA. These results indicate that choosing the optimal extrusion level is essential to maintain a balance between mixing and structural stability. Also, in the 3D printing process, single-extruded samples with desirable microstructural characteristics were selected for the filament and granular methods. In the granular method, fewer voids were observed compared to the filament method and a denser structure was provided for 3D printing, which improved the structural quality of the parts. The granular method was selected as a more suitable method for chair printing due to the advantages of reducing thermal stresses, improving uniform material distribution, and reducing voids. Abstract: Problem Definitionand and Objectives: Growing concerns about plastic pollution have increased the interest in biopolymers such as polylactic acid (PLA) due to their biodegradability and processability. However, the brittleness of PLA poses limitations in structural applications. Natural reinforcements such as wood flour (WF) and microcrystalline cellulose (MCC) can improve the mechanical properties of PLA, but their uniform dispersion and phase coherence depend on the extrusion method and the type of 3D printing. This study investigates the effect of extrusion repetition and comparison of two 3D printing methods, fused filament (FFF) and fused granulation (FGF), on the morphological and structural properties of PLA-WF-MCC biocomposites to determine the most optimal production conditions for structural applications such as chair printing. Materials and Methods: In this study, PLA granules were used as the main matrix, MCC as the reinforcing phase, and WF as the filler to produce biocomposites. The PLA-WF-MCC blend was passed through a single-stage and two-stage twin-screw extruder to make the composite. After the extrusion process, the biocomposites were divided into four different methods to investigate the effects of the extrusion process repetition and 3D printing methods on their morphological characteristics. 3D printing methods including fused filament (FFF) and fused granule (FGF) were used to make 3D samples. All the setting parameters in the two 3D printing methods included a temperature of 210°C for filament and granule, 60°C for the printing bed, a printing speed of 40 mm/s, a layer thickness of 0.2 mm, and a filler density of 100%. In order to investigate the interphase adhesion, particle dispersion, microstructure, porosity and structural quality, scanning electron microscope (SEM) images of extruded and printed samples were prepared and analyzed. These images were recorded at different magnifications and used to analyze and compare morphological features and structural density. Results: The results of SEM images showed that in the single-extruded samples, uniform and homogeneous dispersion of MCC was observed in the PLA matrix and the adhesion between the phases was well established. Also, in these samples, no clear boundary was observed between the polymer matrix and MCC, indicating good and homogeneous mixing of the materials. In contrast, the double-extruded samples suffered from interphase separation and the formation of micropores in the phase boundary areas. These differences were due to the high thermal sensitivity of PLA and its partial degradation in the two-step extrusion process, which reduced the structural quality and created porosity in the samples. These results indicate that in biocomposites, the number of extrusion steps plays an important role in maintaining the balance between proper mixing and structural integrity. In the 3D printing process, the once-extruded samples were selected for printing due to their uniform dispersion and better morphological properties. Among the two printing methods, the samples fabricated by the granular method had better morphological properties and showed less porosity than the filament samples. In this method, due to the reduction of thermal stresses and improved bonding of the layers, a denser structure was obtained, which is more suitable for printing a chair. Finally, the chair was successfully printed by the granular method. Conclusion: Based on the results of this study, the single-extruded samples had a uniform dispersion of MCC in the PLA matrix, which improved interfacial adhesion and structural integrity. In PLA/WF/MCC biocomposites, the double-extrusion process caused interfacial separation and voids, which is related to the high thermal sensitivity of PLA. These results indicate that choosing the optimal extrusion level is essential to maintain a balance between mixing and structural stability. Also, in the 3D printing process, single-extruded samples with desirable microstructural characteristics were selected for the filament and granular methods. In the granular method, fewer voids were observed compared to the filament method and a denser structure was provided for 3D printing, which improved the structural quality of the parts. The granular method was selected as a more suitable method for chair printing due to the advantages of reducing thermal stresses, improving uniform material distribution, and reducing voids.

https://www.ijwp.ir/article_735482_c8e9f3efef2fd89ff51d253a045c23b1.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Microwave-Assisted Pectin Extraction: Response Surface Optimization of Power, Time, and pH Microwave-Assisted Pectin Extraction: Response Surface Optimization of Power, Time, and pH 173 190 735483 10.22034/ijwp.2026.2078226.1741 FA Seyedeh Motahareh Mohseni Shektaii Department of Wood and Cellulosic Products Engineering, Sari Agricultural Sciences and Natural Resources University, Mazandaran, Iran Maryam Ghorbani Kokandeh Department of Wood and Cellulosic Products Engineering, Sari Agricultural Sciences and Natural Resources University, Mazandaran, Iran Ghasem Asadpour Department of Wood and Cellulosic Products Engineering, Sari Agricultural Sciences and Natural Resources University, Mazandaran, Iran Journal Article 2025 11 18 Abstract Problem definition and objectives: The global trend toward sustainable valorization of agro-industrial residues has increasingly emphasized the recovery of high-value bioactive compounds. Among these, pectin is one of the most important polysaccharides, widely utilized in the food, pharmaceutical, and bio-based packaging industries. Despite its significance, conventional extraction methods, such as hot acid extraction, are associated with high energy and solvent consumption and often result in degradation of the pectin polymeric structure, thereby reducing the quality of the final product. Accordingly, the present study aimed to develop and optimize a green process for pectin extraction from lime (Citrus aurantifolia) peel using microwave-assisted extraction (MAE). Response surface methodology (RSM) based on a Box–Behnken design was employed to evaluate the effects of three key variables—microwave power, irradiation time, and pH—on extraction yield, degree of esterification (DE), and galacturonic acid (GalA) content, with the objective of identifying optimal conditions that maximize both the yield and purity of the extracted pectin. Methodology: Fresh lime albedo (white peel) was dried at 50 °C, milled, and sieved. The independent variables were microwave power (270–470 W), irradiation time (2–4 min), and pH (1–3), each examined at three levels. Based on the Box–Behnken design, 15 experimental runs were conducted. The extraction yield was determined gravimetrically, galacturonic acid (GalA) content was quantified using the m-hydroxydiphenyl colorimetric method at 520 nm, and the degree of esterification (DE) was calculated by acid–base titration. Data were analyzed using Design-Expert® version 13, and second-order polynomial models were fitted for each response. Results: The mathematical models developed for all three responses exhibited high coefficients of determination (R²Y = 0.9990, R²DE = 0.9974, and R²GalA = 0.9994), and the lack-of-fit test was not significant for any response (P > 0.05). Response surface analysis indicated that decreasing the pH to a strongly acidic range (approximately 1) had the greatest enhancing effect on extraction yield, while moderate increases in microwave power and irradiation time promoted the release of the polygalacturonic network. The optimal conditions for maximum extraction yield were identified as 450 W, 4 min, and pH 1, resulting in a yield of 50.6 ± 0.3%. In contrast, the highest degree of esterification (DE = 64.07%) was achieved at 470 W, 2 min, and pH 3, corresponding to the production of high-methoxyl pectin (HM-pectin). Moreover, the maximum galacturonic acid content (GalA = 92.16%) was obtained under conditions of 470 W, 3.78 min, and pH 2.98. Excessive microwave power or harsh acidification (pH < 2) led to degradation of polymer chains and a subsequent reduction in GalA purity. Conclusion: Overall, the findings demonstrate that MAE, with appropriate control of process variables, can produce pectin with high yield, desirable purity, and tunable structural properties. Extraction under low pH and moderate power enhanced recovery while preserving the polygalacturonic backbone, whereas more moderate conditions with shorter irradiation favored retention of esterified groups and higher DE. Thus, MAE not only outperforms conventional extraction in terms of efficiency, but also offers environmental advantages by reducing energy and chemical consumption and enabling the targeted production of low-methoxyl (LMP) and high-methoxyl (HMP) pectins. These results provide a robust basis for the industrial development of green pectin extraction from citrus processing residues and the production of sustainable bio-based ingredients for food, pharmaceutical, and packaging applications. Abstract Problem definition and objectives: The global trend toward sustainable valorization of agro-industrial residues has increasingly emphasized the recovery of high-value bioactive compounds. Among these, pectin is one of the most important polysaccharides, widely utilized in the food, pharmaceutical, and bio-based packaging industries. Despite its significance, conventional extraction methods, such as hot acid extraction, are associated with high energy and solvent consumption and often result in degradation of the pectin polymeric structure, thereby reducing the quality of the final product. Accordingly, the present study aimed to develop and optimize a green process for pectin extraction from lime (Citrus aurantifolia) peel using microwave-assisted extraction (MAE). Response surface methodology (RSM) based on a Box–Behnken design was employed to evaluate the effects of three key variables—microwave power, irradiation time, and pH—on extraction yield, degree of esterification (DE), and galacturonic acid (GalA) content, with the objective of identifying optimal conditions that maximize both the yield and purity of the extracted pectin. Methodology: Fresh lime albedo (white peel) was dried at 50 °C, milled, and sieved. The independent variables were microwave power (270–470 W), irradiation time (2–4 min), and pH (1–3), each examined at three levels. Based on the Box–Behnken design, 15 experimental runs were conducted. The extraction yield was determined gravimetrically, galacturonic acid (GalA) content was quantified using the m-hydroxydiphenyl colorimetric method at 520 nm, and the degree of esterification (DE) was calculated by acid–base titration. Data were analyzed using Design-Expert® version 13, and second-order polynomial models were fitted for each response. Results: The mathematical models developed for all three responses exhibited high coefficients of determination (R²Y = 0.9990, R²DE = 0.9974, and R²GalA = 0.9994), and the lack-of-fit test was not significant for any response (P > 0.05). Response surface analysis indicated that decreasing the pH to a strongly acidic range (approximately 1) had the greatest enhancing effect on extraction yield, while moderate increases in microwave power and irradiation time promoted the release of the polygalacturonic network. The optimal conditions for maximum extraction yield were identified as 450 W, 4 min, and pH 1, resulting in a yield of 50.6 ± 0.3%. In contrast, the highest degree of esterification (DE = 64.07%) was achieved at 470 W, 2 min, and pH 3, corresponding to the production of high-methoxyl pectin (HM-pectin). Moreover, the maximum galacturonic acid content (GalA = 92.16%) was obtained under conditions of 470 W, 3.78 min, and pH 2.98. Excessive microwave power or harsh acidification (pH < 2) led to degradation of polymer chains and a subsequent reduction in GalA purity. Conclusion: Overall, the findings demonstrate that MAE, with appropriate control of process variables, can produce pectin with high yield, desirable purity, and tunable structural properties. Extraction under low pH and moderate power enhanced recovery while preserving the polygalacturonic backbone, whereas more moderate conditions with shorter irradiation favored retention of esterified groups and higher DE. Thus, MAE not only outperforms conventional extraction in terms of efficiency, but also offers environmental advantages by reducing energy and chemical consumption and enabling the targeted production of low-methoxyl (LMP) and high-methoxyl (HMP) pectins. These results provide a robust basis for the industrial development of green pectin extraction from citrus processing residues and the production of sustainable bio-based ingredients for food, pharmaceutical, and packaging applications.

https://www.ijwp.ir/article_735483_f5b5123181a017adcf031abfddcba54a.pdf

Iranian Scientific Association of Wood and Paper Industries Iranian Journal of Wood and Paper Industries 2008-9066 17 1 2026 04 21 Biometrics,, Physical and structural Properties of Amygdalus haussknechtii Wood in the Forests of Chaharrmahal and Bakhtiari Province Biometrics,, Physical and structural Properties of Amygdalus haussknechtii Wood in the Forests of Chaharrmahal and Bakhtiari Province 191 206 735484 10.22034/ijwp.2026.2079736.1746 FA Mohsen Bahmani Associate Professor Faculty of Natural Resources and Earth Sciences, Shahrekord University Fatemeh Ebrahimi Dept. of Forestry, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran ., Saleh Kahyani Dept. of Forestry, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran ., Yaghoub Iranmanesh Associate Prof., Forests and Rangelands Research Dept. Isfahan Agricultural and Natural Resources Research and Education 2 Center (AREEO), Isfahan, I. R. Iran Leila Fathi Assistant Professor, Department of Furniture Industry Engineering, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran Nasrin Gharahi Associate Professor, Department of Environmental Engineering, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran. Elham Ghehsareh Associate Professor, Department of Natural Engineering, Faculty of Natural Resources and Earth Sciences, Shahrekord University , Shahrekord, Iran. Journal Article 2025 12 05 Problem definition and objectives: The Zagros region is one of the most important natural forest ecosystems in Iran, where Amygdalus haussknechtii plays a significant ecological role. This study aimed to evaluate the effects of site conditions on the physical and biometric properties of this species’ wood in two distinct sites, Kareh-Bas and Cholicheh, located in Chaharmahal and Bakhtiari Province. Methodology: Wood samples were collected from healthy, even-aged trees at breast height, and traits such as oven-dry density, basic density, volumetric swelling and shrinkage, as well as fiber characteristics (length, diameter, and cell wall thickness) were measured. To investigate the impact of habitat and environmental factors on the physical and biometric properties of A. haussknechtii wood, the data were first evaluated for normality. Pearson correlation coefficient was used to analyze relationships between variables, and principal component analysis was employed to reduce data dimensions and identify principal components. MANOVA was applied to examine multivariate separation among habitats. To identify the variables influencing dry density, multiple linear regression models were performed using stepwise forward. Results: Results indicated that differences between the two sites were significant for most traits (P < 0.01). In Kareh-Bas, oven-dry density was 0.92±0.03 g/cm3 and basic density was 0.77±0.02 g/cm3, which were lower than the values recorded in Cholicheh (1.01±0.03 g/cm3 and 0.84±0.06 g/cm3, respectively). Fiber length in Cholicheh averaged 0.98 mm compared to 0.78 mm in Kareh-Bas (P < 0.01). Fiber diameter (20.75 µm) and cell wall thickness (6.02 µm) were also higher in Cholicheh than in Kareh-Bas (P < 0.01). The Pearson correlation pattern indicates that the dominant axis of variation aligns with dry density, fiber diameter, cell wall thickness, wet density, and fiber length. These same variables emerge as the dominant and habitat-separating components in the first principal component analysis. Therefore, the correlation structure provides an intuitive basis for explaining the PCA separation and the significance of the MANOVA. PCA results revealed that the dominant axis of variation in the data aligns with fiber and moisture-related traits (fiber diameter, cell wall thickness, dry density, wet density, and fiber length), and this same axis appeared as the primary habitat separator in the first principal component (PC1). The MANOVA statistically confirmed the separation observed in the biplot. Regression models showed that fiber diameter is the most significant predictor of dry density across the entire dataset. In the Choliche habitat, in addition to fiber diameter, shrinkage had a positive effect and swelling had a negative effect, whereas in the Kareh-Bas habitat, only the constant (intercept) was significant. These results indicate that in the Choliche habitat, a combination of fiber and dimensional traits determines wood quality, whereas in the Karebas habitat, wood density is primarily influenced by the overall tissue average. Conclusion: Overall, wood grown in Cholicheh exhibited longer fibers, thicker cell walls, and higher density, whereas wood from Kareh-Bas showed lower density and greater porosity. These findings highlight the direct influence of environmental factors such as temperature, precipitation, and altitude on the wood structure of A. haussknechtii. It can be concluded that site-specific differences lead to substantial variations in the physical and biometric properties of this species, and such information is valuable for selecting optimal sites for industrial utilization and genetic improvement programs Problem definition and objectives: The Zagros region is one of the most important natural forest ecosystems in Iran, where Amygdalus haussknechtii plays a significant ecological role. This study aimed to evaluate the effects of site conditions on the physical and biometric properties of this species’ wood in two distinct sites, Kareh-Bas and Cholicheh, located in Chaharmahal and Bakhtiari Province. Methodology: Wood samples were collected from healthy, even-aged trees at breast height, and traits such as oven-dry density, basic density, volumetric swelling and shrinkage, as well as fiber characteristics (length, diameter, and cell wall thickness) were measured. To investigate the impact of habitat and environmental factors on the physical and biometric properties of A. haussknechtii wood, the data were first evaluated for normality. Pearson correlation coefficient was used to analyze relationships between variables, and principal component analysis was employed to reduce data dimensions and identify principal components. MANOVA was applied to examine multivariate separation among habitats. To identify the variables influencing dry density, multiple linear regression models were performed using stepwise forward. Results: Results indicated that differences between the two sites were significant for most traits (P < 0.01). In Kareh-Bas, oven-dry density was 0.92±0.03 g/cm3 and basic density was 0.77±0.02 g/cm3, which were lower than the values recorded in Cholicheh (1.01±0.03 g/cm3 and 0.84±0.06 g/cm3, respectively). Fiber length in Cholicheh averaged 0.98 mm compared to 0.78 mm in Kareh-Bas (P < 0.01). Fiber diameter (20.75 µm) and cell wall thickness (6.02 µm) were also higher in Cholicheh than in Kareh-Bas (P < 0.01). The Pearson correlation pattern indicates that the dominant axis of variation aligns with dry density, fiber diameter, cell wall thickness, wet density, and fiber length. These same variables emerge as the dominant and habitat-separating components in the first principal component analysis. Therefore, the correlation structure provides an intuitive basis for explaining the PCA separation and the significance of the MANOVA. PCA results revealed that the dominant axis of variation in the data aligns with fiber and moisture-related traits (fiber diameter, cell wall thickness, dry density, wet density, and fiber length), and this same axis appeared as the primary habitat separator in the first principal component (PC1). The MANOVA statistically confirmed the separation observed in the biplot. Regression models showed that fiber diameter is the most significant predictor of dry density across the entire dataset. In the Choliche habitat, in addition to fiber diameter, shrinkage had a positive effect and swelling had a negative effect, whereas in the Kareh-Bas habitat, only the constant (intercept) was significant. These results indicate that in the Choliche habitat, a combination of fiber and dimensional traits determines wood quality, whereas in the Karebas habitat, wood density is primarily influenced by the overall tissue average. Conclusion: Overall, wood grown in Cholicheh exhibited longer fibers, thicker cell walls, and higher density, whereas wood from Kareh-Bas showed lower density and greater porosity. These findings highlight the direct influence of environmental factors such as temperature, precipitation, and altitude on the wood structure of A. haussknechtii. It can be concluded that site-specific differences lead to substantial variations in the physical and biometric properties of this species, and such information is valuable for selecting optimal sites for industrial utilization and genetic improvement programs

https://www.ijwp.ir/article_735484_dccb16241bb39d1d3e139028c89b86b8.pdf