Fabrication and Properties of Novel Lyocell/Poly(lactic acid) and Lyocell/Poly(butylene succinate) Biocomposites and Lyocell-Based Carbon Fabric/Phenolic Composites Jae Young Lee Department of Polymer Science and Engineering, Graduate School Kumoh National Institute of Technology Abstract Since Petr...
Fabrication and Properties of Novel Lyocell/Poly(lactic acid) and Lyocell/Poly(butylene succinate) Biocomposites and Lyocell-Based Carbon Fabric/Phenolic Composites Jae Young Lee Department of Polymer Science and Engineering, Graduate School Kumoh National Institute of Technology Abstract Since Petroleum-based plastics do not degrade in landfill or composting environments, they may have serious environmental problems. Recently, there are increasing needs for developing environmentally friendly biocomposite materials using natural fibers and renewal resources with the emphasis of environmental regulation, social concerns, and sustainability and due to high-cost petroleum. Biodegradable polymers like poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) have also increasly attracted attention as matrix for biocomposites. Lyocell is an environmentally benign man-made fiber because lyocell can be produced by cellulose dissolution in N-methyl morpholine N-oxide. In particular, deviations in the properties, shape and microstructure between different batches of Lyocell fibers are very low unlike in natural fibers. Although lyocell fiber/biodegradable polymer composites are very attractive in the view point of environmentally friendliness and the novelty, little literature has been reported yet. The first part of the present study deals with an investigation on the fabrication and properties the biocomposites composed of Lyocell fabrics as reinforcement and biodegradable polyesters (PLA and PBS) as matrices. The later part of the study deals with the composites composed of Lyocell-based carbon fabrics and phenolic resin matrix. Lyocell fabric-reinforced PLA biocomposites were fabricated by compression molding technique using a sheet-interleaving method. The mechanical and thermal properties before and after modification of Lyocell fabric-reinforced PLA biocomposites by the silane treatment of Lyocell. Lyocell fabrics were treated at different concentrations of 0, 0.5, 1 and 3 wt% 3-glycidoxypropyltrimethoxy silane (GPS). 1 wt% GPS silane-treated Lyocell/PLA biocomposites significantly improved their mechanical properties. The heat deflection temperature of Lyocell/PLA biocomposites was significantly higher than that of neat PLA. The thermal properties of GPS silane-treated Lyocell biocomposites were higher than neat PLA. Moreover, morphological studies by scanning electron microscopy demonstrated the improved adhension between the Lyocell fibers and the PLA matrix, of the biocomposites. Lyocell fabric-reinforced poly(butylene succinate) biocomposites with different fiber loadings of 0, 30, 40, 50 and 60 wt% were also fabricated by compression molding using a sheet-interleaving method. The effect of Lyocell fabric loading on flexural and tensile properties, coefficient of thermal expansion, and heat deflection temperature of Lyocell/PBS biocomposites was investigated. The result strongly depends on the fiber loading. The properties was significantly improved by incorperating Lyocell fabrics. The greatest tensile, flexural and thermal properties of Lyocell/PBS biocomposites were obtained with Lyocell fabrics of 50 wt%. Researches on cellulose-based carbon fibers have focused on improving properties and yield and also on eliminating pollution problems. It is well known that Lyocell fiber is a new 100% cellulosic fiber spun from wood or cotton pulp in a closed amine oxide solvent system and is made by an environmentally friendly production process. The mechanical properties of Lyocell including tenacity, tensile modulus and shear strength are superior to those of rayon fibers. It has been proposed that Lyocell is an excellent candidate for making high performance carbon fibers. In this work, Lyocell-based carbon fabrics were prepared through stabilization and carbonization processes using heat-treatement furnace. Lyocell-based carbon fabric-reinforced phenolic composites were fabricated by compression molding technique using Lyocell-based carbon fabric/phenolic prepregs lay-up. The flexural properties, interlaminar shear strength (ILSS) and thermal properties Lyocell-based carbon fabric/phenolic composites before and after nitric acid (HNO3) treatment of Lyocell-based carbon fabrics were explored HNO3 solution with different concentrations of 0, 20, 40, and 60 wt% were used for the treatment of Nitric acid-treated Lyocell-based carbon fabric/phenolic composites exihibited the improved mechanical properties. The flexural properties and ILSS of 60 wt% HNO3 treated Lyocell-based carbon fabric/phenolic composites are significantly higher than those of the untreated counterpart. The coefficient of thermal expansion and thermal stability of Lyocell-based carbon fabric/phenoilc composites were also examined. The result strongly depends not only on the presence of the acid treatment but also on the concentration.
Fabrication and Properties of Novel Lyocell/Poly(lactic acid) and Lyocell/Poly(butylene succinate) Biocomposites and Lyocell-Based Carbon Fabric/Phenolic Composites Jae Young Lee Department of Polymer Science and Engineering, Graduate School Kumoh National Institute of Technology Abstract Since Petroleum-based plastics do not degrade in landfill or composting environments, they may have serious environmental problems. Recently, there are increasing needs for developing environmentally friendly biocomposite materials using natural fibers and renewal resources with the emphasis of environmental regulation, social concerns, and sustainability and due to high-cost petroleum. Biodegradable polymers like poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) have also increasly attracted attention as matrix for biocomposites. Lyocell is an environmentally benign man-made fiber because lyocell can be produced by cellulose dissolution in N-methyl morpholine N-oxide. In particular, deviations in the properties, shape and microstructure between different batches of Lyocell fibers are very low unlike in natural fibers. Although lyocell fiber/biodegradable polymer composites are very attractive in the view point of environmentally friendliness and the novelty, little literature has been reported yet. The first part of the present study deals with an investigation on the fabrication and properties the biocomposites composed of Lyocell fabrics as reinforcement and biodegradable polyesters (PLA and PBS) as matrices. The later part of the study deals with the composites composed of Lyocell-based carbon fabrics and phenolic resin matrix. Lyocell fabric-reinforced PLA biocomposites were fabricated by compression molding technique using a sheet-interleaving method. The mechanical and thermal properties before and after modification of Lyocell fabric-reinforced PLA biocomposites by the silane treatment of Lyocell. Lyocell fabrics were treated at different concentrations of 0, 0.5, 1 and 3 wt% 3-glycidoxypropyltrimethoxy silane (GPS). 1 wt% GPS silane-treated Lyocell/PLA biocomposites significantly improved their mechanical properties. The heat deflection temperature of Lyocell/PLA biocomposites was significantly higher than that of neat PLA. The thermal properties of GPS silane-treated Lyocell biocomposites were higher than neat PLA. Moreover, morphological studies by scanning electron microscopy demonstrated the improved adhension between the Lyocell fibers and the PLA matrix, of the biocomposites. Lyocell fabric-reinforced poly(butylene succinate) biocomposites with different fiber loadings of 0, 30, 40, 50 and 60 wt% were also fabricated by compression molding using a sheet-interleaving method. The effect of Lyocell fabric loading on flexural and tensile properties, coefficient of thermal expansion, and heat deflection temperature of Lyocell/PBS biocomposites was investigated. The result strongly depends on the fiber loading. The properties was significantly improved by incorperating Lyocell fabrics. The greatest tensile, flexural and thermal properties of Lyocell/PBS biocomposites were obtained with Lyocell fabrics of 50 wt%. Researches on cellulose-based carbon fibers have focused on improving properties and yield and also on eliminating pollution problems. It is well known that Lyocell fiber is a new 100% cellulosic fiber spun from wood or cotton pulp in a closed amine oxide solvent system and is made by an environmentally friendly production process. The mechanical properties of Lyocell including tenacity, tensile modulus and shear strength are superior to those of rayon fibers. It has been proposed that Lyocell is an excellent candidate for making high performance carbon fibers. In this work, Lyocell-based carbon fabrics were prepared through stabilization and carbonization processes using heat-treatement furnace. Lyocell-based carbon fabric-reinforced phenolic composites were fabricated by compression molding technique using Lyocell-based carbon fabric/phenolic prepregs lay-up. The flexural properties, interlaminar shear strength (ILSS) and thermal properties Lyocell-based carbon fabric/phenolic composites before and after nitric acid (HNO3) treatment of Lyocell-based carbon fabrics were explored HNO3 solution with different concentrations of 0, 20, 40, and 60 wt% were used for the treatment of Nitric acid-treated Lyocell-based carbon fabric/phenolic composites exihibited the improved mechanical properties. The flexural properties and ILSS of 60 wt% HNO3 treated Lyocell-based carbon fabric/phenolic composites are significantly higher than those of the untreated counterpart. The coefficient of thermal expansion and thermal stability of Lyocell-based carbon fabric/phenoilc composites were also examined. The result strongly depends not only on the presence of the acid treatment but also on the concentration.
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