Effects of waste polyester fibers on the mechanical and thermal properties of WPC products

This study has been undertaken to investigate effects of synthetic waste fibers of polyester in improving mechanical properties of wood plastic composites. Two types of polyester fibers (carpet fibers and polish fibers), high density polyethylene along with 40 wt% wood flour of populus, 2 wt% of maleic anhydride grafted polyethylene (MAPE) and ethylene- glycidyl methacrylate copolymer (E-GMA) as coupling agent were used. After two-stage mixing, resulted granules were hot pressed (at160℃, under 10 Mpa pressures) to produce test boards measuring 20×20×0.7 cm in dimensions. Results from measurement of mechanical properties of the samples have shown that with increasing the amount of polyester fibers (carpet fibers and polish fibers), tensile modulus of elasticity of wood plastic composites decreases and increases his flexural modulus of elasticity. Also by increasing amount carpet fibers, the tensile, flexural strengths of wood plastic composites-carpet fibers increases and the maximum of flexural strength is in a sample that contained 20 wt% carpet fibers. But about the plush fiber, 10 wt% of it is efficient for increasing the flexural and tensile strengths of wood plastic composites-plush fibers. Then on the composites contained the optimal polyester (polish fiber 10% and carpet fibers 20%) for increasing the mechanical strength, TGA and DSC testes for experience the thermal behavior of the composites were analyzed. Thermal analyses results have shown that with addition of polyester in the wood composite plastic, are reduced the percentage of crystallization, temperature of crystallization and the temperature of stability and degradation thermal of the composite.Morphologic study by Scanning Electron Microscopy indicates that with the increasing percentage of polyester fibers, is more denser and smoother the integration between the fracture surface of the composite material