Preparation and recycling of polymer eco-composites i. Comparison of the conventional molding techniques for preparation of polymer eco-composites

摘要

The interest in natural fiber-reinforced polymer composites is growing rapidly due to their high performance inudterms of mechanical properties, significant processing advantages, excellent chemical resistance, low cost and lowuddensity. In this study, the compression and injection molding of polypropylene (PP) and polylactic acid (PLA) basedudcomposites reinforced with rice hulls or kenaf fibers was carried out and their basic properties were examined. Riceudhulls from rice processing plants and natural lignocellulosic kenaf fibers from the bast of the plant Hibiscus Cannabinusudrepresent renewable sources that could be utilized for composites. Maleic anhydride grafted PP (MAPP) andudmaleic anhydride grafted PLA (MAPLA) were used as coupling agents (CA) to improve the compatibility and adhesionudbetween the fibers and the matrix. Composites containing 30 wt % reinforcement were manufactured by compressionudand injection molding, and their mechanical and thermal properties were compared. It was found that theudtechniques applied for manufacturing of the eco-composites under certain processing conditions did not induce significantudchanges of the mechanical properties. The flexural strength of the compressed composite sample based on PPudand kenaf is 51. 3 MPa in comparison with 46.7 MPa for the same composite produced by injection molding technique.udParticularly, PP-based composites were less sensitive to processing cycles than PLA-based composites. Theudexperimental results suggest that the compression and injection molding are promising techniques for processing ofudeco-composites. Moreover, the PP-based composites and PLA-based composites can be processed by compressionudand injection molding. Both composites are suitable for applications as construction materials.