Fully return-to-nature polymer research for sustainability of resources

Abstract

Upcycling of resources becomes an important social issue because of the extensive utilization of nonbiodegradable polymers. Land fill is undesirable due to space limitation and ground pollution. Incineration is not also preferred because of emission of toxic gases which is generated from decomposition of polymer chains and residual additives. To resolve these waste management roblems, the recycling method and fully return to nature biocomposites were investigated in this research. The poly (ethylene terephthalate) (PET) bottle wastes were chemically recycled. The recycled PET was melt blended with virgin PET to improve the thermal and mechanical properties of recycled PET. Biomass derived polylactide is fully return to nature polymer and expected to replace petroleum-based commodity polymers because of its excellent physical properties. Polylactide biocomposites reinforced by nanofillers such as nanocellulose and nanosilica, were prepared for high performance biocomposites. The various modifications of nanocellulose such as acid hydrolysis, acetylation, and alkylation were performed for dispersion enhancement, resulting in efficient reinforcement effect of modified nanocellulose in the polylactide matrix. The mechanical properties, crystallinity, and thermal stability of polylactide biocomposites were investigated. Furthermore, the theoretical prediction in the mechanical properties and crystallization behaviors of polylactide biocomposites were additionally analyzed to clarify the reinforcing potential of modified nanocellulose and nanosilica. Biobased polyurethane (BPU) was also successfully synthesized from castor oil to replace petroleum-based polyurethane and the properties of BPU composite and nanoweb were investigated.