Bio-based plastics reinforced with natural fibers/hybrid composites through reactive processing

Abstract

The reinforced PLA composite and hybrid composites with natural fibers, inorganic filler and/or synthetic fiber were fabricated by in situ reactive melt-blending in one-step process and their properties were investigated. The PLA/natural fiber interfacial adhesion was improved due to the presented multifunctional epoxide-based reactive agent (CEGMA) as proved by SEM images and Molau test. The highest tensile strength was obtained from PLA biocomposites incorporated with 1.0 phr CEGMA, which was improved by 13.9% compared to non-reactive biocomposite. The reactive PLA hybrid composite with 1:1 fiber:talc ratio fabricated using twin-screw extruder showed the highest improvement on storage modulus in the rubbery region. In order to provide more reactive site on filler surface, fiber and talc were successfully treated with MAH during the drying process, which was revealed by FT-IR spectra. Tensile strength and impact strength of the PLA hybrid composites were slightly improved by 6% when only CEGMA was added. However, MAH-treated fillers reinforced PLA with CEGMA and peroxide loading not only showed the most improvement on tensile and impact strength by 11 and 36% but also their interfacial adhesion compared to non-reactive hybrid composite. The reactive PLA/MAH-treated Jute/Carbon fiber hybrid composite was prepared using direct fiber feeding injection molding in term of practical use. Tensile strength of the reactive composite and hybrid composite was higher than non-reactive hybrid composite by 14.9 and 6.8% due to strong interfacial adhesion. It was confirmed that the in situ compatibilization between MAH-treated fiber and PLA chain could occur in short reaction time.

-