Sustainable composite materials from renewable resources for automotive applications

As part of an ongoing program on the development of biocomposites from renewable resources, e.g. cellulosic fibers and cellulosic plastics, to produce more eco-friendly/green automotive parts, this thesis deals with the development of a cellulose acetate (CA) biopolymer. Through plasticization, CA was found to be processable at 170--180°C, approximately 50°C below the melting point of neat CA. Eco-friendly green/biocomposites were fabricated from chopped hemp fiber and cellulose ester biodegradable plastic through two process engineering approaches: powder impregnation through compression molding (Process I) and extrusion followed by injection molding (Process II). Cellulose acetate plasticized with 30% citrate plasticizer proved to be a better matrix compared to polypropylene (PP) for hemp fiber reinforcements in terms of flexural and damping properties. In addition to plasticized CA, we used cellulose acetate butyrate plastic (CAB) as matrix in developing the biocomposites. Both matrices had good interaction (hydrogen bonds) with hemp fibers with CAB having higher strength. The addition of a small amount of compatibilizer (maleic anhydride functionalized CAB) into the system led to formation of ester linkages (covalent bonds) between hemp fibers and the matrix to improve the adhesion and to enhance their thermomechanical properties.