Chopped industrial hemp fiber reinforced cellulosic plastic biocomposites: thermomechanical and morphological properties

Abstract

Biocomposites, i.e., biopolymers reinforced with natural fibers, offer an environmentally benign alternative structural material for automotive applications. Cellulose esters (bioplastic made from cellulose) are potentially useful biosourced polymers. By embedding inexpensive plant-based cellulosic fibers (chopped hemp fiber) into a biopolymeric matrix (cellulose ester) novel biocomposites have been made utilizing two different processing approaches: powder impregnation (process I) and extrusion followed by injection molding (process II). The resulting biocomposites have been evaluated for their physicomechanical and thermomechanical properties. 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. Biocomposites with 30 wt % of industrial hemp fiber processed through extrusion and injection molding exhibited a flexural strength of ∼78 MPa and modulus of elasticity of ∼5.6 GPa. Cellulose acetate butyrate plastic (CABP) proved to be a better matrix than plasticized cellulose acetate (CAP) for biocomposite applications. The fiber−matrix adhesions are evaluated through environmental scanning microscopy (ESEM) analysis.