Mechanical properties of soy protein based “green” composites reinforced with surface modified cornhusk fiber

In this study, fibers were extracted from cornhusk by using alkali solution. Scanning electron microscopic observations on the morphological structure of cornhusk fiber showed that wax and other noncellulosic substances were removed after alkali treatment. The fibers were further surface modified with silane and used for the reinforcement of bioplastic made from defatted soy flour, soy protein, and polylactic acid (PLA). Mechanical properties including tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, and water absorption of PLA-soy protein based biocomposites containing surface modified cornhusk fiber were superior to the biocomposite reinforced with untreated fibers. Significant improvement of all mechanical properties were observed with the use of silane treated cornhusk fiber at 5 wt% fiber loading. The enhancement in mechanical properties of the composites was corresponding to better interfacial adhesion between the PLA-soy protein matrix and cornhusk fibers.