Novel Biocomposites from Native Grass and Soy Based Bioplastic: Processing and Properties Evaluation

Indian grass fiber reinforced soy based biocomposites were fabricated by using twin-screw extrusion and injection molding technology. The thermal and mechanical properties and the morphology of the biocomposites were evaluated using a dynamic mechanical analyzer (DMA), a universal testing system (UTS), and an environmental scanning electron microscope (ESEM). Raw Indian grass fiber improved the tensile and flexural properties as well as the heat deflection temperature (HDT), but did not improve the impact strength of the biocomposites. The impact fracture of the raw Indian grass fiber reinforced biocomposites was found to occur on the outer surface of the fiber, due to intrinsic differences in the morphological structure between the outer and inner surfaces of the grass fiber. Treatment of the Indian grass fiber with an alkali solution significantly improved the tensile, impact, and flexural strengths of its reinforced soy based biocomposites, presumably due to the homogeneous dispersion of fibers in the matrix and the enhanced aspect ratio of the fibers.