Mechanical Properties of Sugarcane Bagasse Fiber-Reinforced Soy Based Biocomposites

The effects of protein content and polylactic acid (PLA) on mechanical properties of soy based bioplastics were investigated. The bioplastic extruded from defatted soy flour (DSF) with protein content of 50 wt% exhibited impact strength at 3.1 kJ/m(2) with low tensile strength, 0.19 MPa. The use of soy protein isolate (SPI) which had higher protein content (95 wt%) could increase tensile strength of the bioplastic obtained up to 0.63 MPa, but the impact strength of the sample was decreased. Soy based bioplastic was prepared from DSF and SPI with the addition of PLA at 40 wt% to improve the tensile property of the samples and sugarcane bagasse fiber was used as the reinforcement. The addition of non-treated bagasse at 15 wt% could significantly improve tensile strength, Young's modulus, flexural modulus and impact strength of the obtained biocomposite, by about 61, 53, 113 and 52 %, respectively. The use of alkali-treated bagasse fiber could increase the impact strength of the biocomposite, with less effect on the tensile and flexural properties.