Synthesis of biodegradable plastics using corn starch and corn husk as the fillers as well as chitosan and sorbitol

Abstract

Bio plastics are polymers prepared from renewable materials. In this study, maize-derived cornstarch and milled corn husk were used as the base material and filler, respectively. Corn husk powder with two-grain sizes of 150 mesh and 200 mesh, respectively, were used. Chitosan was used at concentrations of 0.02 %, 0.04 %, 0.06 %, 0.08 %, and 0.1 % by weight at a constant ratio of 1:1 to cornhusk powder and maize for improving the mechanical properties of bio plastics. The mixture was diluted using a solution containing 2.5 mL of acetic acid (25 %), 1.75 mL of sorbitol, and 70 mL distilled water. Optimum mechanical properties were observed using a cornhusk grain size of 150 meshes with 0.04% of chitosan by weight. This sample exhibited a tensile strength of 11.7164 MPa, elongation of 10.05 %, a Young's modulus of 1.1668 MPa, and tear strength of 763.86 mN. A biodegradability of 70-100 % was achieved in 21 days with the evidence of fungal growth after 14 days. In addition, the sample was able to withstand a temperature of 140 °C for 1 h.