Mechanical properties of starch-based biocomposite: The effect of acidic atmosphere treatment

Abstract The objective of this study was to obtain the mechanical properties of starch-based biocomposites after treated in an acidic atmosphere. The research applies the tapioca starch, glycerol, distillate water, and nanoclay as biocomposite raw materials. Starch-based biocomposite was made by casting method. Acid sources for acidic atmosphere treatment were acetic acid with various pH of 1, 3, and 5 with exposure time for 4 hours. Characterization of biocomposite was conducted using tensile test, SEM and FTIR analysis. The acidic atmosphere treatment results decreasing both in the tensile strength and modulus in higher acidic atmosphere. The tensile test of biocomposite treated by the acidic atmosphere with acidic source pH 5 has an optimum modulus of 36.9 MPa and tensile strength of 9.1 MPa. The functional group of biocomposite changed after treatment in wavenumber of 2358 cm−1.