Preparation and characterization of thermoplastic starch/wheat gluten composites

Thermoplastic starch (TPS) and TPS/wheat gluten composites were prepared using compression molding. The wheat gluten contents ranged from 0 wt% to 20 wt%. The morphology of the fractured surfaces, thermal decomposition temperatures and mechanical properties of the TPS and TPS/wheat gluten composites were investigated using scanning election microscopy (SEM), thermal gravimetric analysis (TGA) and tensile testing, respectively. The maximum tensile strength of TPS/wheat gluten composites (1.1 MPa) was obtained when 10 wt% of wheat gluten was used. The crosslinking between wheat gluten protein chains caused an increase in the tensile strength of the TPS/wheat gluten composites. The temperature at the maximum weight loss of the TPS/wheat gluten composites was higher than for TPS. Moreover, wheat gluten decreased the water absorption.