Bio-based blends of starch and poly(butylene succinate) with improved miscibility, mechanical properties, and reduced water absorption

Poly(butylene succinate) (PBS) was blended with thermoplastic starch (TPS) to improve the mechanical properties and reduce water absorption of the resulting starch-based plastics. In order to enhance the miscibility between TPS and PBS, reactive PBS (RPBS) with terminal NCO group was synthesized first and then blended with TPS. The mechanical properties of the TPS were greatly improved after blending with RPBS, the tensile strength was increased to 10 times more than TPS even only 10 wt% RPBS was introduced. The water absorption of the blend was significantly reduced with increasing RPBS content. SEM results suggest RPBS to be uniformly distributed in the TPS matrix, and the size of the RPBS phase was decreased with reducing intrinsic viscosity of RPBS. The study of contact angle indicated that the hydrophobicity of the blend was largely enhanced toward TPS. With improved mechanical properties and reduced water absorption, the materials could find more extensive applications.