Enhanced Thermal Stability and Water Resistance in Silylated Starch/Poly(Propylene Carbonate) Composites via Hydrophobic Modification

ABSTRACT Poly(propylene carbonate) (PPC) which serves as a biodegradable plastic has been widely applied. However, its thermal stability and mechanical properties are poor, which greatly limits its development. Herein, cassava starch was modified by trimethylchlorosilane, and then silylated starch/PPC composites were prepared through a physical blending procedure. The hydrogen bonding interaction is formed between silylated starch and PPC, bringing about a good interfacial compatibility. Therefore, the thermal stability and mechanical properties of silylated starch/PPC composites have been enhanced. The degradation temperature of PPC at 279.08°C has risen to 311.09°C for TMCS‐starch/PPC = 80/20. The tensile strengths of composites have been improved from 10.35 ± 1.07 MPa for pure PPC to 15.35 ± 0.62 MPa for TMCS‐starch/PPC = 50/50. Additionally, the water resistance of composites was studied. Due to the contributions of hydrophobic groups on the silylated starch molecule and the hydrophobic PPC chain, modified starch could effectively hinder the permeation of water molecules to avoid starch molecule dissolution. This study proposed a simple and effective process technique by utilizing silylated starch and PPC to fabricate the composites with superior properties.