Preparation and properties of biodegradable poly(propylene carbonate)/thermoplastic dried starch composites

The biodegradable poly(propylene carbonate) (PPC)/glycerol-plasticized thermoplastic dried starch (GPTPS) composites are prepared in a screw extruder. The dried starch is used, because the moisture in native starch easily induces the degradation of PPC during the processing. The effects of succinic anhydride (SA) on the morphology, thermal properties, dynamic mechanical thermal analysis, as well as mechanical properties of PPC/GPTPS composites, are investigated. Scanning Electron Microscope (SEM) shows that SA improves interfacial adhesion between PPC and GPTPS. Fourier Transform Infrared (FTIR) Spectroscopy reveals that SA can improve the interaction between PPC and GPTPS. Thermogravimetric Analysis (TGA) results show that SA leads a significant improvement of thermal stability for PPC/GPTPS composites. Mechanical testing illustrates that SA can increase mechanical properties of PPC/GPTPS composites. The tensile strength and elongation at break of PPC/GPTPS/SA(75/25/1) composite can reach 19.4 MPa and 88.5%, respectively.