Study on the Compatibilization Mechanism of Poly(Propylene Carbonate) /Thermoplastic Starch CompositesAuthor(s): Hongguang Dai, Qian Wang, and Zhengdong Ding
Poly (propylene carbonate)/thermoplastic starch composites (PPC/TPS) are environment-friendly materials. Compatibilization of PPC and TPS in PPC/TPS using anhydrides as compatibilizers is reported, but the compatibilization mechanism of PPC and TPS is not studied. In the paper, succinic anhydride (SA) is used as compatibilizer for PPC/TPS (SAPPC/TPS) and succinic acid (S) is used as compatibilizer for PPC/TPS (SPPC/TPS) too. Compatibilization mechanism is analyzed by comparing SAPPC/TPS with SPPC/TPS. Scanning electron microscope demonstrates that compatibilization effect of S is better than that of SA. Thermal property of composites is characterized by differential scanning calorimetry. The mechanical properties of SPPC/TPS are better than those of SAPPC/TPS. The composites are extracted by methanol firstly, and then by acetone. The acetone extract products are characterized by attenuated total reflection-fourier transform infrared (ATR-FTIR). In the presence of acid or anhydride, transesterification of PPC and starch is the major reaction, which produces the starch-g-PPC graft copolymer. The production of starch-g-PPC copolymer improves the compatibilization of PPC and TPS.