异氰酸酯接枝改性淀粉/聚碳酸亚丙酯共混物及性能

Preparation and properties of grafting modification on starch/poly(propylene carbonate) composites by diphenylmethane diisocyanate

为提高淀粉(Starch)与聚碳酸亚丙酯(PPC)的界面作用力,在淀粉颗粒与PPC复合时加入二苯基甲烷二异氰酸酯(MDI),进行反应性共混改性,通过FTIR、DSC、TGA、SEM、拉伸测试等手段对共混物进行表征,验证了接枝作用的发生,同时讨论了在熔融状态下,MDI对共混物接枝改性的作用效果。结果表明:有PPC大分子接枝到淀粉颗粒表面上。正是接枝的PPC在两相间充当兼容剂,提高了其相容性,增强了PPC相与淀粉颗粒之间的界面粘接力,使得形态结构稳定化,从而使得力学性能和热稳定性得到有效改善。

To enhance the interfacial bonding between starch and matrix Poly（propylene carbonate）（PPC）,Starch / PPC composites was modified by diphenylmethane diisocyanate（MDI） through the reactive blending,the blends were characterized by infrared spectroscopy（FTIR）、differential scanning calorimetry（DSC）、thermogravimetric analysis（TGA）、scanning electron microscopy（SEM）、and tensile test,and tested the graft reaction were occurred.The effects of MDI on properties of the composites are discussed.The results show that PPC chains were grafted onto the surface of starch granules.As compatibility agent,the grafted PPC improves the compatibility between starch and matrix PPC,and it enhances the interfacial bonding and makes morphological structure stabilization,so the mechanical property and thermal stability are improved effectively.