应用单宁与淀粉为交联剂改性聚氨酯

通过植物原料单宁与淀粉对聚氨酯的改性可提高聚氨酯的机械性能和热性能 ,单宁成分的导入还能有效提高聚氨酯交联点密度、组分相容性和体系的形态结构均匀性 .当单宁的含量占投入的植物原料的6 0wt%时 ,单宁和淀粉聚氨酯网络互相贯穿表现出良好的相容性 ,其拉伸强度、杨氏模量分别提高到 5 1 9MPa和 30 8 4MPa ,积分程序分解温度达到 375℃ .同时单宁成分有望在一定范围内调节聚氨酯的降解速度 .

APPLICATION OF TANNIN AND STARCH AS CROSSLINKER IN MODIFICATION OF POLYURETHANE

A series of casting films of starch and tannin-based polyurethane were prepared and the effect of tannin and starch amounts on the properties of polyurethane was investigated.It was found that when tannin was added,the thermal behavior and mechanical properties of films were improved,especially when the content of tannin reached 60% (weight percent in biomass),tannin and the network of starch-based polyurethane interpenetrated and showed good miscibility.Its integral procedural decomposition temperature(IPDT) was 375℃,its tensile strength and Young's modulus were 51 9 MPa and 308 4 MPa,respectively.The results indicated that tannin had great effect on the density of crosslinking,miscibility of components and the morphology of starch polyurethane.The degradation test in phosphate buffer solutions showed that tannin could adjust the speed of starch polyurethane degradation,to some extent.