聚乙烯-超支化聚醚接枝共聚物的合成、改性及增容研究

Synthesis,Modification and Application of Polyethylene-Hyperbranched Polyether Graft-copolymers

采用烯烃配位共聚合的方法制备了支链末端带羟基的功能化聚乙烯大分子引发剂,然后采用缩水甘油开环聚合的方法合成了线性-超支化接枝共聚物(LHGCs),并对聚合物末端进行功能化,获得末端为苯酯基的线性-超支化接枝共聚物(LHGCs-Bz)。通过傅里叶红外光谱(FTIR)、核磁分析表征了所合成聚合物的结构。采用TGA、DSC对聚合物热性能进行研究,表明接枝聚合物具有很好的热稳定性。XRD测试表明端基和超支化支链对线性聚乙烯链的结晶性能有一定影响。通过将LHGCs-Bz作为增容剂加入到线性低密度聚乙烯/聚己内酯(LLDPE/PCL)共混体系,证明了LHGCs-Bz这种同时拥有非极性聚乙烯主链和极性超支化聚醚支链的聚合物有一定的增容性,共混体系的相尺寸随增容剂的加入而减小,并且与极性/非极性的嵌段比例有关。

The ethylene/undecylenyl alcohol copolymers,employed as macroinitiators which offer the sites for initiating graft-from copolymerization,were obtained via olefin coordination polymerization.Subsequently,the hyperbranched side chains were synthesized in a post-polymerization grafting step by controlling the growth of hyperbranched polyglycerol（hbPG）onto the deprotonated linear macroinitiators via a ring-opening multibranching polymerization（ROMBP）,and were then modified by benzoyl chloride.The polymer structures of LHGCs and LHGCs-Bz were characterized by FTIR,^1 H/^13 C NMR.TGA and DSC test results show that the LHGCs have good thermal stability.Effects of terminal groups and hyperbranched side chains on the degree of crystallinity of LHGCs were studied by XRD.LHGCs-Bz,with a linear apolar polyethylene chain and polar hbPG side chains,was also added into the LLDPE/PCL blends as a compatibilizer to investigate its amphiphilic properties.SEM results showed the LHGCs-Bz compatibilizers can reduce the phase size and increase the interfacial tension.