C_(60)/C_(70)及其衍生物(C_(60)Cl_n/C_(70)Cl_n)在丁二烯阴离子聚合中的偶联作用

Fullerene(富勒烯)独特的结构和性质吸引了高分子界广泛的关注.迄今,已通过和自由基共聚[1]、活性自由基聚合[2]、阳离子聚合[3]、阴离子聚合[4～8]以及配位聚合[9～13]等诸多方法相结合制备出了种类繁多的富勒烯高分子衍生物.不仅如此,富勒烯家族的重要分支--富勒烯卤化物,其独特的分子结构和具有的新性质也甚引起人们的重视[14,15].

COUPLING EFFECT OF C60/C70 AND ITS DERIVATIVE (C60Cln/C70Cln) IN ANIONIC POLYMERIZATION OF BUTADIENE

The fullerenes chloride,C 60 Cl n /C 70 Cl n, was used as a novel coupling agent in n BuLi initiated anionic polymerization of butadiene(Bd).Its coupling behavior was investigated by comparing with the commonly used coupling agent SiCl 4.The broader polydispersity of the coupling products and a new peak in GPC chromatograms demonstrated that coupling reactions happened and polybutadiene chains were covalently bonded to the molecule of C 60 Cl n /C 70 Cl n .But the coupling efficiency needs to be improved.The intrinsic viscosity of the coupling products([ η ]) was also measured.Double peaks in the coupling agent curves appeared when C 60 Cl n /C 70 Cl n was used,while a single peak in the coupling agent curves occurred when SiCl 4 was used.The results above showed that C 60 Cl n /C 70 Cl n had the specific coupling mechanisms which were different from SiCl 4.Two coupling mechanisms of C 60 Cl n /C 70 Cl n including addition and substitution were deduced.The experiment also revealed that in the anionic polymerization of Bd,the molecule C 60 could influence the polymerization.A new living center formed in the reaction system by n BuLi and C 60 might be able to initiate the polymerization of Bd,which increased the products' molar mass and broadened polydispersity.The structure of the star shaped products with polybutadiene as arms and C 60 Cl n /C 70 Cl n as core should be studied further.