新型稀土催化剂下苯乙烯与异戊二烯的共聚合

考察以乙酰丙酮（acac）为配体的三氟甲磺酸钕配合物Nd（CF3SO3）3.2H2O.2.5acac]和三异丁基铝Al（i-Bu）3]组成的催化体系催化苯乙烯（St）和异戊二烯（Ip）共聚合行为.讨论单体配比n（St）/n（Ip）、n（Al）/n（Nd）、聚合温度、第3组分四氢呋喃（THF）对共聚合反应及产物微观结构的影响.结果表明：该催化体系可以实现St与Ip共聚.共聚活性随着聚合温度、单体配比中苯乙烯含量的增加而增加.共聚产物的相对分子质量高达106.所得共聚物为含苯乙烯短嵌段的无规共聚物,其中异戊二烯结构单元以cis-1,4结构为主,且cis-1,4含量不随苯乙烯含量的增加而改变.共聚物中苯乙烯摩尔分数最高可达27.1%.

Copolymerization of Styrene and Isoprene with Novel Rare-earth Catalyst System

In this article,copolymerization behavior of styrene（St） and isoprene（Ip） using a novel rare-earth catalyst system trifluoromethanesulforic neodymium complex Nd（CF3SO3）3·2H2O·2.5acac activated by Al（i-Bu）3 was studied.The effect of polymerization conditions,such as /,/,polymerization temperature,and the third component THF upon the copolymerization behavior and the microstructure of the product was investigated mainly.The results showed that copolymerization of styrene and isoprene could be achieved by the given catalyst system.Copolymerization activity was increased with the increasing of polymerization temperature and styrene feed ratio.The molecular weight of the product reached up to 106.The obtained copolymer was random copolymer in which the isoprene units were mostly cis-1,4 structure,and the cis-1,4 content independent of St incorporation.The maximum St incorporation was 27.1 %.