Development of rare earth polymerization catalysts

利用阳离子半夹心氨基苯钪配合物，首次实现了1,5 -己二烯与苯乙烯的共聚，以及1,5 -己二烯与苯乙烯和乙烯的共聚合，形成了一个具有间二规苯乙烯单元、环戊基单元和乙烯支基的新型高分子材料家族。通过使用两种不同的钪金属催化体系，这两种催化体系在链穿梭剂（三异丁基铝）的存在下，分别对苯乙烯聚合和异戊二烯和丁二烯聚合表现出双特异性和顺式- 1,4选择性，我们首次实现了苯乙烯、异戊二烯和丁二烯的区域特异性和立体特异性链穿梭共聚，得到了前所未有的多嵌段共聚物，如sps -顺式- 1,4 - pi -顺式-1。4-PBD具有高区域选择性和立体选择性。

By using the cationic half-sandwich aminobenzyl scandium complexes, we have achieved for the first time the copolymerization of 1, 5-hexadiene with styrene and terpolymerization of 1, 5-hexadiene with styrene and ethylene to give a new family of polymer materials which possess syndiotactic styrene units, cyclopentyl units and vinyl branch units. By using two different scandium metal catalytic systems, which show syndiospecific selectivity for styrene polymerization and cis-1, 4-selectvity for isoprene and butadiene polymerization, respectively, in the presence of a chain-shuttling agent(triisobutylaluminum), we have achieved for the first time the regio-, and stereospecific chain-shuttling copolymerization of styrene, isoprene and butadiene to give unprecedented multi-block copolymers such as sPS-cis-1, 4-PI-cis-1, 4-PBD with high regio-and stereoselectivity.