新型茂钛催化剂的分子设计与苯乙烯间规聚合

Molecular Design of Novel Metallocene Catalysts and Styrene Syndiospecific Polymerization

合成了ＣｐＴｉＣｌ３／ＭＡＯ、Ｃｐ＊ＴｉＣｌ３／ＭＡＯ、Ｃｐ＊Ｔｉ（ＯＣＨ２ＣＨＣＨ２）３／ＭＡＯ和Ｃｐ＊Ｔｉ（ＯＭｅ）３／ＭＡＯ四种均相催化体系．结果发现，［Ｃｐ＊Ｔｉ（ＯＣＨ２ＣＨＣＨ２）３］／甲基铝氧烷（ＭＡＯ）催化体系热稳定性较高，在３３３～３６３Ｋ下进行苯乙烯间规聚合具有最高的催化活性；聚合反应产物用沸丁酮抽提８ｈ，不溶部分间规聚苯乙烯（ｓＰＳ）占总聚合产物重量的９８％以上，ｓＰＳ的分子量Ｍｖ达到４．１５×１０５～２．４６×１０５范围，熔融温度高达５４３Ｋ．

CpTiCl 3, Cp *TiCl 3, Cp *Ti(OMe) 3 and Cp *Ti(OCH 2CHCH 2) 3 were compared as styrene syndiospecific polymerization catalysts activated with methylaluminoxane(MAO) in toluene solution. η 5 pentamethylcyclopentadienyltriallyloxy titanium Cp *Ti(OCH 2CHCH 2) 3 /MAO is a highly active catalyst for styrene syndiospecific polymerization at 333～363 K. The influence factors of polymerization temperature and time, catalyst and styrene concentration on styrene polymerization have been studied. When the total polymerization product was extracted with boling butanone for 8 h, the insoluble fraction is over 98 7%. The syndiotactic polystyrene(sPS) obtained by extraction has high molecular weight( M v=4 15×10 5～2 46×10 5) and high melting temperature(542 5～543 K) determined by DSC.