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新型单茂钛/改性甲基铝氧烷催化剂合成立构多嵌段聚丁烯-1
Syntheses of Multi stereoblock Polybutene 1 with Novel Mono cyclopentadienyltitanium/Modified Methylaluminoxane Catalyst
【摘要】 茂金属聚烯烃以其高附加值而受到广泛重视.有关桥联或非桥联二茂基金属催化剂用于合成无规、等规、间规聚丙烯和聚丁烯-1已有报道[1~5].Llinas等[6]用rac-Et(CpMe4Ind)·TiCl2和甲基铝氧烷(MAO)催化剂合成了等规/无规立构嵌...
【Abstract】 Butene was polymerized using novel mono ( η 5 pentamethylcyclopentadienyl) tribenzyloxy titanium Cp *Ti(OBz) 3 /modified methylaluminoxane(mMAO) as catalyst. The resulting multi stereoblock polybutene 1 was characterized by 13 C NMR and DSC analysis. The influences of various oxidation state of titanium active species on 1 butene polymerization were investigated. It was indicated that Ti(Ⅳ) active species is in favour of producing polybutene 1. 13 C NMR analyses of polymers obtained show that propagation of 1 butene involves primarily head to tail 1,2 insertions, with involving some head to head or tial to tail 2,1 misinsertions. There is a remarkable decrease in 2,1 misinsertions with decreasing temperature of polymerization. Regiopentad distribution indicates stereoblock polybutene 1 with melting temperature( T m) comprising isotactic, syndiotactic and atactic multi sequences polybutene 1.
- 【文献出处】 高等学校化学学报 ,CHEMICAL RESEARCH IN CHINESE UNIVERSITIES , 编辑部邮箱 ,1999年07期
- 【分类号】O632.12
- 【被引频次】15
- 【下载频次】139