茂金属/烷基铝/B(C_6F_5)_3催化体系催化乙烯聚合
Ethylene polymerization catalyzed by metallocene/AlR_3/B(C_6F_5)_3
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摘要: Cp2 Zr Cl2 、Et( Ind) 2 Zr Cl2 与烷基铝原位生成二烷基化茂金属 ,然后与 B( C6 F5) 3作用组成新的催化体系 ,研究了这种催化体系对乙烯聚合的影响 .发现用三乙基铝的体系对乙烯聚合没有活性 ,用三异丁基铝的体系对乙烯聚合有较高活性 ,其原因在于形成了不同的活性中心 ,用紫外光谱的方法研究活性中心的结构及其变化 ,并与聚合活性进行了关联Abstract: A convenient catalytic system dichlorometallocene/AlR_3/B(C_6F_5)_3 was developed. Very low activity and no activity was observed when AlEt_3 used, high activity was observed when Al(iBu)_3 used. A plausible mechanism is presented to interpret the ethylene polymerization activity changes with the different R_3Al used, main related the different active center formed, these can be proved by UV-visible spectroscopy.
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