茂金属催化剂体系及其丙烯聚合性能调控

Metallocene Catalyst Systems and Control over the Propylene Polymerization

国内聚丙烯的生产基本上使用传统的Ziegler-Natta催化剂,国外已经使用茂金属催化剂.茂金属催化剂生产的聚丙烯提升了产品性能,市场需求份额逐年增加,国内需要开发茂金属催化剂并拓展工业应用.茂金属催化剂与传统的Ziegler-Natta催化剂相比,结构类型丰富,反应调控能力强,可以催化生成结构多样的聚丙烯.以茂金属催化剂的发展为主线,探讨催化剂结构对反应性能的影响;分析体系中多种因素如温度、压力、催化剂浓度、助剂等对反应活性的调控;讨论催化反应机理.

While the metallocene catalysts were widely used to produce the metallocene polypropylenes (mPP)in other counties,the traditional Ziegler-Natta catalyst has still been dominantly employed for mahufacturing the polypropyienes (PP)in our coUntry at current time,The property of the mPP appears more improved than that of the PP produced by the Ziegler-Natta catalyst,and the market demand for the mPP is worldwidely increasing every year.Therefore,it is urgent to develop the metallocene catalysts for the industrial use in domestic companies.The metallocene cataysts are of versatile structures,which are able to show more exact control over the propylene polymerization activity and the polypropylene stereostructures than the Ziegler-Natta catalyst,and thus catalyze to generate new PPs of the diverse structures.This manuscript will give a detailed summary on the metallocene catalysts so far reported.The important factors such as temperature,propylene pressure,catalyst concentration,cocatalyst types and so on will be illustrated,which all have significant influence On the catalytic reaction activity.The reaction mechanism will be discussed as well.