新型高效铬系催化剂的研究进展

摘要

Chromium based catalysts for ethylene polymerization have been research hotspots of olefins polymerization in recent years. Compared with other types of catalysts,the product polyethylene with broad molecular weight distribution,high molecular weight and a small amount of long chain branches are obtained over chromium based catalysts. The high toxicity,long induction period and difficult control of molecular weight of traditional chromium based catalysts limited their further developments,so some modification for chromium based catalysts with titanium and aluminum was carried out to improve their properties. In this paper,the latest progress in novel chromium based catalysts for ethylene polymerization at home and abroad was reviewed. Though the design and preparation of chromium based catalyst were introduced into China for a short time,the research progress in chromium based catalysts for polyethylene production was achieved rapidly. The chromium based catalysts will continue to play an important role in polyethylene industry and it is very urgent to realize the demestic production of chromium based catalysts in the near future.%铬系乙烯聚合催化剂是近年来烯烃聚合催化剂的研究热点。与其他类型催化剂相比，铬系催化剂生产的聚乙烯产品分子量分布宽、分子量高，且聚合物中含有少量的长支链。但由于铬系催化剂的高毒性、引发诱导期长和分子量控制难度大等缺点，通常利用钛和铝对其进行改性。对近年来国外新型高效铬系乙烯聚合催化的研究进展进行重点综述，讨论近年来乙烯聚合用高效铬系催化剂的品种和国内外研发现状。我国铬系催化剂的设计与合成起步较晚，进步较快，尽快在现有工业装置上实现催化剂的国产化具有重要意义。