茂金属催化剂的负载化

Immobilization of Metallocene Catalysts

茂金属催化剂是继齐格勒-纳塔催化剂之后的新一代烯烃聚合催化剂,与多活性中心催化剂相比,这种单一活性中心类型的催化剂具有聚合活性较高、聚合物分子量分布较窄等特点。其中,负载化是茂金属催化剂实用化的重要课题,它克服了均相催化体系中聚合物形貌不可控的缺点,降低了助催化剂的用量。近些年来茂金属负载化的研究仍很活跃。本文总结了近十年来茂金属负载化的研究进展,主要对载体的形貌、载体的改性处理、茂金属催化剂的负载方法和负载化茂金属催化剂的应用进行了评述并展望了茂金属催化剂负载化的发展趋势。

Metallocene catalysts form a new generation of catalysts for olefin polymerization after Ziegler-Natta catalysts. Compared w ith multi-active site catalysts,this kind of single-site catalysts has higher polymerization activity and produces polyolefin w ith narrow er molecular w eight distribution and composition distribution. Immobilization of metallocene catalysts on solid supports is an important step tow ard its industrial application,as it can largely overcome the draw backs of homogeneous catalysts in controlling nascent polymer morphology. The amount of alkylaluminoxane cocatalyst can also be reduced after immobilization. Thus, research on immobilization of metallocene catalysts is still active in recent years. This paper review s the progress in immobilization of metallocene cataylsts in recent ten years w ith emphasis on the morphologies and modifications of supports, immobilization methods of metallocene catalysts, and applications of supported metallocene catalysts. The prospects and development trends on immobilization of metallocene catalysts are also discussed.