双峰聚乙烯因兼具优良的加工性能和优异的力学性能,被广泛应用于PE100、PE100RC等高等级管材的生产,其在聚乙烯市场中的地位越来越重要。目前工业上基本采用双釜串联工艺生产双峰聚乙烯,该工艺设备投资及能耗较高,且均被国外公司垄断。相比之下,单釜双峰工艺因采用双金属中心催化剂在单一反应器中生产双峰聚乙烯,其设备投资和操作费用更低,且更加绿色环保,因而成为近年来国内外研究的热点。综述了本课题组近期基于铬系催化剂开发的新型双金属中心双峰聚乙烯催化剂,同时对其他双金属中心聚乙烯催化剂进行了介绍,并对该领域的未来发展进行了展望。
Bimodal polyethylene are widely used to produce high performance pipes, such as PE100 and PE100 RC, and shows increasing importance in polyethylene market because of their excellent mechanical and processing properties. Nowadays, commercialized bimodal polyethylene is synthesized primarily in tandem-reactor process, which needs high energy consumption and capital investment in equipment, beside, the technology is under monopoly of foreign companies. By contrast, bimodal polyethylene synthesis using bimetallic catalyst in single reactor process is becoming research hotspot in domestic and abroad, because this process is more environment friendly and needs much lower cost in equipment investment and operation. Recent work in this group on Cr-based bimetallic catalysts is reviewed. Development on other bimetallic catalysts is also introduced and future trend is prospected.