新一代功能性聚丙烯催化剂的研发进展

Research and Development of New-Generation Functional Ziegler-Natta Catalysts for Propylene Polymerization

为适应聚丙烯树脂高性能化和功能化的发展需求,提出了基于MgCl2负载的高效Ziegler-Natta催化剂,借助于茂金属及非茂金属单中心催化剂丰富多样且明确可控的烯烃聚合催化能力,通过多重载体化制备了Ziegler-Natta/(非)茂金属复合型催化剂,从而获得兼具高活性、高立体定向性和可调、可控的共聚性能的新一代功能性聚丙烯催化剂,用于以聚丙烯/乙丙多相共聚物、高熔体强度聚丙烯和极性改性的功能化聚丙烯等为代表的高性能聚丙烯树脂的制备。通过对聚丙烯催化剂与聚合物结构性能之间对应关系的分析,及Ziegler-Natta/(非)茂金属复合型催化剂在制备多相共聚聚丙烯和高熔体强度聚丙烯等树脂中的实践,指出了以获得催化功能性为目标的Ziegler-Natta/(非)茂金属复合型催化剂是今后聚丙烯催化剂的发展方向。

The future development of Ziegler-Natta catalysts for propylene polymerization is discussed, of which the tactful incorporation of single-site catalysts（ SSCs, including both metallocene and non-metallocene types ） with state-of-the-art MgCl2-supported Zielger-Natta catalysts to form Ziegler-Natta/SSC hybrid catalysts is deemed to represent a leading trend. This lies in the fact that SSCs are of versatile yet defined catalytic properties for olefin polymerization, and their being incorporated will, in a controllable way, improve the copolymerization capabilities of Ziegler-Natta catalysts and give rise to new-generation functional Ziegler-Natta catalysts capable of producing high performance i-PP （PP： polypropylene）. Some well-designed and prepared Ziegler-Natta/SSC hybrid catalysts with specific catalytic functions have been tested in propylene polymerization, where the successful preparations of PP/EP （ E ： ethylene ; P ： propylene） heterogeneous copolymers and highmelt-strength PP validate the rationality of the Ziegler-Natta/SSC hybrid catalyst design.