基于聚合反应的聚丙烯可控长链支化新方法

由于聚合反应的固有属性，长链支化是聚丙烯链结构控制中的难点。催化剂本身的技术进步并不能有效解决此问题。突破聚丙烯长链支化结构控制化学，将会大大扩展聚丙烯链结构范畴，丰富聚丙烯产品结构。非共轭α, ω-双烯烃/丙烯共聚合合成长链支化聚丙烯的方法本质上仍然依赖大分子单体共聚，因此虽然适用于茂/非茂催化剂体系，但并不适用于在聚丙烯工业中占绝对主导地位的Ziegler-Natta催化剂。本项目基于氯硅烷取代α-烯烃反应性共单体，发展基于聚合反应的聚丙烯可控长链支化新方法，突破目前非共轭α, ω-双烯烃共聚方法囿于大分子单体共聚的限制，使之不仅适用于茂/非茂均相催化剂，也适用于Ziegler-Natta催化剂。利用此化学方法，基于不同的催化剂体系，结合分子量和分子量分布控制、共单体/短链支化及分布控制、以及长链支化结构的调控，合成系列新型链结构聚丙烯，帮助我国聚丙烯工业拓展产品结构，实现可持续发展。

Inherently, long chain-branching is the Achilles' heel of polypropylene. Catalyst advancement alone can do little to help the issue. Nevertheless, once the issue is resolved, the structural domain of polypropylene will be greatly expanded, so will its product portfolio. Nonconjugated α, ω-diolefin/propylene copolymerization has been a way to long chain-branched polypropylene, which however is still a macromonomer copolymerization approach per se and limited to metallocene/non-metallocene catalysts, ineffective to Ziegler-Natta catalysts which dominate the polypropylene industry. This proposal aims at developing new chemistry to long chain-branched polypropylene based on polymerization reaction using chlorosilane-functionalized α-olefins as reactive comonomer, which will overcome the limitations of the nonconjugated α, ω-diolefin/propylene copolymerization approach and can apply to both metallocene/non-metallocene catalysts and Ziegler-Natta catalysts. Combining the new chemistry with different types of Ziegler-Natta and metallocene/non-metallocene catalysts, we will synthesize a set of new polypropylene polymers with a broad range of chain structure variations in molecular weight and molecular weight distribution, comonomer/short chain-branching, and long chain-branching, boosting and helping sustain our national polypropylene industry.