Regiochemistry-Aligned Copolymerization of Propylene with p-Methylstyrene and 1,4-Divinylbenzene Using an ansa-Metallocene Catalyst
Regiochemistry-Aligned Copolymerization of Propylene with p-Methylstyrene and 1,4-Divinylbenzene Using an ansa-Metallocene Catalyst
复制标题
使用 ansa-茂金属催化剂进行丙烯与对甲基苯乙烯和 1,4-二乙烯基苯的区域化学定向共聚
DOI：
10.1002/macp.201400136
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发表时间：
2014
影响因子：
2.5
通讯作者：
Dong Jin-Young
中科院分区：
文献类型：
--
作者：
Dong Cheng;Wang Ning;Qin Yawei;Niu Hui;Dong Jin-Young
丙烯与苯乙烯- α -烯烃单体的共聚在c2 -对称金属-茂金属型催化剂上是罕见的，这是丙烯等比聚合的主要单位点催化剂。这使得很难获得具有等规立体规则（iPP）的含苯和苯乙烯基团的窄分布反应性聚丙烯，而苯和苯乙烯是iPP功能化的重要前体。本文将rac‐CH2(3‐t‐Bu‐1‐Ind) 2zrcl2与甲基铝氧烷（MAO）配对，用于丙烯与对甲基苯乙烯（p‐MS）和1,4‐二乙烯苯（DVB）的共聚反应。由于催化剂对丙烯和苯乙烯单体具有统一的初级区域化学反应，两种共聚反应都是可行的，苯乙烯单体的加入不会严重降低催化剂的活性。丙烯和p - MS/DVB的指纹一级-一级连续序列通过13c NMR得到了清晰的识别。在相当高的催化活性下，ipp中掺入了高达1.37 mol%的p - MS和0.93 mol%的DVB。值得注意的是，DVB与选择性单链模式结合，使ipp在线性主链上具有悬垂的苯乙烯基。ipp /p - MS和dipp /DVB共聚物均表现出较窄的分子量分布（<3），表明共聚具有单位点特征。总的来说，通过共聚单体的插入区域化学的统一，丙烯与p - MS和DVB在aC2 -对称茂金属催化剂上的共聚成为可能。
Copolymerization of propylene with styrenic α‐olefin monomers is rare withC2‐symmetricansa‐metallocene‐type catalysts, which are the dominant single‐site catalysts for isospecific propylene polymerization. This makes it difficult to obtain compositionally narrow‐distributed reactive polypropylene with isotactic stereoregularity (iPP) bearing benzyl and styryl moieties, which are important precursors foriPP functionalization. In this paper,rac‐CH2(3‐t‐Bu‐1‐Ind)2ZrCl2is paired with methylaluminoxane (MAO) and used in copolymerization of propylene withp‐methylstyrene (p‐MS) and 1,4‐divinylbenzene (DVB). Due to the unified primary regiochemistry of the catalyst toward both propylene and the styrenic monomers, both copolymerizations are viable, with the incorporation of the styrenic monomers not disastrously decreasing the catalyst activity. The fingerprint primary–primary consecutive sequences of propylene andp‐MS/DVB are clearly identified by13C NMR. As high as 1.37 mol% ofp‐MS and 0.93 mol% of DVB are incorporated intoiPP at fairly high catalyst activities. It is noteworthy that DVB is incorporated with a selective mono‐enchainment mode, leavingiPP with pendant styryl groups on the linear backbone. Both theiPP/p‐MS andiPP/DVB copolymers show narrow molecular weight distributions (<3), indicating a single‐site characteristic of the copolymerizations. Overall, copolymerization of propylene withp‐MS and DVB with aC2‐symmetricansa‐metallocene catalyst is made possible by unification of the insertion regiochemistry of the comonomers.