Control of both molecular weight and comonomer response of ethylene polymerization via utilization of alkyl branches at the para-xylene bridge of new dinuclear constrained geometry catalysts
作者:Nguyen Thi Le Nhon、Nguyen Thi Le Thanh、Cao Phan Tuy My、Seok Kyun Noh
DOI:10.1016/j.polymer.2012.04.011
日期:2012.6
polymerization properties of DCGCs was determined by the nature of the alkyl substituent at para-xylene bridge. Catalyst 14 having isopropyl substituent at the bridge produced the longest polymer with the lowest catalytic activity. On the other hand, DCGCs 15 and 16 exhibited the greatest comonomer reactivity to make ethylene/styrene copolymers with the highest styrene contents.
我们合成了一系列四个含有烷基取代的对二甲苯桥[TiCl 2 N(t Bu)Si(Me)2 } C 9 H 5 ] 2 [(CH 2)(R )2 C 6 H 2 }(CH 2)]:13(R =氢),14(R =异丙基),15(R = 正己基)和16(R = 正辛基)。合成的配合物的结构和组成可以通过1方便地确定1 H NMR,13 C NMR和元素分析(EA)。为了确定各种烷基支链的空间和电子性质对二甲苯基的影响,已经进行了使用这些茂金属的乙烯均聚物和共聚实验。陶氏CGC([我2的Si(μ 5 -Me 4的Cp)N吨的TiCl卜] 2)已被用作用于比较的对照催化剂。发现催化剂13的活性最高,而新的DCGC的活性远高于Dow CGC。可以从新的DCGC成功地生产出分子量超过1,000,000 g / mol的聚乙烯,可以将其归类为超高分子量聚乙烯(UHMWPE)。最重要的是,证明了DCGC