氢气对氯硅烷功能化非共轭α,ω-双烯烃和丙烯共聚物链结构的影响  

Effect of Hydrogen on Copolymerization between Dichlorosilanefunctionalized Nonconjugated α,ω-Diolefin and Propylene

作　　者：尹学敏 秦亚伟[1,2] 张丽洋 马帅[4] 董金勇 Xue-min Yin;Ya-wei Qin;Li-yang Zhang;Shuai Ma;Jin-yong Dong(Key Laboratory of Engineering Plastics,Institute of Chemistry,Chinese Acadamy of Sciences,Beijing 100190;University of Chinese Acadamy of Sciences,Beijing 100049;Petrochemical Research Institute of PetroChina Co.,Ltd,Beijing 102206;Fushun Petrochemical Company Research Institute of PetroChina Co.,Ltd,Beijing 113000)

机构地区：[1]中国科学院化学研究所中国科学院工程塑料重点实验室,北京100190 [2]中国科学院大学,北京100049 [3]中国石油天然气股份有限公司石油化工研究院,北京102206 [4]中国石油天然气股份有限公司抚顺石化分公司研究院,抚顺113000

出　　处：《高分子学报》2020年第4期377-384,I0003,共9页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号21574143,51373178)资助项目.

摘　　要：基于Ziegler-Natta催化剂的氯硅烷功能化非共轭α,ω-双烯烃与丙烯共聚,在水的引发下脱水缩合可有效地形成长支链结构的聚丙烯树脂.而氢气常作为丙烯聚合中的链转移剂,调控聚丙烯的分子量,基于此,研究了氢气对氯硅烷功能化非共轭α,ω-双烯烃与丙烯共聚物链结构的影响.核磁共振氢谱(~1H-NMR)测试结果表明,氢气抑制了氯硅烷功能化非共轭α,ω-双烯烃的插入,随着氢气用量的增加,共聚物分子链中端基乙烯基含量由0.12 mol%降低到0.05 mol%.熔体流变行为测试结果显示,聚合物熔体的储能模量、损耗模量和零剪切黏度均随着氢气用量增加而降低,这主要是由于相对分子质量减小和长支链密度的减少.Dichlorosilane functionalized nonconjugated α,ω-diolefin and propylene copolymers, prepared by heterogeneous Ziegler-Natta catalysts, have been newly found to trigger dehydration condensation reaction among/between polypropylene chains to form long-chain branched(LCB) structures in the presence of water.Hydrogen is often used as a chain transfer agent to regulate the molecular weight of the polymer in olefin polymerization. Therefore, whether or how hydrogen affects the insertion of the di(5-hexenyl)dichlorosilane in the polymerization of propylene is a topic worthy of study. Herein, the copolymerization of di(5-hexenyl)dichlorosilane and propylene has been investigated based on MgCl2/TiCl4 catalyst(9,9-bis(methoxymethyl)fluorine(BMMF), as internal electron donor) in bulk polymerization conditions. The polypropylene microstructure was analysed by changing hydrogen content while the amount of di(5-hexenyl)dichlorosilane was fixed. It was found that hydrogen significantly improved the activity of catalyst and reduced the molecular weight of polymer. The 1H-NMR results show that the pendant double bonds in the polypropylene chain decreased from 0.12 mol% to 0.05 mol%, illustrating that hydrogen inhibited the insertion of di(5-hexenyl)dichlorosilane in the polymerization. The higher the hydrogen content, the lower the insertion of di(5-hexenyl)dichlorosilane in the polypropylene chain, which corresponds to the decreasing density of longbranched chains in the polymer. Analysis of the insoluble portion of the polymer in the xylene showed that there is no gel in the presence of hydrogen. The creep test results exhibit that the value of Mb/Mw increases from 0.70 to 0.95, which quantitatively indicates that the long-chain branching density in the polymer decreases with the increasing hydrogen content. The long-branched chain density in polymer decreases with the increasing hydrogen content, which is also confirmed by the results of small amplitude oscillatory shear rheology test.

关 键 词：ZIEGLER-NATTA催化剂 氢气 氯硅烷功能化α ω-双烯烃 长链支化结构 链转移反应 

分 类 号：TQ325.1[化学工程—合成树脂塑料工业]