甲基铝氧烷在丙烯高温聚合中的作用  

Influence of Methylaluminoxane on Propylene Polymerization at the High Temperature

作　　者：钟赤锋[1] 毛炳权[2] 

机构地区：[1]东莞理工学院东莞市清沾生产科技中心,广东东莞523808 [2]中国石油化工股份有限公司北京化工研究院,北京100013

出　　处：《高分子材料科学与工程》2013年第12期30-34,共5页Polymer Materials Science & Engineering

摘　　要：采用核磁共振碳谱(13C-NMR)方法研究了高温聚合所得聚丙烯端基的结构。研究表明,聚合时加入改性甲基铝氧烷,所得聚丙烯端基中异丁基含量会显著提高。这表明,改性甲基铝氧烷参与链引发反应,形成新的活性中心。研究结果还表明,100℃聚合时链转移反应以向烷基铝转移反应为主;而120℃聚合时链转移反应有β-H消除反应和向烷基铝转移反应,以前者为主。ABSTRACT：The chain-end structures of polypropylene （PP） prepared with MgC12-supported Ziegler-Natta catalysts at high temperature was studied by 13C-NMR. The chain-end groups of PP polymerized with Et3A1 at 100℃ consisted of the i-Bu group and Et group with the molar ratio of 0.71 ： 1. When ＂TMA-depleted＂ methylaluminoxane （MMAO） was added during the polymerization process with Et3A1 at 100 ℃, the terminal groups of PPs show that the molar ratio of i-Bu group to Et group changes from 0.71：1 to 2：33：1. These changes of the terminal structures of PPs indicate that a new active species ＂Ti-Me＂ was formed when MMAO was added. The species ＂Ti-Me＂ coexist with species ＂Ti-Et＂ in these polymerization processes. The chain-end groups of PPs polymerized with Et3A1 at 120 ℃ indicate that the chain-transfer reaction by 13-H abstraction and by R3A1 took place at 120 ℃ , the former was the main reaction.

关 键 词：聚丙烯 核磁共振碳谱 结构 温度 端基 

分 类 号：TQ316.31[化学工程—高聚物工业]