外给电子体对MgCl_2负载TiCl_4催化剂催化乙烯/丙烯共聚合的影响  

Effect of external electron donors on ethylene / propylene copolymerization with Mg Cl_2 -supported Ti Cl_4 catalyst

作　　者：齐晓梅 胡雁鸣[2] 张贺新[2] 张春雨[2] 张学全[2] 

机构地区：[1]中国石油锦州石化公司,辽宁锦州121000 [2]中国科学院长春应用化学研究所,长春130022

出　　处：《合成橡胶工业》2014年第6期443-448,共6页China Synthetic Rubber Industry

基　　金：国家自然科学基金资助项目(51203147);吉林省科技发展计划应用基础研究资助项目(20130102007 JC)

摘　　要：采用邻苯二甲酸二异丁酯（DIBP）为内给电子体的Mg Cl2负载Ti Cl4催化剂,考察了在无外给电子体及以环己基甲基二甲氧基硅烷（简称C-donor）、二环戊基二甲氧基硅烷（简称D-donor）、苯基三乙氧基硅烷（简称PTES）为外给电子体的条件下,催化剂对乙烯/丙烯共聚合活性、单体竞聚率、共聚物序列分布和热性能的影响。结果表明,在不同外给电子体作用下,随着乙烯进料比的增加,聚合活性先增加后逐渐减小,并呈现出明显的＂共单体效应＂;DIBP与D-donor有很好的协同效应,二者配合可提高催化剂活性,最高可达8.3 kg（以1 g Ti计）;当乙烯/丙烯（摩尔比）为40%~65%时,共聚物链段中乙烯和丙烯分布更均匀,无规度更高,具有更短的平均序列长度;当乙烯/丙烯为50%时,所得共聚物的熔融温度最低,可达108℃,玻璃化转变温度为-48.6℃,表明聚合物具有较好的耐低温性能。Mg Cl2-supported Ti Cl4 catalyst with diisobutyl phthalate（ DIBP） as internal donor was prepared and applied to ethylene / propylene copolymerization. The effects of the prepared catalysts in the absence / presence of external donors of cyclohexyl methyl dimethoxy silane, dicyclopentyl-dimethoxy silane（ D-donor） and phenyltrimethoxysilane（ PTES） on polymerization activity,monomer reactive ratio,monomer sequence distribution and thermal properties of ethylene-propylene copolymer were investigated. The results showed that the catalyst activity increased first and then decreased with increasing ethylene feed ratio,indicating apprarent comonomer effect in the copolymerization. In addition,due to the good synergistic effect between DIBP and D-donor,the highest activity of 8. 3 kg（ per gram Ti） was obtained. When mole fraction of ethylene was 40%- 65%,the distribution of ethylene and propylene was uniform,the degree of randomness was higher,and the average sequence length was shorter. On the other hand,the lowest melting point of the copolymer was 108 ℃ and the glass transition temperature was- 48. 6 ℃ when mole fraction of ethylene was 50%,indicating relatively good low temperature resistance of the copolymer.

关 键 词：氯化镁 负载钛系催化剂 内给电子体 外给电子体 乙烯 丙烯 聚合 协同效应 

分 类 号：O631.5[理学—高分子化学]