颗粒持液条件下乙烯/1-辛烯共聚合行为研究

Ethylene/1-Octene Copolymerization Characteristics under the Condition of Particle Liquid-Holding

本文考察了不同反应条件对乙烯/1-辛烯共聚合行为以及聚合产品的影响。结果表明,在不存在惰性冷剂的条件下,1-辛烯在共聚体系中亦发挥了冷剂的作用,可提高乙烯在活性位点周围的局部浓度,使得聚合活性随1-辛烯浓度的增加而增加;而在加入惰性冷剂后,共聚单体效应令乙烯在共聚反应中插入速率降低。同时,反应中随着共聚单体浓度的增加,聚合产品中1-辛烯支链含量也逐渐增加,这是由于随着1-辛烯的加入,其在催化剂活性位点处的浓度也提高,1-辛烯在聚合反应中的插入率增大。据此可确定优选的反应温度。

In this work,the effects of different reaction conditions on the ethylene/1-octene copolymerization behavior and polymerization products are studied.The results showed that in the absence of inert condensate,1-octene also played the role of a condensing agent in the copolymerization system,which increased the local concentration of ethylene around the active sites of particles,leading to the increase of polymerization activity with the 1-octene concentration.In the present of inert condensate,the comonomer effect reduced the ethylene insertion rate during the copolymerization reaction.Moreover,as the comonomer concentration increased during the reaction,the 1-octene branch content in the polymerization product was also gradually increased.This was because with the addition of 1-octene,its concentration around the active sites of catalyst was also increased,which enhanced the insertion ratio of 1-octene in the polymerization reaction.By this way,the optimal reaction temperature can be determined.