微量杂质对丙烯聚合性能的影响

摘要

采用液相本体聚合法考察了原料丙烯中的微量杂质(CO、H2O、O2、甲醇)对NG与DQ催化剂催化丙烯聚合性能的影响.实验结果表明,CO、H2O、O2和甲醇对NG与DQ催化剂的聚合性能均有较大的影响,其中,对聚合活性影响最大的杂质是CO,对催化剂定向能力有显著影响的杂质是H2O.当丙烯中H2O含量为(4～5)×10-5(w)时,制得的聚丙烯等规度降至91％左右.相对毒性系数比较结果表明,杂质对NG催化剂聚合活性的影响大小顺序为:CO＞O2＞H2O＞甲醇；对DQ催化剂聚合活性的影响大小顺序为:CO＞H2O＞O2＞甲醇.%The effects of trace impurities(CO,H2O,O2,methanol) in propylene on the polymerization performances of NG and DQ catalysts were investigated via the liquid bulk polymerization of propylene.The results indicate that,all the impurities have evident effects on the polymerization.The effect of CO on the catalyst activity is the biggest and H2O significantly affected the isotacticity of the product polypropylene.The isotacticity decreased to 91％ when H2O amount in propylene was (4-5)× 10-5(w).The relative toxicity coefficients of the impurities indicate that the effects of the impurities on NG catalyst activity are of CO ＞ O2 ＞ H2O ＞ methanol,while the effects of the impurities on DQ catalyst activity are of CO ＞ H2O ＞ O2 ＞ methanol.