硫化物对丙烯聚合催化剂性能的影响

Effect of Sulfides on the Catalysts for Propylene Polymerization

采用液相本体聚合考察了原料丙烯中的微量硫化物杂质对NG和DQ催化剂聚合性能的影响.实验结果表明,COS,H2S,SO2对丙烯聚合催化剂的性能均有较大影响.其中,COS主要影响NG和DQ催化剂的聚合活性,在工业生产中,COS在丙烯中的含量应小于3×10-8（w）.H2S对NG和DQ催化剂的定向能力有显著的影响,当丙烯中H2S含量为（8～ 10）×10-6（w）时,聚丙烯等规度降至92.0％左右.硫化物杂质对NG催化剂聚合活性影响的大小顺序为：COS＞H2S＞SO2;对DQ催化剂聚合活性影响的大小顺序为：COS＞SO2＞H2S.

The effects of trace sulfide impurities, namely COS, H2S and SO2, in propylene on the polymerization performances of the NG and DQ catalysts were investigated via the liquid bulk polymerization of propylene. The results indicated that, all the impurities had evident effects on the catalyst performances. COS mainly affected the activities of the NG and DQ catalysts, and its content in propylene should be controlled at less than 3 × 10.8 （w） in industrial production. Furthermore, H2S significantly affected the isotacticity of the product polypropylene, and the isotacticity decreased to 92.0% when its content in propylene was （8-10） × 10-6（W）. As a result, the effects of the trace sulfides on the NG catalyst activity are of COS〉HES〉SO2, while their effects on the DQ catalyst activity are of COS〉SO2〉HES.