乙丙共聚型黏度指数改进剂剪切稳定指数的影响因素

Influenceing factors of shear stability index of ethylene-propylene copolymer viscosity index improver

采用连续聚合工艺制备了乙丙共聚型黏度指数改进剂,考察了相对分子质量及其分布、乙烯含量及序列结构对其剪切稳定指数(SSI)的影响。结果表明,在研究范围内,增加乙烯含量、降低相对分子质量及其分布,均有助于SSI的降低,提高黏度指数改进剂的剪切稳定性。另外,乙烯平均序列长度的增加及丙烯平均序列长度的下降均有助于SSI的下降。

Ethylene-propylene copolymer viscosity index improver was prepared by continuous polyme-rization. The effects of relative molecular weight and its distribution, ethylene content and sequence structure on shear stability index(SSI) were investigated. The results showed that both the increase of ethylene content and the decrease of relative molecular weight and its distribution were helpful to the decrease of SSI, and the better the shear stability of the viscosity index improver was, in research scope. In addition, both the increase of the average sequence length of ethylene and the decrease of the average sequence length of propylene contributed to the decrease of SSI.