活性自由基引发星形PMA黏度指数改进剂合成及其剪切稳定性研究

SYNTHESIS THROUGH LIVING RADICAL POLYMERIZATION AND SHEAR STABILITY OF A STARSHAPED POLYMETHACRYLATE COPOLYMER AS A VISCOSITY INDEX IMPROVER

通过可逆-加成断裂链转移(RAFT)活性自由基聚合得到了主要成分为聚甲基丙烯酸酯类化合物的星形聚合物黏度指数改进剂,其中星形结构的臂数不小于3,其臂的分子量具有可控且分布窄的特点。通过圆锥滚子轴承法对其抗剪切性能进行了评价,结果显示所合成的星形聚合物黏度指数改进剂与组成类似的线性聚合物相比,在增稠能力相当时,所合成的星形聚合物具有优良的抗剪切能力;在增粘程度和抗剪切性能相当的情况下,只需要很少的加剂量。

A star-shaped polymethacrylate copolymer as a viscosity index improver was synthesized through living radical polymerization with reversible addition-fragmentation chain transfer（RAFT polymerization）. The average number of the arms of the star-shaped polymethacrylate,the molecular weight of which is controllable and has narrow distribution,is larger than 3.Compared with linear polymethacrylate,the prominent shear stability of the star-shaped polymethacrylate copolymer was verified by tapered roller bearing tests（CEC L-45-A-99）.At the same level of thickening power,the star-shaped copolymer has better shear stability.Likewise at the similar grade of shear stability,much less star-shaped copolymer is required.