OCP粘度指数改进剂低温流变学与分子结构的关系

RELATION BETWEEN SUBZERO RHEOLOGY OF OCP VISCOSITY INDEX IMPROVER AND ITS MOLECULAR STRUCTURE

采用冷启动模拟机 ( CCS)和 MRV对小型旋转粘度计 ( OCP)粘度指数改进剂的低温流变学性能进行了测试 ,并将分析结果与粘度指数改进剂的分子结构进行了关联。发现 CCS比MRV测得的流变学性能变化明显 ,但趋势相似 ,即随着相对分子质量的增加 ,低温性能下降 ,随着相对分子质量分布的增宽和高分子链中乙基序列的增加 ,低温性能改善。从高分子的立体化学结构层次进行了结构与流变学性能关系的分析。

The low temperature rheological properties of olefin copolymer (OCP) viscosity index improvers were measured by CCS (cold cracking simulator) and MRV (mini rotary viscometer). The results were correlated with the molecular structures determined with 13 C NMR and gel permeation chromatography. It was found that the varieties of rheological properties measured by CCS were more obvious than those measured by MRV, however, their trends were similar. The low temperature performance was worse with molecular weight increase, and was improved with broader distribution of molecular weight and higher mole fraction of ethylene sequence in molecular. The relationship between rheological performance and the structure of OCP has been probed from stereoscopic chemistry of polymer.