润滑剂结构对聚氯乙烯加工性能的影响

通过转矩流变仪测定了采用不同润滑剂PVC-U体系的加工性能和热稳定性能,引用"铆钉作用"概念从润滑剂结构的角度分析了实验数据。结果表明,PVC润滑剂的润滑作用与其本身极性相关,在使用非极性聚乙烯蜡和强极性硬脂酸时,PVC-U体系不能形成较高抗撕裂强度的润滑膜,极性适中的硬脂酸季戊四醇酯与PVC粒子形成稳定的络合点,并组成较高抗撕裂强度的润滑膜,起到"铆钉"作用,即极性适中的脂肪酸酯润滑剂兼具内-外润滑作用,提高了体系的加工性能和热稳定性能。

Influence of Lubricant's Structure on Processing Property of PVC

The processing properties and thermal stability of PVC-U blends with different lubricants were measured by torque rheometer,thus the concepts of ＂rivet effect＂ were cited to analyze the data obtained theoretically.The result showed that the lubricating effect of PVC lubricants is related with its polar,when polyethylene wax and stearic acid are used,the tearing strength are low,but to use stearic pentaerythriteol ester instead,the chemical adsorption complex bonds are formed between its polar part,the ＂rivet effect＂ occurrs,which increased the lubricant film strength of nonpolar part.Basing on the theoretical analysis on the chemical structure of lubricants,the author concluded that fatty acid ester with moderate polar both has internal and external lubricating effect,perform excellent processing property and thermal stability.