复合分散体系对聚氯乙烯树脂颗粒特性的影响

以三氯乙烯模拟氯乙烯(VC),考查聚乙烯醇(KH20)/羟丙基甲基纤维素(60SH50)复合分散剂的分散能力和保胶能力,发现分散能力和保胶能力均随分散剂用量的增加而提高;复合分散剂中KH20比例增大,分散能力下降而保胶能力增强。以此为基础进行VC悬浮聚合,研究分散剂对聚氯乙烯(PVC)树脂颗粒特性的影响。发现适量的分散剂可同时提高PVC树脂的表观密度和增塑剂吸收量;增大KH20的比例可提高PVC树脂的表观密度,同时使粒度分布变窄,但是增塑剂吸收量有所下降。

The effect of composite dispersants on particle features of PVC resins

The dispersibility and colloid protection ability of the composite dispersant system composed of KH20(polyvinyl alcohol) and 60SH50(hyhroxypropyl methyl cellulose) were investigated by using trichloroethylene as the model chemical of vinyl chloride.It was found out that both the dispersibility and the colloid protection ability improved with the increase of the composite dispersant concentration,and the dispersibility decreasing and the colloid protection ability improved when increasing the proportion of KH20 in the composite dispersants.The suspension polymerization of vinyl chloride was carried out on the basis of the above results.The effect of dispersants on the characteristics of PVC resin particles was studied.It was shown that the addition of suitable amount of dispersants could increase both the apparent density and the plasticizer absorption of the PVC resins,and that increasing the proportion of KH20 could increase the apparent density,sharpen the particle size distribution but decrease the plasticizer absorption.