低发泡PS熔体流变特性及其制品泡孔结构

Study on the Rheological Behavior and Pore Structure of Low-foaming PS

研究了低发泡聚苯乙烯 (PS)熔体的流变特性及其制品的表观密度和泡孔结构 .结果表明 :低发泡PS熔体是切力变稀的非牛顿流体 ,熔体中成核剂和气体的共同作用 ,使低发泡PS熔体的表观粘度在 1 80℃下比PS熔体的低 ,而在 1 90℃及 2 0 0℃下比PS熔体的高 ;低发泡PS熔体的粘流活化能比PS熔体的低 ;低发泡PS熔体的非牛顿指数比PS熔体的大 ,即低发泡PS熔体偏离牛顿流体的程度小 ;在较低的成型温度下 ,低发泡PS制品的表观密度较低 ,泡孔尺寸分布均匀 。

The rheological behavior, apparent density and pore structure of low foaming PS were studied in this paper. The results show that the low foaming PS melt is pseudoplastic fluid. At lower temperature, the apparent viscosity of low foaming PS melt is lower than that of PS melt, higher at higher temperature. The activation energy of low foaming PS melt is lower than that of PS melt, which indicates that the processing temperature for low foaming PS may be lower than that of normal PS. At the same time, the non Newtonian index of low foaming PS melt is bigger than that of PS melt. Lower processing temperature leads to low foaming PS products with lower apparent density and good performance.