高填充性聚丙烯基纳米复合材料挤出胀大行为研究

使用毛细管流变仪考察了3种高填充聚丙烯（PP）纳米复合材料的挤出胀大行为，研究了口模温度、剪切速率、熔体压力、纳米粒子填充比例和纳米粒子形貌对PP纳米复合材料熔体挤出胀大比的影响。结果表明，3种PP纳米复合体系熔体的挤出胀大比均随口模温度的增加而减小，且大致呈线性关系；随着剪切速率的增大而增加，且随着填料填充比例的增加有减小的趋势；随着熔体压力的增大而增加，并且随着熔体压力的增加，其挤出胀大比随填料填充比例的增加而减小的幅度下降；3种颗粒形貌纳米粒子填充体系中，在相同的体积分数和温度下，片状结晶纳米氢氧化镁［Mg（OH）2］填充体系熔体挤出胀大比最小，球状纳米碳酸钙（CaCO3）填充体系熔体挤出胀大比最大，棒状粒子埃洛石纳米管（HNTs）填充体系熔体挤出胀大比介于两者之间。

Study on Extrusion Swell Behavior of Highly Filled Polypropylene Nanocomposites

Three types of highly filled polypropylene (PP) nanocomposites were investigated by a capillary rheometer, and the effects of die temperature, shear rate, melt pressure, nano-particle filling ratio and morphology of nanoparticle on the melt-extrusion swell ratio of PP nanocomposites were studied. The results indicated that these three types of PP nanocomposites presented a decrease in melt extrusion swell ratio with an increase of die temperature by a linear relationship. The melt extrusion swell ratio also increased with an improvement of shear rate but decreased with an increase of filler filling ratio. However, it increased with an increase in melt pressure and melt pressure. There was a retarded decreasing trend observed in melt extrusion swell ratio with an increase of filling ratio. The flake nano Mg (OH)2 filling system exhibited the smallest melt extrusion swell ratio in the three composite systems at the same volume fraction and temperature, but the spherical nano-CaCO3 filling one presented the greatest value.