振动共混对聚丙烯/聚碳酸酯流变性能的影响

在传统转矩流变仪上叠加机械振动制成了振动共混流变仪。实验证明，振动共混降低了70／30聚碳酸酯／聚丙烯共混物的粘度和储存模量，随着制备时的振动振幅和频率的提高，这种效果更加突出。但过大振幅振动中，低剪切与高剪切间的频繁更换，特别是明显的低剪切下相翻转转慢，导致形成了部分不稳定“双连续”相态，这时共混物粘度和模量反而比小振幅振动下制备的共混物的高。一个描述该体系表面张力／液滴半径之比与剪切速率关系的经验表达式较好地分析了流变参数与微观相形态之间的关系，说明了振动促使分散相粒子的破碎和两相的分散，确实影响共混物的相形态。振动共混对聚丙烯／聚碳酸酯流变性能的影响上海交通大学化学化工学院高分子材料研究所，上海　200240振动共混　聚丙烯　聚碳酸酯　流变性能　影响　转矩共混流变仪　相形态在传统转矩流变仪上叠加机械振动制成了振动共混流变仪。实验证明，振动共混降低了70／30聚碳酸酯／聚丙烯共混物的粘度和储存模量，随着制备时的振动振幅和频率的提高，这种效果更加突出。但过大振幅振动中，低剪切与高剪切间的频繁更换，特别是明显的低剪切下相翻转转慢，导致形成了部分不稳定“双连续”相态，这时共混物粘度和模量反而比小振幅振动下制备的共混物的高。一个描述该体系表面张力／液滴半径之比与剪切速率关系的经验表达式较好地分析了流变参数与微观相形态之间的关系，说明了振动促使分散相粒子的破碎和两相的分散，确实影响共混物的相形态。

THE EFFECT OF VIBRATION MIXING ON THE SUBSEQUENT RHEOLOGICAL PROPERTIES OF POLYCARBONATE/POLYPROPYLENE BLENDS

A novel vibration internal mixer was formed from the conventional internal mixer through parallel superposition of vibration on steady shear. The effects of superimposed vibration history on the subsequent rheological properties of 70/30 polycarbonate(PC)/polypropylene(PP) blends were investigated.In general, larger amplitude or higher frequency vibrations led to more droplet breakages of dispersed phase PP and better dispersion of components, the produced blends were of lower viscosity and of lower storage modulus. However, too large amplitude of the vibration mixing resulted in the partial unstable co continuous phase morphology probably due to a delay of the phase transition in blending under the frequent alternations between the strong shear and the weak shear. Such blend was of higher viscosity and of larger storage modulus than the blends prepared in smaller amplitude vibration. An empirical relationship for the ratio of interfacial tension versus droplet radius with shear rate is found to analyze the correlation of storage modulus with phase morphology.