粘弹性变化对聚对苯二甲酸丁二酯/聚苯乙烯共混物分散相尺寸的影响

粘弹性变化对聚对苯二甲酸丁二酯／聚苯乙烯共混物分散相尺寸的影响曾继军何嘉松沈蓓（中国科学院化学研究所工程塑料国家重点实验室北京１０００８０）关键词共混物，粘弹性，凝聚效应近五年来，不相容聚合物共混物（ＩＰＢ）形态形成的具体过程引起了人们的关注．...

INFLUENCE OF VISCOELASTICITY CHANGE ON THE MORPHOLOGY OF POLY(BUTYLENE TEREPHTHALATE)/POLYSTYRENE BLENDS DURING PROCESSING AT DIFFERENT TEMPERATURES

Based on the equilibrium size of PBT minor phase vs. its concentration at 250℃ and 280℃, the effects of viscoelasticity change and coalescence in the melt on the morphology of immiscible PBT/PS blends were investigated. It is shown that the viscoelasticity of blend components, degradation of polymers, and coalescence of minor phase have different influences on the minor phase size. At the initial stage of blending, the dispersed phase size is mainly determined by the viscosity ratio and elasticity ratio of blend components. The dispersed phase size of 280℃ is larger than that of 250℃ due to the much larger elasticity ratio of PBT to PS at 280℃, With increasing mixing time, the viscoelasticity ratio of PBT to PS are changed by the degradation. For lower PBT contents, e.g.5%, the minor phase size at 250℃ is larger than that of 280℃ because of a sharp decrease of elasticity ratio of PBT to PS at 280℃. For higher PBT contents, the coalescence of the minor phase plays a more important role, which keeps the phase size at 280℃ greater than that of 250℃.