熔体的粘性和弹性对LDPE／PS共混物形态的影响

研究了粘性和弹性对低密度聚乙烯／聚苯乙烯共混物形态的影响。结果表明，不相容聚合物在均匀剪切流动中的分散程度以及分散相的形状与组分的粘度比、相对弹性和体积分数有关。当分散相的粘性和弹性较基相大得多时，随分散相的体积分数增加，球状的液滴形成葡萄串状。若两组分的粘性和弹性相当，在适中的混合比下，分散相产生高度变形。不管组分的粘反比和弹性比大小，若分散相的体积分数非常低，共混物的主要形态皆为分散相的球状液滴分散在基体中。

EFFECTS OF THE VISCOSITY AND ELASTICITY OF MELTS ON THE MORPHOLOGY OF LDPE/PS BLENDS

The effects of the viscosity and elasticity of melts on the morphology of low density polyethylene/ polystyrene blends were studied. The results shown that the level of dispersion of immiscible polymer blends in uniform shear flows and the shape of the dispersed phase depends on the viscosity ration of the components, their relative elasticity and the volume fraction of the blend. For a minor with much higher elasticity and higher viscosity than the major, clusters of spherical droplets are formed as the volume fraction increases. When the viscosity and elasticity are comparable, highly deformed domains are formed at moderate composition. At very low volume fractions, the predominant morphology consists of spherical droplets dispersed in the major phase, regardless of viscosity/elasticity ratio of the components.