尼龙6/聚苯乙烯共混物融合缝的形态及其对力学性能的影响

采用扫描电镜(SEM)、力学性能测定，研究了尼龙6／聚苯乙烯(PA-6／PS)共混体系融合缝的形态及力学性能．鲒果表明，分散相和连续相的粘度比对融合缝的形态有重要影响．当η分散相／η连续相＞1时，融合缝处分散相的形态不同于本体．融合缝处分散相沿融合缝取向；当η分散相／η连续相＜1时．融合缝处分散相的形态与本体形态相似．均以球形粒子分散于基体中。融合缝的存在使共混体系的力学性能有较大下降，主要由融合缝处分散相形态所致。

WELD LINE MORPHOLOGY OF POLYAMIDE-6/POLYSTYRENE BLENDS AND ITS EFFECT ON THE MECHANICAL PROPERTIES OF THE BLENDS

In this study, the weld line morphology and mechanical strength of polyamide-6/ polystyrene (PA-6/PS) blends were investigated. The experimental results show that the viscosity ratio of dispersed phase over matrix plays a very important role in the control of weld line morphology of the immiscible blend. When the viscosity of dispersed PA-6 phase is higher than that of PS matrix, the morphology of dispersed phase at weld line is quite different from that of bulk. But when the viscosity of dispersed PS phase is lower than that of PA-6 matrix, the morphology of dispersed PS phase at weld line is the same as that of bulk. The mechanical strength of blends gets greatly decreased due to the presence of the weld line. The difference of morphology of dispersed domains at weld line for the blends with different viscosity ratio causes the distinction of fracture mechanism of the blends.