游离链段在PA6／ABS共混物中的作用研究

Effects of Un-grafted Segments in ABS Modifier on Properties of PA6/ABS Blends

采用种子乳液聚合方法合成了丙烯腈-丁二烯-苯乙烯共聚物(ABS)改性剂,采用超速离心分离方法,分离出ABS改性剂中的游离SAN链段。采用熔融共混技术,将ABS改性剂与聚己内酰胺(PA6)进行共混,研究了ABS改性剂中游离的SAN链段对PA6/ABS共混物性能的影响。结果表明,去除ABS改性剂中的游离SAN链段后,对PA6/ABS共混体系的加工流动性影响不大。除去ABS改性剂中的游离链,对共混物的弹性模量和屈服强度影响不大,共混物的冲击强度和断裂伸长率明显提高。动态力学分析仪(DMA)测试发现PA6/ABS共混体系的相容性有所改善,扫描电子显微镜(SEM)形态表明,分离游离链后核壳粒子更加均匀地分散在共混物中。

The acrylonitrile-butadiene-styrene （ABS） core-shell structure modifiers were synthesized by seeded emulsion polymerization. The un-grafted styrene-acrylonitrile （SAN） segments in the ABS core-shell structure modifiers were separated by uhra-centrifugation. The modifiers were melt blended with polyamide 6 （PA6）. The effect of un-grafted SAN segments of ABS core-shell structure modifiers on the mechanical properties of PA6/ABS blends was investigated. The resuhs show that the separation of un-grafted SAN segments shows little effect on the processing viscosity and elastic modulus and yield strength of the blends. And the separation of un-grafted SAN segments induced higher the notched impact strength and the higher elongation at break of blends. Dynamic mechanical analysis （DMA） results show that the separation of un- grafted SAN segments improves the compatibility of PA6/ABS blends. The morphology of blends shows that the separation of un-grafted SAN segments deduces uniform dispersion of core-shell particles in the matrix.