PSt-b-PEO增容PA6/PS共混体系的研究

STUDY ON THE NYLON 6/POLYSTYRENE BLENDS WITH THE STYRENE b ETHYLENE OXIDE DIBLOCK COPOLYMER AS COMPATIBILIZER

采用动态力学方法（ＤＭＡ），形态学方法（ＳＥＭ），研究了ＰＳｔｂＰＥＯ存在下尼龙６（ＰＡ６）／聚苯乙烯（ＰＳ）共混体系的相容性．研究表明，ＰＡ６和ＰＳ的简单共混体系，分散相相畴尺寸大，相界面清晰，断裂面光滑，呈脆性断裂，相容性极差，属不相容体系．而加入少量ＰＳｔｂＰＥＯ后分散相尺寸变小，界面层变厚，界面粘结力增强，表现出韧性特征．

Dynamic mechanical analysis (DMA) and scanning electron microscopy(SEM) were used to study the compatibility of nylon6/polystyrene(PA6/PS) blends with poly(styrenebethylene oxide) (PStbPEO) diblock copolymers as compatibilizer. It has been found that the compatibility of the blends prepared by pure PA6 and PS is very poor. The boundary between the phase domains of PA6 and PS without PSt b PEO is sharp and clear. When 2 parts of PStbPEO copolymer per hundred of resin(phr) were added, the glass transition temperatures of the constituent polymers converge, the size of the dispersed phase domain decreases and the thickness of the interfacial layer increases, because PSt b PEO is efficient in lowering the interfacial tension and enhancing the interfacial adhesion in PA6/PS blends. And the compatibilization effects of PStbPEO diblock copolymers with different molecular weight and composition ratio on PA6/PS(80/20) blends were also discussed. The compatibilizing efficacy of PSt b PEO is dependent on the actual amount of the compatibilizers in the boundary region of PA6/PS blends. When the molecular weight is appropriate and ethylene oxide block length in PSt b PEO is more than that of styrene, the compatibilization is more efficient for PA6/PS(80/20) blends.