【摘要】 研究了氯化聚乙烯(CPE)对三元乙丙橡胶/尼龙(EPDM/PA)共混体系的增容机理。Molau实验表明 ,在一定的共混温度下 ,共混时间越长 ,PA与CPE发生的化学反应越多。TEM照片显示 ,分散相颗粒由相互镶嵌的两种物质组成 ,二者之间有一定的过渡层 ;硫化使分散相与基质胶产生共交联 ;观察到了以微纤形式存在的分散相。SEM照片显示 ,硫化明显改善了分散相颗粒与基质胶的粘合。DSC的研究表明 ,该体系为典型的三元共混体系 ,CPE的加入大幅度降低了PA的玻璃化转变温度 (Tg) ,但对EPDM的Tg 无影响。DMA分析表明 ,存在于分散相颗粒中的CPE使分散相更加细小均匀 ,从而增强了两相间的相互作用。以上测试表明 ,在分散相颗粒与基质胶的界面处CPE向PA渗透及锚入 ,形成镶嵌结构 ,渗透方向对PA的增强有特殊的作用 ,PA的Tg 向低温移动的程度可以作为共混体系相容性改善程度的定量判据。更多还原

【Abstract】 The miscibility between chlorinated polyethylene(CPE) with ethylene pro pylene diene monomer/nylon resin(EPDM/PA) was studied. A compatibility mechanism is proposed based on TEM and SEM results, and is confirmed by DSC and DMA studies of the blends. The solubility characteristics of the blends in formic acid solution give an approximate idea about the amount of CPE reacted with PA. TEM shows that almost each dispersed particle is composed of two kinds of polymers inserted or anchored each other and between them there is a certain extent transitional interface, vulcanization makes matrix and dispersed particle crosslink each other, some particles whose shape is of micro-fiber are observed. SEM reveals that adhesion between the matrix and the dispersed particle is improved significantly through crosslinking. DSC shows that, while CPE is added to the blend, glass transition temperature(Tg) of PA decreases significantly , but Tg of EPDM remains stable. DMA shows that CPE is mainly blended into dispersed particle. It makes dispersed particle smaller and well-distributed and thus significantly increase interaction between two phases. These investigations show that EPDM/PA/CPE blend system is a heterogeneous blending system. Extent of Tg (PA) decrease may be considered as a measure of compatibility. The permeation of CPE segments towards nylon substrate may be considered as a determinant for improvement of miscibility of this blending system.更多还原