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EPDM/PA高性能弹性体的增容机理 马军 熊茂林 冯予星 朱玉俊 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。 Study on the miscibility of EPDM/PA blending system Ma Jun Xiong Maolin Feng
Yuxing Zhu Yujun 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 showsthat,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 andwell-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 ofcompatibility.The permeation of CPE segments
towards nylon substrate may be considered as a determinant for improvement of miscibility
of this blending system. 基金项目:国家“九五”攻关项目(95-HG-8)。 参考文献 1,马军,雷昌纯,冯予星,等.EPDM共混改性研究概况[J].合成橡胶工业,2000,23(3):186~191 收稿日期:1999-08-17 |