直接注射制备聚丙烯/蒙脱土复合材料及其性能研究

Preparation by Direct Injection and Properties of Polypropylene/Montmorillonite Composites

采用直接注射法制备了聚丙烯 /蒙脱土复合材料 ,考察了其材料结构与性能方面的特征。结果表明 :蒙脱土可以在插层剂存在的条件下被插层 ,且其硅酸盐层片之间距离的变化完全取决于插层剂对蒙脱土的溶剂化作用 ,而和熔融混炼中热或机械能的作用无关 ;插层剂虽不能使非极性的PP分子本身对蒙脱土产生插层作用 ,但有助于使其易于分散在蒙脱土颗粒之间 ,使PP/蒙脱土复合体系中作为复合分散相的蒙脱土形成两种结构层次 ,第一种结构层次是被分散在PP树脂中的蒙脱土颗粒 ,第二种结构层次是处于蒙脱土颗粒中被插层剂等间隔地隔离开的多层硅酸盐片层 ;复合体系的冲击强度和硅酸盐层片层间距有良好的相关关系 ,插层剂添加量的增加 ,可以使PP/蒙脱土复合体系实现较好的增韧效果 。

Polypropylene/montmorillonite composite was prepared by direct injection, properties and structure of the composite were studied. The result indicates that montmorillonite can be intercalated in case of the presence of intercalation reagent, and the change of distance between two silicate layers of montmorillonite is not determined by the heat or mechanical energy in the process of injection, but totally determined by the solvent effect on montmorillonite by the intercalation reagent. Though intercalation reagent can not make polypropylene itself do intercalation effect on the montmorillonite, it can help polypropylene disperse in the granules of montmorillonite easily and make the montmorillonite which is the dispersed phase in polypropylene/montmorillonite composites form two levels of structure. The first level is the granules of montmorillonite which is dispersed in polypropylene. The second level is the layers of silicate in granules of montmorillonite which is separated by the intercalation reagent with same distance. There is good interrelationship between the impact strength and the distance of two silicate layers of montmorillonite. With the increasing of the content of intercalation reagent, good effect of toughening of polypropylene/montmorillonite composites can be achieved, but the tensile strength will decrease to some extent.