核壳胶粒增韧改性聚丙烯研究 2.分散相性质的影响

Toughening Polypropylene by Core-Shell Particles 2. Effects of Dispersed Phase Properties

以甲基丙烯酸缩水甘油酯接枝改性聚丙烯 ( PP- g- GMA)作为界面改性剂 ,采用尺寸可控的聚丙烯酸丁酯 ( PBA) /聚甲基丙烯酸甲酯 ( PMMA)反应性核壳胶粒与聚丙烯 ( PP)进行反应共混 ,研究了核壳胶粒及胶粒核层交联度对 PP/PP- g- GMA/核壳胶粒共混物冲击力学性质的影响 .结果表明 ,当核壳胶粒在 0 .38～ 1 .58μm变化 ,较大尺寸的胶粒有利于增韧 ;随胶粒核层的交联剂浓度由 0增加到 5%,发现存在最适合于增韧的胶粒核层交联度 .研究还显示 ,核壳胶粒尺寸与核层交联度对 PP增韧的影响之间存在相互作用 ,最适合于增韧的胶粒核层交联度 (交联剂浓度 )随胶粒尺寸变化而改变 ,这可用空穴化

Reactive core shell particles with controllable sizes were reactively blended with polypropylene(PP) by the addition of glycidyl methacrylate(GMA) grafted PP(PP g GMA) as interfacial modifier. Effects of the diameter and cross linking degree of core shell particles on the impact properties of PP/PP g GMA/core shell blends were investigated.As the diameter of core shell particles is in the range from 0.38 to 1.58 μm,the results indicate that the core shell particle with a relative large diameter is favorable for toughening.The cross linking degree of core shell particles is represented by the concentration of cross linking agents in core.As the concentration of cross linking agents in the core of core shell modifier increases from 0 to 5%,there exists an optimum concentration of cross linking agents for toughening.The results also show that the effects of core shell diameter and cross linking degree of core on toughening are interdependent,which can be explained by the cavitation/yielding mechanism.