PP-EPR二嵌段共聚物作PP/EPT共混增容剂的探讨

对以实验室合成的PP-EPR二嵌段共聚物作为PP/EPT二元共混物的增容剂进行了探讨。共混物在增容前后的物理力学性能的变化说明PP-EPR对PP/EPT共混物具有优良的增容效果;同时又有克服通常因橡胶增韧塑料而强度下降的优点。形态结构的表征结果说明共混物为两相结构,阐明了PP-EPR的作用以及低温冲击强度大幅度提高和在增容后抗张强度损失减少的原因。

INVESTIGATION OF PP-EPR DIBLOCK COPOLYMER AS COMPATIBILIZER FOR PP/EPT BLEND

Much attention has been paid in recent years to the toughening of isotactic polypropylene (PP), and blending PP with ethylene-propylene terpolymer (EPT) is one of the most effective ways. In order to further improve the toughness of PP/EPT blend and to enhance the stability of the dispersed rubber phase, a diblock copolymer composed of PP and ethylene-propylene rubber blocks (PP-EPR) was added into the blend, as it is considered that "forced compatibility" of the two components will be effected through the two chemically bonded blocks, while two-phase structure still remains. Experimental results indicate that PP-EPR is an effective compatibilizer for PP/EPT blend. It not only increased the toughness of the blend, but also decreased the loss of tensile strengths usually accompanying the toughening of plastics with an elastomer, which is very well explained by the changes in morphological structure when an appropriate amount of PP-EPR was added into the blend.