增容剂对PP/PA共混体系动态力学性能的影响(英文)

Influence of Compatibilizer on the Dynamic Mechanical Behavior of PP/PA Blends

采用2种不同的增容剂对PP/PA共混体系进行增容:PP与马来酸酐的接枝共聚物PP-g-MAH和接枝改性的热塑性弹性体TPE-g.并对它们应变率从10-4 s-1到103 s-1范围内的力学性能进行了研究.试验结果表明:采用PP-g-MAH作增容剂的PP/PA两元体系,在高应变率冲击条件下,界面损伤演化加速,应变约6％时即发生宏观应力应变曲线软化,应变率约2 000 s-1,应变约23％时即发生剪切破坏.采用TPE-g界面相容剂的PP/PA两元体系,由于形成分散相为核,界面相客荆为柔性壳的核壳结构,在尼龙粒子及壳层的协同作用下,使该共混体系的韧性得到大幅度提高.该体系在应变率高于3 500 s-1,应变约45％时才发生剪切破坏.断裂时单位体积吸收能量大幅度提高.

Two different kinds of compatibilizers were used for PP/PA polymer blends: polypropylene grafted with maleic anhydride (PP-g-MAH) and thermoplastic elastomer grafted with maleic anhydride (TPE-g) . The dynamic mechanical behavior of these two binary polymer blends at strain rate ranging from 1×10-4-1×103s-1 was studied. The experimental results show that at high strain rate for PP/PA/ PP-g-MAH the damage evolution process of interface between the minor disperse phase and the matrix was accelerated. When its strain reaches about 6% , the stress softening of its stress strain curve is observed. Its shearing failure happens at strain about 23% under the strain rate of 2 000 s-1. For PP/PA/ TPE-g situation, the compatibilizer TPE-g forms a soft shell around a small core of the second minor phase PA. Under the synergetic action of the fining PA particles and the flexible shell, the toughness of the binary blends with core-shell structure is enhanced obviously. Its shearing failure strain is increased as high as to 45 % under the strain rate 3 500 s - and its absorbed fracture energy for unit volume is raised remarkably.