动态硫化PP/EPDM强化增韧机理的动态力学研究

Study on the Toughning Mechanism of the Dynamic VulcanizedPP/EPDM Blends by the Dynamic Mechanical Analysis

采用动态力学试验方法，研究了不同ＥＰＤＭ含量的动态硫化和简单共混两种ＰＰ／ＥＰＤＭ材料动态力学响应的差异及其特征。结果显示：与简单共混ＰＰ／ＥＰＤＭ相比，动态硫化ＰＰ／ＥＰＤＭ具有ΔＴｇ小，内耗峰扩宽程度大，低温和室温内耗峰强度高，所处温度低，６０～７０℃时内耗峰强度发生高低变位，在ＥＰＤＭ相的α转变（Ｔｇ）以下还显示β和γ次级转变等特性。研究结果同时还预示动态硫化ＰＰ／ＥＰＤＭ具有耐寒性好、高温下模量保留率大的优点。

The differences and the characteristics of the dynamic mechanical resonances between dynamic vulcanized and unvulcanized PP/EPDM blends with deffrent content of EPDM were studied by means of the dynamic mechanical analysis. The results showed that, compared with the unvulcanized PP/EPDM blend, the dynamic vulcanized PP/EPDM has the characteristics of smaller Tg larger mechanical loss peak width, higher mechanical loss strength and lower mechanical loss peak temprature at the room and low temprature, a change in the peak value of the mechanical loss at 6070 and some appearances of and secondary transition under the transition (Tg) of EPDM etc. The main reason why the toughning effect of the dynamic vulcanized PP/EPDM blend was better than the unvalcanized PP/EPDM blend is that, the dynamic vulcanized PP/EPDM can increase the compatibility between the two phases PP and EPDM, increase the mobility of the molecular segments and form the new chemical structures which can have the mobility at the low t emprature etc. From the results it can be also predicted that the dynamical vulcanized PP/EPDM blends may have the advantages of the high cold properties and high holding ratio of the modulus at the high temprature.