Abstract:

Poly-phenylene terephthalamide (PPTA-pulp)-reinforced ethylene propylene diene elastomer (EPDM)composites were prepared in an open mixer. The effects of fiber content on medium-resistance performance and heat aging resistance of the composites were investigated. With swelling behavior of the composites studied by the weighing method, the experimental curves were fitted by computer. The swelling dynamic rate equations were established. Experimental results showed that medium-resistance performance, and heat aging resistance of the composites increased greatly by adding PPTA-pulp. When the content of the fiber was up to 25% (mass), the composites showed the best performance. The swelling behavior of EPDM/PPTA-pulp composite could be described by the Voigt parallel dashpot-spring model.Basic equation was not changed, but equilibrium swelling ratio and relaxation time of chain movement were changed on the addition of fiber. Both swelling ratio and relaxation time decreased with increasing fiber content.

摘要：

利用开练机制备了三元乙丙橡胶(EPDM)/芳纶浆粕(PPTA-pulp)复合材料。考察了PPTA-pulp用量对EPDM/PPTA-pulp复合材料耐热老化性能以及耐介质性能的影响。采用称重法研究复合材料的溶胀行为，通过Voigt并联粘壶弹簧模型对实验曲线进行软件拟合，获得复合材料的溶胀动力学方程。结果表明：PPTA-pulp的加入有效地改善了复合材料的耐热老化性能以及耐介质性能，在相同条件下，当PPTA-pulp质量分数为25%时，复合材料的耐热老化性能和耐介质性能达到最佳；EPDM/PPTA-pulp复合材料的溶胀行为可以用Voigt模型描述。PPTA-pulp的加入并不会改变基体的溶胀规律，仅对基体的平衡溶胀度和链段溶胀运动的松弛时间产生影响；链段溶胀运动的松弛时间与平衡溶胀度均随着PPTA-pulp用量的增加而减小。