【摘要】 对掺杂了导电碳黑(CB)的高密度聚乙烯(HDPE)/三元乙丙橡胶(EPDM)和HDPE/EPDM/Sirubber(硅橡胶)的挤出样品进行了辐照前后的电性能表征。研究了正温度系数(PTC)功能材料挤出后的特性,发现挤出后粒子和聚合物取向对材料电性能都有较大影响。经γ射线辐照后HDPE/EPDM/Sirubber/CB功能复合材料稳定性大为提高,初步探讨了辐射对PTC功能材料稳定性的影响。加入硅橡胶,可增强CB粒子与基体的亲和力,增加粒子的分散性,提高电阻的长期稳定性,并使工作温度得以长期保持。更多还原

【Abstract】 High-density-polyethylene (HDPE), Si rubber (SR) and ethylene-density-polyethylene (EPDM) were used as the polymer matrices, A kinds of carbon blacks was used as the conductive filler. The positive temperature coefficient (PTC) intensity of the HDPE/CB, HDPE/EPDM /CB composites flow during extrusion to produced was tested before and after irradiation. Compared to that of HDPE/CB composites, the electrical reproducibility of the irradiated HDPE/EPDM /CB composites of is better. The effects of γ-rays irradiation were also estimated. The results showed that the reproductive of the PTC effect was related to the adhesion between the interface of the polymer matrices and CB particles. These PTC phenomena and their distinctive aspects were described. The explanations were given from the structural characteristics of the blends, CB particles distribution and motion of polymer segments.更多还原