Structure and AC breakdown performance of polypropylene/propylene-based elastomer blends

Recently, a variety of elastomers have been widely explored in PP modification to improve mechanical and electrical properties. However, the reduced breakdown strength due to elastomer addition becomes the major challenge in PP modification. This paper evaluates morphological analysis and AC breakdown properties of polypropylene (PP) and PP/propylene-based elastomer (PBE) blends. Six samples were prepared by using the melt-mixing technique including neat PP and PP/PBE blends at different elastomer content. The morphology was evaluated by using scanning electron microscopy (SEM). AC breakdown test was conducted towards PP and PP/PBE blends based on standards set out in ASTM D149. The obtained results show PBE dispersed uniformly in the PP matrix. PP blend with minimum PBE content presents the highest AC breakdown strength. Meanwhile, the inclusion of PBE beyond 10 wt% in PP blends show comparable result with neat PP.