Effect of film structure and morphology on the dielectric breakdown characteristics of cast and biaxially oriented polypropylene films

摘要

Graphical abstractDisplay OmittedHighlights?Cast film morphology affects the large-area breakdown performance of BOPP films.?Relationship between β→α transformation and dielectric breakdown strength is found.?Comparison of BOPP with non-oriented films shows the essential role of orientation.AbstractEffects of cast film extrusion and biaxial orientation on morphological development and DC dielectric breakdown performance of non-oriented and biaxially oriented polypropylene (BOPP) films were studied. Cast films, based on two capacitor-grade isotactic polypropylene (iPP) homopolymers, were manufactured using three different extruders under different crystallization conditions and subsequently biaxially orien