The conductivity of polypropylene films increases and breakdown properties decrease at high temperatures. The reason is that the molecular chains in the amorphous region of polypropylene have weak intermolecular forces and slip and relaxation occur at high temperatures. Gamma irradiation can cross-link the molecular chains of polypropylene to form a three-dimensional network structure, and the intermolecular forces will be enhanced. In this paper, the effects of different radiation conditions and sensitizer content on the crosslinking degree of polypropylene were investigated, and a correlation between the crosslinking degree and the improvement of dielectric properties was established.

polypropylene,gamma irradiation,Cross-linking