Analysis of Influence of Trap Introducing Methods on Polymer Insulation Properties

Introducing chemical groups as electron traps is a common method for preparing high-performance insulating polymers. In this paper, PP-g-5St and PP-b-5PS was prepared by chemical grafting method and blending method respectively, and the leakage current and breakdown strength of the two samples were compared. The results presented that the leakage current of PP-g-5St and PP-b-5PS is obviously better than that of unmodified PP, while breakdown strength of PP-b-5PS presents a terrible performance. In order to compare the effective mechanism of different chemical group introduction methods, PP/PS section samples were prepared by argon ion polishing method, and the surface potential was detected by developed section-Kelvin Force Probe Microscope (SKPFM) method. It was found that a lower potential appeared in the PS region, and the results showed that benzene ring structure has a stronger electron trapping ability. The grafting method is more effective at introducing electron traps than blending, possibly because the grafting sites provide a stronger PP/PS phase interaction, which make charges more conducive to be captured by the PS phase so that the leakage current and breakdown process are inhibited.