Influence of Electron Beam Irradiation on Electrical Insulating Properties of PLA with Soft Resin Added †

Polylactic acid (PLA), a bioplastic, is a hard resin, and requires softening in order to be used in electric wire sheaths. A soft resin was added to PLA in order to soften it, but this caused the electric breakdown strength (E(B)) to decrease. In this study, PLA with soft resin added was irradiated with an electron beam and the influence of the electron beam irradiation on E(B) was examined. The irradiation dose was set at 100 kGy. At 25 °C, the E(B) of PLA with no soft resin added decreased due to the irradiation. On the other hand, the E(B) of PLA with soft resin added showed almost no change due to the irradiation. At 80 °C, the E(B) of PLA with no soft resin added decreased due to the irradiation, as was the case at 25 °C. On the other hand, the E(B) of PLA with soft resin added increased due to the irradiation.