低密度聚乙烯薄膜的结构变化对电气击穿特性的影响(英文)

THE EFFECT OF ELECTRICAL BREAKDOWN CHARACTERISTICS DUE TO MORPHOLOGICAL CHANGE IN LOW DENSITY POLYETHYLENE FILM

为了研究结构变化对电气击穿的影响，本文对先在温度为100℃的硅油中加热60分钟，然后以不同方式冷却的低密度聚乙烯薄膜进行了直流击穿和交流击穿试验。对于分别在空气中缓慢冷却、在水中冷却、以及在液氮中冷却的样品和原始样品，其结晶度是用红外吸收和X线衍射法来测定的。作为试验的结果，测得的结晶度分别为从347％～70．23％。晶体的大小和分布用不同的扫描量热计法测量。在温度为30和50℃时，由于结晶度下降和热电子击穿过程的减弱，样品的脉冲击穿强度提高。随着温度的升高，脉冲击穿强度减小，这就意味着Frohlich型击穿理论。直流击穿强度在低温区几乎与结晶度无关，但在高温区则与结晶度有关。

A study has been carried out on DC and impulsebreakdOWn phewna of low density POlyethylene films an-nealed at 100℃ for 60 mlviutes. in silicone oil and subsequentlycooled in various way to investigate the effects 'of morphologi-cal changes on electrical breakdown. The degree of crystallini-ty was estimated by the infrared absorption and X-raydiffraction measurements for the specimens slowly cooled inair, cooled in water,original,and cooled in liquid nitrogen. As aresult, we rktained the degree of crystallinity from 34.7% to70. 23% respectively. The size and distrlbution of crystallinewere measured by differential scanning calorimetry methods.The impulse breakdown strength at 30 and 50℃ was increasedas the decreasing of the degree of crystallinity, and the ther-mal electronic breakdown process.The impulse breakdown strength was decreased according to theincreasing temPerature, which nzeans the Frohlich-type break-down theory. The DC breakdown strength hardly depends onthe degree of crystallinity in low temPerature regbo, but de-Pends on it in high temperature region.