真空紫外辐照对交联乙烯-四氟乙烯线缆的影响

Effect of vacuum ultraviolet radiation on X-ETFE cable

以航天器舱外用交联乙烯-四氟乙烯共聚物(X-ETFE)线缆为试验对象,采用5倍加速因子对XETFE线缆累计进行了8000等效太阳小时(ESH)真空紫外(VUV)辐照,并通过极限耐电压、绝缘材料电阻测试分析X-ETFE线缆电性能,采用FTIR和SEM表征X-ETFE材料分子结构和微观形貌,以此研究不同VUV辐照时间对X-ETFE线缆的影响。试验结果表明,随着VUV辐照时间的增加,材料表面累积了碳而发生暗化,线缆外观颜色逐渐变为深棕色;X-ETFE线缆的极限耐压和绝缘电阻呈总体下降趋势,但整体电性能水平未发生本质变化;X-ETFE材料在1628 cm^(−1)处的吸收峰逐步增大,说明X-ETFE材料分子链中的−C=C−自由基团随辐照时间而增多,致使材料表面出现了微裂纹现象。

Taking the cross-linked ethylene tetrafluoroethylene copolymer(X-ETFE)cable used outside the spacecraft as the test object,the X-ETFE cable was irradiated with 8000 equivalent solar hours(ESH)vacuum ultraviolet(VUV)with a 5-fold acceleration factor.The electrical properties of the X-ETFE cable were analyzed through the limit voltage resistance and insulation material resistance tests.The molecular structure and micro morphology of the X-ETFE material were characterized by FTIR and SEM,The effects of different VUV irradiation time on X-ETFE cable have been studied..The experimental results show that with the increase of VUV irradiation time,carbon accumulates on the material surface and darkens,and the appearance color of the cable gradually changes to dark brown;The ultimate withstand voltage and insulation resistance of X-ETFE cable show an overall downward trend,but the overall electrical performance level has no substantial change;The absorption peak of X-ETFE material at 1628 cm^(−1) gradually increases,indicating that the−C=C−free group in the molecular chain of X-ETFE material increases with irradiation time,resulting in microcracks on the surface of the material.