典型空间聚合物介质的抗内带电改性技术

Internal charging protection technology of typical space polymer dielectric material

消除航天器介质内带电所产生脉冲放电威胁的最佳方式,除有效屏蔽外,就是研制不会产生脉冲放电的介质材料和绝缘结构件.通过对航天器用聚酰亚胺、环氧树脂和聚四氟乙烯等几种典型聚合物的改性研究发现,采用微米级无机粉料对聚合物介质材料进行改性,只要添加剂的电导率显著低于聚合物的电导率,该复合介质材料即可产生显著的非线性电阻率特性,可以实现在介质内带电程度达到放电阈值时迅速以非脉冲电导电流方式释放掉所储存的危险电荷,有可能达到消除脉冲放电的目标;当该添加剂含有微量"施主"杂质时甚至还可以提高介质材料在正常情况下的电阻率.对复合介质非线性电阻特性的产生机理进行了分析.

Besides efficient shield,the best method for eliminating the pulsed discharge induced by the deep charge of spacecraft dielectric was to use dielectric materials or insulation structural components that never produce any pulsed discharges.By non-linearity modification experiment research on several typical polymer dielectrics like Polyimide,Epoxide resin and Teflon,it was found that through the addition of the inorganic powder that possess a conductivity much higher than that of the polymer,the composite dielectric material would produce a remarkable non-linearity conductance character.By this way,the excessive charges would be discharged as a method of non-pulsed conducting current before the deep dielectric charging reaches the discharge threshold.It was proved that,even the normal resistance could be increased by this method.Finally,the mechanism on the non-linearity conductance of the composite material was investigated.