DEGRADATION OF MECHANICAL AND ELECTROPHYSICAL PROPERTIES OF TEFLON FEP FILMS UNDER COMBINED ACTION OF FAR ULTRAVIOLET AND THERMAL CYCLING

摘要

The change in electrophysical and mechanical properties of Teflon-FEP films under the combined action of far ultraviolet and thermal cycling has been investigated. The following effects were detected while studying the physical properties: the permittivity decreased during and after thermal cycling; the permittivity and tangent of dielectric loss angle diminished, and the surface resistance was noticeably increased on exposure to far ultraviolet; thermal cycling partially compensated for the effects of far ultraviolet radiation on surface resistance upon simultaneous action. Simultaneous action of far ultraviolet and thermal cycling resulted in increased elongation and decreased durability of the loaded films.