New Reflectable Materials on the Basis of Polyimides

Electroconductive and reflective metallized polyimide films have been prepared by heterogeneous chemical modification of polyimide surface. By carrying out the chemical reactions in situ in the modified layers of polyimide surface, thereby a metal phase strongly impregnated into the polyimide surface is obtained. The steps of chemical modification have been studied on the model compound – poly(amic acid) on the basis of pyromellite dianhydride and oxydianiline, which forms insoluble sodium or potassium poly(amicacid) salts (polyamate). Metallization of Kapton® HN & JP (from DuPont) and Upilex® S films have been carried out and the films have been characterized by XRD, XRFD, and measurements of reflectivity in the visible range and surface resistivity at elevated temperatures. It is shown that reflectivity coefficients of silvered films are 90-92% and surface resistivity is about 0.5 Ω

The Microhardness as an Express Method for Estimation the Depth of Metal Particle Distribution

By measurement of microhardness of silver layer on polyimide films and its reduction after removing the stress, the depth of silver distribution in the polyimide films was calculated. A significant hardening of Kapton 100 HN films was observed especially for cobalt-impregnated materials, which was about 10 µm. The distribution of silver in the film layers was obviously deeper that manifested as entirely lower hardening at microhardness measurement. Because of the initial microhardness of Upilex it was observed strong hardening of the effort, which was led to shallow distribution of metals in the films. For example, Cometallized films showed 5 µm distribution in the top film layers. Such method could allow precisely and rapidly estimating the distribution of metal particles impregnated in metallized polymeric materials