Control of reflectivity and surface conductivity in metallized polyimide films prepared via in situ silver(I) reduction

Optically reflective and surface-conductive polyimide films have been prepared by the incorporation of silver(I) acetate and trifluoroacetylacetone into a dimethylacetamide solution of the poly(amic acid) formed from 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride (BTDA) and 4,4'-oxydianiline (4,4'-ODA). Thermal curing of the silver(I)-containing poly(amic acid) leads to imidization with concomitant silver(I) reduction, yielding a reflective and conductive silver surface if the silver(O) concentration is greater than ca. 12% by weight and the film is cured to a final temperature of 340 degrees C. The metallized BTDA/4,4'-ODA films retain the essential mechanical properties of undoped films and have good thermal stability particularly in nitrogen atmospheres. The bulk of the polymer is not electrically conducting. Films were characterized by X-ray, DSC, TGA, XPS, TEM, SEM, and AFM.