Polyimide/metal composite films via in situ decomposition of inorganic additives: Soluble polyimide versus polyimide precursor

Polyimide-metal oxide (Co₃O₄ or CuO) composite films have been prepared via in situ thermal decomposition of cobalt (II) chloride or bis (trifluoroacetylacetonato) copper (II). A soluble polyimide (XU-218) and its corresponding prepolymer (polyamideacid) were individually employed as the reaction matrix. The resulting composites exhibited a greater metal oxide concentration at the air interface with polyamideacid as the reaction matrix. The water of imidization that is released during the concurrent polyamide acid cure and additive decomposition is believed to promote metal migration and oxide formation. In contrast, XU-218 doped with either HAuCl₄ · 3H₂O or AgNO₃ yields surface gold or silver when themolyzed (300 °C).