CONDUCTING POLYPYRROLE POLYIMIDE COMPOSITE FILMS

Novel polypyrrole-polyimide composite films are reported which combine high electrical conductivity with high thermal stability. The composite films were prepared either by electrochemical polymerization of pyrrole on a polyimide coated electrode (type I films) or by exposing polyimide films containing ferric chloride as an oxidizing agent to pyrrole vapour (type II films). Type I films consist of a sequence of three layers with the polyimide sandwiched between two layers of polypyrrole. The maximum conductivity is about 10 S cm-1. Type II films consist of polyimide containing finely dispersed polypyrrole particles of 10 to 500 nm in diameter. The maximum conductivity is about 5 × 10-4 S cm-1. The composite films are thermally stable up to 350°C. © 1990.