Conductive thin film formation onto radiation grafted polymeric surfaces using electroless plating technique

Surface modification of polypropylene films (PP) was carried out via radiation induced graft copolymerization of 4-vinyl pyridine (4VP) and acrylamide (AAm) to enhance the adhesion ability of the PP surface for electroless deposition of copper. Factors affecting the grafting process such as suitable solvent, comonomer composition and concentration and irradiation dose were optimized. The grafted films produced were characterized by studying their Fourier-transform infrared (FTIR) spectra and thermal stability. The grafted films were copper-plated by electroless deposition using Pd as the catalyst to initiate the redox reaction. The influence of catalytic activation method parameters on the plating rate were studied. Scanning electron microscopy revealed a dense and void-free copper deposited film. The adhesion of the deposited copper film to the modified PP films was determined by measuring the tensile strength of the copper plated films. The electrical characteristics of the copper plated films in comparison with grafted films were studied. The results showed the high adhesion of the deposited copper film to the grafted PP film as well as the high electrical conductivity. Copyright (C) 2008 John Wiley & Sons, Ltd.