Thermally induced surface graft copolymerization with concurrent lamination of polyaniline films under atmospheric conditions

Abstract

Simultaneous lamination of emeraldine base (EB) films of polyaniline (PANI) was achieved during thermally induced surface graft copolymerization with various monomers, such as N,N′-dimethyl(methacryloylethyl)ammonium propanesulfonate (DMAPS), sodium salt of styrenesulfonic acid (NaSS), 1-vinyl imidazole (VIDz) and acrylic acid (AAc). The simultaneous thermal grafting and lamination process can be carried out under atmospheric conditions, and in the complete absence of an added polymerization initiator and surface preactivation of the EB substrates. The structure and chemical composition of the graft copolymerized surfaces from the self-delaminated junction in water were investigated by X-ray photoelectron spectroscopy (XPS). The effects of monomer concentration, thermal grafting/lamination temperature, and the physicochemical attributes of the various monomers on the observed lamination strength were studied. The efficiency of surface graft copolymerization and the lamination strength were found to increase with increasing temperature in the temperature range of 80–120°C. Maximum lap shear adhesion strengths of greater than 350 N/cm 2 and exceeding the yield strength of the substrate EB film could be readily achieved for grafting/lamination carried out in the presence of DMAPS, VIDz and AAc monomer.