Thermal behavior of polyaniline films and polyaniline-polystyrene blends

Thermal Properties and Electrical Conductivity of Graft Copolymers from Polystyrene and Polyvinyl Propionate with Polyaniline

A synthesized graft copolymer from polystyrene (PS) and polyvinyl propionate (PVPr) with polyaniline (PANi) with suitable electrical properties, thermal resistance, solubility and processability was optimized. Samples were prepared in the form of smooth and thin films. Four-point probe method was adapted to examine electrical DC conductivity. It was found that the electrical conductivity and thermal stability of copolymers were increased, but their processability and solubility decreased when PANi increased. Thermal stability of copolymers was investigated by Differential Scanning Calorimetry (DSC) and Thermal Gravimetrical Analysis (TGA). The prepared copolymers were much more thermally stable, soluble, flexible and ability to form a film than polyaniline, polystyrene and polyvinyl propionate. An irreversible exothermic transition was observed by DSC, which is believed to be an indication of cross-linking. Percentage of grafted PANi electrical conductivities of PS-g-PANi and PVPr-g-PANi have been examined and produced conductivities, 3.3 × 10−2 and 4.6 × 10−2 S/cm respectively.