Synthesis and characterization of polyurethane/polythiophene conducting copolymer by electrochemical method

In the first step of this study, conducting homopolymers of thiophene were synthesized by electrochemical method using three different supporting electrolytes (LiClO4, Et4NBF4, Bt4NPF6) and two different solvents (acetonitrile and benzonitrile) in anhydrous medium. Polythiophene (PT) (LiClO4) was shown the highest conductivity with 0.35 S cm−1 in the acetonitrile solvent medium, PT (Et4NBF4) was shown the highest conductivity with 0.54 S cm−1 in the benzonitrile solvent medium. Then, polyurethane/polythiophene (PU/PT) conducting copolymers were prepared using PU as an insulating matrix, their structures and properties were analyzed. The electrochemical properties of polymers were investigated by cyclic voltammetry (CV). The conductivities of polymers were measured by four probe technique. It was found that all homopolymers and bipolymers which were of conducting mechanism from the Gouy balance magnetic measurements. FTIR spectra were taken to analyze the structural properties of polymers. Surface analyses of polymers were clarified by scanning electron microscopy (SEM). Thermal analyses of the polymer films was done by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). From thermal analyses, it was found that among the PTs, PT (Et4NBF4) and among the copolymers PU/PT (Et4NBF4) were shown the highest thermal stability as 191 and 210 °C, respectively.