Conducting polymers of terepthalic acid bis-(2-thiophen-3-yl-ethyl) ester and their electrochromic properties

Terepthalic acid bis-(2-thiophen-3-yl-ethyl)ester (TATE) was synthesized through the reaction of 2-thiophen-3-yl-ethanol and terepthaloyl chloride. Homopolymer of TATE was synthesized via potentiostatic and potentiodynamic methods by using tetrabutylammonium tetrafluoroborate (TBAFB) as the supporting electrolyte in dichloromethane/borontrifluoride ethylether solvent mixture (DM/BFEE) (8:2, v/v). Copolymerisation of TATE with thiophene was achieved in DM/BFEE solvent mixture (8:2, v/v) by using TBAFB as the supporting electrolyte in the presence of thiophene. The chemical structure of monomer is characterised via NMR and FTIR. Both homopolymer (PTATE) and copolymer P(TATE-co-Th) were characterised by various techniques including cyclic voltammetry, FTIR, scanning electron microscopy and UV–VIS spectroscopy. Conductivities of samples were measured by four probe technique. Optoelectrochemical analysis indicates that the homopolymer and copolymer have an electronic band gap, measured as the onset of the π-to-π* transition, as 2.17 and 2.00 eV, respectively.