Homopolymer and copolymer of N-(2-(thiophen-3-yl)methylcarbonyloxyethyl) maleimide (NMThi) with thiophene [P(NMThi-co-Th)] were synthesized electrochemically in acetonitrile[borontrifluoride ethylether solvent mixture (1: 1, v/v). Spectroelectrochemical analysis of the resulting copolymer reflected electronic transitions at 488 and 718 nm revealing pi to pi* transition and polaron formation, respectively. Switching ability was evaluated by a kinetic study via measuring the transmittance (%T) at the maximum contrast. Dual-type polymer electrochromic devices (ECDs) based on homopolymer (P(NMThi) and copolymer P(NMThi-co-Th) were constructed with poly(3,4-ethylenedioxythiophene) (PEDOT). Spectroelectrochemistry and switching ability of the devices were investigated by UV-vis spectroscopy and cyclic voltammetry. (c) 2007 Elsevier Masson SAS. All rights reserved.