Polymers and copolymers comprising repeating units of 5 thieno[3,4-b]thiophene. Water-borne dispersions of such polymers and copolymers can be cast by conventional methods to provide uniform, thin films which possess utility in numerous electroactive applications including electrochromic displays, optically transparent electrodes and antistatic coatings. The compositions of this invention can be doped with conventional p-dopants or n-dopants. The invention also presents an aqueous process for preparing such polymeric compositions.