Tunable Surface Properties of a Conductive PEDOT/EVAL blend

Conductive polymers have been studied extensively during recent years. Especially,poly(3,4-ethylenedioxythiophene) (PEDOT) have found many application areas and arebroadly considered one of the most promising conductive polymers. In order to broadenthe application field of PEDOT we have developed an azide functional poly(3,4-ethylenedioxythiophene) (PEDOT-N₃)1. The azide functional conductive polymer canbe postpolymerization functionalized to introduce a large range of molecules onto theconductive backbone through click chemistry2.Here we present a study of the incorporation of poly(ethylene-co-vinyl alcohol) (EVAL)into a copolymer of EDOT and EDOT-N₃ (poly(EDOT-co-EDOT-N3)). Poly(ethyleneco-vinyl alcohol) (EVAL) is known to swell in polar solvents, which was exploited inthis study to permit a good blending of the two polymers. Since both polymers haveresidual functional groups the polymer blend permits post-functionalization througheither the alcohols from EVAL or the azides from EDOT-N3 (as shown in Scheme 1below). In addition to this, the influence of the EVAL incorporation on the mechanicalproperties is tested.The presented procedure is a simple and easy way to prepare functional PEDOT(N₃)with a substantially improved mechanical stability. The increase in mechanical stabilitytogether with high functionality broadens the possible applications of PEDOT as themechanical stability of the polymer is of critical importance in many applications.