One-pot preparation of waterborne PEDOT:PSS/epoxy dispersions for mechanically sound, water-resistant, and antistatic coatings

Abstract

As one of the most studied intrinsically conductive polymers (ICPs), poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), has been widely utilized in electronic applications. However, its relatively high cost, significant moisture absorption propensity, and poor mechanical properties (anti-scratch, hardness, adhesion, etc.) considerably limit its applicability. Herein, through facile oxidative polymerization of 3,4-ethylenedioxythiophene (EDOT) in the presence of waterborne epoxy emulsion (WEP) via one-pot preparation method, a series of waterborne PEDOT:PSS/epoxy dispersions were prepared. They were further combined with bio-based epoxy curing agent and various solvents such as propylene glycol monomethyl ether (PM) to reduce the curing agent’s viscosity and dimethyl sulfoxide (DMSO) to modulate the curing agent’s viscosity and the final coatings’ electrical conductivity. The surface morphology, bulk resistance, wettability, and water immersion stability of these coatings were investigated. Of them, PEDOT:PSS/epoxy/curing agent (DMSO) coating with optimal component ratio demonstrated advantages like enhanced electrical conductivity, improved water resistance (stable even after 45 days immersion), high hardness (2H), and strong adhesion ability (level 2) on glass substrates, etc. This work could facilitate the utilization of PEDOT:PSS in organic electronic fields like antistatic coatings, in a facile, reliable, and environmentally friendly manner.