Synthesis and performance of cross-linked PEDOT:MOI-P(SS-HEA) transparent conductive films by UV irradiation

Poly(3,4-ethylenedioxythiophene) (PEDOT) is a promising conductive polymer due to its high conductivity and optical transparency. However, two main challenges remain to be solved for its practical application, including improving the humidity stability and water resistance. Here, a novel cross-linkable copolymer of methacryloyloxyethyl isocyanate grafted poly(styrene sulfonate-co-2-hydroxyethyl acrylate) [MOI-P(SS-HEA)] is synthesized by a radical polymerization and condensation reaction. MOI-P(SS-HEA) is used as a multi-functional counter anion to obtain the UV-curable conductive dispersion of PEDOT:MOI-P(SS-HEA). The electrical conductivity, humidity stability, and water resistance of the cross-linked PEDOT:MOI-P(SS-HEA) [PEDOT:MOI-P(SS-HEA)-C] conductive films are investigated. The results indicate that the UV cross-linked reaction significantly improves the humidity stability and water resistance of the PEDOT:MOI-P(SS-HEA)-C conductive film.