Partially sulfonated ethylene-vinyl alcohol copolymer as new substrate for 3,4-ethylenedioxythiophene vapor phase polymerization

ABSTRACT A new conducting composite polymer film is obtained by vapor phase polymerization of 3,4‐ethylenedioxythiophene (EDOT) on a biocompatible polyanion derived from the partial sulfonation (32%) of statistical ethylene vinyl alcohol copolymer (EVAL32). EVALS32 and the oxidant (iron(III) p‐toluenesulfonate, [PTS]) are contemporaneously spin coated from a methanol/water solution on glass slide. EVALS32–PTS‐coated glass slides are exposed to EDOT vapors, and the polymerization is followed by Vis–NIR spectroscopy. We observed that PEDOT slowly grows into the bulk of EVALS32 matrix. Thanks to the sulfonic groups of the polyanion acting as doping agents, a highly conjugate p‐doped EVALS32‐PEDOT composite film with a good conductivity (1.6 × 102 S cm−1), transparency, and stability in water is obtained. The EVALS32–PEDOT film seems an ideal candidate for the preparation of organic devices to be applied in electronics, biosensor, or actuation technology. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1203–1210 A new biocompatible partially sulfonated ethylene vinyl alcohol copolymer (EVALS32) was synthesized and used as a supporting insulating matrix for EDOT vapour phase polymerization. This sulfonated polymer is able to provide stability to the PEDOT film and to suppress the oxidant crystallization without the use of specific additives. A homogeneous EVALS32–PEDOT composite film layered on a glass slide characterized by a good conductivity (1.6 × 102 S cm−1), optical transparency, surface smoothness, and stability in water was obtained.