Structural characterization of triphenylamine (TPA)-based polymers during the oxidative reaction by two-dimensional (2D) infrared correlation study

This paper reports the oxidative reaction of triphenylamine (TPA)-based polyamide films. A two-dimensional (2D) gradient mapping method and 2D correlation analysis were applied to the ultraviolet–visible (UV–Vis) and infrared (IR) spectra of TPA-based polyamide films to examine the spectral changes induced by electrochemical oxidation. The benzenoid and quinoid units were present together during the electrochemical oxidation of TPA-based polyamide films. The oxidative reaction of TPA-based polyamide films strongly affects the spectral changes to the benzenoid and quinoid rings in the TPA units as well as the amide linkages adjacent to the TPA units. The oxidative reaction of TPA-based polyamide film in the range of 0–1.0 V induces spectral changes to the quinoid ring, amide linkage and benzenoid ring.