Structural studies of poly(p-phenyleneamine) and its oxidation

Abstract

The structural changes associated with the chemical oxidation of poly(p-phenyleneamine) or 'leucoemeraldine' (PLM) were determined quantitatively by X-ray photoelectron spectroscopy (XPS) and qualitatively by infrared (IR) absorption spectroscopy and t thermogravimetric analysis (TGA). Oxidative 'doping' of PLM by organic electron acceptors such as tetrachloro-o-benzoquinone (o-chloranil) and tetrabromo-o-benzoquinone (o-bromanil) involved first the oxidation of the amine nitrogen and also the formation of the imine structure through hydrogen transfer from the pristine amine nitrogen to the acceptor. The so-produced imine nitrogen was in turn doped by the acceptor. XPS data of the PLM-halobenzoquinone complexes indicated that the nitrogenonium cations of the polymer were balanced by the halogen and the oxygen or benzoquinone anions.