The identification of peroxy-features at polymer surfaces by ESCA

A preliminary investigation of the identification of peroxy-features at polymer surfaces by ESCA is described. Oxidation of a hydrocarbon polymer in the effluent of a singlet molecular oxygen generator, based on a microwave discharge in oxygen, produces surfaces rich in peroxy-features. By comparison with experimental and theoretical studies of model systems these features can be identified in ESCA spectra by their characteristic O_1s binding energies. The oxygen atoms in the peroxy-linkage have essentially the same binding energy, which is within a narrow range of 534.0 eV for simple peroxides and hydroperoxides and a narrow range of 535.2 eV for peroxy-features in more highly oxygenated environments; for example, peracids and peresters. Peroxy-linkages decompose rather rapidly under the typical x-ray flux used in the ESCA experiment.