Tribochemical reactions in polycapromide

The chemical composition and secondary structure of the surface layer of PA-6 were studied with the aim to elucidate tribochemical processes proceeding in this polymer. The high and fluctuating values of the friction coefficient of PA6 were attributed to tribochemical reactions promoted in the presence of oxygen. Two simultaneous processes are involved in tribochemical reactions of PA-6 in air; mechanical degradation of amidic bonds and tribochemical oxidation of the carbon atom in position, α, leading to the formation of branched and/or crosslinked structures.