Tribochemical Processes in a Phenol Formaldehyde Polymer Modified by Polyformaldehyde Copolymer

Abstract

Thermal and tribochemical processes in a phenol formaldehyde composite reinforced with polyoxadiazole fibers and modified with finely dispersed particles of a polyformaldehyde copolymer were studied by mass spectrometry and X-ray photoelectron spectroscopy. Under thermal exposure to polyformaldehyde, the liberated formaldehyde sharply reduces the amount of phenol that is released. In the case of friction, polyformaldehyde is a bifunctional modifier. It forms a discrete surface, which helps reduce the coefficient of friction. The released products can play the role of a “tribochemical lubricant” and, at the same time, a cross-linking agent. Tribological tests of the modified composite showed a decrease in the coefficient of friction (from 0.20 to 0.18) compared with the original composite, and a significant (approximately 2-fold) decrease in the vibration amplitude of the friction coefficient.