The Antifriction Properties of Amorphous Poly(Arylene Ether Ketone) Copolymers with a Low Content of Cardo Groups

The causes of an abrupt decrease in the wear and in the friction coefficient from 0.6 to 0.24 for poly(arylene ether ketone) copolymers containing 10, 15, and 25 mol % of cardo bisphenol moieties in the main chain have been investigated. The presence of cardo groups in the copolymers promotes an increase in the microhardness from 12 to 22 kgf/mm2 and maintains a high antifrictionality as a parameter that characterizes the dispersion interaction energy contribution to the total energy of the intermolecular interaction. The XPS examination of the copolymers has shown that only in the case of poly(arylene ether ketone) copolymer containing 10 mol % cardo groups, wear products do not undergo any considerable structural changes in the friction process. The studies demonstrated that a significant improvement of friction-and-wear parameters in the case of a poly(arylene ether ketone) copolymer containing a 10 mol % of cardo groups is caused by an optimal combination of increasing microhardness, formation of a discrete surface, and by maintaining a high antifrictionality. With increasing cardo group content in the copolymers to 15 and 25%, a gradual increase in the friction coefficient to 0.5 and 0.75, respectively, was observed.