The correlation of chemical structure to tribological properties of polyimide thin films

Abstract

The friction and wear behavior of three thin polyimide films of known chemical structure was tested. An attempt was made to correlate differences in chemical structure, primarily the presence of flexible linkages and highly polar side groups, to differences in tribological properties. The wear test results showed lowest wear for the polyimide with the flexible oxygen linkage. The wear mechanism was deduced to be fatigue since wear did not occur immediately and a strong correlation was noted between wear rate and elastic modulus. Increasing sliding speed increased both wear rate and friction coefficient. The friction results showed highest friction for the polyimide with the highest density of polar side groups. Even though some effects of the deformation component of friction were seen, the adhesive component of friction predominated.