Surface Property Development in Polymeric Coating Systems

A high-throughput tribometer was used to study the development of friction and adhesion properties during cure of a reactive epoxy film system. During the early stages of cure, a film experiences increases in adhesion, but remains soft and malleable, leading to a relatively low coefficient of friction. As the solvent evaporates and the film solidifies, an increase in the plowing contribution to the friction force leads to high coefficients. As the film cure progresses, decreases in the adhesion contribution lead to a reduction in the engineering coefficient until a final stable film forms. Results from both the surface property measurements, as well as post-test damage profilometry and microscopy, are interpreted in light of the principle tribological mechanisms reflecting the different stages of the curing process.