Effects of moisture and other contaminants in friction composites

The role of water and other contaminants like salt water, iso‐octane, and ethylene glycol on neat resin, composites, and friction materials have been investigated. The maximum solvent uptake and the diffusion coefficient of the solvent in these systems were determined and the experimental data was fitted to a Fickian model. The nature of the diffusion process was determined in each case and deviations from Fickian behavior were accounted for. For the neat resin and the composites, the diffusion coefficients of the liquids were of the order of 10 cm/s. After exposure to these contaminants, mechanical properties of all the systems were determined and a general degradation in properties was found. The flexural strength and fracture toughness showed reduction in values while the flexural modulus was not affected. Copyright © 1993 Society of Plastics Engineers