Abstract
The present manuscript deals with the prediction of the lifetime of NBR compound based rubber gaskets for use as fuel cells. The material was investigated at 120, 140 and 160 degrees C, with aging times from 3 to 600 h and increasing H2SO4 concentrations of 5, 6, 7 and 10 vol%. Both material and accelerated acid-heat aging tests were carried out to predict the useful life of the NBR rubber gasket for use as a fuel cell stack. To investigate the effects of acid-heat aging on the performance characteristics of the gaskets, the properties of the NBR rubber, such as cross-link density and elongation at break, were studied. The hardness of the NBR rubber was found to decrease with decreasing acid concentration at both 120 and 140 degrees C, but at 160 degrees C, the hardness of the NBR rubber increased abruptly in a very short time at different acid concentrations. The tensile strength and elongation at break were found to decrease with increases in both the H2SO4 concentration & temperature. The observed experimental results were evaluated using the Arrhenius equation.