Publications Details
Predictive aging of elastomers in air: The importance of understanding diffusion-limited oxidation effects
Whenever a new elastomer is formulated or an old formulation is modified, it is important to estimate the material's anticipated lifetime in various use environments. For extended lifetimes (years) this often requires the application of accelerated aging techniques which typically involve the modelling of results obtained at higher-than-ambient environmental stress levels. For many practical applications of elastomers, air is present during environmental exposures -- this usually implies that important oxidation effects underly the degradation of the material. Unfortunately, exposure of elastomers to air during aging often results in inhomogeneously oxidized samples, a complication which impacts attempts both to understand the oxidation process and to extrapolate accelerated exposures to long-term conditions. As has been clear for many years, in order to confidently extrapolate shorter-term accelerated simulations to long-term, air-aging conditions, one must be able to monitor and quantitatively understand diffusion-limited oxidation effects. In this review we will highlight some of the recent developments in both experimental techniques and theoretical modelling of relevance to this goal. 28 refs., 12 figs.