AWWA JAW34252

Evaluating elastomer degradation involved an accelerated life cycle testing protocol whereby sets of tension-mounted coupons were exposed to specific chlorine and ammonia concentrations at elevated temperature. The coupons were inspected regularly for evidence of oxidative degradation and cracking. After a set exposure period, the coupons were assessed for tensile performance, swelling, and surface characterization. With few exceptions, solutions of chloramines produced greater elastomer swelling, deeper and denser surface cracking, more rapid loss of elasticity, and greater loss of tensile strength than equivalent concentrations of free chlorine. Elastomers most susceptible to attack were those formulated with natural or synthetic isoprenes. Includes 13 references, tables, figures.