Stability of Urethan Elastomers in Water, Dry Air and Moist Air Environments

Abstract

Abstract Effects of long-term exposure in moisture-containing environments were examined for corresponding poly (e-caprolactone), polyadipate, and polyether urethan elastomers. Polycaprolactone urethans were more stable than polyadipate. When water-immersed, hydroxyl-cured and amine-cured cast polyether systems were five to ten times more stable than the polycaprolactone. This reduced to about two times when the hydroxyl-cured systems were compared in saturated moist air. A carbodiimide stabilized the polycaprolactone urethan to about the same level as the polyether. Sulfur-cured polycaprolactone urethan millable systems were about twice as stable as similar polyether elastomers. Polyether urethan elastomers degraded more than polycaprolactone systems when exposed to hot, dry air environments. The practical implication of these findings is that, for most applications, polycaprolactone and polyether based urethan elastomers can be formulated to provide continuous service in moisture-containing environments.