Hydrolytic stability and mechanical properties of poly(ester urethanes)

The effect of hydrolysis time at 70°C on molar mass and mechanical properties of commercial poly(ester urethanes), i.e., Estanes 54600, 54610, and 54650, was analyzed. Kinetics of hydrolysis is plausibly described in terms of a first‐order reaction with an average induction period of about 7 days. The resulting reduction of molar mass brought about a significant decrease in ultimate properties, particularly in stress at break and tensile energy to break, while elastic properties were affected much less. A quantitative correlation between relative changes in tensile strength and molar mass was attempted. Hydrolysis resistance of Estanes decreasing in the succession 54650 > 54600 > 54610 was related to their chemical composition.