Hydrolytic stability of ternary and quaternary urethane end-capped oligoesters

The hydrolytic stability was evaluated for a series of oligoesters comprised of three or four different monomers. The oligoesters were prepared from adipic acid (AA) and isophthalic acid (IPA) with six different diols, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-butene-1,4-diol, and one triol, trimethylolpropane. The hydroxyl-terminated ternary and quaternary oligoesters were end-capped using phenyl isocyanate. The hydrolysis rate constants were obtained from acid number. The flexibility of diacids had a determinative effect on the hydrolytic stability of the carbamate end-capped oligoesters.