Eight poly(oxyethy(or propy)lene diol and triol)s, M = 350-3600, OH no. 45-340 mg KOH/g, had kinematic eta (triols > diols) of 30-270 mm(2) /s at 40degreesC, low pour points (< -20degreesC), low or nil solubility In water very good lubricating properties, biodegradabilities of 35-87%, and high thermooxidative resistance (no tars, no sediments). Direct esterification with pentanoic acid or with a mixture of C-4-C-6 monocarboxylic acids (recovered from E-caprolactam process) still reduced the eta, pour points, solubility in water, and occasionally the lubricating properties, and enhanced the biodegradability.