Application of waste carboxylic acids to the manufacture of biodegradable polyolester base oils

Abstract

AbstractThe results described in this paper represent a contribution towards finding feedstocks, such as monocarboxylic acids, for the production of polyolester base oils. The research has shown that it is possible to obtain a mixture of monocarboxylic (butyric, valeric, and caproic) acids from the waste stream produced by the catalytic oxidation of cyclohexane to cyclohexanone in the industrial production of caprolactam. The mixture of C4—C6 carboxylic acids separated from this waste by distillation was used to esterify neopentyl alcohols such as trimethylolpropane (TMP) and pentaerythritol (PE). Thus, polyolester synthesis was strongly dependent on the choice of suitable catalyst and the neturalisation of unreacted acids. Polyolester oils obtained from TMP or PE with monocarboxylic C4—C6 acids have better physicochemical properties than conventional mineral oils, namely ISO 10 or ISO 22, including higher viscosity indices, higher flash points, lower pour points, and lower volatilities. In addition, the polyolesters tested are readily biodegradable under the conditions of the CEC‐L‐33‐T‐82 test and the Zahn‐Wellens test.