Deuterated grease thickener

The ‘Deuterium Isotope Effect’ was investigated as a means of further increasing the oxidation resistance of soap-thickened greases utilized in miniature bearing applications. Using lithium stearate as a model compound, the bearing performance life and induction period for oxidation were determined on four different greases prepared from non-deuterated and deuterated base oil and thickener. The expected increase in oxidation resistance and bearing performance life was observed for the deuterated base fluid; however, the use of a deuterated thickener did not provide any significant improvement. Details concerning the preparation of thickener and grease formulations and their properties are presented.