Heat-hardening of sodium and lithium greases based on soaps of stearic and hydroxystearic acid

Abstract

1. Sodium greases based on soaps of hydroxystearic acids show considerably less heat-hardening than do the corresponding products made with stearic acid. However, after severe homogenization, the reverse is true. 2. Increasing the heat-treating temperature results in more severe heat-hardening of the original and homogenized Na greases. 3. The heat-treating time does not affect the heat-hardening process. 4. There is a clear relationship between increasing dispersity of the soap fibers and increasing susceptibility of Na greases to heat-hardening. 5. Lithium greases made with either stearic or hydroxystearic acid do not heat-harden.