The Elastohydrodynamic Film Thicknesses of Binary Ester-Ether Mixtures

Abstract

Mixtures of various proportions of a polyolester and a polyphenylether (5P4E) have been prepared and their elastohydrodynamic film thicknesses measured in a rolling point contact. It has been found that small amounts of polyolester reduce the film thickness of 5P4E far more than viscosity values would predict. One explanation for this is that the pressure-viscosity coefficient of 5P4E is very sensitive to small amounts of polyolester, and is reduced by a factor of five with only 20 percent of polyolester. This might result from the ester acting as a plasticizer in reducing the glass transition temperature of 5P4E. Alternatively, 5P4E may be behaving in a non-Newtonian fashion over the range of shear rates studied.