Load carrying activities of some hydroxy compounds and their ester derivatives

Abstract As mineral oil becomes increasingly scarce, water based fluids are likely to become more important. This paper describes an investigation into the load carrying activities of aqueous solutions of polyhydroxy compounds and their oil soluble derivatives in mineral oil. Aqueous solutions of polyhydroxy compounds, ranging from ethylene glycol to sucrose, exhibited load carrying properties proportional to the number of hydroxyl groups in the molecule. In contrast, liquid paraffin blends of polyol esters were only slightly more effective than esters of di- and triols. Auger examination of the wear surfaces formed using the blend which gave the best performance, a solution of mannitol tri-n-octanoate in liquid paraffin, showed a high level of carbon near the surface