Neopentyl Polyol Esters for Jet Engine Lubricants-Effect of Tricresyl Phosphate on Thermal Stability and Corrosivity

摘要

Chrome-alloy steel AMS-5504 and mild steel promote thermal decomposition of most neopentyl polyol ester base stocks and some Specification MIL-L-23699 lubricant formulations at 500F. Without metals, these esters are stable at this temperature. A few such polyol ester base stocks show a much lower sensitivity to steel at 500F; these exceptions are attributed to the effect of as yet unidentified components. Tricresyl phosphate (TCP) in 1 to 5 percent concentration effectively stabilizes metal-sensitive polyol esters by passivating the active metal surfaces. As in the case of the diester oils, the combination of TCP and water promotes ester hydrolysis and lead corrosivity; this hydrolytic degradation is inhibited by suitable aliphatic amines. (Author)