Title

VaporPhase Lubrication: Reaction of Phosphate Ester Vapors with Iron and Steel

Document Type

Article

Publication Date

2002

Publication Source

Chemistry of Materials

Abstract

Aromatic phosphate esters such as triphenyl phosphate, tricresyl phosphate (TCP), and tri(tert-butylphenyl) phosphate, have been degraded in the presence of pure iron or metal alloys such as M-50 or 52100 steel. Among these volatile degradation products are those generated from the addition of an aromatic ring to the phosphate ester. Other products, which have been identified, include substituted biphenyls and diphenyl ethers derived from the decomposition of the above-mentioned addition product. Still other products are fused ring aromatic compounds such as anthracene, which arise from secondary reactions of the initial decomposition reactions. The decomposition reactions leave a nonvolatile phosphate film on the surface of the metal. Characterization of the film with Auger spectroscopy suggests iron phosphate as the product. X-ray photoelectron spectroscopy shows the presence of a bound organic layer at the surface. A mechanism that explains many of the decomposition products and the formation of a bound glassy iron phosphate film is proposed.

Inclusive pages

3767–3775

ISBN/ISSN

0897-4756

Comments

This work was conducted under Contract F33615-93-C-2307 for the United States Air Force, Air Force Research Laboratory, Propulsion Directorate, Wright-Patterson Air Force Base, OH. The Air Force Office of Scientific Research, with Drs. Hugh C. DeLong and Paul C. Trulove as program managers, provided support for this research. Partial support from the Ohio Board of Regents and Dr. Allen Garscaden, Chief Scientist, Propulsion Directorate, WPAFB, is gratefully acknowledged.

Publisher

American Chemical Society

Volume

14

Issue

9

Peer Reviewed

yes