Accession Number : ADA305554

Title :   Volatility and Performance Studies of Phosphate Ester Boundary Additives With a Synthetic Hydrocarbon Lubricant.

Corporate Author : AEROSPACE CORP EL SEGUNDO CA TECHNOLOGY OPERATIONS

Personal Author(s) : Didziulis, S.V. ; Bauer, R.

PDF Url : ADA305554

Report Date : 20 DEC 1995

Pagination or Media Count : 24

Abstract : The development of advanced synthetic hydrocarbon oils having very low vapor pressures for spacecraft applications has both enabled the use of boundary additives developed for mineral oils and amplified the shortcomings of these additives. For example, tricresylphosphate (TCP) is widely used in the spacecraft industry as a boundary additive to limit wear, but the vapor pressure of TCP is several orders of magnitude higher than that of Pennzane, a synthetic hydrocarbon oil. In this report, we document the volatility of TCP and higher molecular weight commercial phosphate esters with experimental evaporation studies and supercritical fluid chromatography (SFC) analyses. The performance of these additives under accelerated screening tests is also presented. The test results show that the least volatile additive provides the greatest endurance in these vacuum wear tests, but the performance of the four different additives does not strictly follow this trend. The results indicate that the short-term tests may be too severe to distinguish additive performance based solely on volatility. Further test results demonstrate that the effect of formulating the oil with the additive is much greater than merely pre-treating the bearing components with TCP, and that the protective film developed early in the wear life with a formulated oil provides significant protection. jg p3

Descriptors :   *BOUNDARIES, *HYDROCARBONS, *ADDITIVES, *VOLATILITY, *ESTERS, *LUBRICANTS, *SYNTHETIC MATERIALS, *PHOSPHATES, TEST AND EVALUATION, EXPERIMENTAL DATA, SPACECRAFT, PERFORMANCE TESTS, PHASE TRANSFORMATIONS, HIGH TEMPERATURE, VACUUM, FILMS, TEST METHODS, LOW PRESSURE, GASES, ENDURANCE(GENERAL), FLUIDS, SUPERCRITICAL FLOW, BEARINGS, EVAPORATION, OILS, VAPOR PRESSURE, MINERAL OILS, ACCELERATED TESTING, CHROMATOGRAPHY, WEAR RESISTANCE.

Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Lubricants and Hydraulic Fluids

Distribution Statement : APPROVED FOR PUBLIC RELEASE