SBIR-STTR Award

The objective of the proposed investigation is the production and characterization of liquid space lubricants of high viscosity index, a kinematic viscosity of 90-150 cs at 40 deg C, good compatibility with bearing materials, and a vapor pressure of <<10 -9 mm hg at 20 deg C, e.g., a boiling point of >>225 deg C under a pressure of 1 mm hg. A further objective is to investigate the thermal stability and the antiwear characteristics of all compounds produced, e.g., determining the viscosity and vapor pressure of the materials after exposure to elevate temperature. The three compound classes proposed for investigation are silahydrocarbons, hydrogenated polyalphaolefins, and, to a lesser extent, alkylbenzenes. All of these compositions are known to possess good lubricant properties, relatively high viscosity indices, and acceptable thermal stability; yet none has been produced thus far that will meet the specified low volatility/vapor pressure characteristics. The proposed approach will therefore be to reproduce structural arrangements similar to those already known, but of molecular weights high enough to decrease the vapor pressure to or below the. Desired range with sufficient structural and compositional variety to ensure the needed liquid character.

The objective of the proposed investigation is to develop liquid space lubricants of high viscosity index, a kinematic viscosity of 100-150 cs at 40 deg c, good compatibility with bearing materials, and a vapor pressure of <<10(-9) mm hg at 20 deg c, e.g. A boiling point >>255 deg at 1 mm hg. The materials are to exhibit high thermal stability, antiwear characteristics, good performance under boundary lubrication, and should respond to normal additivies. Under the phase i program, candidate silahydrocarbon arrangements were identified, precursor systems were synthesized, and the feasibility of end-product synthesis was established. Based on these results and the behavior of the semi-model systems produced, the synthetic efforts under the envisioned phase ii program will be directed at development of lubricant compositions exhibiting the optimum viscosity temperature characteristics while meeting or exceeding the low volatility requirements. At least two candidates will be finally selected a) 100 cs at 40 deg c; b) 150 cs at 40 deg c. One quart of fully formulated batches of these two lubricants and one pint each of base fluids will be prepared and delivered for evaluation by the air force. Another objective of the program is to optimize and scale-up synthesis processes so as to be amenable to pilot plant operations under phase III.