ABSTRACT
The silahydrocarbons have been developed and investigated as base fluids for candidate ultralow volatility liquid and grease lubricants for space applications. Hydrosilation has been utilized in the preparation of tetraalkylsilanes. While it is likely not of preparatory significance, R. G. Austin et al. reported an interesting route to tetraalkylsilanes. Silahydrocarbons were compared to a mineral oil and a polyalphaolefins (PAO). In comparison to PAOs, the superior thermal stability, higher viscosity index, and low volatility seem to be the advantages that would lead one to consider a silahydrocarbon as a candidate fluid. The hydrolytic stability of silahydrocarbons, silicate esters, and polysiloxanes was evaluated with regard to the possible use as dielectric coolants in military aircraft. The key features of silahydrocarbons are low-temperature fluidity, high thermal stability, low volatility, and high viscosity index. The literature contains numerous reports on methods of preparation of silahydrocarbons. The types of reaction that appear to be useful include alkylation of silicon halides and hydrosilation of olefins.
