Thermooxidative stability of cyclic polyhydric alcohol esters

Abstract

stability was investigated. The characteristics established allow synthesizing the esters purposefully and selectively, which suggests them as the base and components for promising lube oils.One factor that determines the performance characteristics of lube oils is the thermooxidative stability, which is directly correlated with the chemical structure of their molecules [1][2][3].The thermooxidative stability (TOS) of lube oils of the ester type is primarily a function of the number and position of the ester groups, length and structure of acid and alcohol fragments, the type of functional groups or heteroatoms in the esters, and the type and conformational state of cyclic fragments and other factors.From this point of view, studying the dependence between the chemical structure and thermooxidative stability of cyclic neopolyols and cyclic norbornene diols is of great interest.A series of esters and their phosphorus-and silicon-containing derivatives was synthesized by reacting cyclic neopolyols -2,2,6,6-tetramethylcyclohexanol A [4], 2,2,5,5-tetramethylolcyclopentanol B [5], cyclic diols -1,1-dimethylol-3-cyclohexene C, and 2,2-dimethylolbicyclo(2,2,1)heptane-5 D [6] with C 3 -C 8 aliphatic monocarboxylic acids and C 5 -C 6 synthetic fatty acids (SFA) [7][8][9]. The quality of these esters was comparatively analyzed.Esters A and B with C 5 -C 6 SFA were successfully tested as a dispersion medium for high-temperature plastic greases to replace pentaerythritol ester in LZ-31 grease (MASMA Co., Kiev) and compressor oils used in production of high-pressure polyethylene (AZOT Co., Severodonetsk) instead of the imported oil Ondina.