Branched chain derivatives of alkyl oleates: Tribological, rheological, oxidation, and low temperature properties

We report the evaluation of four previously prepared oleochemical branched chain ethers (1–4) and soybean oil methyl esters (SME) against cloud point, pour point, oxidation stability, kinematic viscosity, specific gravity, lubricity, and surface tension. Ethers 1–4 exhibited excellent low temperature, oxidation stability, and lubricity behavior; however, at low blend levels (0.5, 1.0, 2.0 wt%) in SME, 1–4 had minimal impact on cloud point and pour point of SME. The specific gravity and surface tension behavior of 1–4 are nearly identical to SME. Ethers 1–4 displayed increased viscosity when compared to SME, but were still within ASTM D 6751 specifications at low blend levels in SME. Conversely, ethers 3 and 4 at 2.0% in SME were out of specification for kinematic viscosity in EN 14214. Both SME and 1–4 exhibited excellent tribological properties, as evidenced by HFRR wear scar behavior well within prescribed ASTM and CEN petrodiesel specifications.