Synthesis of esters of oxypropylated 2,2,5,5-tetramethylolcyclopentanol and investigation of them as base of promising lubricating materials

Синтез сложных эфиров оксипропилированного 2,2,5,5-тетраметилолциклопентанола и исследование их в качестве перспективных смазочных материалов

DOI: 10.32758/2782-3040-2022-0-2-06-10

H.N. Gurbanov, L.M. Yusifova, M.A. Mammadyarov, M.M. Abdullayeva

(Institute of Petrochemical Processes named after Y.H. Mammadaliyev of Azerbaijan National Academy of Sciences, Baku) E-mail: huseynqurbanov1948@gmail.com

Keywords: esterification reaction, esters of oxypropylated polyol, lubricating oils, performance characteristics, correlation dependence

Abstract. At present, with the development of modern technology, the requirements for lubricating oils, especially their viscosity-temperature, thermo-oxidative and lubricating characteristics, are becoming more stringent. In this aspect, the synthesis and study of esters of oxypropylated 2,2,5,5-tetramethylolcyclopentanol (TMCP) with cyclic fragments, active centers, multipolar ester groups is promising, have a certain scientific and practical significance. The esters were synthesized by the esterification reaction of oxypropylated TMCP with aliphatic monocarboxylic acids C₄-C₈, and their physicochemical, viscosity-temperature, thermal-oxidative and lubricating properties were studied. After determining the viscosity-temperature properties, it was established that they have a low pour point (minus 38-minus 43⁰C), an average viscosity at 100⁰C (ν₁₀₀ = 23.50-40.22 mm²/s), a high viscosity index (133-150 units) and flash point (305-380⁰C). When determining the thermo-oxidative stability of esters, it was found that they have low acid numbers after oxidation (2.51-3.28 mg KOH/g), corrosion of electrodes AK-4 (0.06-0.16 mg/cm²), ШХ -15 (0.08-0.11 mg/cm²) and the precipitate is insoluble in isooctane is low (0.120-0.248% of the mass), the volatility is 0.30-0.50% of the mass. The lubricating properties of esters were also determined: critical load Р_к,Н = 750-900, spot wear diameter D_i,mm at Р = 196Н = 0.50-0.65. Oxypropylated esters in comparison with reference esters — TMCP ester with caproic acid and pentaerythritol ester (PET) and mixture of fatty acids (MFA) fr. C₅-C₆ surpass them in almost all parameters, are higher molecular weight and promising, and this makes it possible to create on their basis high-temperature lubricating oils special purpose, components or additives to other lubricating oils.