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

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 Рк,Н = 750-900, spot wear diameter Di,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.