Synthetic Biolubricant Basestocks from Epoxidized Ricinoleic Acid: Improved Low Temperature Properties

Abstract

This paper presents a series of structural modifications of epoxidized ricinoleic acid for biolubricant to improve the cold flow behavior and oxidation stability of vegetable oils through measurement of pour point (PP) and oxidation onset temperature (OT) and signal maximum temperature (SMT) of each synthetic compound. The results showed that butyl 10,12-dihydroxy-9-behenoxystearate with bulky ester behenyl mid-chain exhibited the most favorable low-temperature performance ϑPP=– 47 °C). On the other hand, butyl 10,12-dihydroxy-9-octyloxystearate exhibited higher oxidation stability (ϑOT = 221 °C) than the other synthetic esters. It was discovered that increasing chain length of the mid-chain ester had a positive influence on the low temperature properties of synthesized compounds. Improved oxidation stability is achieved when the chain length of the mid-chain ester decreases. The synthesized ester structures were confirmed by NMR and FTIR analysis.

Keywords

• Vegetable oils
• epoxidized ricinoleic acid
• chemically modified biolubricants
• pour point
• oxidative stability