Application of quantitative 13C nuclear magnetic resonance spectroscopy to the characterisation of solvent‐refined aromatic‐rich lubricant base oils

Abstract

AbstractNuclear magnetic resonance (NMR) spectroscopy has emerged as a powerful technique for studying the molecular composition of base oil matrices. The usefulness of this technique lies in its ability to explain the chemistry involved in the molecular changes observed in various lubricant refining and extraction stages. This paper discusses the use of this technique in understanding the variation of gross properties observed in base oils during lubricant processing steps. The variations in weight percent of sulphur, viscosity index (VI), Conradson carbon residue (CCR), characterisation factor (KUOP), etc., are explained at the molecular level using high‐resolution quantitative 1H and 13C NMR. A single well‐recorded quantitative spectrum of a sample can be used to generate sufficient information on the different properties used for the specification of base oils.