Modification and synthesis of low pour point plant-based lubricants with ionic liquid catalysis

Due to the poor biodegradability and toxicity of mineral-based lubricants, the development and application of plant-based biolubricants are increasing. However, low stability and poor low temperature performance restrict plant oils to use as lubricants directly. Hence, the paper tried to find an efficient and green way to modify the plant oil derivate oleic acid and obtained high-performance biolubricants. This study demonstrated that modification of oleic acid through epoxidation combined with ring opening reaction, and further esterification, was an efficient strategy for modifying unsaturated fatty acids for the biolubricant production. Meanwhile, catalytic effects of ionic liquids were compared with other catalysts. The results indicated that ionic liquid [HMIm][PF6] is an efficient catalyst for the ring opening and esterification for the synthesis of biolubricants with different kinds of fatty acids. Modified biolubricants from this research exhibited excellent viscosity index (>116) and low temperature performance (pour point < -48 degrees C). The results of high frequency reciprocating friction experiments exhibited superior lubrication performance of the lubricant. These findings provide a new green and efficient method for improving plant oils as biolubricants. (C) 2020 Elsevier Ltd. All rights reserved.