Efficient greener methodology for the preparation of bio-based phase change materials from lipids

Abstract

In the present work, a new, highly efficient and simple strategy has been developed for the synthesis of long chain esters from fatty acids and fatty alcohols as phase change materials. Equivalent amounts of the selected starting compounds were taken to the esterification reaction at 110 °C in a solventless medium. In order to catalyze the esterification reaction, non-hygroscopic triphenylphosphine-sulfur trioxide adduct was used (0.83 mmol%) which is an easily accessible compound. The relevant reaction was completed in a very short time (2 h) and under optimized esterification conditions, excellent conversion were reached. The targeted mono ester compounds (15 examples) were obtained in good to excellent yields even after a simple crystallization step (72-99%). Additionally, a catalyst reuse investigation and study covering the scale-up production of stearyl stearate was also carried out. The triphenylphosphine-sulfur trioxide catalyzed solvent free process can compete with existing processes and proved to be a cheaper, practical and environmentally-friendly method for the esterification of fatty acids and alcohols.