Water-Doped Brønsted Acidic Protic Ionic Liquids for Enhanced Tributyl Citrate Synthesis in a Two-Phase Esterification System

Chem Asian J. 2024 Apr 2;19(7):e202400006. doi: 10.1002/asia.202400006. Epub 2024 Mar 19.

Abstract

Tributyl citrate (TBC) plays a crucial role as a plasticizer, enhancing the flexibility of polymers such as polyvinyl chloride. Its biodegradability and non-toxic nature contribute to eco-friendly appeal, making it a preferred additive in diverse industries, including food packaging, medical devices, toys, and consumer goods. Herein, a method for the synthesis of TBC using inexpensive Brønsted acidic protic ionic liquids (ILs) in a two-phase reaction system is presented. The esterification process is carried out with high yield (>99 %), selectivity (up to 98 %) and short reaction time of 2 h. The catalyst in the form of IL shows excellent performance and stability, desirable for industrial applications.

Keywords: Brønsted acidic ionic liquids; esterification; plasticizers; protic ionic liquids; tributyl citrate.