Cellulose Benzoate Synthesis via Homogeneous Transesterification Catalyzed by Superbase-Derived Ionic Liquids for Advanced Applications

Abstract

A novel method for the controllable synthesis of cellulose benzoate was developed via homogeneous transesterification catalyzed by the superbase-derived ionic liquid (1,8-diazabicyclo (5.4.0) undec-7-ene levulinate, [DBUH]Lev), which could largely address the need for efficient and sustainable cellulose modification, thus broadening its functional applications. A series of cellulose benzoates with different degree of substitution (DS) on, ranging from 0.93 to 2.91, were successfully achieved by varying the reaction conditions. Density functional theory (DFT) calculations revealed that the catalytic system significantly lowered the free-energy barrier for cellulose transesterification. Furthermore, the study demonstrated that the system is reusable. Modern instrumental analyses were used to investigate the chemical structure and physical properties of cellulose benzoate, confirming the occurrence of transesterification. The synthesized cellulose benzoates showed tailored properties for versatile applications. Poly(vinylidene difluoride) (PVDF)/cellulose benzoate membranes exhibited high oil–water separation efficiency, while the cellulose benzoate aerogels displayed low thermal conductivity and strong mechanical properties, highlighting their potential as sustainable materials for advanced applications. The findings of this study have the potential to advance the field of cellulose derivatives and pave the way for their applications in environmental and energy-relevant technologies.