Efficient one-step synthesis of cellulose acetate in ionic liquid using sodium acetate as a homogeneous catalyst

Cellulose acetate (CA) has traditionally been synthesized through processes that require the activation of cellulose, the use of corrosive acid catalysts, and subsequent hydrolysis. These factors make the process complex, costly, and environmentally harmful. This study proposed a method for preparing cellulose acetate by coupling sodium acetate (a non-toxic metal salt) with 1-butyl-3-methylimidazole chloride (BmimCl) ionic liquid. Single-step synthesis of cellulose acetate with a degree of substitution (DS) ranging from 0.71 to 3.0 was achieved under varying reaction conditions. The experimental results demonstrated that adding sodium acetate significantly enhanced the acetylation efficiency of cellulose in an ionic liquid across a broad temperature range. In addition, the cellulose acetate film prepared by this method has 95 % transparency, a tensile strength of 64.5 ± 1.9 MPa, and a water vapor permeability of 34.48 ± 1.47 g/m²h^-1. These remarkable properties give the film significant potential to serve as a replacement for petroleum-based plastics. Overall, this study presents a novel and efficient strategy to boost cellulose acetylation in an ionic liquid, delivering a sustainable, cost-effective, and scalable solution for producing cellulose acetate with precise DS control in just one step.