Rapid synthesis of cellulose triacetate from cotton cellulose and its effect on specific surface area and particle size distribution

Abstract

A highly rapid process is described for the preparation of cellulose triacetate and its effect on particle size and surface area of the product. The process involves microwave-assisted rapid synthesis of cellulose triacetate with very low amount of acetic anhydride (10–15% of acetic anhydride is used in conventional methods) in the presence of iodine as a catalyst using a designed reaction vessel. The technique used is simple and rapid; it is also characterized by a high conversion ratio (yield 100%). A small amount of iodine (115 and 230 mg, 1.15 and 2.3% of cellulose weight) was found to be effective in the production of cellulose triacetate using 25, 30 to 40 mL acetic anhydride for 10 g cellulose under microwave irradiation for 2–4 min. The production of cellulose triacetate and the degree of substitution were confirmed by FTIR, Raman, 1H NMR, and thermogravimetric analysis. The optimal reaction condition was discovered to be 3 min microwave radiation and 30 mL acetic anhydride in the presence of 230 mg iodine for 10 g cellulose. The effects of the amount of acetic anhydride, and amount of catalyst and reaction time on the specific surface area, pore volume, mean pore diameter, and particle size distribution were investigated. The highest surface area obtained was 39.63 m2/g. The specific surface area and particle size distribution are highly dependent on the amount of acetic anhydride and I2 catalyst. About 10% of the synthesized cellulose acetate showed particle size less than 200 nm.