Optimization of Reaction Conditions for Preparation of Carboxymethyl Cellulose from Sugarcane Bagasse

Carboxy methyl cellulose is a water-soluble polymer that is used in various industries. There are various sources for carboxy methyl cellulose one of them is bagasse. Sugarcane bagasse is composed of cellulose, hemicellulose, and lignin. Since 30-40% of this fibrous residue contains cellulose, it can be used as a source of cellulose for the preparation of carboxymethyl cellulose. In this project hemicellulose and lignin were separated from bagasse by diluted acid and sodium hydroxide solution and cellulose were extracted. The results showed that dilute sulfuric acid removed more hemicellulose than dilute nitric acid in the acid treatment stage. In order to separate cellulose completely, various concentrations of sulfuric acid and sodium hydroxide were used at different reaction times. The normalized areas under the characteristic peaks of FT-IR spectra of the samples were calculated by Origin software and the sample with the highest yield of extracted cellulose was selected. In the next stage, the extracted cellulose was used to prepare carboxymethyl cellulose. Response Surface Methodology (RSM) with Box-Behnken Design (BBD), was used to achieve the highest degree of substitution of carboxymethyl cellulose. The independent variables were reaction temperature, the concentration of sodium hydroxide solution, and the amount of sodium mono-chloroacetate per gram of cellulose. The highest degree of substitution was 0.66 while the calculated satisfaction factor was 97.14 percent, which shows good correspondence with the experimental data. Viscosity and molecular weight for the solution of 2% carboxymethyl cellulose in water with 0.66 degrees of substitution were 24.8 cp and 261000 grams per mole respectively which has been used in detergent materials.