Study of Different Operating Conditions during Carboxymethyl Chitosan Synthesis

Carboxymethyl chitosan (CMCh) was obtained under various conditions as a product of the etherification reaction between chitosan and monochloroacetic acid (MCA) in the presence of sodium hydroxide. Some variables used to synthesize carboxymethyl chitosan were of sodium hydroxide concentrations (10-50% w/v), etherification times (1-5hr), and temperatures (40-90oC). The psysicochemical properties of the carboxymethyl chitosan were characterized through the estimation of degree of substitution (DS), swelling and solubility test, and FTIR analysis. There was an optimum condition for each variable based on the obtained highest DS, swelling degree and solubility. The highest value of DS being obtained when the carboxylation reaction conditions were performed at concentration of NaOH 30% (w/v), carboxymethylation time for 3 hours and carboxymethylation temperature at 60°C. Carboxymethyl chitosan (CMCh) has strong FTIR adsorption of carboxyl group in 1593.67 cm-1 and 1320.8 cm-