High Swelling Carboxymethyl Cellulose Synthesized from Coconut Fibers

To attain the zero waste and green chemistry goals, much emphasis has shifted toward the use of cellulose derived from agricultural biomass. In this study, carboxymethylation of microcrystalline cellulose from coconut fiber by use of monochloroacetic acid in the presence of an alcohol medium under alkaline conditions was suitable for the synthesis of carboxymethyl cellulose. The carboxymethyl cellulose was prepared, and the physical properties, degree of substitution, swelling capacity, and characterization were investigated. The results indicated that the yield of carboxymethyl cellulose, degree of substitution, and swelling capacity were 9.45 ± 0.76 g, 1.82 ± 0.12, and 11.23 ± 0.28 g, respectively. The Fourier Transform Infrared spectra of carboxymethyl cellulose displayed a broad OH peak at 3352 cm−1 and a sharp peak at 1600 cm−1 attributed to -COO. Thermal behavior was investigated by Thermal gravimetric analysis, and the phase transition was determined by Differential Scanning Calorimetry, which revealed that alkalization and esterification of cellulose lead to a decrease in the thermal stability of the polymer. In conclusion, zero waste can be achieved in the coconut industry as it is rich in cellulose that can be converted to carboxymethyl cellulose, which can be utilized to produce emulsifiers and superabsorbent polymers.