Synthesis, characterization, and application of carboxymethyl cellulose from asparagus stalk end

Abstract

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Cellulose from Asparagus officinalis stalk end was extracted and synthesized to carboxymethyl cellulose (CMCas ) using monochloroacetic acid (MCA) via carboxymethylation reaction with various sodium hydroxide (NaOH) concentrations starting from 20% to 60%. The cellulose and CMCas were characterized by the physical properties, Fourier Transform Infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). In ad-dition, mechanical properties of CMCas films were also investigated. The optimum condition for producing CMCas was found to be 30% of NaOH concentration for the carboxymethylation reaction, which provided the highest percent yield of CMCas at 44.04% with the highest degree of substitution (DS) at 0.98. The melting point of CMCas decreased with increasing NaOH concentrations. Crys-tallinity of CMCas was significantly deformed (p < 0.05) after synthesis at a high concentration. The L* value of the CMCas was significantly lower at a high NaOH concentration compared to the cellulose. The highest tensile strength (44.59 MPa) was found in CMCas film synthesized with 40% of NaOH concentration and the highest percent elongation at break (24.99%) was obtained in CMCas film treated with 30% of NaOH concentration. The applications of asparagus stalk end are as biomaterials in drug delivery system, tissue engineering, coating, and food packaging.