Synthesis and characterization of sodium carboxymethylcellulose from cavendish banana pseudo stem (Musa cavendishii LAMBERT)

Banana pseudo stem has been known as a potential cellulose source, though usually discarded as agricultural waste in Indonesia. This work reports concisely on a method to utilize cavendish banana pseudo stem for preparing sodium carboxymethylcellulose (CMC) and its characteristics. The banana pseudo stem was obtained shortly after the mature fruit had been harvested. The pseudo stem was dried, ground to pass 20 mesh screen. The powder was extracted using 8% NaOH at 100 °C for 3.5 h, and then bleached using 5% NaOCl at 30 °C for 3 h. The cellulose was alkalized using NaOH at 5–30% at 25 °C for 1 h. Sodium Monochloracetate (ClCH2COONa, NaMCA) at 3–7 g per 5 g cellulose was added to the slurry and the temperature was adjusted to 55 °C for 3 h. Alkalization using 15% NaOH and etherification using 1.2 g (w/w) NaMCA gave CMC the highest degree of substitution (DS), viscosity, purity and crystallinity, i.e. 0.75; 4033 cps; 98.23 and 38.33% respectively.