Spectral analysis of the chemical structure of carboxymethylated cellulose produced by green synthesis from coir fibre

Abstract

In this work, CMC was synthesized from cellulose obtained from coir fibres. The obtained CMC yield was about 64.0%. The Degree of Substitution value obtained was 0.44. The spectral pattern and thermogravimetric analysis of the synthesized CMC and cellulose were evaluated using FT-IR, XRD, and TGA/DTG. Characterization of the cellulose and CMC revealed their high crystallinity with cellulose showing a lower crystallinity value due to its lignin content. The CMC also showed a higher degree of crystallinity (56.93%) and hydrogen bonding compared to some earlier literature reports for CMC. The DTG curve revealed that the CMC had a maximum rate of degradation at about 310 °C. The FT-IR spectra of the obtained CMC showed a finger print region characteristic of CMC (1590 cm-1). This work shows that the spectral characteristic and crystallinity of CMC can be related to the synthetic method applied in obtaining the cellulose prior to CMC synthesis.