A Solid-State Carbon-13 CP-MAS NMR Analysis of Carboxymethyl Cellulose Sodium Salt (CMC) Derived From Cotton and Other Sources

Abstract

Synthetic and commercial carboxymethyl cellulose (CMC) sodium salts were analyzed by CP-MAS ¹³C-NMR and plasma emission analysis. CMC was synthesized in the lab from cotton alkali cellulose and sodium chloroacetate. The progressive changes in the chemical composition and morphology (and reflected in the degree of substitution, DS) were followed by solid-state NMR. Observed differences in solid-state NMR spectra are discussed in terms of DS, chemical composition, dynamics, and polymorphism. The effect of molecular weight in CMC morphology and dynamics can be assessed by small differences observed in peak shapes and peak positions in the CP-MAS spectra.