Synthesis and nondestructive detailed structure characterization of carboxymethyl xylan from bagasse

Carboxymethyl xylan (CMX) was synthesized and characterized. A method based on quantitative 13C NMR was developed to obtain detailed structural information. The total degree of substitution (DS), partial DS at 2- and 3-O-positions, and the quantitation of each unit in CMX could be acquired simultaneously by this method without decomposing the polymer backbone, thus avoiding errors caused by polymer hydrolysis with traditional methods using HPLC and 1H NMR spectrometry. Moreover, different from methods of direct detection of carboxyl groups, such as acidometric and potentiometric titrations, this method was not affected by probable impurity introduced during carboxymethylation.