Dissolution behavior of arabinoxylan from sugarcane bagasse in tetrabutylammonium hydroxide aqueous solution

Arabinoxylan is one of the main components of xylan-rich hemicellulose of sugarcane bagasse. The study on the dissolution behavior of arabinoxylan from sugarcane bagasse (AXSB) is beneficial to its efficient utilization. The dissolution behavior of AXSB in a 50% TBAH aqueous solution was investigated by small angle X-ray scattering and rheological methods. SAXS analysis showed that the radius of gyration (R_g) of AXSB is between 8.5 nm and 21.6 nm, and R_g has a larger value with the rising AXSB concentration. Rheological measurements showed that AXSB is completely dissolved in TBAH aqueous solution at low concentration, aggregating after reaching a certain concentration. The estimated critical concentration is approximately 0.033 g mL^-1. The rheological curves at the high concentration indicated shear thinning behavior, causing the failure of the Cox-Merz rule. The storage modulus grows gradually with the increasing AXSB concentration, inferring the probable formation of AXSB aggregation in TBAH aqueous solution.