Facile Preparation and Properties of Ionic-Bonded Hydrophobically Associating Anionic Sesbania Gum

We prepared a novel ionic-bonded hydrophobically associating anionic sesbania gum (IHASG) via a simple blending method. The effects of different variables on the viscosity and non-Newtonian behavior of this system were investigated. Upon increasing the degree of substitution, the apparent viscosity increased, and a stronger non-Newtonian viscosity was observed compared to that of standard anionic sesbania gum. The apparent viscosity was enhanced upon increasing the IHASG concentration, and small quantity of NaCl enhanced the solution polarity, leading to stronger intermolecular associations. The maximum viscosity appeared at pH 6–7, while increased temperatures enhanced the hydrophobic association effects and improved the heat resistance of the IHASG solutions. The viscosity of cross-linked IHASG increased upon increasing the B(OH)3 content and well-ordered multi-layered structures were formed. IHASG therefore exhibited superior associating properties like normal hydrophobically associating polysaccharides, and so exhibit potential for various applications due to the simple blending method employed.