Structure and rheological characterization of konjac glucomannan octenyl succinate (KGOS)

Konjac glucomannan octenyl succinate (KGOS) has excellent emulsifying and thickening properties as a new polymeric surfactant. The reaction extent of KGOS was determined by using high-performance liquid chromatography. The molecular aggregation state of KGOS was observed and analyzed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results showed that KGOS aggregated particles formed irregular spheres or ellipsoids, and the average particle diameter and height were approximately 30 nm and 5 nm, respectively. Thermal analysis indicated that the carbonization temperature of KGOS is slightly lower than that of konjac glucomannan (KGM). The steady shear rheology showed that KGOS solution fit to non-Newtonian fluid properties and the Carreau model, and the apparent viscosity increased with increase of KGOS concentration. The type and valence of the ions affected the apparent viscosity of KGOS solution. The trends of the dynamic mechanical spectra indicated KGOS solution could be an entanglement system. The ions had a similar effect on the dynamic modulus (G', G '') and loss factor tan delta except for Fe3+ and H2PO4- . (C) 2017 Elsevier Ltd. All rights reserved.