Physicochemical and rheological properties of hydrophobically modified starch by octenyl succinic anhydride (OSA) have been evaluated in order to investigate the effects of concentration and temperature on its aggregation phenomenon in an aqueous solution. The analysis of particle size distribution showed the existence of two modes of aggregation by intramolecular bonds, whereas beyond the critical aggregation concentration a second population appears which seems to be induced by the intermolecular interactions. From the rheological analysis of OSA starch solutions, three behaviour classes were observed. The first class presents a non-Newtonian shear-thinning behavior characterized by two Newtonian regions. The second class exhibits a gel like behavior due to the entanglement of the macromolecular chains by intermolecular bonds, where its destructuring makes it possible to find the first morphology of the aggregated macromolecules. The third class exhibits a liquid behavior in a concentrated domain due to the phase separation between the modified and unmodified parts. Otherwise, the thermo-rheological analysis demonstrated indeed the presence of a thermosensitive behavior in tangled solutions of OSA starch.
Simple emulsions (o/w) stabilized by octenyl succinic anhydrous (OSA) starch were studied. They were characterized by the evaluation of the rheological and physicochemical properties and, the observation under the light microscope in combination with granulometric analysis after formulation. The obtained results demonstrated the effects of the amount of OSA starch on the variation of the diameter of particles, stability of emulsions and their rheological behavior. The best characteristics were found in the emulsion with a ratio 40/60 (o/w) at high OSA starch concentration, because the substitution of the oil phase by the network created by the chains of the modified polysaccharides which could be the major factor in stabilisation of emulsions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.