Hydroxyethyl starch with high surface activity via ethylene carbonate functionalization

Abstract

Biosurfactants‐hydroxyethyl starches (HES‐EC) with the total degree of substitution (DSt) of 26, 37, and 46% are prepared via ethylene carbonate functionalization. GC–MS semi‐quantitative analysis results show that monosubstituents, especially, C‐2 monosubstituents are predominant in all substituents. A small amount of disubstituents with O(CH2CH2O)2H group per polyethylene chain exist in HES‐EC. The structural characteristics of HES‐EC demonstrate that hydroxyethyl groups distribute more uniformly on starch main chains as compared with corresponding HES‐EO. The even distribution of hydroxyethyl groups further promotes the formation of the hydrophilic–hydrophobic structure inside HES‐EC. HES‐EC exhibits lower surface tension and more notable emulsion ability than HES‐EO and traditional petroleum‐based surfactant NP‐10. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48807.