Influence of hydroxypropylsulfonation on adhesion-to-fibers and film properties of corn starch

The objective of this work was to investigate the influence of hydroxypropylsulfonation on the adhesion-to-fibers and film properties of starch for improving its end-use ability in warp sizing. A series of hydroxypropylsulfonated corn starch (HPSS) with different degrees of substitution (DS) were synthesized by the reaction of granular corn starch with 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na) in an alkaline aqueous medium. The adhesion was accessed by determining the tensile force of starch to cotton fibers according to a standard method (FZ/T 15001-2008), while film properties were estimated in terms of breaking elongation, tensile strength, degree of crystallinity, and moisture regain. In addition, desizability of HPSS was also evaluated by measuring the time interval required to break the film in water. The estimation was undertaken through the comparison of HPSS with ACS. Compared with ACS, HPSS exhibited stronger tensile force, higher breaking elongation and moisture regain of the film, and lower tensile strength, degree of crystallinity and time required to break the film in water. Therefore, hydroxypropylsulfonation was able to improve the adhesion, reduce film brittleness, and enhance the desizability. The increase in the hydroxypropylsulfonation level favored the increase in adhesion, reduction of film brittleness, and enhancement in desizability. Based on the results, HPSS prepared with a DS range of 0.03 similar to 0.041 showed the potential for the application of sizing cotton warp yarns.