Deriving 3-propanesulfonic-2-hydroxy substituents in the molecular chains for overcoming the drawbacks of oxidized cassava starch

The objective of this study was to improve paste stability, adhesion-to-fibers and film performances of oxidized cassava starch (OCS) for ameliorating end-use issues in various applications. For this purpose, a starch derivative with 3-propanesulfonic-2-hydroxy (PSH) substituents was prepared by an etherification of OCS with 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt. The etherified OCS (EOCS) granules were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy techniques. Viscosity stability was investigated by measuring the change of viscosity over a period of time. Adhesion was evaluated by a legal method (FZ/T 15001-2008). Film performances were also studied in terms of tensile strength, percentage elongation at break, flex-fatigue resistance and degree of crystallinity. The successful introduction of PSH substituents was not only able to improve the stability of OCS, enhance its bonding forces to cotton and polylactic acid (PLA) fibers, but was also capable of increasing the elongation and flex-fatigue resistance of the film and decreasing its tensile strength and degree of crystallinity, thereby obviously stabilizing paste viscosity, improving the adhesion and lessening film brittleness. With the increase in the etherification extent, the gradually increased stability and adhesion, and a reduced film brittleness were exhibited. The EOCS displayed potential in the applications of cotton and PLA sizing.