Monophosphorylation of Acid‐thinned Starch to Enhance the Quality of Viscose Yarns Sized at Reduced Temperature

Abstract

AbstractAcid‐thinned cornstarch was monophosphorylated by reaction with orthophosphates to obtain an agent for sizing heat‐sensitive viscose warp yarns under reduced temperature. Influences of the modification and sizing temperature on paste behavior, adhesion to viscose fibers, and properties of sized viscose yarns were studied for a range of substitution of 0.021–0.082 and temperatures from 60°C to 95°C. The modification resulted in an increase in viscosity stability of the starch paste, enhancement of the adhesion to the viscose fibers, improvement of mechanical properties of the sized viscose yarns, and a decrease in hairiness of sized yarns even if the temperature of the starch paste was lowered to 60°C. The modification is capable of improving the sizing properties of starch for viscose yarns at 60–80°C when the degree of substitution with phosphate groups is about 0.05.