Improving the Wrinkle Recovery of Wool/Cotton Blends by Simultaneous Treatment with Synthappret BAP and DMDHEU

Abstract

A simple pad-dry-cure procedure is described that significantly improves the dry (conditioned) wrinkle recovery of fabrics made from a range of intimate blends of wool and cotton. The method involves simultaneous application of a mixture of a cellulose crosslinking agent dimethyloldihydroxyethylene urea (DMDHEU) and the carbamoyl sulphonate-terminated poly (ether) urethane Synthappret BAP from pad liquors containing a nonionic surfactant. The latter is necessary to prevent precipitation of the magnesium salt formed from Synthappret BAP by the magnesium chloride catalyst used to crosslink cellulose with DMDHEU. The two reagents act, by different mechanisms, by improving the dry wrinkle recovery of only the cellulosic component of the fabric. DMDHEU acts by increasing the resilience of the cotton fibers and Synthappret BAP by reducing the frictional component of wrinkling that is due largely to the cotton in the blend. When applied simultaneously, the effects of the two reagents are additive. This permits higher levels of wrinkle recovery than are possible by treat ment with either compound alone, with only small accompanying adverse effects on abrasion resistance. A simultaneous treatment with low levels of the reagents also controls shrinkage in laundering and improves the wet wrinkle recovery properties of the wool/cotton fabrics.