Treatment of Wool Fabrics with Potassium Cyanide in Organic Solvent-Water Mixtures

Abstract

Wool fabrics were treated with 0.08M KCN in water, a 1:3 (v/v) mixture of acetone and water or a 1:3 (v/v) mixture of 2-propanol and water at 50 or 80°C. The wool fabrics were shrunk in two stages (at the KCN treatment and at air-drying) and the thickness of the fabrics was increased by the treatment in mixed solvent systems but the air permeability of the treated fabrics was increased because pin holes were formed at the interseptions of the warp and filling yarns. Scanning electron microscopic observations of the fabrics treated in mixed solvent systems showed that the cross sections of the fibers were much deformed and sometimes fibers adhered each other. Deep longitudinal striations were found at the surfaces of the fibers. Experiments with single wool fibers showed that the bilateral distribution of ortho-and paracortical cells was reversed in relation to the crimps of the fibers by the treatment: orthocortical cells located on the outer side of the crimps before the treatment were located on the inner side after the treatment, and the striations were preferentially distributed on the orthocortical side of the crimps. The changes in the structures of fabrics, yarns and fibers were the most significant when treated with KCN in aqueous 2-propanol in which both hydrophilic and hydrophobic bonds in wool were cleaved the most effectively so that wool fibers swelled the most in this system.