The Liquid Ammonia Treatment of Cotton Fibers-Structural Changes of Cotton Fibers after Liquid Ammonia and Hot Water Treatment-

Abstract

Five kinds of cotton fabrics were treated using a practical liquid ammonia unit and consequently treated with hot water at 70°C or 130°C for two hours. The lattice type, the washing shrinkage, the water retention, the moisture absorbency, the dry and wet crease recovery angle and the bending repulsion were measured. Five data items for each measurement were averaged and analyzed. Due to the hot water treatment after liquid ammonia treatment, the dry crease recovery angle and the bending repulsion were decreased; on the other hand, the water retention, the wet crease recovery angle and the moisture absorbency were increased. These changes represent a rearrangement of the hydrogen bonding from a non-swollen state to a swollen state and stabilization of the fiber shape in the swollen state. Through this stabilization, a decrease in the washing shrinkage is thought to occur. The changes of the lattice type by the hot water treatment occurred a little at 70°C and occurred largely at 130°C. On the other hand, the washing shrinkage and other physical properties changed largely at 70°C. These results suggest that the decrease of washing shrinkage and the changes in the other properties depend mainly on the changes in the amorphous region.