Reaction of Cellulosic Fabrics to Air Contaminated with Sulfur Dioxide

Fabrics made from cotton, viscose rayon, or high-wet-modulus rayon were exposed to air or to air containing 0.1 ppm sulfur dioxide and simultaneously to light from a xenon arc lamp. The presence of sulfur dioxide caused an additional loss in the breaking strength of yarn taken from the cotton and regenerated cellulose fabrics, compared to the loss in light and air alone. The chemical modifications that occurred in the fabrics were followed by measuring copper numbers, carboxyl contents, and fluidities. The changes that were observed were compared to similar samples degraded by hy drolysis in dilute sulfuric acid. In a set of preliminary experiments, fabric made from cotton containing a durable-press finish was also exposed to the same conditions as the cotton and regenerated cellulose materials. There was no loss in strength of yarn from the resin- treated fabric, when exposed to light plus air or to light plus air containing sulfur dioxide. In fact, exposure to light and air caused a significant increase in breaking load.