Flame Retarding of Polymers with Sulfamates. I. Sulfation of Cotton and Wool

Some results of work carried out on flame retarding of cotton and wool fabrics are reviewed.* Cotton fabrics are rendered flame retardant upon treatment with ammonium sulfamate (AS) with urea or a urea-based cross linking agent, as co-additive, in the pad-dry-cure finishing treatment, with curing at 180-200°C for one to three minutes. Wool fabrics are similarly treated with sul famic acid (SA) in the presence of urea at 140-160°C. In both cases a very high de gree of flame retardancy is obtained and the treated fabrics pass the vertical strip test (VST) also after fifty hard water alkaline launderings. In both cases, the fab rics retain their soft hand. In order to overcome the afterglow in cotton, a com bined sulfation-phosphorylation process was developed.