Flame retardant cotton

Abstract

The water-soluble organophosphorus compound, namely, hexahydroxymethylamidocyclotriphosphatriazatriene (HHMAPT) was synthesized by reacting phosphonitrile chloride with liquid ammonia followed by reaction with formaldehyde. It is rich in phosphorus and nitrogen and as a polyfunctional compound it can undergo several reactions with itself forming an in situ polymer or with cotton cellulose similar to conventional N-methylol finishing agents. It was successfully used as a flame retarding agent in the absence and presence of etherified methylolated melamine (EMM). Investigations into the different factors that affect these reactions and the effect of these on the properties of the finished fabrics give rise to the following points; (1) P%, N% and crease recovery increase by increasing the curing time and temperature; (2) the most effective catalyst is NH4Cl; P% and N% increase by increasing the concentration of NH4Cl from 5 to 12.5 g/l (3) an increase in EMM and HHMAPT concentrations is accompanied by enhancement in P%, N% and crease recovery; (4) the fabric samples exhibit durable flame retardancy at temperatures higher than 120°C in the absence of EMM while in the presence of EMM, all samples exhibit durable flame retardancy properties, regardless of the temperature of curing; (5) the durable flame retardancy is achieved at concentrations higher than 60 g/l HHMAPT and 7.5 g/NH4Cl. All samples exhibit loss in tensile properties but within an acceptable range (20%), crease recovery is improved in all samples. Copyright © 1999 John Wiley & Sons, Ltd.