Nonformaldehyde Flame Retardant Finishing of the Nomex/Cotton Blend Fabric Using a Hydroxy-Functional Organophosphorus Oligomer
Multifunctional carboxylic acids, such as 1,2,3,4-butanetetracarboxylic acid (BTCA), have been used as durable press finishing agents to produce wrinkle-resistant cotton. In our previous research, we used BTCA as a nonformaldehyde bonding agent in the flame retardant finishing system based on a hydroxy-functional organophosphorus oligomer (HFPO) for cotton. In this research, we investigate the application of HFPO to the 65%/35% Nomex/cotton blend fabric using BTCA as a bonding agent and triethanolamine (TEA) as a co-reactant. We found that the addition of TEA in the flame retardant finishing system improves the hydrolysis resistance of the HFPO bound to the Nomex/ cotton blend and enhances the flame retardant performance of HFPO by means of phosphorus—nitrogen synergism. Moreover, TEA reduces the deposit of calcium salt on the treated fabric during laundering by esterifying the free carboxylic acid groups on cotton. The Nomex/cotton blend fabric treated with the HFPO/BTCA/TEA system shows high flame retardant performance at relatively low add-on levels. It is a completely nonformaldehyde flame retardant finishing system.