Formaldehyde free binding system for flame retardant finishing of cotton fabrics

The promising application of citric acid (CA) and 1,2,3,4-butanetetracarboxylic acid (BTCA) for the purpose of flame retardant (FR) finishing was investigated. Both polycarboxylic acids (PCAs) were applied as an environmentally friendly binder in a reaction with N-hydroxymethyl-3-dimethylphosphonpropionamide. The results were compared with a conventional agent based on melamine formaldehyde. The purpose of melamine resin is to provide nitrogen in order to enhance the flame retarding performance of the treated fabric through synergism with phosphorus. In our previous investigations it was determined that the best catalyst to be used with PCAs is sodium hypophosphite monohydrate (SHP). The FR effectiveness was tested according to the ISO 6940 method, as well as with the limiting oxygen index (LOI) technique according to ASTM D 2863-97. Moreover, the thermal degradation of raw cotton and FR treated cotton fabrics was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).