Flame retardant polyurethanes based on novel phosphonamidate additives

Development of new halogen-free flame retardants for application in polymer is becoming important due to ban of some existing halogenated flame retardants, ineffectiveness of existing flame retardant additives and higher fire performance requirements for materials. Polyurethane is an important class of polymer finding application in diverse areas like textile coatings, wood coatings, foams, fibers, cables, adhesives etc. There is a great need to develop halogen free flame retardants for various PU based materials. In this work we have reported synthesis of novel phosphonamidates as flame retardant additives and their application in manufacturing flame retardant flexible PU foams and flame retardant polyester PU coated fabrics. Furthermore the flame retardant properties and thermal decomposition characteristics of the PU based materials have been evaluated. The novel phosphonamidate derivatives have superior fire performance properties as compared to existing commercial flame retardant additives and work primarily in gas phase by recombining H* and OH* radicals.