Synthesis of novel phosphite flame retardant and its use for formaldehyde free durable finish

Novel flame retardant of penthaerythritol phosphite was synthesized from pentaerythritol and triphenyl phosphite.Cellulose fabric was finished by the flame retardant using toluene-2,4-diisocyanate(TDI) as crosslinking agent.Chemical structures of the flame retardant agent and the treated cotton fabric were analyzed by the IR spectrum.Flammability of the finished cellulose fabric was tested by vertical flammability tester and limiting oxygen index(LOI) test apparatus.The results indicate that the flame retardant can bond with cellulose by crosslinking agent.LOI of the flame retardant treated cotton fabric still reach 27.8% after 12 washing cycles,having formaldehyde free and durable flame retardant properties.