Study on flame retardancy and thermal stability of rigid polyurethane foams modified by amino trimethylphosphonate cobalt and expandable graphite

Abstract Amino trimethylphosphonate cobalt (Co 2+ -ATMP) flame retardant was prepared by ion exchange method, and rigid polyurethane foam (RPUF) modified by Co 2+ -ATMP and expandable graphite (EG) was prepared by one-pot and free-rise method. The flame retardancy, thermal stability and smoke toxicity of modified RPUF were studied by limiting oxygen index (LOI), cone calorimeter (Cone), thermogravimetric analysis (TG) and smoke toxicity characterization. The results showed that the flame retardancy, thermal stability and smoke toxicity of RPUF modified by Co 2+ -ATMP and EG are significantly improved. When the ratio of Co 2+ -ATMP to EG is 1:5, the LOI value is the highest, and the toxicity of flue gas was the lowest. The peak heat release rate (PHRR) and total heat release rate (THR) were both the lowest, 138 kW/m 2 and 15.9 MJ/m 2 , respectively. Compared with RPUF-0, it decreased by 39.2% and 16.8% respectively. The research results can provide reference for the subsequent flame retardant modification of RPUF.