Thermal Stability, Combustion Behavior, and Toxic Gases in Fire Effluents of an Intumescent Flame-Retarded Polypropylene System

Flame-retarded polypropylene (FRPP) was prepared with pentaerythritol and melamine phosphate as flame retardant, organic montmorillonite (OMMT) as synergistic agent, and PP by reactive extrusion. TGA testing indicated that the T onset temperatures of FRPPs are lower than that of pure PP; however, the T max temperatures of FRPPs are higher than that of pure PP. The LOI and UL-94 tests indicate that the flame retardancy of FRPPs could be enhanced obviously with a low dosage of OMMT. The cone calorimeter coupled with online FTIR test shows that the loading of intumescent flame retardant (IFR) significantly reduces the heat release rate, smoke production rate, total heat release, total smoke production, mass loss rate, and toxic gases in fire effluents of the FRPPs, and the low dosage of OMMT in FRPPs further reduces the above corresponding values. Moreover, the addition of OMMT could decrease the production of HCN and NO x in fire effluents of FRPPs.