Abstract: Thermal stability and thermal degradation kinetics of polypropylene(PP) and flame retardant polypropylene (IFR/PP) were investigated by a conventional dynamic thermogravimetric analysis(TG) under highly purity N2 atmosphere at different heating rates between 15 and 35 ℃/min-1and the flame retardant of PPand IFR/PP were studied by limiting oxygen index (LOI) and Cone method. The thermal degradation activation energyof PP and IFR/PP were determined by using Kissinger and Flynn-Wall-Ozawa method. The thermal degradation kinetic mechanism and the isothermal kinetic equations of PP and IFR/PP were determined by Coast-Redfern method. The flame retardant of PP by the addition of IFR was improved, and thermal stability of IFR/PP was lower than that of PP because the IFR degradated in advance, The thermal decomposition mechanism of PP and IFR/PP was random nucleation reaction and the kinetic equation can be expressed as g(α)=-ln(1-α), and the reaction order was n=1.

Key words: polypropylene, intumescent flame retardance, thermal degradation, kinetic, flame retardant mechanis