Effect of Halloysite on Flame Retardancy Intumescent Flame Retardant Modified Polypropylene

Halloysites were introduced into PP/IFR composites containing ammonium polyphosphate(APP) and pentaerythritol(PER).Limiting oxygen index,cone calorimeter test(CCT),and thermal gravimetric analysis(TGA) were carried out to characterize the flammability and thermal behavior of PP composites.The morphology of the char was observed and analyzed by scanning electron microscope(SEM).It was found that there existed a synergism between IFR and halloysite in improving the fire performance of PP.The composite containing 2 phr HNTs had a limiting oxygen index of 32 %,the UL-94 grade reached V0 level and heat release rate(HRR) reduced to 222 kw/m2.HNTs of 2 phr was the optimal loading in the composites and could provide the best flame retardant result.