Abstract: halloysites were introduced into PP/IFR composite containing ammonium polyphosphate (APP) and pentaerythritol (PER). Limiting oxygen index (LOI), cone calorimeter test (CCT) and thermal gravimetric analysis (TGA) were used to characterize the flammability and thermal behaviour of PP composites. The morphology of the char was observed and analyzed by scanning electron microscope (SEM). It has been found that there exists a synergism between IFR and halloysite in improving the fire performance of PP. The composite containing 2phr HNTs has a LOI value of 32%, UL-94 test can reach V0 level and heat release rate (HRR) can lower to 222kw/m2. SEM results show that 2phr HNTs is the optimal loading in the composites and can provide the best flame retradant result.

Key words: polypropylene, halloysite, non-halogen flame retardant