Study on Flame Retardance of Co-microencapsulated Ammonium Polyphosphate and Pentaerythritol in Polypropylene

Co-microencapsulated ammonium polyphosphate and pentaerythritol [M(A&P)] was prepared using a hydroxyl silicone oil by in situ polymerization method, and characterized by X-ray photoelectron spectroscopy. The flame-retardant effect of M(A&P) in polypropylene (PP) is evaluated using limiting oxygen index, UL 94 test, cone calorimeter test, and thermo-gravimetric analysis. The flame-retardant properties of the PP/M(A&P) composites are much better than those of the PP/ammonium polyphosphate/pentaerythritol composites. Moreover, the thermal stability and the water resistance properties of the PP/M(A&P) composites are improved compared with the PP/APP/PER composites.