HIS WORK is a continuation of the previous works by the authors to increase the efficiency of ammonium polyphosphate (APP) as flame retardant for polypropylene(PP).In this work a more abundant kaolin was used.Also to improve the efficiency of kaolin, an acid modification by sulfuric acid was used.XRD, XRF, IR, SEM and BET were used to characterization the samples.TGA and DTA were used to evaluate ...