Studies on Synergistic Effect of a-Zirconium Phosphate in Intumescent Flame Retarded Polypropylene Composites

Intumescent flame retardant polypropylene(PP)/organophilic α- zirconium phosphate (α-ZrP) composites are prepared by melt-blending process. TGA reviles that it has an increased charred residue compared with PP/IFR systems or pure PP. When the PP matrix contains 25% IFR, the LOI is 33 and UL-94 is V-1 rating. When the PP matrix contains 22.5% IFR and 2.5% α-ZrP, the LOI is 37 and UL-94 is V-0 rating. Combined with the analysis of charred residue of composites. α-ZrP is found to be a good synergistic agent in the PP/IFR flame retardant systems.