Flame Retardancy of the Oxystarch/Ammonium Polyphosphate Synergetic System on Polypropylene
Oxystarch(OS)was used as a carbonizing agent and introduced into the ammonium polyphosphate(APP)flame retardant system to enhance the fire safety performance of polypropylene(PP).Cone calorimetry tests show that the introduction of OS can effectively enhance the flame retardant efficiency of the APP flame retardant system and inhibit the release of heat,smoke and harmful gases during the combustion process of PP composites.The investigation of the flame retardant mechanism indicates that the introduction of OS effectively improves the generation of char residues and the formation of a higher quality char layer with the increase of OS addition.The high quality char layer effectively isolates the transmission of combustible gases and oxygen to protect the internal matrix.