Study on Flame Retardancy of Halogen-free Retardants Retarded High Impact Polystyrene

Masterbatch of micro-capsulated red phosphorus(MRP) and polyphenylene oxide(PPO) were compounded forming a flame retardant,which was applied in high impact polystyrene(PS-HI) via melt blending.The flame retardant effect was studied through oxygen index,vertical burning test,and thermal gravimetric analysis.Residue collected during thermal gravimetric analysis was characterized by Fourier transform infrared spectroscopy.It was revealed that with the incorporation of the compound flame retardant,when the contents of MRP and PPO were 10 % and 18 %,respectively,PS-HI displayed an oxygen index of 34 % and a vertical burning level of FV-0(1.5 mm).There was a synergetic effect between MRP and PPO,and the flame retardant acted mainly in the condensed phase.