Flame Retardant Property of Sb2O3/SnO2 and their Synergism in Flexible PVC

Abstract

The use of tin dioxides, antimony trioxides, and their mixture as flame retardants for flexible PVC systems is considered as a means of enhancing the ability of flame retardancy. The flame retardant property of tin dioxides is studied through the limiting oxygen index (LOI) test, char yield, DTA–TG, SEM, and elemental analysis. The results show that tin dioxides, antimony trioxides, and their mixture are good flame retardants in flexible PVC and a small amount of them can enhance the LOI and the char yield greatly. SnO2 exerts its flame retardant role in the solid phase. The flame retardant role of SnO2 appears to be in the condensed phase. Moreover, SnO2 exhibits a marked flame retardant synergism with Sb2O3 in the flexible PVC flame retardant system.