Improving flame-retardant efficiency by incorporation of fullerene in styrene-butadiene-styrene block copolymer/aluminum hydroxide composites

The effects of fullerene (C-60) and aluminum hydroxide (ATH)/C-60 combination on the thermal stability, flame retardancy and mechanical properties of styrene-butadiene-styrene block copolymer (SBS) were investigated. Adding small amount (0.5-2 mass%) of C-60 into SBS matrix raised the initial decomposition temperature of the composites slightly, while C-60 alone had little influence on the flame-retardant behavior. In SBS/ATH/C-60 system, however, the addition of C-60 significantly improved the UL-94 vertical combustion grade and limiting oxygen index. The total content of the flame retardant in SBS/ATH/C-60 system (56 mass%) was lower than that in SBS/ATH system (60 mass%) when UL-94 reached V0 level. Consequently, the adverse effects on the mechanical properties due to the high level of flame-retardant loading reduced. Meanwhile, the data obtained from cone calorimetric test indicated that C-60 can not only reduce the heat release rate, but also raise the char residue of SBS/ATH composites.