Effects of Hollow CeO2 Nanospheres on Flame Retardance and Smoke Suppression of Room-Temperature-Vulcanized Silicone Rubber

The effects of hollow CeO2 nanospheres on the flame-retardance and smoke-suppression properties of room-temperature-vulcanized (RTV) silicone rubber were studied. It was observed that the flame retardance of RTV silicone rubber composites was improved by hollow CeO2 nanospheres. Surprisingly, the nanospheres also enhanced the smoke-suppression characteristics of the composites. The limited oxygen index of RTV/Mg(OH)(2) was raised from 23.7 to 25.9 by the addition of hollow CeO2 nanospheres, while the smoke density was reduced markedly, from 35.1 to 17.6. The thermal stability and char yield of the RTV silicone rubber composites were characterized by thermogravimetric techniques. Furthermore, the degradation product of the composites was analyzed by pyrolysis-gas chromatography-mass spectroscopy. A mechanism to explain the observed results is proposed.