Preparation and properties of condensed silicone rubber fireproof foam for power plugging

The effects of the viscosity and content of vinyl silicone oil and fireproof fillers with different shape on the cell structure and fire resistance of condensed silicone rubber foam materials were stu-died. The foaming rate and crosslinking rate of silicone rubber foam during the foaming process was characterized by the rubber processing analyzer. At the same time, the effects of the shape of aluminum hydroxide, mica and wollastonite on the fire resistance of silicone rubber foam were also investigated. The results showed when no vinyl silicone oil was added, storage modulus of silicone rubber foam whose cell structure of was mainly closed was lower. The addition of vinyl silicone oil increased the crosslinking rate and storage modulus of silicone rubber foam, and caused easily more open cell structures, and also had an impact on the cell size distribution of silicone rubber foam. The addition of lamellar mica was likely to result in the collapse and rupture of cell. However, the integrity of the cell structure and the ablation surface were well maintained after the flame ablation, and the complete ceramic barrier layer could play a good role in the fire prevention. In the other hand, silicone rubber foam materials with aluminum hydroxide and wollastonite were seriously cracked after the flame ablation.