"Preparation and properties of condensed flame retardant ceramic silicone rubber"

Abstract

Flame retardant ceramic silicone rubber was prepared by dehydrogenation condensation using α,ω-hydroxy-terminated polysiloxane as matrix, and composite ceramic powder and fumed silica as fillers. The effects of the amount of composite ceramic powder, type of raw rubber side groups and ablation temperatures on the properties of the flame retardant ceramic silicone rubber were investigated. The results showed that the physical and mechanical properties of 107 silicone rubber containing side methyl group were almost the best when the amount of composite ceramic powder was 120 phr (mass), the tensile strength was 4.69 MPa, elongation at break was 686%, Shore A hardness was 48 and flexural strength was 12.29 MPa. Compared with 107 silicone rubber and 108 silicone rubber containing pendant phenyl group, the ceramic silicone rubber prepared from 109 silicone rubber containing pendant methyl vinyl group had better thermal stability, and the residual carbon mass fraction of composite up to 86% at 1 000 ℃. The ceramic silicone rubber from 109 silicone rubber had better flame retardancy, the limiting oxygen index was 49.5%, and the vertical combustion grade was V-0. In addition, it had a lower ceramization temperature and a good ceramization effect at 600 ℃.

Keywords

• silicone rubber， dehydrogenation condensation， ceramization， physical and mechanical property， flame retardancy，thermal stability，