Improving the mechanical and ceramifiable properties of low temperature prepared silicone rubber composites

Abstract

Silicone rubber has been widely used in electronic appliances, nuclear power cable, aerospace and so on, However, silicone rubber will continue to burn when exposed to flame, so flame retardant modification is required. In this work, aluminum hypophosphite (AHP) and Mica were used fluxing agent to make ceramizable silicone rubber material (CSR). The ceramization mechanism was investigated based on microstructure, mechanical and flame retardation properties. The scanning electron microscope result shows that the addition of AHP reduce the ceramization temperature effectively. AHP/Mica modified CSR have better flame retardation properties than pure silicone rubber, the addition of AHP increase LOI to 33.9%, and the LOI is 34.8% and the UL-94 is FV1 as 25 parts of Mica are added. When the 10 phr aluminum hypophosphite replaces Mica, the compression strength reach 14.46 MPa, increased by 42.5%. Moreover, the phenomenon of expansion into ceramics was founded and studied.

Keywords

• CSR
• fire-resistant
• silicone rubber
• ceramization
• expansion