Investigation of the Effect of Huntit Filler on Flame Retardancy and Mechanical Properties of Silicone Rubber-based Materials in Cable Applications

Silicone rubber is an organic/inorganic hybrid macromolecular polymer with properties such as fire resistance, strength, flexibility, chemical resistance, thermal stability, hydrophobicity, dielectric characteristics, resistance to environmental conditions, and biocompatibility. It is an elastomer and exhibits high-performance characteristics compared to most materials in its class. Its current properties and the relative ease of enhancing its characteristics have significantly increased the industrial utilization of silicone rubber. Due to its mineral structure, silicone rubber is frequently used as an insulating material to ensure circuit integrity in the production of fire-resistant cables. It exhibits low smoke zero halogen (LSZH) characteristics, with low level release of toxic gases as a result of combustion reactions. In this study, silicone rubber compounds including a natural mineral Huntite with improved fire-resistant properties compared to standard silicone materials suitable for cable production were prepared. After cable production the fire performance properties alongside the physico-mechanical characteristics of the final products were examined. To determine the flame retardancy of the material, limiting oxygen index (LOI%) and fire performance tests were performed according to the ISO 4589-2 and BS 6387 standards, respectively. The results show that Huntite is a suitable alternative material to improve silicone materials' flame resistance.