Full definition
An inorganic elastomer based on a silicon-oxygen polymer backbone (polysiloxane) that provides the widest useful temperature range of any commercial rubber: -60 to +230°C continuous (special grades to -100°C and +300°C). The Si-O bond is inherently more stable than the C-C bonds of organic rubbers, giving silicone exceptional thermal, oxidative, and UV resistance. Key properties: FDA and USP Class VI biocompatibility (non-toxic, odorless, tasteless), excellent ozone and weathering resistance (essentially permanent outdoor exposure), outstanding electrical insulation (dielectric strength 15-25 kV/mm), and low compression set at extreme temperatures. Limitations: lowest tensile strength among common elastomers (5-10 MPa), poorest abrasion resistance, attacked by steam and some hydrocarbon solvents, relatively high cost ($8-25/kg). ASTM D2000: FC/FE/GE. Applications: food-grade seals and gaskets, medical devices and implants, oven door gaskets, automotive spark plug boots, LED encapsulation, baby care products, and high-voltage insulators. Types: solid HCR (high consistency, compression/extrusion molded) and liquid LSR (two-component, injection molded).