Silicone is chemically known as polydimethylsiloxane (PDMS) and consists of an Si-O-Si backbone. The Si-O bond has higher bond strength than the C-C bond found in carbon-based polymers, such as polyethylene and polypropylene. As a result, silicone can withstand higher temperatures. It also doesn’t absorb as much energy at the wavelengths typically found in UV as well as gamma irradiation, so it is weathers well and is well suited for medical applications that require gamma sterilization. It is also considered to be very chemically inert. Its Si-O-Si bond has wide angle and little energy is needed to rotate, so silicone polymers are very flexible even at low temperature such as -50°C.
Silicone elastomers are typically filled with inorganic fillers, such as silica or carbon black, to enhance the mechanical properties as well as reduce some costs. Silicone can be cured by addition chemistry (eg. Platinum catalyst), free radical (Peroxide cured system) or condensation cure. Since it was first commercialization in 1940s silicone has found a number of applications in medical devices, implants, biopharmaceutical manufacturing, transportation, aerospace, construction, electronics, as well as other industries due to its performance.