Physically, silicones are based on silicon, an element derived from quartz. To create this class of synthetic elastomers, pendant organic groups such as methyl, phenyl and vinyl are attached to silicon atoms. The different addition of side chains can achieve significant variations in properties. Silicones have excellent heat, ozone and corona resistance, very well dielectric stability, and resistance to many oils, chemicals, and solvents. And for all elastomers, silicones possess the best flexible property at low temperature. But it also have some weakness like low tensile strength, poor tear and wear resistance.
For Silicones the service temperature are from -60℃ to 225℃. Some special types can be used in extreme temperature up to 300℃ and down to -100℃.