Chemical resistance silicones
With regards to the effects of solvents and industrial chemicals on silicone rubber, the following data has been complied: Silicones are chemically inert and are attacked by very few common materials. Among them are concentrated sulphuric acid, hydrofluoric acid and, after long term exposure, high pressure steam. Like any elastomer, silicone has a tendency to physically absorb those materials with a solubility parameter near its own. This absorption may cause the rubber to swell and to soften slightly. In a few applications, this volume increase is advantageous. For example, a silicone rubber gasket exposed to certain solvents will swell to form a tighter seal. The change undergone by silicone rubber in contact with an absorbed solvent is primarily physical. After the solvent has completely evaporated, the silicone rubber will return to its original physical properties.