Generally speaking, silicone rubber has excellent resistance to chemicals, solvents and oils. The main effects of solvents on silicone rubber are expansion and softening. Once the solvents evaporate, most of the original properties of silicone rubber will be restored. Silicone rubber has good resistance to polar solvents such as ethanol and acetone, as well as edible oils, etc. They generally cause very little expansion, while the mechanical properties remain basically unchanged.
Silicone rubber also has a relatively good resistance to the action of low concentrations of acids, alkalis and salts. For instance, when immersed in 10% sulfuric acid at room temperature for 7 days, its volume and weight changes are less than 1%, while its mechanical properties remain basically unchanged. However, it is not resistant to concentrated acids, concentrated alkalis, and non-polar solvents such as carbon tetrachloride and toluene. To enhance the solvent resistance of silicone rubber, some methyl groups on the silicon atoms can be replaced with trifluoropropyl or cyanoethyl groups.
Silicone rubber has excellent resistance to oxygen, ozone and ultraviolet radiation, etc. Therefore, it will not crack when used outdoors for a long time. It is generally believed that silicone rubber can be used outdoors for more than 20 years.