Because of the silicon-oxygen backbone, silicone rubber is resistant to sunlight, heat and is
flexible over a wide range of temperatures. But, unlike the EPR backbone, the silicon-oxygen
bond is susceptible to heterolytic cleavage, i.e., attack by acids and bases [15]. Silicone rubber
has low physical properties compared to EPR based materials [16]. Silicone rubber is a hydrophobic
material (repels water). This is due to the organic groups attached to the silicon atom. Silicone
rubber is also over 10 times more permeable to moisture than EP rubber.