Silicone Chemistry Overview

By analogy with ketones, the name silicone was given in 1901 by Kipping to describe new compounds of the generic formula R2SiO. These were rapidly identified as being polymeric and actually corresponding to polydialkylsiloxanes, with the formulation: The name silicone was adopted by the industry and most of the time refers to polymers where R = Me (polydimethylsiloxane). The methyls along the chain can be substituted by many other groups, e.g., phenyl, vinyl or trifluoropropyl. The simultaneous presence of “organic ” groups attached to an “inorganic ” backbone gives silicones a combination of unique properties and allows their use in fields as different as aerospace (low and high temperature flexibility), electronics (high electrical resistance), medical (excellent bio-compatibility) and construction (resistance to weathering). The principal steps in the development of silicone chemistry are1,2: • The discovery of silicon by Berzelius in 1824 from the reduction of potassium fluorosilicate with potassium: 4 K + K2SiF6 → Si + 6 KF Reacting silicon with chlorine gave a volatile compound later identified a