Siloxanes
Siloxanes
Siloxanes are a class of compounds containing alternate silicon and oxygen atoms arranged either linearly or in a cyclic manner, with SiûOûSi linkage. The word siloxane is derived from the words silicon, oxygen and alkane. The parent siloxanes include oligomeric and polymeric hydrides, while their alkyl analogues are known extensively. Siloxanes have gained considerable recognition among researchers, largely due to their ease of synthesis coupled with their valuable properties. For instance, polysiloxanes that are prepared from siloxanes are chemically inert as they are stable towards water and oxidation, at both high and low temperatures. This stability is achieved through a strong Si-O bond, which makes them an attractive material for applications that are wide-ranging, from lubricating greases to biomedical implants.
Siloxanes are used as silane coupling agents. Silanes are commonly applied on to the surface of inorganic substrates to improve water repellency. Aryl-aryl coupling reactions involving siloxane partners have been effectively carried out under a variety of conditions including using the microwave method, aqueous coupling method, and with ionic liquids. Siloxanes are also widely used in chemistry as silylating agents, crosslinking agents, and in the preparation of organosilanes.
