Silicones

Abstract

Silicones are a class of materials with unique properties that make them useful in a variety of applications of commercial interest and support a thriving global industry. This article updates a comprehensive survey of the chemistry and technology of silicones last published in Kirk‐Othmer Encyclopedia of Chemical Technology in 1997. The update contains more than 235 references not cited in the previous version and includes literature published through 2001. A new section dealing with fiber finishing applications has been included in the current version. The review provides an excellent primary reference for this interesting area of chemistry and technology.

Direct Human Contact with Siloxanes (Silicones) – Safety or Risk Part 1. Characteristics of Siloxanes (Silicones)

“…A rapid development of the synthesis of organosilicon compounds was noted in subsequent years. Charles Friedel and James Crafts obtained tetraethylsilane, which was the first compound containing Si-C bond ( Brook, 2000 ; Butts et al, 2002 ). However, the greatest achievements in the field of synthesis are attributed to Frederic Stanley Kipping, who in 1904 used the Grignard reaction for the preparation of organosilicon compounds, and discovered the intermolecular condensation of silanols leading to obtain siloxanes and polysiloxanes.…”

“…Rapid development of silicones chemistry occurred in the thirties of the 20th century. Technological breakthrough was the development of so called direct methylchlorosilanes synthesis method by Eugene Rochow in the United States in 1941 ( Brook, 2000 ; Chojnowski and Cypryk, 2000 ; Butts et al, 2002 ; Thomas, 2010 ). Methylchlorosilanes became the starting compounds (monomers) in various preparation reactions of silicones.…”

“…Methylchlorosilanes became the starting compounds (monomers) in various preparation reactions of silicones. The technology for direct synthesis was developed nearly at the same time, in the year 1942 in Germany, under the supervision of Richard Miller ( Butts et al, 2002 ). The production of silicones, the first generation of these unique polymers, started during World War II in the USA in Dow Corning Corporation ( Chojnowski and Cypryk, 2000 ; Thomas, 2010 ).…”

“…Silicon (Si) as a chemical element is more electropositive than carbon (C) and, like carbon, forms covalent bonds with different elements, e.g., with oxygen (O) (siloxanes and polysiloxanes), nitrogen (N) (silazanes and polysilazanes), sulfur (S) (siltianes and polysiltianes), silicon (Si) (silanes and polysilanes), carbon (C) (carbosilanes and polycarbosilanes) ( Brook, 2000 ; Butts et al, 2002 ). This is an element that forms a wide variety of group of organosilicon compounds.…”

“…The chemistry of siloxanes distinguishes four levels of functionality, which, together with the type of functional groups, determine structure geometry. These are the monofunctional units (M) which act as terminators of the chains, difunctional ones (D) which form the multiparticle skeleton of oligomers and polymers linear chains, or cyclic compounds, trifunctional (T) and tetrafunctional (Q), which result in branched and spatially cross-linked molecules, observed in resins, rubbers and elastomers ( Tomanek, 1991 ; Fendinger et al, 1997 ; Kuo, 1999 ; Dow Corning, 2000–2016c ; Butts et al, 2002 ; Colas and Curtis, 2004 ; Omidian et al, 2011 ; Mojsiewicz-Pieńkowska, 2012 , 2014 ). Siloxane molecule may be thus linear, cyclic, branched or cross-linked ( Figure 1 ) ( Dow Corning, 2000–2016a ; Mojsiewicz-Pieńkowska, 2015 ).…”