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Silicone resins are a type of silicone material which is formed by branched, cage-like Siloxane with the general formula of where R is a non-reactive substituent, usually methyl (Me = ) or phenyl (Ph = ), and X is a functional group: hydrogen (), hydroxyl (), chlorine () or alkoxy (). These groups are further condensed in many applications, to give highly crosslinked, insoluble polysiloxane networks.S.J. Clarson, J.A. Semlyen, Siloxane Polymers, Prentice Hall, New Jersey (1993).
When R is methyl, the four possible functional siloxane monomeric units are described as follows: Dow Corning nomenclature of silicon resins
Note that a network of only Q groups becomes fused quartz.
The most abundant silicone resins are built of D and T units (DT resins) or from M and Q units (MQ resins); however, many other combinations (MDT, MTQ, QDT) are also used in industry.
Silicone resins represent a broad range of products. Materials of molecular weight in the range of 1000–10,000 are very useful in pressure-sensitive adhesives, silicone rubbers, coatings, and additives. List of silicone resins produced by Dow Corning Database of silicon resins produced by Momentive Performance Materials (formerly GE Silicones) Polysiloxane polymers with reactive side group functionality such as vinyl, acrylate, epoxy, mercaptan, or amine, are used to create thermoset polymer matrix composites, coatings, and adhesives.B. Boutevin et al., in Silicon-Containing Polymers, ed. RG Jones et al., Springer, Netherlands, 2000, pp 79-112,
Silicone resins are prepared by hydrolysis condensation of various silicone . In early processes of preparation of silicone resins, sodium silicate and various were used as starting materials. Although the starting materials were the least expensive ones (something typical for industry), structural control of the product was very difficult. More recently, a less reactive tetraethoxysilane - (TEOS) or ethyl polysilicate and various disiloxanes are used as starting materials.
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