Silicone resin

Silicone resins are a type of silicone material which is formed by branched, cage-like oligosiloxanes with the general formula of RnSiXmOy, where R is a non-reactive substituent, usually methyl (Me = −CH3) or phenyl (Ph = −C6H5), and X is a functional group: hydrogen (−H), hydroxyl (−OH), chlorine (−Cl) or alkoxy (−O−).

[1] When R is methyl, the four possible functional siloxane monomeric units are described as follows:[2] Note that a network of only Q groups becomes fused quartz.

Materials of molecular weight in the range of 1000–10,000 are very useful in pressure-sensitive adhesives, silicone rubbers, coatings, and additives.

In early processes of preparation of silicone resins, sodium silicate and various chlorosilanes were used as starting materials.

[1] The algae Stichococcus bacillaris and certain fungal species have been seen to colonize silicone resins used at archaeological sites.