The most basic class of silicones is the conventional inert polydimethylsiloxane series. They are trimethylsiloxy terminated and possess no reactive chemical functionality. These fluids find utility as plasticisers, lubricants, defoamers, in high temperature baths, and cosmetic products. Typical service temperatures are to 250° celsius. UCT offers the full line of these materials from very low to gum like viscosities.
Although conventional fluids are stable thermally to 250° celsius, many high performance coating applications require higher temperature stability. Introduction of aromatic groups (phenyl rings) raises thermal stability to greater than 300° celsius. The indices of refraction and the rigidity of cured resins are also increased over conventional fluids. Figure 2 describes these materials in more detail. They are available with curable vinyl terminals at the polymer terminals and containing variable viscosities and mole percentages of phenyl groups. The most utilized UCT product line of curable aromatic silicones is the PS732-PS793 series of vinyl terminated fluids.
The product of silicones sealant for example that produce by Dow Chemicals Have specification as follows:
- Dow Corning Sealants are used in a wide range of industries including construction, electronics, automotive, aerospace, and industrial assembly and maintenance.
- Silicone sealants are used to protect and seal anything from the smallest silicon chip to the worlds tallest skyscrapers.
- Sealants are available in a wide range of product forms including free flowing, cure in place gasketing, elastomeric silicone rubber and lubricating greases.
- Our construction sealants are approved for use all over the globe and comply to ASTM, OSI, GB/T (China), BS 5889 and others.
- Dow Corning sealants are available in use ranges from -40° to 450° F (-40° to 232° C).