Silicone rubbers compounding

Dihydroxydiphenylsilane is used as a stabiliser in the processing of silicone rubber compounds and as a raw stock in the production of branched, spirocyclic or cyclolinear oligoorganodiphenylsiloxanes. 

The rubber compounds prepared in this way are analysed and packed into polyethylene bags. Then they are loaded into metal cylinders or rubberised bags and sent to the consumer. Silicone rubber compounds can be stored for 3 to 6 months depending on the type of fillers and stabilisers. 

Silicone rubber compounds can be molded, extruded and calendered. The vulcanisation of rubber compounds occurs in two stages 1) in a press or steam boiler at high pressure and 120-150 °C 2) by thermostatic control at atmospheric pressure and 200-250 °C. 

Table 20. The main properties and applications of silicone rubber compounds and rubbers based on them...

Use Manufacture of a white, easily colored silicone rubber compound having good heat stability at temperatures up to 500F electronics. 

Red 10. [Laur Silicone Rubber Compounding 66.67% inxi oxide pigment in silicone rubber base. 

Suzuki, N. Kiba, S. Kamachi, Y. Miyamoto, N. Yamauchi, Y., Unusual Reinforcement of Silicone Rubber Compounds Containing Mesoporous Sillica Particles as Inorganic Fillers. Phys. Chem. Chem. Phys. 2012,14, 3400-3407. 

Claritech 5300 Series, Silicone rubber compound, Silicone Products Technology Inc. 

Softbelly, Dual-durometer silicone rubber compound, SiUcone Products Technology Inc. 

These developments of the polymerization methods and silicone rubber compounding date back to the early 1940 s, based on work done at the Dow-Coming laboratories (Warrick) as well as at General Electric (Rochow). ... 

Details are given of quality control procedures used by Dow Corning STI Midwest in silicone rubber compounding. 

Unlike hydrated precipitated silica, fumed silica is used almost exclusively in silicone rubber compounds. Fumed silica is incorporated into silicone gum stock with the use of dough mixers. Fumed silica is unique to silicone rubber because it significantly improves the physical properties of the cured compound (better than hydrated precipitated silica). On the other hand, fumed silica will have a greater tendency than the hydrated precipitated silica to impart crepe hardening to the uncured silicone compound. Many times, the use of fumed silica in silicone rubber is extended with the less expensive precipitated silica. 

Since fumed silica is generally used only in silicone rubber compounds, the rubber industry uses far less fumed silica than hydrated precipitated silica. On the other hand, fumed silica demand is growing significantly faster than the hydrated precipitated silica normally used. 

Besides being used in silicone rubber compounds, fumed silica is commonly used as a flow agent in adhesives, coatings, cosmetics, and so on. 

Trichlorosilane is used to make silicon tetrachloride, which is used to make fumed silica that is mainly used as the filler in silicone rubber compounds. 

Heat-curable rubber (HeR) These are typically silicon rubber compounded with catalyst, color, and additives mixed and milled into siloxane polymers. HCRs are often used in molded parts for high-temperature service or in applications that utilize their chemical and weathering resistance, but also see applications as seals and gaskets. 

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