The Basics of Silicon Chemistry

Silanes and Intermediates

Dow Corning is the industry leader in supplying silane and intermediate product solutions, which is one of our core businesses. Our silanes business unit covers the following product groups:

• Chlorosilanes
• Organofunctional silanes
• Specialty silanes
• Alkylsilanes

Chloromethylsilanes
Chloromethylsilanes are the basic building blocks of all of our silicon-based materials. They are used in the basic synthesis of silanes and siloxanes and as protecting agents for intermediates in pharmaceutical syntheses.

Chlorosilanes
Chlorosilanes are essential raw materials in the electronics and telecommunications industries and are used for the production of optical fibers, silicon wafers and chips, as well as the starting material for fumed silicas.

Organofunctional Silanes

Industries that use organofunctional silanes include: • Adhesives and sealants • Electronics • Foundry resins • Glass fibers/fabrics • Mineral fillers • Paints and coatings • Pharmaceuticals • Pigments • Silicones • Textiles • Thermosets • Wire and cable		Dow Corning's silane product line includes chlorosilanes and organofunctional silanes with diverse market applications. These include oleophobic and hydrophobic textile applications, as well as materials reinforcement, coatings, construction chemicals, electronics, and pharmaceutical applications.

The organofunctionality and primary applications are as follows.

Amino

• Adhesion promoter, coupling agent, and resin additive
• Improves chemical bonding of resins to inorganic fillers and reinforcing materials
• Used for epoxies, phenolics, melamines, nylons, PVC, acrylics, poly(olefins), poly(urethanes), and nitrile rubbers
• Surface pretreatment of fillers and reinforcers

Vinyl

• Used for free-radical, cross-linked polyester, rubber, poly(olefins), styrenics, and acrylics
• Used to couple fiberglass to resins
• Used to copolymerize with ethylene
• Used to graft to poly(ethylene) for moisture cure

Epoxy

• Adhesion promoter for epoxies, urethanes, and acrylics
• Surface treatment for fillers and reinforcers

Methacryl

• Adhesion promoter and coupling agent
• Used for free-radical, cross-linked polyester, rubber, poly(olefins), styrenics, and acrylics
• Used to couple fillers or fiberglass to resins
• Moisture cross-linking of acrylics

Sulfur

• Used as coupling agent for inorganic fillers in sulfur-vulcanized rubber mixtures

Alkyl

• Hydrophobic surface treatment of fillers and inorganic surfaces
• Silicone synthesis

Phenyl

• Synthesis of silanes and siloxanes
• Hydrophobic surface treatment
• Hydrophobic additive to other silane coupling agents
• Thermal stability additive to other silanes

Learn more about:

• Silicones
• Siloxane polymerization
• Evolution of silicon science

Sources:

• E. Plueddemann, Silane Coupling Agents, 2nd ed, Plenum Press, New York (1991).
• K.L. Mittal (ed), Silanes and Other Coupling Agents, VSP, The Netherlands (1991).