Silicones are particularly stable and exceptionally resistant to such influences as heat and electromagnetic radiation. Above all, silicone fluids from WACKER are ideal for use in all kinds of industries – cosmetics, pharma and textiles, to name but a few.
Silicones consist of an inorganic backbone made of alternate silicon and oxygen atoms. Chemists refer to them as polydiorganosiloxanes. The two other valencies of the silicon atoms are occupied with organic groups (mainly methyls). These are responsible for silicones’ semi-organic nature.
The bond energy of a silicon-silicon bond is much greater than that of a carbon-carbon bond. This make silicones much more stable and more resistant to diverse influences.
A key advantage of silicone fluids is their excellent thermal and thermooxidative resistance. More precisely, they are resistant to temperatures ranging from -60 to +300°C.
Silicone fluids are also much more stable than organic polymers toward electromagnetic and particle radiation (UV, alpha, beta and gamma radiation) .. Silicone fluids additionally possess
Silicone fluids have no known harmful effects and are transparent liquids that have no taste or odor. Their viscosities lie between 0.65 and 1,000,000 mm2/s, depending on the type. Since there are only very weak intermolecular forces between the individual methylsilicone chains, they are liquid over wide ranges of their molecular weight.
|Viscosity [mPa s]||Molecular weight [D]||Mean chain length|
Thanks to these properties, silicone fluids make ideal
They are also used for water-repellent treatment of glass and mineral wool and for various applications in cosmetics, pharmaceuticals and textiles.
Silicone fluids are the starting materials for further silicone products which are created by chemical functionalization. The siloxane backbone is most often modified in two ways:
This affords a way of transforming hydrophobic silicone fluids into more or less hydrophilic molecules. Reactive silicone fluids are siloxanes terminated with reactive groups. They include, e.g., OH polymers (hydrolyzates) or silicone fluids with amino or epoxy groups.
Silicone fluids are often used in the form of aqueous emulsions. As these can be readily diluted with water, small amounts of the substance can be uniformly distributed on substrates.
There are basically two types:
To provide a stable silicone emulsion, the surfaces of the fluid droplets are covered with surfactants (emulsifiers). The lipophilic – oil-loving – ends of the emulsifier are oriented toward the oil droplet. The hydrophilic – water-loving – centers provide the solubility in water.
Silicone emulsions are typically used in the textile, cosmetic and household care industries. As components of shampoos, silicone emulsions lend hair a silky softness, making it easy to comb after washing. Silicone emulsions are also used as water-repellent agents for protecting textiles or building and insulation materials against water and damp.
Silicone pastes can be used in various applications by virtue of their basic properties:
Silicone pastes are used, for example, as lubricants and installation aids, both for technical purposes and in food-contact applications, and as sealing aids for sealing parts and connections that can be disassembled, and as release agents for high-temperature use.
Silicone waxes are polydimethylsiloxanes that are modified by long-chain alkyl groups. To an extent depending on the chain length and number of alkyl groups, modification yields products of different melting point. These behave like typical hydrocarbon waxes.
Silicone waxes combine the properties of organic waxes – such as water repellency or providing structure – with the typical properties of silicones, such as wetting power and good sensory properties.
They are thus ideally suited to all applications in which lubrication is required and the transition from solid to liquid is critical. Silicone waxes are used as oil and wax components in skin and face creams, or in decorative cosmetic articles for improving the skin feel. In addition, silicone waxes optimize the distribution of pigments and sunscreen additives and increase the spread of oils and active compositions. In the textile sector, for example, leather is treated with silicone waxes. These confer very good long-term protection and have a water-repellent effect.
Silicone Antifoam Compounds These are oily, viscous, opaque or slightly cloudy liquids. They are mostly used in systems containing little or no water. The compounds can be used neat or mixed with suitable formulation components such as surfactants.
Self-Dispersing Silicone Antifoam Agents These are a combination of antifoam agent compounds with organic active agents and auxiliaries. They disperse spontaneously on contact with foaming formulations and show good compatibility and spreading properties.
Silicone Antifoam Emulsions These are o/w emulsions of antifoam agent compounds with an active ingredient content of 5 to 50%. They are mainly used for water-borne formulations and applications.
Silicone Antifoam Powders These are ideal for use in powder products, such as powder-form detergents.
Silicone Fluids These are characterized by good antifoam properties in water-free, non-polar systems. They are suitable for applications in which compatibility with other substances is not required.