Evonik

Dynasylan SILBOND Pure

Tetraethyl orthosilicate 99.0%

Dynasylan SILBOND Pure is a clear, low-viscosity liquid that is essentially pure tetraethyl orthosilicate monomer (99.0%). Dynasylan SILBOND Pure is used as a building block for zeolites and catalyst carriers, crosslinking agent, chemical intermediate, clear-coat component, and in any other application requiring pure TEOS monomer.

Key Features

Dynasylan SILBOND Pure is immiscible with water, so hydrolysis requires the use of a co-solvent such as ethanol. Suitable catalysts are mineral acids or ammonia, or even acetic acid and amines.

Partial hydrolysis gives hydrolysates of Dynasylan SILBOND Pure whose shelf-life depends on the amount of water and solvent used.  The amount of water determines the activity of the hydrolysate.  Activity and shelf-life are inversely proportional. The correct choice for the amount of water can give hydrolysates, which have a shelf life of up to a year (from the time of manufacture).

Recommended Applications

Dynasylan SILBOND Pure can replace Dynasylan SILBOND Condensed in every application, where higher purity is needed. Dynasylan SILBOND Pure is a ready source of silicic acid for many applications. Silicic acid is usually obtained by hydrolysis, or thermally by condensation at elevated temperatures.

The resulting silicic acid bonds well to many inorganic substrates and can be deposited in-situ in a controlled manner. The surfaces of glass, metals, pigments, fillers, and synthetic fibers can be coated withy a very thin SiO2 layer in order to improve chemical and thermal stability, and mechanical properties.

Other applications are:  

  • Building blocks for zeolites and catalyst carriers
  • Raw material for optically clear coatings
  • Binders for fillers in inorganic zinc-rich paints or precision investment castings
  • Crosslinkers in silicone rubber systems
  • Drying agents in sealant compositions

Dynasylan SILBOND Pure is an important starting material for sol-gel processes, where the additional use of alkylalokoxysilanes (e.g. Dynasylan MTES) can give the siloxane network a slight organic character as a result of the incorporation of alkyl groups.

It is also possible to construct an inorganic/organic network by adding silanes containing organofunctional groups (e.g. aminopropyl groups) and polymerizing with organic precursors.  This principle makes it possible to obtain highly scratch- and abrasion-resistant coatings.