Dynasylan A Tetraethyl orthosilicate Degussa-Silanes Abrasion Resistance Scratch/ Srcub/ Mar resistance agent Coatings Metal Other industry >> Glass Coating Dynasylan® A, the ethyl ester of orthosilicic acid, is industrially the most important of the tetraalkyl silicates. In the literature it is frequently also referred to under the name TEOS (tetraethoxysilane). Dynasylan® A is a colourless, low-viscosity liquid with SiO2 content of 28.5%. Use requires acid- or alkali-catalysed hydrolysis. Since all 4 ethoxy groups are able to participate in this reaction, Dynasylan® A is regarded as tetrafunctional. Hydrolysis leads to silanol groups which, in a subsequent condensation reaction, form very stable siloxane bonds (-Si-O-Si-). Condensation starts before hydrolysis is complete. During storage of these hydrolysates condensation, continues until a gel is formed. The rate of gelation depends on the concentration of water. The surfaces of glass, metals, pigments, fillers and synthetic fibres can be coated with a very thin SiO2 layer in order to improve chemical and thermal stability and mechanical properties. 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. Ethyl ester of orthosilicic acid. Used in glass, metals, pigments, fillers and synthetic fibres coatings. Improves chemical and thermal stability and mechanical properties. Possesses high scratch and abrasion resistance.