Acetoxy - Methyltriethoxysilane - Dynasylan® MTES, an alkyltrialkoxysilane is an important component in sol-gel systems.
Dynasylan® MTES is a colorless, low-viscosity liquid. Use requires acid- or alkali-catalysed hydrolysis. Dynasylan® MTES is regarded as trifunctional since all three alkoxy groups are able to participate in this reaction. Additionally Dynasylan® MTES contains a methyl group that adds organic character to the products. Hydrolysis leads to silanol groups which, in a subsequent condensation reaction, form very stable siloxane bonds (-Si-O-Si-). Condensation occurs parallel to hydrolysis once a certain amount of silanol groups have been formed. The absolute and relative rates of hydrolysis and condensation depends on a number of factors. The most important factors include pH, concentration, solvent, temperature and the catalyst.
In some sol-gel applications Dynasylan® MTES is partially hydrolyzed to form a preproduct that can be further crosslinked using temperature. This prehydrolysis is often done in conjunction with other organofunctional silanes, silicic acid esters (e.g. Dynasylan® A) or even a aqueous silica sol. This preproduct can be further modified by addition of organic resins or inorganic nanoparticles such as AEROSIL®. It is also possible to construct an inorganic/organic network by adding silanes containing organofunctional groups (e.g. aminopropyl groups) and organic resins and polymerizing using standard organic methods. This principle makes it possible to obtain mar resistant coatings having a higher UV-stability than traditional organic coatings. This can also lead to more flame resistant materials than using traditional resins.