Vinyl Silane Moisture Scavenger

Storage stability water scavenger silanes used as drying agents can capture any latent moisture present in the immediate environment.

Vinyl silane moisture scavenger.

Due to the electron interactions of the vinyl group the si methoxy groups in this silane hydrolyze substantially faster than in saturated aliphatic alkylalkoxysilanes. Dynasylan 6490 dynasylan 6490 by evonik is a vinyl silane concentrate. The vinyl functional groups of dynasylan 6498 react with the polymer phase in the presence of radicals. The high reactivity of the aromatic diisocyanate results in absorption of moisture and liberation of co2 bubbles at roomtemperature leading to undesired defects in applied coatings.

Methanol is formed as a by product and vinyl silane is cross linked in the formulation to an inert material. A very common moisture scavenger is vinyltrimethoxysilane. These silanol groups react with the filler via silicon oxygen bridges. Silanil 258 silanil 289 silanil 919 and silanil 176 are popular to be used for post addition.

Additive to moisture cure silane modified polyurethanes as a water scavenger to prevent premature cure used in microparticle surface modification einecs number. Acts as an adhesion promoter. Vinyltrimethoxysilane is the most common moisture scavenger due to the electron interactions of the vinyl groupit reacts with moisture faster than other alkoxy silanes enabling it to function as a moisture scavenger in the presence of. Increases the rate of silane hydrolysis.

In the presence of moisture the ethoxy groups of dynasylan 6498 hydrolyse to produce ethanol and reactive silanol groups. Silane dosage in post addition epoxy and amino silanes e g. Key features and benefits feature benefit vinyl functionality vinyl functionality allows free radical addition to polymers. Trimethoxy silane functionality.

Sisib pc6110 vinyltrimethoxysilane is the most common moisture scavenger in adhesive and sealant formulations. The presence of vinyl attached to the silicon increases the reaction rate of methoxysilane with water effectively eliminating water. Because of the rapid hydrolysis of the vinyltrimethoxy silane in the acidic water it can be used as moisture scavenger in the polyurethane coatings where the hydrolysis products are 3 moles of methanol and one mole of vinyl silanol scheme 1.