Choosing a Silicone Primer / Adhesive System for Healthcare Applications
12/8/2011 12:00:00 AM - Biomaterials |
Silane primers are used to promote adhesion between two non-bonding surfaces. Although designed for use with silicone adhesives, they can also be used with other adhesives, such as epoxies. The primers usually consist of one or more reactive silanes, a condensation catalyst and some type of solvent carrier. The reactive silanes typically have two different reactive groups; one compatible with the substrate and the other with the adhesive.
These different groups form a compatible interface between the incompatible substrates and promote adhesion. The reactive silanes are usually added as moisture sensitive alkoxy silanes and, in the presence of water and a condensation catalyst, form the priming surface. The silanes and the condensation catalysts form a very thin polymeric film on the surface of the substrate; the silanes begin hydrolyzing with atmospheric moisture and the condensation catalyst starts joining all the hydrolyzed groups to form a primer film on the substrate.