Moisture surrounds us, and it is abundant and costs nothing. Wouldn't it be fantastic if moisture could be used as a component in curing adhesives and sealants? And even more amazing if the products would cure without mixing, evaporation of solvent, or significant heating? Indeed, this is the case for many modern and commercially popular products.
Moisture cured adhesives and sealants are formulated to react with atmospheric moisture to form a cured polymer layer with high strength and adhesive properties. These are actually two component products with one component being moisture. Moisture is provided in the ambient air (expressed as the relative humidity), and it is also adsorbed on the surface or absorbed within the porosity of many substrate materials.
The most popular moisture cured resins are cyanoacrylates, silicones, and polyurethanes. The cyanoacrylates operate as adhesives, and the silicone and polyurethane resins are used commonly as sealants, caulking, and gasketing, but they can also be employed as adhesives.