Silanols inorganic substrate

In the text that follows, the term silanols is used as a simplified description of the monosilanols, silanediols, and silanetriols in the case oftrialkoxysilanes. Usually, the hydrolysis of the first OR group is the rate-controlling reaction step. The resultant silanol intermediates (Si—OH) react with active OH groups of the inorganic substrate, building up stable covalent (Si—O—substrate) bonds [12]. 

Adhesion promoter n. A chemical coating that is applied to a substrate before it is coated with a plastic, to improve the adhesion of the plastic to the substrate. Adhesion promoters include materials such as silanes and silicones with hydrolysable groups on one end of their molecules that react with moisture to yield silanol groups, which in turn react with or adsorb to inorganic surfaces to enable strong bonds to be made. At the other ends of the molecules are reactive, but nonhydrolyzable groups that are compatible with resins or elastomers in adhesive formulations. Adhesion promoters are added to the adhesive as water or ethanol solutions. Skeist I (ed) (1990) Handbook of adhesives. Van Nostrand Reinhold, New York. 

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