Thermosetting Component

In the most widely used two polymer adhesive the thermosetting component as a phenol formaldehyde resin, usually a one step resin from phenol itself and having a molar ratio of 1 phenol: 0.9 - 2 formaldehyde. The pH should and be high not above say pH 10, or compatibility with some polymers or side reactions may present a problem.

There is no fundamental reason with a potentially thermosetting novolak resin should not be used. Such a resin often has superior compatibility with synthetic rubber elastomers, a compatibility that is reduced if a relatively large amount of hexamethylenetetramine needs to be added to cure the novolak.