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Urea Formaldehyde Adhesive

Thermosetting Resin Adhesive Article Contents: Thermosetting Resin Adhesive Melamine Formaldehyde Adhesives Urea Formaldehyde Adhesive...

Sunday, September 14, 2008

Phenolic Resins as Curing Agents

The properties obtained by reacting bisphenol A glycidyl ether with a phenol-formaldehyde resin were first recognized in applications other than adhesive use. The phenolic resin may be either a novolac or resite, and used with or without some other curing agent or catalyst. (This is quite different to reacting epichlorohydrin with a phenolic novolak, as discussed before. With some phenolic resins stability and at the same time to catalyse curing at elevated temperatures. The mechanism of the epoxy/phenelic resin reaction has been studied by Bruin.

So far as adhesive are concerned, the interest is mainly in mixture of a thermosetting phenolic resin with either a solid or a liquid bisphenol A glycidyl ether.

Some important high temperature adhesives of this type are now being used in aircraft construction. Generally speaking, the phenolic resin component used is in considerable excess of the epoxy, sometimes many times in excess, and therefore the amount is much greater than that required simply as a hardener. Because of this, phenolic/epoxy adhesives are here considered to be primarily phenolic adhesives, and as such they are dealt in the article before.