Tuesday, October 27, 2009

Polyester Resin Adhesives

In the field of adhesion, polyester resins have not so far found wide applications, that is if we exclude the laminating use of the unsaturated polyester as being a non-adhesive application. Books dealing solely with polyester resins are few in number and general the literature does not contain much information relating to polyester adhesives. Several articles have, however, been published discussing the manufacture, curing methods, and properties of unsaturated polyesters.

Polyester resins can be divided into two chemical classes, the saturated and the unsaturated. Terminology trend to be somewhat confused, for example, the name Alkyd (from alcohol and acid) is a generic term that was originally intended to embrace all types of polyester resin. It is now commonly used to refer more specifically to the saturated polyesters that have been modified with saturated polyesters that have been modified with saturated fatty acids from drying oils, called non-drying alkyds, and those modified by unsaturated fatty acids from drying oils, known as semi-drying or drying alkyds. On the other hand, the term "polyester resin", especially in a molding or laminating context, generally implies on unsaturated polyester, prepared from glycol and dibasic acids or anhydride present as a major constituent.