Saturday, July 30, 2011

Two Polymer Adhesives

Structural adhesives that have assumed increasing importance in recent years, chiefly in metal bonding, are the two polymer adhesives, that comprise a thermosetting and a thermoplastic polymer, including certain elastomers. Although each component has adhesive properties by itself, considered overall, the endjoint system forms a stronger and versatile adhesive. The two polymer systems have been particularly successes as film adhesives.

The physical properties of each component polymer are modified by the addition of the other, thus the best resistance of one may be increased, while that of the other is reduced, similarly, the toughness of one may be increased by sacrificing flexibility of the other. It is therefore possible to formulate a variety of adhesives with a wide range of characteristics by simply varying the ratio of one polymer to the other, and by taking account of the ratio, properties can to some extent the predicted.


The first structural adhesives for metal to establish themselves technically and commercially were two polymer adhesives; these were base on a polyvinyl acetal or a nitrile rubber, used in conjunction with a phenol formaldehyde resin. Their first important use was in gluing light alloys in the construction of aircraft - a courageous innovation that has been spectacularly successful in England. The Netherlands, Sweden and the USA.