Adhesives

Abstract

An adhesive is a material used to join two or more other materials (often called adherends) by means of surface attachment to form a final assembly. In the simplest case, the assembly is called an adhesive joint or adhesive bond. Adhesives can be made from any material that displays the properties required for an adhesive. These properties include: adhesion (the ability to “surface attach”), the handling characteristics of the adhesive (so that it can be easily and economically applied to the adherends), the curing characteristics of the adhesive (if any), and the strength of the final assembly. In this article, we describe various chemistries that have been used to obtain the wide variety of adhesives that are available. Adhesives can be classified in many ways. In this article we they are classified loosely by strength. Thus, the article is divided into classes of adhesives that are based upon the strength of the joints that result from the use of these adhesives. The article will be divided into sections based upon the following classifications: market economics, adhesion, pressure sensitive adhesives, hot‐melt adhesives, solution‐based adhesives, structural adhesives and natural product based adhesives. This final class of adhesives is somewhat broader than the first four since it deals mainly with the source of the adhesive material rather than its strength.