Page 363 - Handbook of Adhesives and Sealants

Chapter
9

Adhesive Composition

and Formulation

9.1 Introduction
Generally, it is not necessary to completely understand the ingredients
in an adhesive formulation or the manufacturer’s reasoning behind
the specific formulation. One can often select a commercial adhesive
based on functional properties, curing procedures, and other relevant
information that are supplied by the adhesive manufacturer. However,
a knowledge of the common materials used in formulating adhesives,
and compositional techniques used to solve common application prob-
lems are especially important to anyone engaged in developing adhe-
sive systems. A general knowledge of these factors is also important
to the casual adhesive user so that he or she can more easily converse
with the adhesive manufacturer regarding modifications that may be
required or regarding certain characteristics of the adhesive system.
This chapter is intended to provide a very basic understanding of
the components that are commonly used in adhesive formulation. The
relationship between these materials and the properties exhibited by
the adhesive system are explained. The customary techniques used to
overcome several everyday problems are also discussed. These tech-
niques include formulation processes and materials to control flow,
extend temperature range, improve toughness, match thermal expan-
sion coefficients, reduce shrinkage, increase tack, and modify electrical
or thermal conductivity.

9.2 Adhesive Composition
Modern-day adhesives are often fairly complex formulations of com-
ponents that perform specialty functions. Very few polymers are used
319