Page 386 - Handbook of Adhesives and Sealants

Chapter
10

Adhesives Families

10.1 Introduction

This chapter will review the common chemical families of materials
that are employed in adhesive formulations. They consist of synthetic
polymeric resins, naturally occurring resins, and inorganic products.
These materials form the base resin portion of the adhesive formula-
tion. Along with additives and modifiers, they govern the chemical and
physical characteristics of the adhesive system. Families of materials
that are normally used in sealant formulations will be described in
Chapter 13.

10.2 Classification Methods
There are many ways of classifying adhesives. In this chapter they
will primarily be grouped as either structural or non-structural. This
grouping is admittedly subjective and broad, but it represents the type
of application where the adhesive is commonly used. We can also clas-
sify adhesives by whether or not they form crosslinked molecules (i.e.,
thermosetting or thermoplastic), by their flexibility (i.e., rigid or elas-
tomeric), and by their form and curing conditions. Table 10.1 identifies
and classifies common adhesive families that are covered in this chap-
ter.
Structural applications are those requiring high strength or per-
manence. Structural adhesive joints are expected to provide a useful
service life that is equivalent to that of the product in which the ad-
hesive joint is a part. Non-structural applications are those that gen-
erally require only low strength or temporary fastening. Examples of
non-structural adhesives are pressure sensitive tapes, hot melts, or
packaging adhesives. Some define structural adhesives as systems

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