Лако-красочные материалы — производство

W. J. van Ooij

University of Cincinnati, Cincinnati, Ohio, U. S.A.

I. INTRODUCTION

This chapter reviews the many different spectroscopic techniques that can be used to study the composition and performance of adhesively bonded materials. Such a review was deemed necessary because many new analytical techniques have been developed lately and a large number of interesting applications have been published recently. The most widely used spectroscopic techniques are x-ray photoelectron spectroscopy (XPS, also called ESCA), Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), and infrared spectroscopies (FTIR). The distinction should be made here between microscopic and spectroscopic techniques for surface and interface characterization. Both types of techniques are invariably applied for the development and failure analysis of adhesives. Examples of microscopic techniques are optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission microscopy (STEM), scanning tunneling microscopy (STM), and atomic force microscopy (AFM). In general, spectroscopic techniques provide qualitative analysis of the chemistry of a surface or an interface, although in certain cases quantitative analysis is possible. Microscopic techniques are primarily employed to study surface and interface morphology of adhesives and adherends. When these techniques are applied to failure surfaces, impor­tant information on failure modes can be obtained.

This review is limited to spectroscopic techniques. Excellent reviews already exist on the use of microscopic methods in adhesive bonding technology [1,2].

In general, the applications of spectroscopic techniques in the study of various aspects of adhesive bonding that have been reported are the following:

Surface characterization of materials prior to bonding; cleanliness, surface contam­ination, oxide thickness, and so forth

Modification of surfaces to improve bondability; examples are modification of poly­mer surfaces by plasma or corona treatments, anodization or other treatments of metals, plasma film depositions, deposition of functional silanes or other coupling agents to metal surfaces, and so forth

Analysis of interfaces between materials, especially for failure analysis after aging and testing of adhesively bonded systems Study of the cure of adhesives.

The outline of this chapter is as follows. The spectroscopic techniques that can be used for surface of interface characterization of adhesively bonded materials are listed in Table 1. The most popular techniques are then discussed briefly in terms of the type of information they provide and where they can be applied. Their limitations are also described briefly. Since just a handful of techniques are used on a regular basis, notably XPS,[6] AES, SIMS, FTIR, and Raman spectroscopy, only these techniques will be dis­cussed in detail. Recent and ongoing instrumental developments are described and specific applications of each of these techniques are presented and discussed. Finally, a bibliogra­phy containing many references to textbooks and important articles is given.