Physical Attributes of Adhesion and Durability

The chemical attributes of adhesion cover a much more subtle and wider range of interactions described as primary or secondary bridging. Primary bridging can result from direct chemical reaction between the adhesive and adherend, while secondary bridging relates to the residual electrical forces which surround the respective molecules. It is assumed that these fundamental energy relationships and their association with the wetting phenomena have been covered in the earlier chapters of this book. It should suffice to state that better wetting of the adherend by the adhesive correlates directly with superior durability of bonded structures in the actual service environments. 

FIGURE 1. Schematic representation of mechanical hooking. (From Reference 25.) 

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The following topics are reviewed chemical and physical attributes of adhesion and durability failure site variabilities bondline characteristics affecting bond... 

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