3. Bonding mechanisms: theoretical principles

3.1 Definitions

A glue (or adhesive) is a chemical product used to join two materials.

Adhesives include traditional glues such as vinyl glues or white glues, rubber-based glues (contact or neoprene glues, etc.) and certain thermosetting glues such as urea-formaldehyde.

Modern, high-performance glues such as epoxies, polyurethanes, hot melts, cyanoacrylates, anaerobic glues and acrylics are increasingly referred to as adhesives.

Initially liquid or fluid, the adhesive is spread over one (or both) of the surfaces to be joined, and clings to them by various physical or chemical mechanisms. This is known as adhesion ...