Polyepoxides are thermosetting resins with good mechanical properties, good temperature resistance and low shrinkage.
The exact term is polyepoxide, but they can be referred to as epoxide and, loosely, epoxy.
The main polyepoxide families are:
• diglycidylether of bisphenol A (DGEBA), the earliest and most widely used resin. The basis of so-called "120°C" systems, it is often mixed with higher performance resins to improve flexibility and workability;
• diglycidylethers of bisphenol A and of tetrabromobisphenol A of which fire resistance is improved;
• Novolacs (EPN) which has better temperature resistance and increased chemical resistance;
• tetraglycidyl methylene dianiline (TGMDA) ethers, the basis of so-called "180°C" systems;
• cycloaliphatic epoxides with superior mechanical and electrical properties and better resistance to ageing.