epoxyadhesive

An epoxy adhesive is a two-component system consisting of a polymer resin with epoxide groups and a curing agent, typically an amine or anhydride hardener. Some epoxy adhesives are one-part and must be heated to cure, but most common forms are two-part systems that are mixed before use.

During curing, the epoxide rings react with the hardener to form a cross-linked thermoset network. This reaction creates a strong, durable bond with high shear strength, good thermal resistance, and excellent chemical resistance. The properties depend on resin and hardener chemistry, formulation, and cure conditions, including temperature and time. Pot life is the working time after mixing, after which the material begins to set.

Applications include structural bonding in aerospace, automotive, electronics, construction, and marine industries, where metals, composite laminates, wood, ceramics, and many plastics can be joined. Epoxy adhesives are valued for strong adhesion, low shrinkage, and good gap-filling capability, though toughened formulations may be used to improve impact resistance and fracture toughness. Surface preparation, cleanliness, and sometimes primers are critical to achieve reliable bonding.

Limitations include brittleness in some grades, sensitivity to moisture during cure, and higher cost compared with some alternative adhesives. They often require controlled curing conditions; ultra-high-temperature environments or continuous immersion may present challenges. Safety considerations include skin and eye irritation from uncured resins and solvents, with proper ventilation and protective equipment recommended.