EpoxidHärter

EpoxidHärter is the curing agent used with epoxy resins to initiate the crosslinking reaction that converts a liquid epoxy resin into a solid thermoset polymer. The hardener supplies reactive groups that open the epoxide rings and form covalent bonds with the resin, creating a three-dimensional network. The performance of an epoxy system depends on the matching of resin and hardener, their proportions, and the curing conditions.

Common hardeners are amine- and anhydride-based systems. Amine hardeners, including aliphatic, cycloaliphatic, and polyfunctional types, generally cure at room temperature to moderate temperatures and yield coatings with good mechanical strength. Anhydride hardeners require somewhat higher temperatures and often provide superior chemical and heat resistance; they are frequently used in high-performance coatings and composites. Other formulations include polyamides or modified amines, sometimes with accelerators, to tailor cure speed and adhesion.

Key properties to consider include pot life, cure temperature, viscosity, exothermic heat release, and compatibility with the resin. The resulting network determines glass transition temperature, hardness, toughness, and environmental resistance. The choice of hardener also influences odor, color, and handling safety.

Applications span adhesives, protective coatings, composite laminates, electronics potting and encapsulation, sealants, and castings. In practice, formulators select a hardener based on required cure schedule, service temperature, and exposure conditions.

Handling and storage require attention to safety data sheets. Many epoxy hardeners are irritants or toxic and need proper ventilation, gloves, and eye protection. They are typically stored in sealed containers, protected from moisture and heat, with shelf life varying by formulation.