Epoksiresiinides

Epoksiresiinides are a family of high-performance epoxy-based resins that incorporate a secondary “resiinide” hardening system. The term combines the Greek root *epoxí* (referring to the epoxy functional group) with *resiin-*, a coined descriptor for a resinized hardener that contains both traditional epoxy or anhydride functionalities and rigid aromatic or heteroaromatic fragments. This dual chemistry confers superior mechanical strength, thermal stability and chemical resistance compared to conventional epoxy systems.

The core chemical structure of an epoksiresiinide consists of bisphenol‑A or bisphenol‑F epoxy resins cross‑linked via alkylene oxide chains whose terminal groups are substituted by aromatic rings carrying epoxy or anhydride groups. During curing, the epoxy groups undergo step‑growth polymerisation, while the resiinide component acts either as a co‑curing agent or as a viscosity‑moderating additive that participates in an additional cross‑linking network. Typical curing temperatures range from 120 °C to 180 °C, and the final cross‑linked network possesses glass‑transition temperatures above 200 °C.

Key properties include high modulus (60–80 GPa), high flexural strength (>80 MPa), excellent adhesion to metal and composite substrates, and low water absorption. Compared with standard epoxy coatings, epoksiresiinides exhibit improved resistance to solvents, acids and alkalis, making them attractive for aerospace, automotive, marine and electrical insulation applications. In additive manufacturing, their rheology allows for smoother extrusion and reduced nozzle wear.

Safety considerations mirror those of other epoxies: unreacted monomers can be skin irritants and inhalation exposure should be minimized. Proper ventilation, personal protective equipment and strict handling protocols are recommended during mixing, loading into moulds and curing. Disposal of cured waste must comply with local hazardous material regulations.