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Electron beam-induced cationic curing: New impetus for sustainable epoxy coatings
A European research team has investigated how epoxy resin systems with cationic curing can be cross-linked quickly and energy-efficiently using electron beams – without thermal post-treatment. The results show great potential for industrial applications.
The energy-efficient curing of epoxy resins using electron beams (EB) is increasingly becoming the focus of industrial coating development. A research team led by Eindhoven University of Technology has now shown that bifunctional epoxy monomers can be polymerised quickly and almost completely (>95%) under mild EB conditions – without subsequent thermal treatment. The polymerisation is cationic, allowing short process times with high reactivity.
The team investigated various cationic initiators and epoxy monomers and was able to systematically demonstrate the relationship between chemical structure, crosslink density and mechanical performance. Depending on the radiation intensity and monomer composition, the hardness and elasticity of the coatings produced varied significantly. Despite the cationic EB curing process, which has been considered slow up to now, the samples exhibited excellent mechanical properties and no unreacted epoxy residues.
Event tip: Powder coatings
On 11 November 2025, the EC Conference “Powder Coatings – Low Temperature Application” (online) will spotlight the latest developments in energy-efficient powder coating technologies. Several key advances will be discussed, including innovations in resin systems (such as low-temperature curable polyesters, epoxies and hybrids), as well as infrared and UV-curing solutions tailored for specific powder types. The programme also covers fast-acting curing agents that enable rapid cross-linking and catalysts that lower the required activation energy – paving the way for high-performance coatings on heat-sensitive substrates like plastics, composites, and wood.
Structure-property relationships as the key to industrialisation
The absence of thermal post-crosslinking is particularly relevant for industrial practice: the materials cure completely under electron beam radiation, which shortens production times and saves energy. The establishment of structural-mechanical relationships also makes it possible to control the properties in a targeted manner by selecting the monomers and beam parameters.
The research thus provides an important basis for the broader application of cationic EB curing in industrial coating technology – especially where fast, energy-efficient and solvent-free processes are required.
Source: Progress in Organic Coatings, Volume 200, March 2025, Article 109017
