Synthesis of three kinds of multi-armed cardanol-based acrylic resins based on different routes for UV/EB-cured coatings

Synthesis of cardanol-based acrylates for UV/EB-cured coatings. [Display omitted] •Three kinds of cardanol-based acrylates were prepared based on different routes.•UV/EB-cured coatings based on the cardanol-based acrylates were researched.•Compared with UV-cured coatings, the EB-cured coatings exhibited high hardness and better adhesion. In this work, we describe three kinds of multi-armed cardanol-based acrylic resins to fabricate UV/EB-cured coatings. Hydroxyethyl cardanol ether reacts with methyl etherified melamine formaldehyde resin to synthesize multi-arm cardanol-based oligomer (HF). HF was used to synthesize multi-arm cardanol-based epoxy acrylate (AEHF), cardanol acrylate (AHF), and cardanol-based polyurethane acrylate (ISHF) based on three different routes. The three synthetic routes were based on homogeneous catalytic system by peroxyacids through epoxidation and acrylate reactions, electrophilic addition reaction, and mercapto-olefin photo-click reaction. The structure and properties of AEHF, AHF, and ISHF were characterized by FR-IR, 1H-NMR and GPC. The three kinds of cardanol-based acrylic resins were used to prepare UV/EB-cured coatings, and the performance of the coatings was tested systematically. The hardness of AHF and ISHF coating has a high pencil hardness (3H), both adhesion of the three coatings can be improve to 0 grade after addition of phosphate resin. Compared with UV curing, EB-cured was not require photo-initiators, the storage modulus and the pencil hardness of the coatings were higher. The three kinds of cardanol-based acrylic resins can be applied in UV/EB-cured coatings for metal protection and other fields.