Bio‐Based Ultraviolet Curable Alkyd Resin and Modification With Succinic Anhydride

ABSTRACT Conventional alkyd resins are widely used for their durability and gloss, but often rely on organic solvents that release harmful volatile organic compounds. In this study, a bio‐based content exceeding 50% ultraviolet (UV)‐curable alkyd resin was synthesized via a solvent‐free, enzyme‐catalyzed process to improve the performance of environmentally friendly coatings. Monoglycerides, glycidyl methacrylate, itaconic anhydride, phthalic anhydride, and succinic anhydride were employed as comonomers to systematically investigate the influence of different anhydride ratios on the properties of the cured films. The results demonstrated that increasing the succinic anhydride content significantly enhanced the flexibility of the films (from 15 to 3 mm), improved adhesion (from grade 3B to 4B), and elevated impact resistance (from 20 to 50 cm). The incorporation of flexible aliphatic segments from succinic anhydride not only improved the film‐forming properties but also enhanced adhesion to hydrophilic substrates. These findings offer valuable theoretical and practical insights for the formulation and application of UV‐curable alkyd resins in advanced functional coatings.