Preparation of UV Curable Resins and their Toughening Effect on Bisphenol A‐Type Epoxy Acrylate

Abstract UV‐curable oligomers were synthesized by the reaction of ethylene glycol (EG) or 1,4‐butanediol (BDO) with isophorone diisocyanate (IPDI), and then terminated with hydroxyethyl acrylate (HEA). The chemical structures and molecular weight of the two oligomers were analyzed by Fourier transform infrared spectroscopy (FT‐IR), nuclear magnetic resonance ( 1 H NMR and 13 C NMR) and high performance liquid chromatography (HPLC). The obtained UV‐curable oligomers were separately mixed with bisphenol A‐type epoxy acrylate (EA) in different mass ratios. The resulting mixture was then mixed with the active diluent tetrahydrofuran acrylate (THFA) and the photoinitiator ethyl 2,4,6‐trimethylbenzoylphosphonate (TPO‐L) for UV curing. The curing reactions were performed at UV light intensity of 120 mW/cm 2 . The unsaturation conversion was monitored by real‐time infrared spectroscopy (real‐time FT‐IR). The mechanical properties and coating properties of the UV‐cured products were analyzed. The results showed that the synthesized UV‐curable oligomers had good toughening effect on EA, and the tensile strength of EA was also improved.