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  • Non-isocyanate epoxy vinyl ...
    Ghasemi, Soheila; Ghezelsofloo, Milad; Naeimi, Mahsa; Tamami, Bahman; Allahyari, Hamed

    Iranian polymer journal, 06/2024, Letnik: 33, Številka: 6
    Journal Article

    Vinyl ester resins (VERs) are one of the main categories of polymeric matrices for fabrication of high-performance commercial composites. They have more desirable properties compared with unsaturated polyester resins. Inserting urethane functional groups in the structure of VERs and producing urethane vinyl ester resin (UVER) improve its impact and chemical resistance, enlongation and toughness. The use of isocyanate as the primary resource in urethane preparation, which is derived from phosgene toxic material, may be associated with environmental hazards; as a result, non-isocyanate polyurethane (NIPU) methods have been developed. Herein, we have described the preparation and characterization of UVER by isocyanate-free system. First, cyclic carbonates of epoxides, 2-hydroxy-3-(4-(oxiran-2-ylmethoxy)butoxy)propyl methacrylate (HOMBPM) and diglycidyl ether of bisphenol-A epoxy resin (DGEBA) were synthesized by treatment of the corresponding epoxides with atmospheric pressure of carbon dioxide and tetrabutylammonium bromide (TBAB) as a catalyst. Then, the as-prepared cyclic carbonates were reacted with ethylenediamine in the presence of different catalysts to produce non-isocyanate epoxy vinyl ester urethane prepolymer. UVER is a potential compound for curing with VERs and fabricating materials with superior mechanical features such as elongation and tensile strength in comparison to VERs. Characterization techniques such as FTIR, 1 H and 13 C NMR spectroscopy and titration methods for measurements of epoxy equivalent weight (EEW), acid number and amine value are used in the synthesis of the desired compounds. Graphical Abstract