Isocyanate-free urethane modified vinyl ester resin: synthesis, characterization and mechanical properties

In this paper, we report the production of a mixture of urethane modified vinyl ester resin through the non-isocyanate polyurethane method without using the poisonous material phosgene. Initially, treatment of 2-((4-((oxirane-2-yl)methoxy)butoxy)methyl)oxirane with methacrylic acid produces a mixture of 3-(((oxirane-2-yl)methoxy)butoxy)-2-hydroxypropyl methacrylate and its non-methacrylated and dimethacrylated analogues (here simply termed OMBM). Then, cyclic carbonate of the as-prepared compound is obtained through treatment of OMBM and carbon dioxide gas applying different catalysts. The reaction of synthesized cyclic carbonate with various diamines produces isocyanate-free urethane modified vinyl ester resin. Afterwards, the corresponding products were cured with varying percentages of vinyl ester resins, applying benzoyl peroxide and N,N-dimethyl aniline as initiator and accelerator, respectively, to enhance the mechanical characteristics of the vinyl ester resins such as tensile strength and elongation. Various characterization methods such as Fourier transform IR, NMR, swelling and tensile tests are conducted to confirm the success of the reactions. (c) 2022 Society of Industrial Chemistry.