Preparation and investigation of a urethane methacrylate containing a tert-butyl terminal group in urethane/acrylate hybrid latexes

A urethane methacrylate with a tert-butyl terminal group, 2-((tert butylcarbamoyl)oxy) ethyl methacrylate (tBEM), was synthesized and incorporated into a series of homogeneous and core-shell model acrylate latexes. Unlike urethane methacrylates with linear or cyclic alkyl terminal groups, the tert-butyl group seems to preclude urethane formation, other than a direct approach of reacting tert-butyl isocyanate with 2-hydroxethyl methacrylate (HEMA) was employed. The effect of tBEM content on latex performance was investigated using minimum film formation temperature (MFFT) tester, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile tests and Fourier transform infrared spectroscopy (FTIR). Increasing the loading level of tBEM led to an increase in film stiffness and tensile strength.