A series of new urethane methacrylate (UMA) monomers were synthesized with the reaction of ethylene carbonate and aliphatic amines, followed by the reaction with methacrylic anhydride. The monomers were characterized by 1H, 13C nuclear magnetic resonance (NMR), mass (MS), and Fourier transform infrared (FTIR) spectroscopies. Urethane latexes were prepared by monomer-starved semibatch polymerization of the new urethane methacrylates with methyl methacrylate (MMA) and butyl acrylate (BA). A uniform morphology and a unimodal particle distribution were observed by a combination of dynamic light scattering (DLS), ultrasound acoustic attenuation spectroscopy (UAAS), and transmission electron microscopy (TEM). The thermal stability, minimum film formation temperature (MFFT) and thermo-mechanical properties of the urethane latexes were also studied. The inclusion of urethane monomers appeared to have lowered the MFFT via a water plasticization effect, while enhancing the Tg of the final film properties.
Available online 8 December 2016