Fig. 2. Characterization of the PU-AAm emulsion. (A) 1H NMR spectra (DMSO, 400 MHz, 25 °C) of AAm (a), PU (b) and PU-AAm emulsion (c); (B) ROESY spectrum of the PU-AAm emulsion; (C) particle-size distribution of PU-AAm emulsions (pure PU represents PU emulsion with 30% (w/w) solid content); (D) UV curing time of different hydrogels (n = 3); (E) FT-IR spectra of PU film, PAAm and PU-PAAm hydrogels.
