Synthesis and characterization of injectable photocrosslinking poly (ethylene glycol) diacrylate based hydrogels

The poly (ethylene glycol) diacrylate (PEGDA)-based hydrogels were prepared by UV radiation under nitrogen, using PEGDA and 2-hydroxyethyl methacrylate (HEMA) as precursors. The PEGDA and HEMA precursors were respectively added into distilled water at a predetermined feed ratio. 2-Hydroxy-1-[4-(hydroxyethoxy)phenyl]-2-methyl-1-propanone (Irgacure2959) was used as a photoinitiator. The PEGDA-based hydrogels were characterized by FT-IR spectra, interior morphology, equilibrium swelling ratio, and Dynamic contact angle (DCA). The results showed: (1) -C=C- bonds of PEGDA and HEMA disappeared after photocrosslinking, which indicated hydrogel formation by consuming -C=C- bonds; (2) swelling ratio of the hydrogels were greatly influenced by the additive precursor ratios and microporous net; (3) with HEMA content increasing in PEGDA-based hydrogels, equilibrium water content (EWC) increased and the contact angle decreased, which resulted from the strong H-bonding interactions of HEMA between the polymer and water.