Briefly, the absorbance bands at 3368 and 1525 cm -1 correspond to stretching vibrations of N-H in urethane groups. The band at 1643 cm -1 corresponds to stretching vibrations of C=C from the coupling of HEMA, and methacrylate from methacrylated L-DOPA. Meanwhile, the bands 2921 and 2853 cm -1 correspond to stretching vibrations of C-H in -CH2 and -CH3. The band at approx. 1732 cm -1 is characteristic for stretching of C=O in ester bonds of the macromonomer.