178973.fig.004
Figure 4: FTIR spectra of (a) TA, (b) PU, TA-PU films prepared by method I in ratios (c) 1 : 2, (d) 1 : 5, TA-PU films prepared by method II in ratios (e) 1 : 2, (f) 1 : 5. The dotted lines and arrows are highlighting the regions that show complexation and intermolecular hydrogen bonding between TA and PU films.