Structural Analysis of Spiropyran Polimers using ATR Spectroscopy

We have used infrared spectroscopy in attenuated total reflection (ATR) mode to analyze the interactions between the polymeric base and solvent with a photochromic material (spyropiran). We used cellulose acetate as polymeric base and the spyropiran; 1,3,3 trimethyl indoline-5-nitro benzopyrane. Thin films with different weight concentrations of SP were deposited in the polymeric base. The infrared spectra show bands whose frequencies are associated to several molecular bondings. It was observed a decreasing in intensity of absorbance for C=O stretching mode of the acetate group at 1720 cm^-1 and for C=C stretching mode for the main chain at 823 and 982 cm^-1 both associated to the presence of SP in polymeric films.