Activation energy of copper-induced thermal degradation of chitosan acetate functional groups

Thin films of chitosan acetate (CSA)-copper (II) [Cu (II)] complex were prepared by mixing Cu (II) oxide (CuO) nanoparticles in acetic acid solution of chitosan and the casting method. The changes in chemical structure of modified chitosan were confirmed by UV-Vis spectroscopy. Fourier transform infrared (FTIR) spectroscopy was applied to monitor thermal degradation processes occurring in chitosan and its composites with Cu. The changes in concentration of chitosan functional groups were observed. On a base of the kinetic constants of group thermal degradation at various temperatures, the activation energies for various groups were calculated. It was found that the presence of Cu (II) ions accelerates the thermal degradation of chitosan acetate. The higher the Cu (II) content was in the CSA matrix, the lower was the activation energy.