RESUMO
Chitosan was effectively degraded by hydrogen peroxide under irradiation with ultraviolet light. The existence of a synergetic effect on the degradation was demonstrated by means of viscometry. In addition, the optimal conditions of degradation were determined on the basis of orthogonal tests. The structure of the degraded product was characterized by Fourier-transform infrared spectra (FTIR) analysis and diffuse reflectance spectra (DRS) analysis. The mechanism of the degradation of chitosan was correlated with cleavage of the glycosidic bond.
Assuntos
Quitosana/química , Quitosana/efeitos da radiação , Peróxido de Hidrogênio/farmacologia , Raios Ultravioleta , Quitosana/metabolismo , Minerais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral , Viscosidade/efeitos dos fármacos , Viscosidade/efeitos da radiaçãoRESUMO
A new supramolecular compound (C(10)H(8)N(2))(3.2).H(3)PW(12)O(40).25.6H(2)O (Bipy-PW(12)) was synthesized by self-assembly design, and characterized by elemental analysis, Fourier-transform infrared spectra (FTIR), and (31)P NMR spectra. Bipy-PW(12) can effectively catalyze oxidative degradation of chitosan with H(2)O(2) in heterogeneous phase. To obtain water-soluble chitosan with an average molecular weight of 5000, the optimum reaction conditions were determined as follows: reaction temperature, 80 degrees C; reaction time, 13min; H(2)O(2) concentration, 2.7mol/L; and mass ratio of Bipy-PW(12) to chitosan, 0.01.