Effect of UV-irradiation and hydrogen peroxide on the molecular weight of chitosan

چکیده مقاله

Molecular weight of chitosan was reduced, by using ultraviolet (UV)irradiation (wavelength=254 nm) and hydrogen peroxide (H₂O₂) simultaneously. The efficiency of the depolymerization was demonstrated by means of determination of viscosity-average molecular weight. The structure of the depolymerized chitosan was X-ray diffraction (XRD), Nuclear magnetic resonance (¹H NMR). ¹H NMR studies demonstrated the breakage of 1,4-β-D-glucoside bonds of chitosan. XRD quantitative analysis showes that crystalline structure of the chitosan changed during depolymerization.  Furthermore, during the process of depolymerization of chitosan, the original chemical structure of depolymerized chitosan was not changed and just its molecular weight decreased. The results showed that combined UV-irradiation/H₂O₂ method was significantly efficient for preparing low molecular weight chitosan and could be applied in scale-up production of the depolymerized chitosan

دریافت لینک دانلود مقاله