New insights into the mechanism of photodegradation of chitosan

Chitosan films were subjected to accelerated artificial weathering at ?>300 nm and 60 °C in the presence of O2. The resulting variations chemical structure characterized by IR spectroscopy UV–vis spectroscopy, a photooxidation mechanism was proposed based on identified oxidation photoproducts. formation gluconolactone derivatives leading chain scissions shown. In addition, low molecular weight photoproducts, which accounted for chitosan deacetylation, detected. Furthermore, crosslinking reactions occurred, as revealed gel fraction characterization. Variations mechanical surface properties AFM, reduction macroscopic correlated with structural changes observed scale multiscale approach.