Antioxidant activities of peptoid-grafted chitosan films.

International audienceThe aim of this study was to investigate the possibility of immobilizing peptoid on chitosan film in order to generate new active material. Chitosan films have been grafted for the first time with short-length peptoid oligomers displaying antioxidant activities. The antioxidant activity of the selected peptoids was initially investigated with the DPPH assay and hydroxyl radical procedure. The metal chelating capacity of peptoids was also evaluated prior to their covalent attachment to chitosan. The benefit of chitosan functionalization with respect to its intrinsic antioxidant properties was finally evaluated in the present study. Interestingly, an increase of up to 90 % of the antioxidant activity of chitosan was observed

Kraft Pulp–Starch Covalent Linking: A Promising Route to a New Material

International audienceWe reported herein, the synthesis process of a direct cross-linking of modified polysaccharides. azidated starch, and alkyne Kraft pulp were cross-linked in the presence of Cu(I) catalyst, a type of Huisgen’s 1,3-dipolar azide–alkyne cycloaddition reaction, leading to the formation of starch cross-linked to kraft pulp fiber. The modified polysaccharides were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM), and their physical properties were tested. The results show that the obtained novel material’s properties present an important enhancement compared to Kraft pulp fiber, about 71% and 44% for tear and break indexes respectively, up to 173% for elongation and of 136% for burst index