Preparation of a Near-Infrared Ray Absorption Film from N-Phenylthiocarbamoyl Chitosan Derivative

摘要

We recently observed that the decanoylation of N-phenylthiocarbamoyl chitosan (>2) with a mixture of decanoic anhydride and pyridine at 60 °C for 24 h afforded N,N-(decanoyl)phenythiocarbamoyl-/2-isothiocynato chitosan decanoate (>3b) rather than the expected product N,N-(decanoyl)phenylthiocarbamoyl chitosan decanoate (>3a). This result suggested that some of the N,N-(decanoyl)phenylthiocarmbamoyl groups had been converted to isothiocyanate groups during the decanoylation process. The subsequent reaction of compound >3b with aniline gave N,N-(decanoyl)phenylthiocarbamoyl/N-phenylthiocarbamoyl chitosan decanoate (>4) in high yield. A solution of compound >4 in CHCl3 was then added to a solution of copper decanoate (>5) in the same solvent, and the resulting mixture was cast onto a glass plate to give a cast film. The film was annealed at 200 °C in an oven to give a greenish film, which showed good near-infrared absorption characteristic in the range of 800–2200 nm.