A Schiff ́s base of chitosan (Glutamate glucan) was obtained by the reaction of chitosan with α-ketoglutaric acid (KGA) and sodium cyanoborohydride (SCB) as a reducing agent. The structure of glutamate glucan was characterized by 1H and 13C-NMR. The 1H-NMR analysis indicated that the degree of substitution (DS) of the product was 40%. The synthesized compound exhibited good solubility in water and in NaOH 1M. Its antibacterial activity against E. coli, S. aureus and M. luteus was explored by the optical density method. The antibacterial activity of glutamate glucan in solution was decreased presumably by its lower free –NH2 content. Chitosan and glutamate glucan were applied to Xerox paper and the antibacterial activity of the treated paper was evaluated by the bacteria reduction method. Paper treated with chitosan dissolved in 1% of acetic acid did not produce any notable activity against bacteria while a paper coated with glutamate glucan showed some inhibition. In this study, however, there was not a noticeable difference between the glutamate glucan and the control sample (untreated paper). Glutamate glucan has been previously evaluated as a dry and wet strength agent for paper. It increases the paper mechanical properties when applied on paper as a coating. Additionally, previous reports of our research group had showed the antifungical action of glutamate glucan. All these benefits together would surely increase its interest for application in the papermaking industry, especially to treat valuable old documents for their preservation.

Synthesis, characterization, and antibacterial activity evaluation of a water-soluble chitosan derivative and its application on paper

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.