Mannich reaction of polysaccharides: Xylan functionalization in aqueous basic medium

In this study modification of xylan via Mannich reaction in aqueous basic solution to obtain dimethylaminomethylated products and characterization of modified xylan were examined. Components were xylan (obtained from corn cob and used without modification) as active hydrogen containing compound, formaldehyde as carbonyl compound having no α-hydrogen and dimethylamine. Mannich reaction was used with different parameters such as component concentration, reaction temperature, and time. The highest modification was observed about 35 °C with a nitrogen content of 4.6% by weight indicating successive modification. Both 1D and 2D NMR measurements displayed new signals related with aminomethyl groups. Spectral characterizations indicated that aminomethylation took place on oxygen sites. Moreover modified xylan could form film while xylan could not without an auxiliary agent. Antimicrobial activity tests indicated that modified xylan acted as a bacteriostatic material.