Synthesis and characterization of birch wood xylan succinoylated in 1-n-butyl-3-methylimidazolium chloride

Abstract

The chemical modification of birch wood xylan was undertaken in the ionic liquid 1-n-butyl-3-methylimidazolium chloride (C₄mimCl) using three different long-chain succinic anhydrides: n-octenyl succinic anhydride (n-OSA), n-dodecenyl succinic anhydride (n-DDSA) and n-octadecenyl succinic anhydride (n-ODSA). Reactions were performed at temperatures of 80–100 °C and reaction times of 0.5–22 hours resulting in a degree of substitution (DS) of 0.08–0.27. The formation of the desired products was confirmed through the use of ¹H NMR and FT-IR, while DS was determined by titration. Thermogravimetric analysis of the modified and native xylans showed a slight lowering of thermal stability with functionalization. Contact angle measurements on spin-coated surfaces of modified xylan films showed a significant increase in hydrophobicity with the introduction of the alkenyl-functionalized succinic anhydride moieties.