QUATERNIZED XYLANS - SYNTHESIS AND STRUCTURAL CHARACTERIZATION

Quaternization xylans were prepared by treating xylans differing in st ructural and molecular properties with 3-chloro-2-hydroxypropyltrimeth ylammonium chloride (CHMAC) in aqueous NaOH under mild reaction condit ions. The degree of substitution with quaternary ammonium groups can b e monitored by altering the amount of CHMAC at optimum molar ratios of NaOH/CHMAC in the range 1.2-1.6, without changing the structure of th e xylan backbones. Hot water pretreatment of the xylans in the alkalin e activation step significantly enhances their reactivity. The presenc e of alkylammonium substituents was revealed by IR and NMR spectroscop y. The applicability of quaternized xylans as a retention aid in paper making is demonstrated on thermomechanical pulp. Xylans, therefore, re present an important renewable resource for the production of novel ca tionic biopolymers.