Xylan quaternized sulfate films were prepared from beech xylan (X) and compared with fully sulfated xylan films (XS). When quaternized xylan (QX) was prepared in the first step (DS(Q)=0.55), than by sulfation of QX in the second step the fully substituted ampholytic derivative (QXS; DS(Q)=0.33; DS(S)=1.67) could be obtained. By sulfation in first step, xylan sulphate (SX, DS(S)=0.70) was obtained and by subsequent quaternization, SXQ film with DSQ=0.55 and DSS=0.33 which contained partially unsubstituted hydroxyls. The molar masses (M(n)) of the film's soluble parts were increasing in order X<SX<SXQ<QX<XS<QXS. In all films there were some insoluble particles present as determined by the amount of recovered masses by SEC-MALS. The materials were further characterized by AFM, XRD, TG/DTG/DTA, NMR and mechanical testing. QXS and SXQ could form mechanically more stable films than XS specimens.
Keywords: Composites; Films; Mechanical testing; Thermal properties; Xylan.
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