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2,3-Dialdehyde celluloses were prepared by homogeneous periodate oxidation in an aqueous solution of methylol cellulose. Since methylol cellulose stays dissolved in water for a certain time before decomposing gradually into regenerated cellulose, the oxidation reaction progressed homogeneously throughout the period. The resulting dialdehyde cellulose achieved an oxidation level of over 90 % in as little as 12 h. Reducing the dialdehyde celluloses with NaBH4 resulted in water-soluble dialcohol celluloses, which have an open-ring structure at the C2-C3 position. The dialcohol celluloses were characterized using nuclear magnetic resonance spectrometry, Fourier transform infrared spectroscopy, and differential scanning calorimetry. The T-g of the products decreased with increasing oxidation levels. The products might be processable, and unique tensile properties were obtained by cutting the C2-C3 bonds in the glucopyranose rings. The dialcohol celluloses prepared using a cast method yielded clear and transparent films which showed unique mechanical properties by tensile tests depending on the values of oxidation level., QC 20140306

Biobased polymers such as starch and hemicelluloses from wood are of interest for packaging applications, but suffer from limitations in performance under moist conditions. Xyloglucan from industrial tamarind seed waste offers potential, but its Tg is too high for thermal processing applications. Regioselective modification is therefore performed using an approach involving periodate oxidation followed by reduction. The resulting polymer structures are characterized using MALDI-TOF-MS, size-exclusion chromatography, FTIR and carbohydrate analysis. Films are cast from water and characterized by thermo-gravimetry, dynamic mechanical thermal analysis, dynamic water vapor sorption, oxygen transmission and tensile tests. Property changes are interpreted from structural changes. These new polymers show much superior performance to current petroleum-based polymers in industrial use. Furthermore, this regioselective modification can be carefully controlled, and results in a new type of cellulose derivatives with preserved cellulose backbone without the need for harmful solvents., QC 20130514. Updated from accepted to published.

Mechanicalpropertiesofdialcoholcellulosefilmsprepared by homogeneous periodate oxidation were studied. Dialdehydecellulosewith a high oxidation level (over 90%) was prepared by the oxidation for 12 hours in an aqueous solution of methylolcellulose. By reducing the dialdehydecellulosewith NaBR), water-solubledialcoholcellulosewhich has open ring structure at C2-C3 position was obtained. Thedialcoholcellulosewas characterized using NMR, FTIR and DSC. Thedialcoholcellulosegave a clear and transparentfilm, which was subjected both to tensile and DMA tests., QC 20120214

QC 20200313