Changes in the intra- and inter-fibrillar structure of lyocell (TENCEL) fibers caused by NaOH treatment- August 28, 2008 Abstract Some effects of NaOH treatment at concentrations of up to 8 M on (1) the porous structure, (2) the degree of swelling, (3) carboxyl content using methylene blue sorption and 9H-fluoren-2-yl-diazomethane (FDAM) methods, (4) dyeing, (5) the molecular weight distribution measured by gel permeation chromatography (GPC), (6) crystallinity determined by wide angle X-ray diffraction (WAXD) and (7) the tensile properties of lyocell fibers were investigated. The porous...http://www.springerlink.com/content/8727866087134277/ Solid-state NMR studies of methyl celluloses. Part 1: regioselectively substituted celluloses as standards for establishing an NMR data basis- August 25, 2008 Abstract Three methyl celluloses with completely uniform substitution pattern, 2-O-methyl cellulose (1), 3-O-methyl cellulose (2) and 6-O-methyl cellulose (3), were prepared according to the cationic ring opening polymerization approaches starting from substituted 1,2,4-orthopivalate derivatives of d-glucose. These samples allowed for the first time to sort out the methyl substitution effects on solid-state NMR chemical shifts and relaxation. Dipolar dephasing experiments allowed...http://www.springerlink.com/content/75w14v8262367m67/ Strength and barrier properties of MFC films- August 19, 2008 Abstract The preparation of microfibrillar cellulose (MFC) films by filtration on a polyamide filter cloth, in a dynamic sheet former and as a surface layer on base paper is described. Experimental evidence of the high tensile strength, density and elongation of films formed by MFC is given. Typically, a MFC film with basis weight 35 gm2 had tensile index 146 18 Nmg and elongation 8.6 1.6%. The E modulus (17.5 1.0 GPa) of a film...http://www.springerlink.com/content/62n75308117vv430/ Synthesis of the perdeuterated cellulose solvents N -methylmorpholine N -oxide (NMMO-d11 and NMMO-15N-d11), N,N -dimethylacetamide (DMAc-d9 a- August 19, 2008 Abstract The syntheses of several perdeuterated substancessome of them isotopically labeled (15N) in additionare described, which act as direct solvents of cellulose either on their own, such as N-methylmorpholine N-oxide (NMMO), 1-butyl-3-methylimidazolium acetate (BMIM-OAc), or 1-ethyl-3-methylimidazolium acetate (EMIM-OAc), or in combination with auxiliaries, such as N,N-dimethylacetamide (DMAcfor the cellulose solvent DMAcLiCl). NMMO-d11 (9) was obtained in an eight-step...http://www.springerlink.com/content/wh323181181j8810/ Influence of ligand type and solution pH on heavy metal ion complexation in cellulosic fibre: model calculations and experimental results- August 15, 2008 Abstract Complexation of heavy metal ions such as Cu2+, Zn2+ and Co2+ by cellulosic fibres cotton, lyocell and viscose was studied in the pH range from pH 713. Glycine and sodium D-gluconate complexes were studied. Complex formation in the cellulose matrix depends on ligand, solution pH, complex species formed and type of cellulosic fibre. Species distribution in solution was calculated using the program SPE and literature data for formation constants of M2+-glycine and...http://www.springerlink.com/content/eutj3704126672h7/ Endoxylanase action towards the improvement of recycled fibre properties- August 15, 2008 Abstract The nature of recycled paper fibres varies widely. Those fibres contain high amounts of heteroxylans and lignin besides cellulose. In order to study the potential effect of xylanases on the quality of recycled fibres, chemithermomechanical pulp fibres (CTMP) are used as model substrates owing to their high content in non-cellulosic components. It has been found that the morphology of CTMP fibres changes by means of xylanase treatment. Treatments of CTMP fibres with an...http://www.springerlink.com/content/w12513272823w76v/ Degrees of polymerization (DP) and DP distribution of cellouronic acids prepared from alkali-treated celluloses and ball-milled native celluloses by T- August 6, 2008 Abstract Various cellulose II samples, ball-milled native celluloses and ball-milled wood saw dust were subjected to 2,2,6,6-tetramethypyperidine-1-oxyl radical (TEMPO)-mediated oxidation to prepare cellouronic acid Na salts (CUAs). The TEMPO-oxidized products obtained were analyzed by 13C-NMR and size-exclusion chromatography (SEC). When the cellulose II samples with degrees of polymerization (DP) of 220680 were used as the starting materials, the CUAs obtained had weight-average.http://www.springerlink.com/content/c667841367h1726j/ The influence of periodate oxidation on the moisture sorptivity and dimensional stability of paper- August 3, 2008 Abstract The hygroexpansion of paper was significantly reduced, up to 28% lower amplitude of change when the paper was subjected to a change in relative humidity from 20 to 85% RH, by oxidation of the fibre wall. Never-dried bleached kraft fibres were oxidised with sodium periodate, which specifically oxidises the C2C3 bond of 1,4-glucans so that the cellulose is partly converted into dialdehyde cellulose. Since both the dry and wet strength of laboratory sheets were significantly.http://www.springerlink.com/content/k545723381647u57/ |