Characterization of cellulose in solvent mixtures with N-methylmorpholine-N-oxide by static light scattering

Drechsler, U.; Radosta, S.; Vorwerg, Waltraud

doi:10.1002/1521-3935(20001001)201:15<2023::aid-macp2023>3.0.co;2-6

Cited by 23 publications

(7 citation statements)

References 9 publications

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“…A refractive index (RI) detector and the software Cirrus v 3.1 (Polymer Laboratories, Amherst, MA, USA) were available. Prior to SEC analysis the samples were tricarbanilated by heterogeneous synthesis with phenyl isocyanate Drechsler et al 2000 ). This step included activation in pyridine, reaction with phenyl isocyanate at 80 ° C for 48 h, quenching by cooling and the addition of methanol (MeOH), precipitation of cellulose tricarbanilate with 100 ml MeOH and 625 μ l acetic acid, and washing with deionized water and MeOH before being dried.…”

Section: Methodsmentioning

confidence: 99%

Effect of various pulp properties on the solubility of cellulose in sodium hydroxide solutions

Kihlman

Aldaeus²,

Chedid³

et al. 2012

Holzforschung

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The dissolution of pulps with varying characteristic properties, for example cellulose chain length or content of hemicellulose, has been investigated in two alkaline solvent systems [sodium hydroxide (NaOH)/urea/thiourea (8:8:6.5 by wt.) and NaOH/zince oxide (ZnO) (9:0.5 by wt.)]. One standard paper pulp, two dissolving pulps and three pretreated pulps were selected for this study. The dissolution parameters in focus were the fi ber dimensions, average degree of poly merization (DP), polydispersity, water retention value and content of hemicelluloses. The solubility was not infl uenced by the fi ber dimensions. The only signifi cant properties, according to variable importance plot, were DP and composition of the hemicelluloses. It was also established that mass transfer effects during the dissolution stage plays an important role in the dissolution of cellulose derived from pulp fi bers.

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Section: Methodsmentioning

confidence: 99%

Effect of various pulp properties on the solubility of cellulose in sodium hydroxide solutions

Kihlman

Aldaeus²,

Chedid³

et al. 2012

Holzforschung

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“…In a ternary solvent system composed of NMMO, water, and diethylenetriamine [bis‐(2‐aminoethyl)‐amine], cellulose is molecularly soluble within a temperature range of 25–60 °C. Therefore, the average molar mass and other properties of the dissolved molecules could be determined by means of light scattering 43…”

Section: Structure and Properties Of Cellulose In The Solid State mentioning

confidence: 99%

Cellulose: Fascinating Biopolymer and Sustainable Raw Material

et al. 2005

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As the most important skeletal component in plants, the polysaccharide cellulose is an almost inexhaustible polymeric raw material with fascinating structure and properties. Formed by the repeated connection of D-glucose building blocks, the highly functionalized, linear stiff-chain homopolymer is characterized by its hydrophilicity, chirality, biodegradability, broad chemical modifying capacity, and its formation of versatile semicrystalline fiber morphologies. In view of the considerable increase in interdisciplinary cellulose research and product development over the past decade worldwide, this paper assembles the current knowledge in the structure and chemistry of cellulose, and in the development of innovative cellulose esters and ethers for coatings, films, membranes, building materials, drilling techniques, pharmaceuticals, and foodstuffs. New frontiers, including environmentally friendly cellulose fiber technologies, bacterial cellulose biomaterials, and in-vitro syntheses of cellulose are highlighted together with future aims, strategies, and perspectives of cellulose research and its applications.

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“…These samples were ball milled for 8 h at a frequency of 40 Hz (2,400 rpm). The molecular sizes/degrees of polymerization (DP) were determined by Standard Cuen and Cuoxam methods, the details of which can be found in Drechsler et al (2000). Molecular sizes of the two cellulose samples are shown on Table 1.…”

Section: Preparation Of Cellulose Samplesmentioning

confidence: 99%

The glass transition and crystallization of ball milled cellulose

et al. 2010

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Samples of ball milled cellulose were prepared by ball milling pulps from eucalyptus and softwood (spruce/pine). Water sorption isotherms were obtained by both dynamic vapor sorption and equilibration over saturated salt solutions, in the water content range of 5-42% db (db = dry basis; water as a % age of total solids). Dynamic mechanical analysis using a pocket technique showed a water content dependent thermal transition occurring at the same temperature for the two pulp samples, which was interpreted as a glass transition. Fitting the data to a Couchman-Karasz relationship predicted a value for T g of the dry cellulose of approximately 478 K, which was similar to values previously reported for other dry polysaccharides. No clear glass transition could be observed calorimetrically, although an endotherm at approximately 333 K was measured, which in polymers is normally attributed to enthalpic relaxation, however the lack of dependence of this endotherm on water content suggests that the melting of some weak associations, such as residual hydrogen bonds, could be a more credible explanation. An exotherm was also observed on heating, which was dependent on water content and which was attributed to partial crystallization of the cellulose. This was confirmed by Wide angle X-ray diffraction and cross polarization magic angle spinning 13C NMR (CPMAS NMR). The recrystallisation was predominantly to form I of cellulose. This was thought to be caused by a small amount of residual form I (probably less than 5%) acting as a template for the crystallizing material. Differential scanning calorimetry reheat curves showed the appearance of freezable water for water contents higher than 20%, as a result of a transfer of water to the amorphous phase following crystallization. The increase in cellulose rigidity following crystallization was also confirmed by CPMAS NMR relaxation. Low resolution proton NMR T 2 relaxation suggested the presence of proton water/cellulose exchange, which was active at water contents of 20% and above

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Characterization of cellulose in solvent mixtures with N-methylmorpholine-N-oxide by static light scattering

Cited by 23 publications

References 9 publications

Effect of various pulp properties on the solubility of cellulose in sodium hydroxide solutions

Effect of various pulp properties on the solubility of cellulose in sodium hydroxide solutions

Cellulose: Fascinating Biopolymer and Sustainable Raw Material

The glass transition and crystallization of ball milled cellulose

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