Das System Cellulose–Natriumhydroxyd–Wasser in Abhängigkeit von der Temperatur

Sobue, Hirosi; Kießig, H.; Heß, Kurt

doi:10.1515/zpch-1939-4324

Cited by 87 publications

(58 citation statements)

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“…It was found that cellulose shows a maximum swelling in aqueous alkali solutions in a specific concentration range, namely 8-10 wt% aqueous sodium hydroxide and 5-10 wt% aqueous lithium hydroxide, at a relatively low temperature. [4][5][6][7][8][9] These in-depth studies on cellulose swelling opened the door to cellulose dissolution in 8-10 wt% aqueous sodium hydroxide and in 6 wt% aqueous lithium hydroxide solution at 4 1C.…”

Section: Introductionmentioning

confidence: 99%

“…59,60 However, we should remember that several cellulose derivatives such as methyl cellulose or hydroxyethyl cellulose may be highly soluble in water even if they have a high, often as high as cellulose itself, capacity for intermolecular hydrogen bonding. In a well known salt system composed of cellulose/dimethylacetamide (DMAc)/LiCl the role of hydrogen bonding has been inferred by FTIR, NMR ( 13 C, 35 Cl, and 7 Li) and conductivity measurements. The authors suggested that the hydroxyl protons of cellulose form strong hydrogen bonds with the Cl À ions, during which the intermolecular hydrogen bonding networks of cellulose are broken with simultaneous splitting of the Li + -Cl À ion pairs.…”

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confidence: 99%

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The relevance of structural features of cellulose and its interactions to dissolution, regeneration, gelation and plasticization phenomena

Lindman

Medronho

Alves

et al. 2017

Phys. Chem. Chem. Phys.

196

109

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aCellulose is the most abundant polymer and a very important renewable resource. Since cellulose cannot be shaped by melting, a major route for its use for novel materials, new chemical compounds and renewable energy must go via the solution state. Investigations during several decades have led to the identification of several solvents of notably different character. The mechanisms of dissolution in terms of intermolecular interactions have been discussed from early work but, even on fundamental aspects, conflicting and opposite views appear. In view of this, strategies for developing new solvent systems for various applications have remained obscure. There is for example a strong need for using forest products for higher value materials and for environmental and cost reasons to use water-based solvents. Several new water-based solvents have been developed recently but there is no consensus regarding the underlying mechanisms. Here we wish to address the most important mechanisms described in the literature and confront them with experimental observations. A broadened view is helpful for improving the current picture and thus cellulose derivatives and phenomena such as fiber dissolution, swelling, regeneration, plasticization and dispersion are considered. In addition to the matter of hydrogen bonding versus hydrophobic interactions, the role of ionization as well as some applications of new knowledge gained are highlighted.

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Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

The relevance of structural features of cellulose and its interactions to dissolution, regeneration, gelation and plasticization phenomena

Lindman

Medronho

Alves

et al. 2017

Phys. Chem. Chem. Phys.

196

109

View full text Add to dashboard Cite

show abstract

“…Various factors influence the formation of Na-cellulose and cellulose II inter alia the origin and pretreatment of cellulose, temperature and alkali concentration (Sobue et al 1939;Purz and Fink 1983;Richter 1991). According to Richter (1991) transformation into the cellulose II lattice occurs after treatment with 7.5-10% NaOH starting from spruce sulfite pulp, and with 10-12.5% NaOH starting from cotton linters or sulfate pulp.…”

Section: Introductionmentioning

confidence: 99%

Influence of the Alkali Concentration on the Formation of Cellulose II. Study by X-Ray Diffraction and FTIR Spectroscopy

Fengel¹,

Jakob²,

Strobel³

1995

HFSG

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The comparative study shows that the lattice transformation Cellulose I/II as evaluated by X-ray diffraction is reflected in the CHa/OH valency vibration range of deconvoluted FTIR spectra. The two methods supplement each other. The phase transition begins with a NaOH concentration of 11-12% and is completed with one of 16.5%. Various changes in the molecular and supramolecular structure of cellulose in this alkali concentration range were identified. The transformation process is determined by splitting and new formation of inter-and intramolecular Η-bonds. There is a direct correlation between decrease in crystallinity and Η-bond splitting. The conformational variation in the cellulose molecules is the result of the interaction between inter-and intramolecular Η-bonds during chain rotation.

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“…According to Sobue et al [16] , the formation of potash (K) cellulose (K-Cell) occurs at well-defined KOH concentrations and temperature. Potash (K) cellulose of a crystalline character were well defined according to their X-ray diffraction diagram.…”

Section: Effect Of Mercerization With Koh In Hot and Normal Conditionsmentioning

confidence: 99%

Role of Urea on the Physico-Mechanical and Degradable Properties of Mercerized and Acid Hydrolyzed Coir (Cocos nucifera) Fibers Photocured with 1,6-Hexanediol Diacylate

Khan

Taslima

Mustafa

2005

Polymer-Plastics Technology and Engineering

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Coir fibers were modified with 1,6-hexanediol diacrylate (HDDA) by using ultraviolet (UV) radiation. Concentration of HDDA, soaking time, and radiation dose were optimized and found to be 30% HDDA in methanol along with photoinitiator Irgacure-500 (2%) and 120 min of soaking time the better performance registered as the optimum conditions, where polymer loading (PL) was 17% and tensile strength (TS) was 50%. Urea of different concentrations (0.5-2%) was incorporated with 30% HDDA to monitor its effect on the properties and 1% urea produced the enhanced PL (25%) and TS (82%). For the improvement of the properties, the fibers were subjected to surface treatment with alkali (5% potassium hydroxide) at various mercerizing times in hot and normal conditions. Among all the mercerized fibers, fibers treated with hot alkali for 6 h and cured under optimized condition demonstrated the maximum enhancement of PL (35.5%) and TS (130%). The fibers were also subjected to acid hydrolysis for different times with different acid (H 2 SO 4 ) concentrations. Again the effect of urea (1%) on the properties of the pretreated fibers was scrutinized. Water uptake and degradable properties of the treated and virgin fibers were performed.

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Das System Cellulose–Natriumhydroxyd–Wasser in Abhängigkeit von der Temperatur

Cited by 87 publications

References 0 publications

The relevance of structural features of cellulose and its interactions to dissolution, regeneration, gelation and plasticization phenomena

The relevance of structural features of cellulose and its interactions to dissolution, regeneration, gelation and plasticization phenomena

Influence of the Alkali Concentration on the Formation of Cellulose II. Study by X-Ray Diffraction and FTIR Spectroscopy

Role of Urea on the Physico-Mechanical and Degradable Properties of Mercerized and Acid Hydrolyzed Coir (Cocos nucifera) Fibers Photocured with 1,6-Hexanediol Diacylate

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