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  • 1
    Electronic Resource
    Electronic Resource
    Dissolution mechanism of cellulose in SO2-amine-dimethylsulfoxide (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 33 (1987), S. 1283-1290 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The dissolution mechanism of cellulose in SO2-amine-dimethylsulfoxide systems was studied by using 1H- and 13C-NMR spectroscopy. SO2 and amine (diethylamine or triethylamine) were found to form a complex in DMSO, and the SO2-amine complex, in turn, reacts with an alcoholic hydroxyl group of methanol to produce a new complex. In the case of cellulose, it was proved that all hydroxyl groups in cellulose react with the SO2-amine complexes and form the same complexes in the solution state as those formed in methanol.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070330419
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  • 2
    Electronic Resource
    Electronic Resource
    Dissolving states of cellulose and chitosan in trifluoroacetic acid (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 45 (1992), S. 1857-1863 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Chemical structures of cellulose and chitosan dissolved in trifluoroacetic acid (TFA) and those of cellulose and chitosan films cast from their TFA solutions were studied by 13C-NMR and infrared (IR) spectroscopy. Cellulose is trifluoroacetylated selectively at the C6-hydroxyl groups in the TFA solution, and chitosan is dissolved in TFA by forming amine salts with TFA at the C2-amine groups. IR analyses of cellulose films cast from its TFA-acetic acid solutions showed that partly trifluoroacetylated cellulose in the solution state turns to partly acetylated cellulose in the solid state during evaporation of the solvents in air by the ester interchange. Chitosan films cast from its TFA-acetic acid solutions still have the amine salts with TFA. These acetyl groups in cellulose films and TFA in chitosan films are removable by soaking the films in 1N NaOH at room temperature for 1 day.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070451020
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  • 3
    Electronic Resource
    Electronic Resource
    Characterization of cellulose-chitosan blend films (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 45 (1992), S. 1873-1879 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Interactions between cellulose and chitosan molecules in cellulose-chitosan blend films, prepared using trifluoroacetic acid as a cosolvent for the two polysaccharides, were studied by X-ray diffraction and Raman analyses and by measurements of mechanical properties of the blend films. Crystallinity of cellulose in the blend films decreased with an increase in chitosan content. The blend films had tensile strengths of 45-100 MPa and Young's moduli of 2-7.5 GPa in dry states. These values had the maximum around 30% chitosan content in the blend films. These results suggested the presence of interactions between cellulose, chitosan, and water molecules in the films. However, Raman analysis suggested that cellulose and chitosan molecules in the blend films seemed to have the same secondary structures as those in 100% cellulose and 100% chitosan films, respectively. Thus, these results indicate the presence of interactions in the interfacial region between small domains of cellulose and chitosan. The presence of chitosan molecules may lead to decrease in the domain size of cellulose, and to increase in the interfacial region between cellulose and chitosan domains.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070451101
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  • 4
    Electronic Resource
    Electronic Resource
    Thermal and structural properties of tri-O-substituted cellulose ethers (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 345-353 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Tri-O-substituted cellulose ethers prepared by the use of SO2-diethylamine (DEA)-dimethylsulfoxide (DMSO) and powdered sodium hydroxide were characterized by measurement of melting points and degradation points and by differential scanning calorimetric (DSC) and X-ray analyses. Their thermal and structural characteristics were ascertained to be dependent on the kinds of substituents. Among the ethers examined, four kinds of arylmethylcelluloses showed the characteristics of thermotropic liquid crystals (smectic). Tri-O-α-naphthylmethyl-cellulose showed the three transformations due to a solid-smectic phase, a smectic-nematic phase, and a nematic-isotropic phase transformation. This thermotropic liquid crystal was enantiotropic below 200°C.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070300130
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  • 5
    Electronic Resource
    Electronic Resource
    Preparation of Tri-O-alkylcellulose by the use of a nonaqueous cellulose solvent and their physical characteristics (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 31 (1986), S. 341-352 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Tri-O-methyl-, -ethyl-, -n-propyl-, -n-butyl-, -n-pentyl-, -iso-amyl-, -n-hexyl-, -n-heptyl-, -n-octyl-, -n-decyl-, and -3-phenoxypropyl-celluloses have been prepared with powdered sodium hydroxide and the corresponding alkyl iodides or bromides in one of nonaqueous cellulose solvents, SO2-diethylamine-dimethylsulfoxide. These new tri-O-alkylcelluloses were characterized by infrared spectra, 13C-NMR spectra, and optical rotations. The first six tri-O-alkylcelluloses described above were obtained as white powders and most of them (tri-O-methyl-, -ethyl-, -n-propyl-, and -n-pentyl-celluloses) showed thermotropic liquid crystals due to smetic or short pitch cholesteric phases. On the other hand, the latter five derivatives were obtained as gummy solids even at room temperature, and easily showed lyotropic liquid crystals in their concentrated chloroform solutions due to choresteric phases. some of these tri-O-alkyl-celluloses (tri-O-methyl-, -ethyl-, -n-propyl-, and -n-butyl-celluloses) were characterized by differential scanning calorimetric and X-ray diffractometric analyses.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1986.070310205
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  • 6
    Electronic Resource
    Electronic Resource
    Preparation of tri-O-benzylcellulose by the use of nonaqueous cellulose solvents (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 2097-2109 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A procedure has been developed for preparing tri-O-benzylcellulose with higher yields than 90%. In this procedure, cellulose was dissolved in a nonaqueous cellulose solvent, SO2-diethylamine (DEA)-dimethyl sulfoxide (DMSO), and then powdered sodium hydroxide was added. To the suspension thus prepared, benzyl chloride was added in four portions under heating. Chemical and physical properties of tri-O-benzylcellulose were studied, and tri-O-benzylcellulose prepared from microcrystalline cellulose powder shows the characteristic of thermotropic liquid crystal.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1984.070290617
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  • 7
    Electronic Resource
    Electronic Resource
    Preparation of tri-O-substituted cellulose ethers by the use of a nonaqueous cellulose solvent (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 3873-3882 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The previously reported method for the preparation of tri-O-benzylcellulose was applied to the preparation of various tri-O-substituted cellulose ethers. By this method, in which a mixture consisting of SO2, diethylamine (DEA), and dimethylsulfoxide (DMSO) and powdered sodium hydroxide were used as a cellulose solvent and a base, respectively, many tri-O-arylmethylcelluloses could be prepared from the corresponding chlorides. Cellulose ethers containing double bonds such as tri-O-allyl, tri-O-methallyl-, and tri-O-2-butenylcellulose were also prepared from the corresponding chlorides under a milder condition than that used for the preparation of tri-O-arylmethylcelluloses. Reaction factors accelerating complete etherification were discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1984.070291220
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  • 8
    Electronic Resource
    Electronic Resource
    Preparation of completely allylated and methallylated celluloses from methylcellulose and cellulose acetate (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 55-63 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Cellulose ethers having various amounts of carbon - carbon double bonds were prepared by allylation or methallylation of commercial methylcellulose (DS = 1.6). Namely, methylcellulose dissolved in dimethylsulfoxide (DMSO) was treated with allyl chloride or methallyl chloride in the presence of powdered sodium hydroxide as a base. Tri-O-allyl and tri-O-methallyl celluloses were also prepared easily from commercial cellulose acetate (DS = 1.75) with powdered sodium hydroxide and the corresponding chlorides. Thermal stabilities of these cellulose derivatives and their behaviors to oxygen in the air were studied by the use of TG-DSC and solubility test, respectively.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070340105
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