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  • 1
    Electronic Resource
    Electronic Resource
    Acid hydrolysis of carboxymethylcellulose of low degree of substitution (1990)
    Springer
    Colloid & polymer science 268 (1990), S. 649-657 
    Details
    ISSN: 1435-1536
    Keywords: Carboxymethylcellulose ; cellulose derivatives ; acidhydrolysis ofcellulose ; accessibility ofcellulose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410407
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  • 2
    Electronic Resource
    Electronic Resource
    Equilibrium sorption of crystal violet by carboxymethylated cellulose with low degree of substitution (1989)
    Springer
    Colloid & polymer science 267 (1989), S. 915-922 
    Details
    ISSN: 1435-1536
    Keywords: Carboxymethylcellulose ; cellulosederivatives ; equilibriumsorption ; cationicdye ; Langmuir-isotherm ; cooperativesorption ; structure ofboundwater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cellulose fabric samples were carboxymethylated for different duration. The degree of substitution was changing through a maximum value during the reaction time. The equilibrium sorption of a cationic dye by cellulosic fibers of different degrees of carboxymethylation was investigated in buffered and in unbuffered systems. The sorption isotherms were interpreted by two kinds of approximations based upon Langmuir isotherm. From the sorption data extrapolated to zero dye concentration affinities were calculated. The temperature dependence of affinities gave the values of heat and entropy of dyeing which were changing along the reaction time similarly to the degree of substitution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410340
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  • 3
    Electronic Resource
    Electronic Resource
    Iodine sorption, porosity, and wettability of carboxymethylcellulose of low degree of substitution (1989)
    Springer
    Colloid & polymer science 267 (1989), S. 349-352 
    Details
    ISSN: 1435-1536
    Keywords: Carboxymethylcellulose ; cellulosederivatives ; iodinesorption ; accessibility ; porosity ; wettability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cellulosic fabric was carboxymethylated by single-bath method for different durations. $$\overline {DS} $$ arrived at a maximum when plotted against the time of reaction. This might be interpreted by the dissolution of the highly substituted fractions. The fibrous character of the carboxymethylated samples $$(\overline {DS} = 0.045 - 0.075)$$ remained unchanged, but the accessibility of the cellulose characterized by iodine sorption, porosity, and wettability changed significantly. The carboxymethylation had a complex effect on the investigated parameters: the values of accessibility were increasing initially, caused by opening the fibrillar structure, but decreasing later as the swollen structure was collapsing during air-drying. The studied properties were depending not only on the changes in $$\overline {DS} $$ but also on the reaction parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01413629
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