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The influence of ex...
The influence of extended mercerization on some properties of carboxymethyl cellulose (CMC)
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- Almlöf, Heléne, 1968- (author)
- Karlstads universitet,Avdelningen för kemiteknik
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- Kreutz, Bjørn (author)
- Borregaard Chemcell, Norway
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- Jardeby, Kristina (author)
- Borregaard Chemcell, Norway
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- Germgård, Ulf, 1950- (author)
- Karlstads universitet,Avdelningen för kemiteknik
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(creator_code:org_t)
- 2012
- 2012
- English.
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In: Holzforschung. - 0018-3830 .- 1437-434X. ; 66, s. 21-27
- Related links:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Subject headings
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- Carboxymethyl cellulose (CMC) is produced commercially in a two stage process consisting of a mercerization stage in which the pulp is treated with alkali in a water alcohol solution and a second etherification stage whereby monochloro-acetic acid is added to the pulp slurry. In this study, the influence of the conditions of an extended mercerization stage was evaluated on the etherification stage concerning the degree of substitution (DS) and the filterability of the resulting CMC. The parameters studied were: (1) the ratio of cellulose I and cellulose II in the original pulp, (2) the concentration of alkali, (3) the temperature and (4) the retention time in the mercerization stage. The DS results indicate that the NaOH concentration in the mercerization stage is the most important among the parameters studied. When the NaOH concentration in the mercerization stage was high (27.5%), cellulose II showed a lower reactivity than cellulose I with respect to the DS obtained in the resulting CMC. The results from the filtration ability of CMC water solutions are interpreted that the amount of cellulose II in the original pulp and the temperature has a negative influence, while the NaOH concentration in the mercerization stage has a positive influence on the filtration ability. Retention time between 1 h–48 h in the mercerization stage had no effect on the DS or the filtration value. The filtration ability was assumed to be highly influenced by the presence of poorly reacted cellulose segments. The CMC samples with the lowest filtration ability at a given DS can be assumed to have the highest degree of unevenly substituted segments.
Subject headings
- TEKNIK OCH TEKNOLOGIER -- Kemiteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Chemical Engineering (hsv//eng)
Keyword
- alkali
- carboxymethyl cellulose
- cellulose I
- cellulose II
- degree of substitution
- filterability
- mercerization
- Chemical Engineering
- Kemiteknik
Publication and Content Type
- ref (subject category)
- art (subject category)
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