Tyck till om SwePub Sök
här!
Search: id:"swepub:oai:DiVA.org:umu-153349" >
Variation of the al...
Variation of the alkalisation conditions during the synthesis of a cellulose ether
-
- Albán Reyes, Diana Carolina (author)
- Umeå universitet,Kemiska institutionen,Umeå University
-
- de Wit, Paul P. (author)
- AkzoNobel Specialty Chemicals
-
- Sundman, Ola (author)
- Umeå universitet,Kemiska institutionen
-
(creator_code:org_t)
- English.
- Related links:
-
https://urn.kb.se/re...
Abstract
Subject headings
Close
- We show the effect of simultaneous variation of i) the NaOH/AGU (anhydroglucose unit) stoichiometric ratio (r), ii) added [NaOH], and iii) mercerization time, on the degree of cellulose substitution (DS), and by-product formation including proportions of insoluble particles and unreacted chemicals, in the synthesis of carboxymethylcellulose (CMC), under conditions resembling those often used for production of non-ionic cellulose ethers and without the use of alcohols. The DS was found to increase when (r) was increased (range 1.0-1.3) and added [NaOH] was decreased (range 50-30%). However, such changes also favoured the formation of unwanted by-products. Decreased (r) and increased [NaOH] resulted in increased the quantities of insoluble particles and unreacted chemicals. In the CMC samples, DS of 0.18-0.7 was obtained. The measured solubility (46%-86%) was lower than expected for a given DS. This, along with a deviation of the substituent distribution from the statistical calculations, indicated a high heterogeneity in the samples. The substitution at hydroxyl positions within the AGU shows the order of < ≈ , and that substitution increases with (r). The relative importance of substitution at increases with an increased [NaOH].
Subject headings
- NATURVETENSKAP -- Kemi -- Polymerkemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Polymer Chemistry (hsv//eng)
Keyword
- Mercerisation
- Alkalinisation
- Cellulose Ethers
- Carboxymethylcellulose
- Sodium glycolate
- Sodium diglycolate
Publication and Content Type
- vet (subject category)
- ovr (subject category)
To the university's database