Bulking method for chemical pulps and its effect on cellulose structure - A CP/MAS 13C-NMR Study
2021 (English)In: TAPPICon LIVE, TAPPI Press , 2021, p. 460-464Conference paper, Published paper (Refereed)
Abstract [en]
Cellulose-rich never-dried acetate grade Eucalyptus dissolving pulp was used to study the effects on the supramolecular structure of cellulose due to the addition of AlCl3 during drying from acidic conditions (pH 3.5). CP/MAS 13C-NMR was the analytical technique used for taking measures of the cellulose supramolecular structure. In this study AlCl3 was used as source of Al3+, but Al2(SO4)3 has been shown to give the same effect and it is believed that any salt of Al3+ will give the same effect. The presence of AlCl3 increased the average lateral fibril aggregate dimensions some 25% above that reached by the pulp dried without addition of AlCl3. The observed changes in cellulose supramolecular structure due to the addition of AlCl3 are large considering the low AlCl3 concentration that was used. No change in degree of crystallinity was observed as the result of drying, either with or without AlCl3 addition. Although the mechanism of action for AlCl3, causing the observed effects on the cellulose supramolecular structure, is currently not fully understood, the interpretation made was that the presence of AlCl3 increased the agglomeration of the cellulose that always take place during the first drying of cellulosic fibres. This can be seen as an increased degree of physical cross-linking in the cellulose network.
Place, publisher, year, edition, pages
TAPPI Press , 2021. p. 460-464
Keywords [en]
Aluminum Chloride, Cellulose, Cross Linking, Crystallinity, Drying, Eucalyptus, Nuclear Magnetic Resonance, Pulps, Supramolecular chemistry, Acidic conditions, Cellulose structures, Cellulosic fibers, Degree of crystallinity, Dissolving pulp, In-Degree, Mechanism of action, NMR studies, Supramolecular structure
National Category
Other Chemistry Topics
Identifiers
URN: urn:nbn:se:ri:diva-60077Scopus ID: 2-s2.0-85130159208ISBN: 9781713848370 (electronic)OAI: oai:DiVA.org:ri-60077DiVA, id: diva2:1692838
Conference
TAPPICon LIVE 2021. Atlanta, USA. 3 October 2021 through 6 October 2021
2022-09-052022-09-052023-06-08Bibliographically approved