Carbonyls in Cellulose: An Investigation into Formation Mechanisms, Analytical Methods, and their Consequential Properties for Fiber Engineering Applications

Thumbnail Image

Files

isbn9789526423401.pdf (6 MB)

URL

Journal Title

Journal ISSN

Volume Title

School of Chemical Engineering | Doctoral thesis (article-based) | Defence date: 2025-02-07
Unless otherwise stated, all rights belong to the author. You may download, display and print this publication for Your own personal use. Commercial use is prohibited.

Authors

Date

2025

Department

Biotuotteiden ja biotekniikan laitos
Department of Bioproducts and Biosystems

Major/Subject

Mcode

Degree programme

Language

en

Pages

95 + app. 154

Series

Aalto University publication series Doctoral Theses, 02/2025

Abstract

This thesis focused on the introduction of carbonyls into the cellulose structure with the wider aim to expand the scope of applications of cellulosic fibers. Thereby, two separate reaction classes were critically re-investigated. First, the periodate oxidation of cellulose combined with modification of the resulting aldehyde functionalities. Second, the carbonization mechanism of cellulose with a focus on the thermal dehydration reactions below 300 °C. Periodate oxidation was investigated for its potential to introduce more flexible segments in the rigid cellulose structure. The low temperature dehydration represents a key yield determining step during the preparation of cellulose-based carbon fibers. To obtain further insights into these well researched topics novel analytical techniques were applied. A recently developed solution state NMR method relying on an ionic liquid electrolyte for the dissolution of crystalline cellulosic materials proved to be useful and was further expanded to a full analytical protocol. The studies on periodate oxidation were significantly hampered by different side reactions. Thus, the research focus shifted on their quantification and mitigation. An updated workup scheme for dialdehyde celluloses was elaborated and an indirect size exclusion chromatography protocol allowed to follow the partial depolymerization reactions in the early stages of periodate oxidation. For further modification the applicability of reductive amination and borohydride reduction was screened. Also there, issues with unwanted degradation or incomplete conversion were encountered and could be highlighted. Overall, the studies on periodate oxidation resulted in an improved understanding of the underlying side reactions. However, they ultimately prevented a meaningful application of this modification strategy for fiber engineering purposes. In the fundamental studies on the thermal dehydration reactions of cellulose different reaction intermediates could be isolated and identified. Application of solution state NMR showed that the first thermal transformations result in depolymerization to levoglucosan end capped structures. In contrast to prevailing mechanistic proposals in the cellulose-based carbon fiber community, the initial dehydration reactions do not include elimination reactions in the pyranose structures. Instead, a polyfuran was isolated as first carbonization intermediate and could be thoroughly characterized. This suggested a localized dehydration mechanism occurring on the reducing end groups, as recently postulated in the literature focusing on other fields of cellulose pyrolysis. This observation also suggests that the chemistry of cellulose carbonization is similar to the carbonization reactions of other sugars. Moreover, the occurrence of a polyfuran intermediate has considerable implications for the potential reactions occurring at higher temperatures, which so far evaded proper analytical characterization.

Description

Supervising professor

Hummel, Michael, Prof., Aalto University, Department of Bioproducts and Biosystems, Finland

Thesis advisor

Schlapp-Hackl, Inge, Dr., Aalto University, Department of Bioproducts and Biosystems, Finland

Keywords

cellulose modification, periodate oxidation, dialdehyde cellulose, carbonization, thermostabilization, carbon fibers, NMR spectroscopy, size exclusion chromatography

Other note

Parts

  • [Publication 1]: L. Fliri; K. Heise; T. Koso; A.R. Todorov; D.R. del Cerro; S. Hietala; J. Fiskari; I. Kilpeläinen; M. Hummel; A.W.T. King: Solution-State Nuclear Mag-netic Resonance Spectroscopy of Crystalline Cellulosic Materials using a Direct Dissolution Ionic Liquid Electrolyte, Nature Protocols, 2023, 18, 2084–2123.
    Full text in Acris/Aaltodoc: https://urn.fi/URN:NBN:fi:aalto-202309065685
    DOI: 10.1038/s41596-023-00832-9 View at publisher
  • [Publication 2]: J. Simon+; L. Fliri+; F. Drexler; M. Bacher; J. Sapkota; M. Ristolainen; M. Hummel; A. Potthast; T. Rosenau: Debugging periodate oxidation of cellulose: Why following the common protocol of quenching excess periodate with glycol is a bad idea, Carbohydrate Polymers, 2023, 310, 120691.
    Full text in Acris/Aaltodoc: https://urn.fi/URN:NBN:fi:aalto-202303152418
    DOI: 10.1016/j.carbpol.2023.120691 View at publisher
  • [Publication 3]: L. Fliri; J. Simon; I. Sulaeva; T. Rosenau; A. Potthast; M. Hummel: Indirect determination of partial depolymerization reactions in dialdehyde celluloses (DAC) by gel permeation chromatography of their oxime derivatives, Cellulose, 2023, 30, 8677–8690.
    Full text in Acris/Aaltodoc: https://urn.fi/URN:NBN:fi:aalto-202310256634
    DOI: 10.1007/s10570-023-05412-4 View at publisher
  • [Publication 4]: J. Simon; L. Fliri; J. Sapkota; M. Ristolainen; S. A. Miller; M. Hummel; T. Rosenau; A. Potthast: Reductive Amination of Dialdehyde Cellulose: Access to Renewable Thermoplastics, Biomacromolecules, 2022, 24 (1), 166-177.
    Full text in Acris/Aaltodoc: https://urn.fi/URN:NBN:fi:aalto-202301181221
    DOI: 10.1021/acs.biomac. 2c01022 View at publisher
  • [Publication 5]: J. Simon; L. Fliri; F. Fröhlich; J. Sapkota; M. Ristolainen; M. Hummel; T. Rosenau; A. Potthast: Insights into the borohydride reduction of dialdehyde cellulose: The dilemma of competing reduction and β-elimination reactions, Cellulose, 2023, 30, 8205–8220.
    Full text in Acris/Aaltodoc: https://urn.fi/URN:NBN:fi:aalto-202310256654
    DOI: 10.1007/s10570-023-05350-1 View at publisher
  • [Publication 6]: L. Fliri; C. Guizani; I.Y. Miranda-Valdez; L. Pitkänen; M. Hummel: Reinvestigating the concurring reactions in early-stage cellulose pyrolysis by solution state NMR spectroscopy, Journal of Analytical and Applied Pyrolysis, 2023, 175, 106153.
    Full text in Acris/Aaltodoc: https://urn.fi/URN:NBN:fi:aalto-202310116261
    DOI: 10.1016/j.jaap.2023.106153 View at publisher
  • [Publication 7]: M. Jang+; L. Fliri+; M. Trogen; D. Choi; J.H. Han; J. Kim; S.K. Kim; S. Lee; S.S. Kim; M. Hummel: Accelerated thermostabilization through electron-beam irradiation for the preparation of cellulose-derived carbon fibers, Carbon, 2024, 218, 118759.
    Full text in Acris/Aaltodoc: https://urn.fi/URN:NBN:fi:aalto-202404243243
    DOI: 10.1016/j.carbon.2023.118759 View at publisher
  • [Publication 8]: L. Fliri; K. Dubivka; D. Rusakov; A. Volikov; C. Guizani; S. Hietala; S. Filonenko; M. Hummel: Identification of a Polyfuran Network as the Initial Carbonization Intermediate in Cellulose Pyrolysis: A Comparative Analysis with Cellulosic Hydrochars, Journal of Analytical and Applied Pyrolysis, 2024, 181, 106591.
    Full text in Acris/Aaltodoc: https://urn.fi/URN:NBN:fi:aalto-202408065216
    DOI: 10.1016/j.jaap.2024.106591 View at publisher

Citation

Permanent link to this item

https://urn.fi/URN:ISBN:978-952-64-2340-1

Collections

[diss] Kemian tekniikan korkeakoulu / CHEM