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Pellegrino, E., Al-Rudainy, B., Larsson, P. A., Fina, A. & Lo Re, G. (2025). Impact of water plasticization on dialcohol cellulose fibres melt processing-structure-properties relationship. Carbohydrate Polymer Technologies and Applications, 9, Article ID 100642.
Open this publication in new window or tab >>Impact of water plasticization on dialcohol cellulose fibres melt processing-structure-properties relationship
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2025 (English)In: Carbohydrate Polymer Technologies and Applications, E-ISSN 2666-8939, Vol. 9, article id 100642Article in journal (Refereed) Published
Abstract [en]

Cellulose and its derivatives are considered sustainable alternatives to non-biodegradable fossil-based plastics. Chemically modified cellulose fibres to dialcohol cellulose (DAC) fibres demonstrated a melt processing window between the glass transition and degradation temperatures which enabled their extrusion by using only water as a temporary plasticizer. With the aim of supporting an industrial upscale of DAC fibres, this study investigates the processing design and the feasibility of melt processing, minimizing the moisture. Melt processes-structure-properties relationships were studied by varying the sequence of primary and secondary melt processes, i.e., extrusion and injection moulding, and by changing the moisture content. The effect of moisture and processing design on the fibre structural properties, such as molecular weight, crystallinity, fibre morphology and fibre suspensions rheology, was assessed. Then, the thermomechanical behaviour of the 3D-shaped DAC injected materials was correlated with DAC fibres structural features obtained by the different processing design and moisture content. Our results identified the injection moulding as a milder process for achieving the preparation of 3D-shaped material with enhanced mechanical properties. Moreover, we disclosed the relevance of controlled moisture in the extrusion process for enabling a secondary shaping directly after compounding and the possibility of 3D-shaping DAC fibres after a rehydration step.

Place, publisher, year, edition, pages
Elsevier BV, 2025
Keywords
Cellulose derivative, Melt processing design, Polyolefin replacement, Processing-structure-properties relationships, Thermoplastic cellulose fibres
National Category
Polymer Chemistry Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-358188 (URN)10.1016/j.carpta.2024.100642 (DOI)001392280600001 ()2-s2.0-85212310978 (Scopus ID)
Note

QC 20250121

Available from: 2025-01-07 Created: 2025-01-07 Last updated: 2025-01-21Bibliographically approved
Engel, E., Lo Re, G. & Larsson, P. A. (2025). Melt processing of chemically modified cellulosic fibres with only water as plasticiser: Effects of moisture content and processing temperature. Carbohydrate Polymers, 348, Article ID 122891.
Open this publication in new window or tab >>Melt processing of chemically modified cellulosic fibres with only water as plasticiser: Effects of moisture content and processing temperature
2025 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 348, article id 122891Article in journal (Refereed) Published
Abstract [en]

To replace petroleum-derived polymers with cellulose fibres, it is desirable to have the option of melt processing. However, upon heating, cellulose degradation typically starts before the material reaches its softening temperature. Alternatives to plastics should also, ideally, be recyclable via existing recycling streams. Here, we address the problem of melt processing cellulose as fibres while preserving recyclability. Native cellulose fibres were partially modified to dialcohol cellulose to impart thermoplastic characteristics. We demonstrate melt processing of these modified fibres with only water as plasticiser. Processability was investigated at selected processing temperatures and initial moisture content by monitoring the axial force of the extruder screws as a rheological indicator. The effects on molecular structure, fibre morphology and material properties were characterised by NMR spectroscopy, microscopy, tensile testing, fibre morphology analysis and X-ray diffraction. When comparing the melt-processed extrudate with handsheets, the already exceptional ductility was further increased. Moderate losses in tensile strength and stiffness were observed and are attributable to a loss of crystallinity and fibre shortening. This is the first report of strong and durable extrudates using cellulosic fibres as the only feedstock. Finally, the potential for recycling the processed material with unmodified fibres by paper recycling procedures was demonstrated.

Place, publisher, year, edition, pages
Elsevier BV, 2025
Keywords
Cellulose, Dialcohol cellulose, Fibre modification, Fibre plasticisation, Melt processing
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-356475 (URN)10.1016/j.carbpol.2024.122891 (DOI)001348212200001 ()39567128 (PubMedID)2-s2.0-85207206219 (Scopus ID)
Note

QC 20241119

Available from: 2024-11-19 Created: 2024-11-19 Last updated: 2025-05-27Bibliographically approved
Sjölund, J., Westman, G., Wågberg, L. & Larsson, P. A. (2025). On the determination of charge and nitrogen content in cellulose fibres modified to contain quaternary amine functionality. Carbohydrate Polymers, 347, Article ID 122734.
Open this publication in new window or tab >>On the determination of charge and nitrogen content in cellulose fibres modified to contain quaternary amine functionality
2025 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 347, article id 122734Article in journal (Refereed) Published
Abstract [en]

Research interest in quaternization of cellulose fibres has increased considerably over the past decades. However, there is little or no consensus regarding how to characterize the material in terms of degree of substitution (DS), and the literature suggests a range of different methods focusing on charge determination as well as nitrogen content quantification. This work aims to fill the knowledge gap regarding how the different methods perform in relation to each other, and for what cellulosic systems each method has advantages, disadvantages and even potential pitfalls. FT-IR and NMR measurements are used to establish successful modification and determine the relative number of substituent groups. Another six methods are compared for the determination of the DS of cellulosic fibres and nanofibrils. The methods include Kjeldahl measurements, nitrogen determination by chemiluminescence, determination of molecular nitrogen by the Dumas method, colloidal titration, conductometric titration and polyelectrolyte adsorption. It can be concluded that most techniques investigated are reliable within certain ranges of DS and/or when using appropriate post-treatment of the quaternized material and suitable sample preparation techniques. The results from the present work hence provide recommendations to make an educated choice of method, and experimental protocol, based on the technique at hand.

Place, publisher, year, edition, pages
Elsevier BV, 2025
Keywords
Cellulose Fibres, Charge determination, Degree of substitution, Nitrogen quantification, Quaternization
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-353929 (URN)10.1016/j.carbpol.2024.122734 (DOI)001316839200001 ()39486964 (PubMedID)2-s2.0-85203849829 (Scopus ID)
Note

QC 20241008

Available from: 2024-09-25 Created: 2024-09-25 Last updated: 2025-05-27Bibliographically approved
Elf, P., Larsson, P. A., Larsson, A., Wågberg, L., Hedenqvist, M. S. & Nilsson, F. (2024). Effects of Ring Opening and Chemical Modification on the Properties of Dry and Moist Cellulose─Predictions with Molecular Dynamics Simulations. Biomacromolecules, 25(12), 7581-7593
Open this publication in new window or tab >>Effects of Ring Opening and Chemical Modification on the Properties of Dry and Moist Cellulose─Predictions with Molecular Dynamics Simulations
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2024 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 25, no 12, p. 7581-7593Article in journal (Refereed) Published
Abstract [en]

Thermoplastic properties in cellulosic materials can be achieved by opening the glucose rings in cellulose and introducing new functional groups. Using molecular dynamics, we simulated amorphous cellulose and eight modified versions under dry and moist conditions. Modifications included ring openings and functionalization with hydroxy, aldehyde, hydroxylamine, and carboxyl groups. These modifications were analyzed for density, glass transition temperature, thermal expansivity, hydrogen bond features, changes in energy term contributions during deformation, diffusivity, free volume, and tensile properties. All ring-opened systems exhibited higher molecular mobility, which, consequently, improved thermoplasticity (processability) compared to that of the unmodified amorphous cellulose. Dialcohol cellulose and hydroxylamine-functionalized cellulose were identified as particularly interesting due to their combination of high molecular mobility at processing temperatures (425 K) and high stiffness and strength at room temperature (300 K). Water and smaller side groups improved processability, indicating that both steric effects and electrostatics have a key role in determining the processability of polymers.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-362972 (URN)10.1021/acs.biomac.4c00735 (DOI)001362815500001 ()39586018 (PubMedID)2-s2.0-85210410701 (Scopus ID)
Funder
Vinnova, 201900047
Note

QC 20250502

Available from: 2025-04-30 Created: 2025-04-30 Last updated: 2025-05-02Bibliographically approved
Atoufi, Z., Gordeyeva, K., Cortes Ruiz, M. F., Larsson, P. A. & Wågberg, L. (2024). Synergistically stabilized wet foams from heat treated β-lactoglobulin and cellulose nanofibrils and their application for green foam production. Applied Materials Today, 39, Article ID 102251.
Open this publication in new window or tab >>Synergistically stabilized wet foams from heat treated β-lactoglobulin and cellulose nanofibrils and their application for green foam production
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2024 (English)In: Applied Materials Today, ISSN 2352-9407, Vol. 39, article id 102251Article in journal (Refereed) Published
Abstract [en]

Achieving a sustainable foam production requires a complete substitution of synthetic components with natural and renewable alternatives, as well as development of an environment-friendly production process. This work demonstrates a synergetic combination of heat-treated beta-lactoglobulin proteins and cellulose nanofibrils (CNFs) to create fully bio-based and highly-stable wet foams. Furthermore, a gradual reduction in the pH, enabled oven-drying of the wet foams without any major structural collapse of the foam, resulting in the preparation of lightweight solid foams with the density of 10.2 kg.m(-3). First, the foaming behavior of heat-treated beta-lactoglobulin systems (HBSs) containing amyloid nanofibrils (ANFs) and non-converted peptides was investigated at different pHs. Subsequently, the HBS foams were stabilized using CNFs, followed by a gradual acidification of the system to a final pH of 4.5. To gain a deeper understanding of the stabilization mechanism of the foam, the interactions between the foam's components, their positioning in the foam structure, and the viscoelasticity of the fibrillar network were investigated using quartz crystal microgravimetry, confocal microscopy and rheology. The analysis of the obtained data suggests that the stability of the foams was associated with the accumulation of CNFs and ANFs at the air-water interface, and that the concomitant formation of an intertwined network surrounding the air bubbles. This together resulted in a significant decrease in drainage rate of the liquid in the foam lamellae, bubble coarsening and bubble coalescence within the foams. The results also show that the major surface-active component participating in the creation of the foam is the free peptide left in solution after the formation of the ANFs. A slow reduction in pH to 4.5 lead to further gelation of the fibrillar network and an improved storage modulus of the foam lamellae. This resulted in a strong coherent structure that could withstand oven-drying without collapse. The density, porosity, microstructure and compressive mechanical properties of such prepared dry foams were assessed. Overall, the results demonstrate the potential of HBSs to replace synthetic surfactants and outlines a sustainable preparation protocol for the preparation of light-weight porous composite structures of ANFs and CNFs.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Amyloid nanofibril, B-lactoglobulin, Cellulose nanofibril, Foams, Foam stabilization, Peptide
National Category
Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-350041 (URN)10.1016/j.apmt.2024.102251 (DOI)001249080600001 ()2-s2.0-85194576753 (Scopus ID)
Note

QC 20240705

Available from: 2024-07-05 Created: 2024-07-05 Last updated: 2024-07-05Bibliographically approved
Sethi, J., Glowacki, E., Reid, M. S., Larsson, P. A. & Wågberg, L. (2024). Ultra-thin parylene-aluminium hybrid coatings on nanocellulose films to resist water sensitivity. Carbohydrate Polymers, 323, 121365, Article ID 121365.
Open this publication in new window or tab >>Ultra-thin parylene-aluminium hybrid coatings on nanocellulose films to resist water sensitivity
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2024 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 323, p. 121365-, article id 121365Article in journal (Refereed) Published
Abstract [en]

Non-sustainable single-use plastics used for food packaging needs to be phased out. Films made from cellulose nanofibrils (CNFs) are suitable candidates for biodegradable and recyclable packaging materials as they exhibit good mechanical properties, excellent oxygen barrier properties and high transparency. Yet, their poor water vapour barrier properties have been a major hindrance in their commercialisation. Here, we describe the preparation of 25 μm thick CNF films with significantly improved water vapour barrier properties after deposition of ultrathin polymeric and metallic coatings, parylene C and aluminium, respectively. When first adding a 40 nm aluminium layer followed by an 80 nm parylene layer, i.e. with a combined thickness of less than one percent of the CNF film, a water vapour transmission rate of 2.8 g m−2 d−1 was achieved at 38 °C and 90 % RH, surpassing a 25 μm polypropylene film (4–12 g m−2 d−1). This is an improvement of more than 700 times compared to uncoated CNF films, under some of the harshest possible conditions a packaging material will need to endure in commercial use. The layers showed a good and even coverage, as assessed by atomic force microscopy, and the parylene-coated surfaces were hydrophobic with a contact angle of 110°, providing good water repellency.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Aluminium, Cellulose nanofibrils, Coatings, Parylene, Vapour deposition, Water vapour barrier
National Category
Condensed Matter Physics Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-337409 (URN)10.1016/j.carbpol.2023.121365 (DOI)001086726500001 ()2-s2.0-85172102025 (Scopus ID)
Note

QC 20231003

Available from: 2023-10-03 Created: 2023-10-03 Last updated: 2023-11-07Bibliographically approved
Jain, K., Wang, Z., Garma, L. D., Engel, E., Ciftci, G. C., Fager, C., . . . Wågberg, L. (2023). 3D printable composites of modified cellulose fibers and conductive polymers and their use in wearable electronics. APPLIED MATERIALS TODAY, 30, Article ID 101703.
Open this publication in new window or tab >>3D printable composites of modified cellulose fibers and conductive polymers and their use in wearable electronics
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2023 (English)In: APPLIED MATERIALS TODAY, ISSN 2352-9407, Vol. 30, article id 101703Article in journal (Refereed) Published
Abstract [en]

There are many bioelectronic applications where the additive manufacturing of conductive polymers may be of use. This method is cheap, versatile and allows fine control over the design of wearable electronic devices. Nanocellulose has been widely used as a rheology modifier in bio-based inks that are used to print electrical components and devices. However, the preparation of nanocellulose is energy and time consuming. In this work an easy-to-prepare, 3D-printable, conductive bio-ink; based on modified cellulose fibers and poly(3,4-ethylene dioxythiophene) poly(styrene sulfonate) (PEDOT:PSS), is presented. The ink shows excellent printability, the printed samples are wet stable and show excellent electrical and electrochemical performance. The printed structures have a conductivity of 30 S/cm, high tensile strains (>40%), and specific capacitances of 211 F/g; even though the PEDOT:PSS only accounts for 40 wt% of the total ink composition. Scanning electron microscopy (SEM), wide-angle X-ray scattering (WAXS), and Raman spectroscopy data show that the modified cellulose fibers induce conformational changes and phase separation in PEDOT:PSS. It is also demonstrated that wearable supercapacitors and biopotential-monitoring devices can be prepared using this ink.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Dialcohol-modified cellulose fibers, 3D printing, Conducting polymer, PEDOT:PSS, Bioelectronics
National Category
Textile, Rubber and Polymeric Materials Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-323583 (URN)10.1016/j.apmt.2022.101703 (DOI)000912019800001 ()2-s2.0-85143488124 (Scopus ID)
Note

QC 20230208

Available from: 2023-02-08 Created: 2023-02-08 Last updated: 2023-02-08Bibliographically approved
Kotov, N., Larsson, P. A., Jain, K., Abitbol, T., Cernescu, A., Wågberg, L. & Johnson, C. M. (2023). Elucidating the fine-scale structural morphology of nanocellulose by nano infrared spectroscopy. Carbohydrate Polymers, 302, Article ID 120320.
Open this publication in new window or tab >>Elucidating the fine-scale structural morphology of nanocellulose by nano infrared spectroscopy
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2023 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 302, article id 120320Article in journal (Refereed) Published
Abstract [en]

Nanoscale infrared (IR) spectroscopy and microscopy, enabling the acquisition of IR spectra and images with a lateral resolution of 20 nm, is employed to chemically characterize individual cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) to elucidate if the CNCs and CNFs consist of alternating crystalline and amorphous domains along the CNF/CNC. The high lateral resolution enables studies of the nanoscale morphology at different domains of the CNFs/CNCs: flat segments, kinks, twisted areas, and end points. The types of nano-cellulose investigated are CNFs from tunicate, CNCs from cotton, and anionic and cationic wood-derived CNFs. All nano-FTIR spectra acquired from the different samples and different domains of the individual nanocellulose particles resemble a spectrum of crystalline cellulose, suggesting that the non-crystalline cellulose signal observed in macroscopic measurements of nanocellulose most likely originate from cellulose chains present at the surface of the nanocellulose particles.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Nanocellulose, Cellulose nanocrystals, Cellulose nanofibrils, Crystalline and amorphous domains, Nano-FTIR spectroscopy, S-SNOM
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-322846 (URN)10.1016/j.carbpol.2022.120320 (DOI)000891746700002 ()36604038 (PubMedID)2-s2.0-85142692194 (Scopus ID)
Note

QC 20230109

Available from: 2023-01-09 Created: 2023-01-09 Last updated: 2023-07-03Bibliographically approved
Lo Re, G., Engel, E. R., Bjorn, L., Sicairos, M. G., Liebi, M., Wahlberg, J., . . . Larsson, P. A. (2023). Melt processable cellulose fibres engineered for replacing oil-based thermoplastics. Chemical Engineering Journal, 458, 141372, Article ID 141372.
Open this publication in new window or tab >>Melt processable cellulose fibres engineered for replacing oil-based thermoplastics
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2023 (English)In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 458, p. 141372-, article id 141372Article in journal (Refereed) Published
Abstract [en]

If cellulosic materials are to replace materials derived from non-renewable resources, it is necessary to overcome intrinsic limitations such as fragility, permeability to gases, susceptibility to water vapour and poor three-dimensional shaping. Novel properties or the enhancement of existing properties are required to expand the applications of cellulosic materials and will create new market opportunities. Here we have overcome the well-known restrictions that impede melt-processing of high cellulose content composites. Cellulose fibres, partially derivatised to dialcohol cellulose, have been used to manufacture three-dimensional high-density materials by conventional melt processing techniques, with or without the addition of a thermoplastic polymer. This work demonstrates the use of melt processable chemically modified cellulose fibres in the preparation of a new generation of highly sustainable materials with tuneable properties that can be tailored for specific applications requiring complex three-dimensional parts.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Dialcohol cellulose, Melt processing, Cellulose composite, Ethylene acrylic acid copolymer
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-324327 (URN)10.1016/j.cej.2023.141372 (DOI)000923645900001 ()2-s2.0-85146173480 (Scopus ID)
Note

QC 20230227

Available from: 2023-02-27 Created: 2023-02-27 Last updated: 2023-02-27Bibliographically approved
Elf, P., Özeren, H. D., Larsson, P. A., Larsson, A., Wågberg, L., Nilsson, R., . . . Nilsson, F. (2023). Molecular Dynamics Simulations of Cellulose and Dialcohol Cellulose under Dry and Moist Conditions. Biomacromolecules, 24(6), 2706-2720
Open this publication in new window or tab >>Molecular Dynamics Simulations of Cellulose and Dialcohol Cellulose under Dry and Moist Conditions
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2023 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 24, no 6, p. 2706-2720Article in journal (Refereed) Published
Abstract [en]

The development of wood-based thermoplastic polymersthat can replacesynthetic plastics is of high environmental importance, and previousstudies have indicated that cellulose-rich fiber containing dialcoholcellulose (ring-opened cellulose) is a very promising candidate material.In this study, molecular dynamics simulations, complemented with experiments,were used to investigate how and why the degree of ring opening influencesthe properties of dialcohol cellulose, and how temperature and presenceof water affect the material properties. Mechanical tensile properties,diffusion/mobility-related properties, densities, glass-transitiontemperatures, potential energies, hydrogen bonds, and free volumeswere simulated for amorphous cellulosic materials with 0-100%ring opening, at ambient and high (150 degrees C) temperatures, withand without water. The simulations showed that the impact of ringopenings, with respect to providing molecular mobility, was higherat high temperatures. This was also observed experimentally. Hence,the ring opening had the strongest beneficial effect on "processability"(reduced stiffness and strength) above the glass-transition temperatureand in wet conditions. It also had the effect of lowering the glass-transitiontemperature. The results here showed that molecular dynamics is avaluable tool in the development of wood-based materials with optimalthermoplastic properties.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-330528 (URN)10.1021/acs.biomac.3c00156 (DOI)001005170600001 ()37166024 (PubMedID)2-s2.0-85160720609 (Scopus ID)
Note

QC 20231122

Available from: 2023-06-30 Created: 2023-06-30 Last updated: 2025-04-30Bibliographically approved
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