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Hedenqvist, Mikael S.ORCID iD iconorcid.org/0000-0002-6071-6241
Publications (10 of 56) Show all publications
Capezza, A. J., Robert, E., Lundman, M., Newson, W. R., Johansson, E., Hedenqvist, M. S. & Olsson, R. (2020). Extrusion of Porous Protein-Based Polymers and Their Liquid Absorption Characteristics. Polymers, 12(2), Article ID 459.
Open this publication in new window or tab >>Extrusion of Porous Protein-Based Polymers and Their Liquid Absorption Characteristics
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2020 (English)In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 12, no 2, article id 459Article in journal (Refereed) Published
Abstract [en]

The production of porous wheat gluten (WG) absorbent materials by means of extrusion processing is presented for the future development of sustainable superabsorbent polymers (SAPs). Different temperatures, formulations, and WG compositions were used to determine a useful protocol that provides the best combination of porosity and water swelling properties. The most optimal formulation was based on 50 wt.% WG in water that was processed at 80 degrees C as a mixture, which provided a porous core structure with a denser outer shell. As a green foaming agent, food-grade sodium bicarbonate was added during the processing, which allowed the formation of a more open porous material. This extruded WG material was able to swell 280% in water and, due to the open-cell structure, 28% with non-polar limonene. The results are paving the way towards production of porous bio macromolecular structures with high polar/non-polar liquid uptake, using extrusion as a solvent free and energy efficient production technique without toxic reagents.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
wheat gluten, protein, extrusion, sustainability, absorbents, porosity, circularity
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-271950 (URN)10.3390/polym12020459 (DOI)000519849800209 ()32079125 (PubMedID)2-s2.0-85080897333 (Scopus ID)
Note

QC 20200415

Available from: 2020-04-15 Created: 2020-04-15 Last updated: 2020-04-15Bibliographically approved
Karlsson, M. E., Xu, X., Hillborg, H., Ström, V., Hedenqvist, M. S., Nilsson, F. & Olsson, R. (2020). Lamellae-controlled electrical properties of polyethylene - morphology, oxidation and effects of antioxidant on the DC conductivity. RSC Advances, 10(8), 4698-4709
Open this publication in new window or tab >>Lamellae-controlled electrical properties of polyethylene - morphology, oxidation and effects of antioxidant on the DC conductivity
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2020 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 10, no 8, p. 4698-4709Article in journal (Refereed) Published
Abstract [en]

Destruction of the spherulite structure in low-density polyethylene (LDPE) is shown to result in a more insulating material at low temperatures, while the reverse effect is observed at high temperatures. On average, the change in morphology reduced the conductivity by a factor of 4, but this morphology-related decrease in conductivity was relatively small compared with the conductivity drop of more than 2 decades that was observed after slight oxidation of the LDPE (at 25 degrees C and 30 kV mm(-1)). The conductivity of LDPE was measured at different temperatures (25-60 degrees C) and at different electrical field strengths (3.3-30 kV mm(-1)) for multiple samples with a total crystalline content of 51 wt%. The transformation from a 5 mu m coherent structure of spherulites in the LDPE to an evenly dispersed random lamellar phase (with retained crystallinity) was achieved by extrusion melt processing. The addition of 50 ppm commercial phenolic antioxidant to the LDPE matrix (e.g. for the long-term use of polyethylene in high voltage direct current (HVDC) cables) gave a conductivity ca. 3 times higher than that of the same material without antioxidants at 60 degrees C (the operating temperature for the cables). For larger amounts of antioxidant up to 1000 ppm, the DC conductivity remained stable at ca. 1 x 10(-14) S m(-1). Finite element modeling (FEM) simulations were carried out to model the phenomena observed, and the results suggested that the higher conductivity of the spherulite-containing LDPE stems from the displacement and increased presence of polymeric irregularities (formed during crystallization) in the border regions of the spherulite structures.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2020
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-271500 (URN)10.1039/c9ra09479b (DOI)000516549000050 ()2-s2.0-85079066076 (Scopus ID)
Note

QC 20200422

Available from: 2020-04-22 Created: 2020-04-22 Last updated: 2020-05-21Bibliographically approved
Rasheed, F., Markgren, J., Hedenqvist, M. S. & Johansson, E. (2020). Modeling to Understand Plant Protein Structure-Function Relationships-Implications for Seed Storage Proteins. Molecules, 25(4), Article ID 873.
Open this publication in new window or tab >>Modeling to Understand Plant Protein Structure-Function Relationships-Implications for Seed Storage Proteins
2020 (English)In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 25, no 4, article id 873Article, review/survey (Refereed) Published
Abstract [en]

Proteins are among the most important molecules on Earth. Their structure and aggregation behavior are key to their functionality in living organisms and in protein-rich products. Innovations, such as increased computer size and power, together with novel simulation tools have improved our understanding of protein structure-function relationships. This review focuses on various proteins present in plants and modeling tools that can be applied to better understand protein structures and their relationship to functionality, with particular emphasis on plant storage proteins. Modeling of plant proteins is increasing, but less than 9% of deposits in the Research Collaboratory for Structural Bioinformatics Protein Data Bank come from plant proteins. Although, similar tools are applied as in other proteins, modeling of plant proteins is lagging behind and innovative methods are rarely used. Molecular dynamics and molecular docking are commonly used to evaluate differences in forms or mutants, and the impact on functionality. Modeling tools have also been used to describe the photosynthetic machinery and its electron transfer reactions. Storage proteins, especially in large and intrinsically disordered prolamins and glutelins, have been significantly less well-described using modeling. These proteins aggregate during processing and form large polymers that correlate with functionality. The resulting structure-function relationships are important for processed storage proteins, so modeling and simulation studies, using up-to-date models, algorithms, and computer tools are essential for obtaining a better understanding of these relationships.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
albumin, globulin, glutelin, monte carlo simulation, molecular dynamics simulation, prolamin
National Category
Biophysics
Identifiers
urn:nbn:se:kth:diva-272650 (URN)10.3390/molecules25040873 (DOI)000522454500109 ()32079172 (PubMedID)2-s2.0-85079697262 (Scopus ID)
Note

QC 20200512

Available from: 2020-05-12 Created: 2020-05-12 Last updated: 2020-05-12Bibliographically approved
Das, O., Kim, N. K., Hedenqvist, M. S., Bhattacharyya, D., Johansson, E., Xu, Q. & Holder, S. (2020). Naturally-occurring bromophenol to develop fire retardant gluten biopolymers. Journal of Cleaner Production, 243, Article ID 118552.
Open this publication in new window or tab >>Naturally-occurring bromophenol to develop fire retardant gluten biopolymers
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2020 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 243, article id 118552Article in journal (Refereed) Published
Abstract [en]

The aim of the study was to impart fire retardancy in wheat gluten polymer through naturally-occurring additives such as lanosol. The fire properties of lanosol were compared with two other conventional brominated fire retardants (Tetrabromobisphenol A and Hexabromocyclododecane). Samples containing fire retardants and gluten were prepared through compression moulding process and then characterised for their fire and mechanical properties. All fire retardants enhanced the reaction-to-fire and thermal properties of gluten while generating V-0 (i.e. vertical position and self-extinguished) ratings in the UL-94 test. The presence of all the fire retardants increased the modulus of the gluten polymer but the fire retardant particles were detrimental for the tensile strength. Nevertheless, lanosol addition delayed ignition and lowered peak heat release rate of gluten by the maximum amount, thereby leading to relatively higher fire performance index (compared to the other fire retardants). Lanosol also allowed the gluten to create a dense char barrier layer during burning that impeded the transfer of heat and flammable volatiles. The fact that only 4 wt% lanosol was able to cause self-extinguishment under direct flame and reduce peak heat release rate by a significant 50% coupled with its inherent occurrence in nature, raises the question if lanosol can be a potential fire retardant in polymeric systems, although it is a bromophenol.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Fire, Lanosol, Polymer, Wheat gluten, Additives, Biopolymers, Polymers, Tensile strength, Hexabromocyclododecanes, Naturally occurring, Peak heat release rates, Polymeric systems, Tetrabromobisphenol A, Vertical positions, Fires
National Category
Polymer Technologies Other Environmental Biotechnology Textile, Rubber and Polymeric Materials
Research subject
Fibre and Polymer Science; Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-263433 (URN)10.1016/j.jclepro.2019.118552 (DOI)000498805600077 ()2-s2.0-85072637743 (Scopus ID)
Funder
Cancerforskningsfonden i Norrland
Note

QC 20191205

Available from: 2019-12-05 Created: 2019-12-05 Last updated: 2020-01-13Bibliographically approved
Özeren, H. D., Guivier, M., Olsson, R., Nilsson, F. & Hedenqvist, M. S. (2020). Ranking Plasticizers for Polymers with Atomistic Simulations; PVT, Mechanical Properties and the Role of Hydrogen Bonding in Thermoplastic Starch. ACS Applied Polymer Materials
Open this publication in new window or tab >>Ranking Plasticizers for Polymers with Atomistic Simulations; PVT, Mechanical Properties and the Role of Hydrogen Bonding in Thermoplastic Starch
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2020 (English)In: ACS Applied Polymer Materials, ISSN 26376105Article in journal (Refereed) Published
Abstract [en]

Virgin biopolymers are often brittle and, therefore, need the addition of plasticizers to obtain the required mechanical properties for practical applications, e.g. in bags and disposable kitchen items. In this article, based on a combined experimental and modelling approach, it is shown that it is possible to rank molecules with respect to their plasticization efficiency (depression in glass transition temperature with PVT data and reduced stiffness and strength) using molecular dynamics simulations. Starch was used as the polymeric matrix material due to its promising potential as a sustainable, eco-friendly, biobased replacement for fossil-based plastics. Three polyols (glycerol, sorbitol and xylitol), two ethanolamines and glucose were investigated. The results indicate that molecular simulations can be used to find the optimal plasticizer among a set of candidates, or to design/identify better plasticizers in a complex polymer system. Glycerol was the most efficient of the six plasticizers, explained by it forming the least amount of hydrogen bonds, having the shortest hydrogen bond lifetimes and low molecular rigidity. Hence, not only was it possible to rank plasticizers, the ranking results could also be explained by the simulations.

Keywords
plasticization, prediction, simulation, starch, polyol, ethanolamine
National Category
Polymer Technologies
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-271900 (URN)10.1021/acsapm.0c00191 (DOI)
Funder
Swedish Research Council, 2016-04453
Note

QC 20200518

Available from: 2020-04-13 Created: 2020-04-13 Last updated: 2020-05-18Bibliographically approved
Alipour, N., Vinneras, B., Gouanve, F., Espuche, E. & Hedenqvist, M. S. (2019). A Protein-Based Material from a New Approach Using Whole Defatted Larvae, and Its Interaction with Moisture. Polymers, 11(2), Article ID 287.
Open this publication in new window or tab >>A Protein-Based Material from a New Approach Using Whole Defatted Larvae, and Its Interaction with Moisture
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2019 (English)In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 11, no 2, article id 287Article in journal (Refereed) Published
Abstract [en]

A protein-based material created from a new approach using whole defatted larvae of the Black Soldier fly is presented. The larvae turn organic waste into their own biomass with high content of protein and lipids, which can be used as animal feed or for material production. After removing the larva lipid and adding a plasticizer, the ground material was compression molded into plates/films. The lipid, rich in saturated fatty acids, can be used in applications such as lubricants. The amino acids present in the greatest amounts were the essential amino acids aspartic acid/asparagine and glutamic acid/glutamine. Infrared spectroscopy revealed that the protein material had a high amount of strongly hydrogen-bonded beta-sheets, indicative of a highly aggregated protein. To assess the moisture-protein material interactions, the moisture uptake was investigated. The moisture uptake followed a BET type III moisture sorption isotherm, which could be fitted to the Guggenheim, Anderson and de Boer (GAB) equation. GAB, in combination with cluster size analysis, revealed that the water clustered in the material already at a low moisture content and the cluster increased in size with increasing relative humidity. The clustering also led to a peak in moisture diffusivity at an intermediate moisture uptake.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
protein, larva, plastic, lipid, Black Soldier fly, moisture sorption
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-246270 (URN)10.3390/polym11020287 (DOI)000460296000101 ()2-s2.0-85061351298 (Scopus ID)
Note

QC 20190126

Available from: 2019-03-26 Created: 2019-03-26 Last updated: 2019-04-04Bibliographically approved
Wei, X.-F., De Vico, L., Larroche, P., Kallio, K., Bruder, S., Bellander, M., . . . Hedenqvist, M. S. (2019). Ageing properties and polymer/fuel interactions of polyamide 12 exposed to (bio)diesel at high temperature. npj Materials Degradation (3), Article ID 1.
Open this publication in new window or tab >>Ageing properties and polymer/fuel interactions of polyamide 12 exposed to (bio)diesel at high temperature
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2019 (English)In: npj Materials Degradation, ISSN 2397-2106, no 3, article id 1Article in journal (Refereed) Published
Abstract [en]

Biodiesel derived from oil crops and animal fats has been developed as a promising carbon-neutral alternative to petroleum fuels in the transport sector, but the compatibility between biodiesel/petroleum diesel and polymer components in the automotive fuel system has not been free from controversy. In this present study, the degradation of polyamide 12 (PA12), one of the most common polymers used in vehicle fuel systems, has been investigated after exposure to petroleum diesel, biodiesel and a mixture of these (20 vol.% of biodiesel/80 vol.% petroleum diesel). Fuel sorption kinetics, glass transition temperature data and mechanical properties all showed that the fuels plasticized the PA12. In addition, monomers and oligomers were extracted from PA12 by the fuels. The long-term exposure led to oxidation and an annealing-induced increase in crystallinity of the polymer. The plasticization, oxidation and annealing effects were combined with the tensile mechanical properties to assess the overall degree of ageing and degradation of the PA12 material. The fuel-polymer interactions and ageing mechanisms, demonstrated here at high temperature for PA12, are 'generic' in the sense that they are also expected to occur, to various degrees, with many other polymers and they indicate that care should be taken when choosing polymers in applications where they will be exposed to fuels at high temperature.

National Category
Textile, Rubber and Polymeric Materials
Identifiers
urn:nbn:se:kth:diva-260464 (URN)
Note

QC 20191111

Available from: 2019-09-30 Created: 2019-09-30 Last updated: 2019-11-11Bibliographically approved
Das, O., Hedenqvist, M. S., Johansson, E., Olsson, R., Loho, T. A., Capezza, A. J., . . . Holder, S. (2019). An all-gluten biocomposite: Comparisons with carbon black and pine char composites. Composites. Part A, Applied science and manufacturing, 120, 42-48
Open this publication in new window or tab >>An all-gluten biocomposite: Comparisons with carbon black and pine char composites
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2019 (English)In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 120, p. 42-48Article in journal (Refereed) Published
Abstract [en]

Three different charcoals (gluten char, pine bark char and carbon black) were used to rectify certain property disadvantages of wheat gluten plastic. Pyrolysis process of gluten was investigated by analysing the compounds released at different stages. Nanoindentation tests revealed that the gluten char had the highest hardness (ca. 0.5 GPa) and modulus (7.8 GPa) followed by pine bark char and carbon black. The addition of chars to gluten enhanced the indenter-modulus significantly. Among all the charcoals, gluten char was found to impart the best mechanical and water resistant properties. The addition of only 6 wt% gluten char to the protein caused a substantial reduction in water uptake (by 38%) and increase of indenter-modulus (by 1525%). It was shown that it is possible to obtain protein biocomposites where both the filler and the matrix are naturally sourced from the same material, in this case, yielding an all-gluten derived biocomposite.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
(Nominated) Biochar, A. Biocomposite, A. Polymer-matrix composites (PMCs), B. Hardness
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-246431 (URN)10.1016/j.compositesa.2019.02.015 (DOI)000463304100006 ()2-s2.0-85062035485 (Scopus ID)
Note

QC 20190402

Available from: 2019-04-02 Created: 2019-04-02 Last updated: 2019-04-29Bibliographically approved
Koemmling, A., Jaunich, M., Pourmand, P., Wolff, D. & Hedenqvist, M. S. (2019). Analysis of O-Ring Seal Failure under Static Conditions and Determination of End-of-Lifetime Criterion. Polymers, 11(8), Article ID 1251.
Open this publication in new window or tab >>Analysis of O-Ring Seal Failure under Static Conditions and Determination of End-of-Lifetime Criterion
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2019 (English)In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 11, no 8, article id 1251Article in journal (Refereed) Published
Abstract [en]

Determining a suitable and reliable end-of-lifetime criterion for O-ring seals is an important issue for long-term seal applications. Therefore, seal failure of ethylene propylene diene rubber (EPDM) and hydrogenated nitrile butadiene rubber (HNBR) O-rings aged in the compressed state at 125 degrees C and at 150 degrees C for up to 1.5 years was analyzed and investigated under static conditions, using both non-lubricated and lubricated seals. Changes of the material properties were analyzed with dynamic-mechanical analysis and permeability experiments. Indenter modulus measurements were used to investigate DLO effects. It became clear that O-rings can remain leak-tight under static conditions even when material properties have already degraded considerably, especially when adhesion effects are encountered. As a feasible and reliable end-of-lifetime criterion for O-ring seals under static conditions should include a safety margin for slight dimensional changes, a modified leakage test involving a small and rapid partial decompression of the seal was introduced that enabled determining a more realistic but still conservative end-of-lifetime criterion for an EPDM seal.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
EPDM, HNBR, seal failure, leak-tightness, DLO, oxygen permeability, DMA, indenter modulus
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-261040 (URN)10.3390/polym11081251 (DOI)000484552900021 ()31362423 (PubMedID)2-s2.0-85073909707 (Scopus ID)
Note

QC 20191002

Available from: 2019-10-02 Created: 2019-10-02 Last updated: 2020-03-09Bibliographically approved
Daenicke, J., Schubert, D. W., Hedenqvist, M. S., Linde, E., Sigl, T. & Horch, R. E. (2019). Evaluation of the influence of crosslink density and penetrant size on the diffusion properties of silicone oils into silicone elastomers. In: Proceedings of the Europe/Africa Conference Dresden 2017 – Polymer Processing Society PPS: . Paper presented at 2017 Europe/Africa Regional Conference of the Polymer Processing Society (PPS), Dresden, Germany, 27 June 2017 through 29 June 2017. American Institute of Physics (AIP), 2055
Open this publication in new window or tab >>Evaluation of the influence of crosslink density and penetrant size on the diffusion properties of silicone oils into silicone elastomers
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2019 (English)In: Proceedings of the Europe/Africa Conference Dresden 2017 – Polymer Processing Society PPS, American Institute of Physics (AIP), 2019, Vol. 2055Conference paper, Published paper (Refereed)
Abstract [en]

Driven by the continuing discussion on safety and quality of silicone breast implants, they have turned into focus of this study with respect to the diffusivity of low molar mass components from the silicone gel filling into the silicone breast implant shell. Therefore, the diffusivity of silicone oils into silicone elastomers were analysed by means of the crosslink density and the penetrant size. The study was focused on the diffusion of the cyclic siloxanes Octamethylcyclotetrasiloxane (D4), Decamethylcyclopentasiloxane (D5) and Dodecamethyl-cyclohexasiloxane (D6) due to their potential occurrence in silicone breast implants. The analysis of the diffusion behavior was carried out with silicone breast implant shells taken from explants and tailor-made silicone elastomer samples varying in crosslink density. Therefore, sorption experiments were performed. The subsequent evaluation of the sorption data yield to the corresponding diffusion properties. Based on the diffusion coefficient related to the crosslink density a model was developed to describe the material behavior.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
Series
AIP Conference Proceedings, ISSN 0094-243X ; 2055
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:kth:diva-244218 (URN)10.1063/1.5084878 (DOI)000464909300077 ()2-s2.0-85061087077 (Scopus ID)9780735417830 (ISBN)
Conference
2017 Europe/Africa Regional Conference of the Polymer Processing Society (PPS), Dresden, Germany, 27 June 2017 through 29 June 2017
Note

QC 20190218

Available from: 2019-02-18 Created: 2019-02-18 Last updated: 2019-05-20Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-6071-6241

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