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Skrifvars, Mikael
Alternative names
Publications (10 of 245) Show all publications
Kadi, N., Baghaei, B. & Skrifvars, M. (2019). Effect of Textile structure in the process parameters of thermoplastic bio-composite. Paper presented at 5ième Congrès International Francophone de Mécanique Avancée (CIFMA 2018), Beirut, 31 October - 2 November 2018.. MATEC Web of Conferences, 261(01005), 1-3
Open this publication in new window or tab >>Effect of Textile structure in the process parameters of thermoplastic bio-composite
2019 (English)In: MATEC Web of Conferences, E-ISSN 2261-236X, Vol. 261, no 01005, p. 1-3Article in journal, Editorial material (Other academic) Published
Abstract [en]

Thermoplastic bio-composite have a higher potential of use based on the sustainability benefits. Natural fibres today are a popular choice for applications in biocomposite manufacturing. Hybrid yarns are a satisfactory solution to improve the fabrication of composites containing a thermoplastic matrix and plant-based fibres. Nevertheless, it is still difficult to produce bio-composites with superior mechanical properties, due to problematic impregnation and consolidation results during the production process. This paper investigates the processing parameters for the compression moulding of two different hemp/PLA textiles structure bio-composites (warp knitting and weaving structure). Finite element simulations are used to optimise the processing parameters (pressure, temperature, and time). The results demonstrated that the textile structure has a small effect on the time of production. Main while the pressure and temperature of processing parameters depend only on the type of matrix and the thickness of biocomposite has a big impact on the time of production.

National Category
Engineering and Technology
Research subject
Textiles and Fashion (General); Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-15721 (URN)10.1051/matecconf/201926101005 (DOI)
Conference
5ième Congrès International Francophone de Mécanique Avancée (CIFMA 2018), Beirut, 31 October - 2 November 2018.
Available from: 2019-01-29 Created: 2019-01-29 Last updated: 2019-01-30Bibliographically approved
Jabbari, M., Lundin, M., Bahadorikhalili, S., Skrifvars, M. & Taherzadeh, M. J. (2019). Finding solvent for polyamide 11 using a computer software. Zeitschrift für Physikalische Chemie
Open this publication in new window or tab >>Finding solvent for polyamide 11 using a computer software
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2019 (English)In: Zeitschrift für Physikalische Chemie, ISSN 0942-9352Article in journal (Refereed) Epub ahead of print
Abstract [en]

The solvent finding step has always been a time-consuming job in chemical-involved processes. The source of difficulty mainly comes from the trial-and-errors, as a repetitive process of chosing solvents and mixing them in different proportions. Computers are good at doing repetitive processes; however, they can only deal with numerical values, rather than qulitative scales. Numerification of qualitative parameters (like solubility) has already been introduced. The most recent one is the Hansen solubility parameters (HSPs). Using the HSPs could provide a solvent or solvent-mixture. In our previous study, we introduced a computer-aided model and a software to find a solvent mixture. In this study, we have used the computer-aided solvent selection model to find some solvent mixtures for polyamide 11, a biobased polymer which has attracted enormous attention recently. Using this numerical model significantly diminished the time of solvent development experimentation by decreasing the possible/necessary trials.

Keywords
Hansen solubility parameters, polyamide 11, nylon, solvent mixture, solvent screening, solvent substitution, the Simplex method
National Category
Industrial Biotechnology
Research subject
Resource Recovery; Resource Recovery; Resource Recovery
Identifiers
urn:nbn:se:hb:diva-22385 (URN)10.1515/zpch-2018-1299 (DOI)
Available from: 2020-01-08 Created: 2020-01-08 Last updated: 2020-01-14Bibliographically approved
Kumar Ramamoorthy, S., Åkesson, D., Skrifvars, M., Rajan, R. & Periyasamy, A. P. (2019). Mechanical performance of biofibers and their corresponding composites. In: Mohammad Jawaid, Mohamed Thariq, Naheed Saba (Ed.), Mechanical and Physical Testing of Biocomposites, Fibre-Reinforced Composites and Hybrid Composites: . Woodhead Publishing Limited
Open this publication in new window or tab >>Mechanical performance of biofibers and their corresponding composites
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2019 (English)In: Mechanical and Physical Testing of Biocomposites, Fibre-Reinforced Composites and Hybrid Composites / [ed] Mohammad Jawaid, Mohamed Thariq, Naheed Saba, Woodhead Publishing Limited, 2019Chapter in book (Refereed)
Abstract [en]

This chapter focuses on mechanical performance of biofibers such as flax, hemp, and sisal and their effect on mechanical performance when they are reinforced in thermoset and thermoplastic polymers. The aim of this chapter is to present an overview of the mechanical characterization of the biofibers and their corresponding composites. The mechanical characterization includes tensile, flexural, impact, compressive, shear, toughness, hardness, brittleness, ductility, creep, fatigue, and dynamic mechanical analyses. Detailed studies of each test have been widely reported and an overview is important to relate the studies. Studies pertaining to the topics are cited. The most common materials used in biocomposites are biofibers (also called natural fibers) and petroleum-based polymers such polypropylene. The use of renewable materials in biocomposites has increased in the past couple of decades owing to extensive research on cellulosic fibers and biopolymers based on starch or vegetable oil. Today, research is focused on reinforcing natural fibers in petroleum-based polymers. However, the emphasis is shifting toward the amount of renewable materials in biocomposites, which has led to the use of biopolymers instead of petroleum-based polymers in composites. The mechanical properties of some renewable resource-based composites are comparable to commercially available nonrenewable composites.

Several plant biofibers have been reinforced in thermoplastics or thermosets to manufacture biocomposites because of their specific properties. The Young's modulus of commonly used biofibers such as hemp and flax could be over 50 GPa and therefore they could be good alternatives to glass fibers in several applications. The good mechanical properties of these biofibers influence the composites' mechanical performance when reinforced in polymers. It is important to understand the mechanical performance of these biofibers and biocomposites in a working environment. A detailed discussion about the mechanical performance of commonly used biofibers and composites is provided in this chapter.

Place, publisher, year, edition, pages
Woodhead Publishing Limited, 2019
Keywords
Biocomposite, Biofiber, Mechanical properties, Natural fiber, Renewable materials
National Category
Polymer Technologies Textile, Rubber and Polymeric Materials Other Mechanical Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-15228 (URN)10.1016/B978-0-08-102292-4.00014-X (DOI)
Available from: 2018-10-22 Created: 2018-10-22 Last updated: 2018-11-16Bibliographically approved
Soroudi, A., Skrifvars, M. & Nierstrasz, V. (2019). Novel Skin-Electrode Conductive Adhesives to Improve the Quality of Recorded Body Signals in Smart Medical Garments. Proceedings, 32
Open this publication in new window or tab >>Novel Skin-Electrode Conductive Adhesives to Improve the Quality of Recorded Body Signals in Smart Medical Garments
2019 (English)In: Proceedings, ISSN 2504-3900, Vol. 32Article in journal (Refereed) Published
Abstract [en]

A main barrier to widespread use of electrocardiography garments for long term heart monitoring of elderly and patients is a poor skin-electrode signal transfer because of a high contact impedance and sensitivity to movement. This leads to unwanted disturbances and errors in recorded signals when the patient moves or even breathe, affecting the reliability and quality of the signals especially for patients with dry/old skin. In two different projects at the University of Borås, we have developed two novel products to solve the above problem; (1) an ongoing project that has fabricated a reusable and sustainable electro-conductive adhesive applicable between the skin and high-porous textile electrodes, and (2) a patent-pending skin-electrode glue (BioEl Glue®) which is a biocompatible electro-conductive water-soluble glue used between skin and low-porous textile electrodes.

Keywords
contact impedance, skin electrode interface, textile electrodes, ECG garments, medical garments, electrocardiography garments, smart textile, wearable electronics, wearable ECG
National Category
Polymer Technologies
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-22341 (URN)10.3390/proceedings2019032009 (DOI)
Available from: 2019-12-29 Created: 2019-12-29 Last updated: 2020-01-10Bibliographically approved
Jabbari, M., Lundin, M., Hatamvand, M., Skrifvars, M. & Taherzadeh, M. J. (2018). Computer-aided theoretical solvent selection using the simplex method based on Hansen solubility parameters. Journal of Information Technology & Software Engineering, 8(4), Article ID 1000242.
Open this publication in new window or tab >>Computer-aided theoretical solvent selection using the simplex method based on Hansen solubility parameters
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2018 (English)In: Journal of Information Technology & Software Engineering, Vol. 8, no 4, article id 1000242Article in journal (Refereed) Published
Abstract [en]

Solvent selection is a crucial step in all solvent-involved processes. Using the Hansen solubility parameters (HSPs)could provide a solvent/solvent-mixture, but there are two main challenges: 1) What solvents should be selected? 2)From each solvent, how much should be added to the mixture? There is no straightforward way to answer the twochallenging questions. This contribution proposes a computer-aided method for selecting solvents (answer to thequestion 1) and finding the adequate amount of each solvent (answer to the question 2) to form a mixture of 2, 3 or4 solvents to dissolve a solute with known HSPs or to replace a solvent. To achieve this, a sophisticated computersoftware package was developed to find the optimized mixture using the mathematical Simplex algorithm based onHSPs values from a database of 234 solvents. To get a list of solvent-mixtures, polyamide66 was tested using itsHSPs. This technique reduces the laboratory effort required in selecting and screening solvent blends while allowinga large number of candidate solvents to be considered for inclusion in a blend. The outcome of this paper significantlydiminished the time of solvent development experimentation by decreasing the possible/necessary trials. Thus, themost suitable solvent/solvent-substitution can be found by the least possible effort; hence, it will save time and costof all solvent-involved processes in the fields of chemistry, polymer and coating industries, chemical engineering, etc.

Keywords
Hansen solubility parameters; Solvent mixture; Solvent substitution; Simplex method, Linear programming, Quadratic minimization, Solvent screening
National Category
Industrial Biotechnology
Research subject
Resource Recovery; Resource Recovery
Identifiers
urn:nbn:se:hb:diva-22384 (URN)10.4172/2165-7866.1000242 (DOI)
Available from: 2020-01-08 Created: 2020-01-08 Last updated: 2020-01-08
Vogt, S., Baghaei, B., Kadi, N. & Skrifvars, M. (2018). Determination of Processing Parameters for Thermoplastic Biocomposites Based on Hybrid Yarns Using Finite Elements Simulation. Journal of Composites Science, 2(1)
Open this publication in new window or tab >>Determination of Processing Parameters for Thermoplastic Biocomposites Based on Hybrid Yarns Using Finite Elements Simulation
2018 (English)In: Journal of Composites Science, ISSN 2504-477X, Vol. 2, no 1Article in journal (Refereed) Published
Abstract [en]

This paper investigates the processing parameters for the compression molding of hemp/PLA hybrid yarn biocomposites and their effect on the final mechanical properties. Finite element simulations are used to develop and assess the processing parameters, pressure, temperature, and time. These parameters are then evaluated experimentally by producing the composites by two different methods, to compare the results of experimentally determined processing conditions to parameters determined by the simulation analysis. The assessment of mechanical properties is done with several experimental tests, showing small improvements for the composites produced with the simulation method. The application of the simulation analysis results in considerably reduced processing times, from the initial 10 min to only three minutes, thereby vastly improving the processing method. While the employed methods are not yet able to produce composites with greatly improved mechanical properties, this study can be seen as a constructive approach, which has the ability to lead to further improvements.

Keywords
fabrics/textiles, mechanical properties, porosity/voids, finite element analysis (FEA)
National Category
Engineering and Technology
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-13783 (URN)10.3390/jcs2010011 (DOI)
Available from: 2018-03-05 Created: 2018-03-05 Last updated: 2018-03-12Bibliographically approved
Temmink, R., Baghaei, B. & Skrifvars, M. (2018). Development of biocomposites from denim waste and thermoset bio-resins. Composites. Part A, Applied science and manufacturing, 106, 59-69
Open this publication in new window or tab >>Development of biocomposites from denim waste and thermoset bio-resins
2018 (English)In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 106, p. 59-69Article in journal (Refereed) Published
Abstract [en]

This paper examines the use of post-consumer denim fabric in combination with thermoset bio-resins in composite manufacturing for structural applications. Bio-epoxy and acrylated epoxidized soybean oil resin (AESO) were used as bio-resins with four different manufacturing techniques in order to create a wide scope of possibilities for research. The four techniques are: compression moulding (COM), vacuum infusion (VAC), resin transfer moulding (RTM) and hand lay-up (HND). The bio-resins were compared to a conventional polyester resin, as this is highly used for structural applications. To determine suitability for structural applications, the biocomposites were tested for their mechanical and thermal properties. Fabricated composites were characterised regarding porosity, water absorption and analysed through microscopic images of the composite. Results show both bio-epoxy and AESO are suitable for use in structural applications over a range of manufacturing techniques. Furthermore, biocomposites from bio-epoxy are superior to those from AESO resin. The conventional polyester has shown to be unsuitable for structural applications.

Keywords
Biocomposites, Recycling, Mechanical properties, Resin transfer moulding
National Category
Composite Science and Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-13450 (URN)10.1016/j.compositesa.2017.12.011 (DOI)000425203100007 ()2-s2.0-85038215194 (Scopus ID)
Available from: 2018-01-14 Created: 2018-01-14 Last updated: 2018-11-29Bibliographically approved
Kumar Ramamoorthy, S., Skrifvars, M., Rajan, R., Rainosalo, E., Thomas, S., Zavasnik, J. & Vuorinen, J. (2018). Mechanical, thermal, and burning properties of viscose fabric composites: Influence of epoxy resin modification. Journal of Applied Polymer Science, 135(36)
Open this publication in new window or tab >>Mechanical, thermal, and burning properties of viscose fabric composites: Influence of epoxy resin modification
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2018 (English)In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 135, no 36Article in journal (Refereed) Published
Abstract [en]

The influence of epoxy resin modification by 3-aminopropyltriethoxysilane (APTES) on various properties of warp knitted viscose fabric is reported in this study. Dynamic mechanical, impact resistance, flexural, thermal properties, and burning behavior of the epoxy/viscose fabric composites are studied with respect to varying content of silane coupling agent. The results obtained forAPTES-modified epoxy resin based composites reinforced with unmodified viscose fabric composites are compared to unmodified epoxy resin based composites reinforced with APTES-modified viscose fabric. The dynamic mechanical behavior of the APTES-modified resin based composites indicates improved interfacial adhesion. The composites prepared from modified epoxy resin exhibited a twofold increase in impact resistance. The improved adhesion between the fiber and modified resin was also visible from the scanning electron microscope analysis of the impact fracture surface. There was less influence of resin modification on the flexural properties of the composites. The 5% APTES modification induced early degradation of composites compared to all other compo-sites. The burning rate of all the composites under study is rated to be satisfactory for use in automotive interior applications.

Keywords
cellulose and other wood products, functionalization of polymers, mechanical properties, thermal properties, thermosets
National Category
Textile, Rubber and Polymeric Materials Polymer Technologies
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-15227 (URN)10.1002/app.46673 (DOI)000436542700011 ()2-s2.0-85049105961 (Scopus ID)
Available from: 2018-10-22 Created: 2018-10-22 Last updated: 2018-11-30Bibliographically approved
Rajan, R., Rainosalo, E., Thomas, S., Kumar Ramamoorthy, S., Vuorinen, J., Skrifvars, M. & Zavasnik, J. (2018). Modification of epoxy resin by silane-coupling agent to improve tensile properties of viscose fabric composites. Polymer Bulletin, 75(1), 167-195
Open this publication in new window or tab >>Modification of epoxy resin by silane-coupling agent to improve tensile properties of viscose fabric composites
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2018 (English)In: Polymer Bulletin, ISSN 0170-0839, E-ISSN 1436-2449, Vol. 75, no 1, p. 167-195Article in journal (Refereed) Published
Abstract [en]

The modification of epoxy resin by 3-aminopropyltriethoxysilane (APTES) to improve the tensile properties of warp knitted viscose fabric composites is reported in this study. The study evaluates the efficiency of modification methods adopted to modify the epoxy resin and the influence of the resin modification on various properties of the cured castings. The influence of matrix resin modification on the tensile properties of viscose fabric composite is compared to those prepared from chemically modified fibre. The efficiency of the modification was determined through titration method to determine the epoxide content of epoxy resin, viscosity measurement and FTIR. The effect of APTES modification on various properties of cured castings is studied through differential scanning calorimeter, contact angle measurement and tensile testing. The addition of APTES into the epoxy resin decreased the epoxide content in the resin as evident from the titration method. The tensile strength of cured castings decreased after the resin modification. The tensile strength and elongation at break of the viscose fabric composites prepared from modified resin, increased up to 14 and 41%, respectively. The improved adhesion of APTES-modified epoxy resin to the viscose fibre is confirmed from SEM analysis of tensile fracture surface.

Keywords
APTES, Composites, Epoxy, Modification, Regenerated cellulose, Silane coupling agent, Tensile, Viscose
National Category
Composite Science and Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-13449 (URN)10.1007/s00289-017-2022-2 (DOI)000419586800012 ()2-s2.0-85018515485 (Scopus ID)
Available from: 2018-01-14 Created: 2018-01-14 Last updated: 2018-12-01Bibliographically approved
Jabbari, M., Skrifvars, M., Åkesson, D. & Taherzadeh, M. J. (2018). New Solvent for Polyamide 66 and Its Use for Preparing a Single-Polymer Composite-Coated Fabric. International Journal of Polymer Science
Open this publication in new window or tab >>New Solvent for Polyamide 66 and Its Use for Preparing a Single-Polymer Composite-Coated Fabric
2018 (English)In: International Journal of Polymer Science, ISSN 1687-9422, E-ISSN 1687-9430Article in journal (Refereed) Published
Abstract [en]

Polyamides (PAs) are one of the most important engineering polymers; however, the difficulty in dissolving them hinders their applications. Formic acid (FA) is the most common solvent for PAs, but it has industrial limitations. In this contribution, we proposed a new solvent system for PAs by replacing a portion of the FA with urea and calcium chloride (FAUCa). Urea imparts the hydrogen bonding and calcium ion from the calcium chloride, as a Lewis acid was added to the system to compensate for the pH decrease due to the addition of urea. The results showed that the proposed solvent (FAUCa) could readily dissolve PAs, resulting in a less decrease in the mechanical properties during the dissolution. The composite prepared using the FAUCa has almost the same properties as the one prepared using the FA solution. The solution was applied on a polyamide 66 fabric to make an all-polyamide composite-coated fabric, which then was characterized. The FAUCa solution had a higher viscosity than the one prepared using the neat FA solvent, which can be an advantage in the applications which need higher viscosity like preparing the all-polyamide composite-coated fabric. A more viscous solution makes a denser coating which will increase the water /gas tightness. In conclusion, using the FAUCa solvent has two merits: (1) replacement of 40% of the FA with less harmful and environmentally friendly chemicals and (2) enabling for the preparation of more viscous solutions, which makes a denser coating.

National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-21557 (URN)10.1155/2018/6235165 (DOI)000448619700001 ()2-s2.0-85062636745 (Scopus ID)
Available from: 2019-08-06 Created: 2019-08-06 Last updated: 2020-01-08
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