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BETA
Bakare, Fatimat Oluwatoyin
Alternative names
Publications (10 of 16) Show all publications
Bakare, F. O., Ramamoorthy, S. K., Åkesson, D. & Skrifvars, M. (2016). Thermomechanical properties of bio-based composites made from a lactic acid thermoset resin and flax and flax/basalt fibre reinforcements. Composites. Part A, Applied science and manufacturing, 83, 176-184
Open this publication in new window or tab >>Thermomechanical properties of bio-based composites made from a lactic acid thermoset resin and flax and flax/basalt fibre reinforcements
2016 (English)In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 83, p. 176-184Article in journal (Refereed) Published
Abstract [en]

Low viscosity thermoset bio-based resin was synthesised from lactic acid, allyl alcohol and pentaerythritol. The resin was impregnated into cellulosic fibre reinforcement from flax and basalt and then compression moulded at elevated temperature to produce thermoset composites. The mechanical properties of composites were characterised by flexural, tensile and Charpy impact testing whereas the thermal properties were analysed by dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The results showed a decrease in mechanical properties with increase in fibre load after 40 wt.% for the neat flax composite due to insufficient fibre wetting and an increase in mechanical properties with increase fibre load up to 60 wt.% for the flax/basalt composite. The results of the ageing test showed that the mechanical properties of the composites deteriorate with ageing; however, the flax/basalt composite had better mechanical properties after ageing than the flax composite before ageing.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Thermosetting resin, fabrics, textiles, mechanical testing, compression moulding
National Category
Polymer Technologies Composite Science and Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-8610 (URN)10.1016/j.compositesa.2015.09.002 (DOI)000372383800019 ()2-s2.0-84958856359 (Scopus ID)
Projects
Thesis
Available from: 2016-01-15 Created: 2016-01-15 Last updated: 2018-04-18Bibliographically approved
Bakare, F. O. (2015). Development of biocomposites from lactic acid thermoset resins and cellulose fibre reinforcements. (Doctoral dissertation). Borås: Högskolan i Borås
Open this publication in new window or tab >>Development of biocomposites from lactic acid thermoset resins and cellulose fibre reinforcements
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Synthesis of polymers from renewable origin has been reported by many authors and it has been found out that it has enormous potential and can serve as alternative to conventional thermoplastics and thermosets in many applications. The use of these renewable resources will provide sustainable platforms to substitute fossil fuel-based materials. To date, efforts made to produce 100% bio-based thermosetting materials have yet to be achieved. Many studies have been reported on increasing the renewability ratio of thermoset materials produced.

A lot of reports have been made on the synthesis of thermoplastic resins from lactic acid for biomedical applications such as tissue engineering but only few reports have been made on composite applications. The issue of high melt viscosity of thermoplastic resins from lactic acid has been of paramount problem because of its difficulty in impregnation into fibre reinforcement. Bio-based thermoset resins have been produced for composite applications from plant oils and improved mechanical properties have been achieved.

In this thesis, an alternative route for synthesis of lactic acid based thermoset resins have been explored to solve the above problem. Thermoset resins were synthesized from lactic acid with different co-reactants and were characterized using NMR, FT-IR, DSC, DMA and TGA. Their rheological properties were also investigated. The resins were reinforced with natural and regenerated cellulose fibres in non-woven and woven form, and with different fibre alignment and fibre loading. The resulting composites were characterized by mechanical testing regarding tensile, flexural and impact strength, and by SEM analysis regarding morphology.

The results showed that these composites could possibly be used in automobile, transport, construction and furniture applications, particularly for interior purposes. The resins produced were found to be promising materials for composite production due to the good mechanical properties achieved.

Place, publisher, year, edition, pages
Borås: Högskolan i Borås, 2015. p. 47
Series
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 58
Keywords
lactic acid, thermoset resin, renewable resources, natural fibre, regenerated cellulose fibre, composite
National Category
Environmental Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-23 (URN)978-91-87525-51-3 (ISBN)978-91-87525-52-0 (ISBN)
Public defence
2015-05-13, E310, University of Borås, Allégatan 1, Borås, 10:00 (English)
Opponent
Available from: 2015-05-19 Created: 2015-03-06 Last updated: 2015-12-18Bibliographically approved
Ramamoorthy, S. K., Bakare, F. O. & Skrifvars, M. (2015). Mechanical and thermal properties of the textile bio-composites: measurement and prediction. In: : . Paper presented at 12th International Conference on Textile Composites (TexComp-12), Raleigh USA, May 26-29, 2015..
Open this publication in new window or tab >>Mechanical and thermal properties of the textile bio-composites: measurement and prediction
2015 (English)In: , 2015Conference paper, Published paper (Refereed)
Keywords
Biocomposites, Lyocell, biopolymer
National Category
Polymer Technologies
Identifiers
urn:nbn:se:hb:diva-8715 (URN)
Conference
12th International Conference on Textile Composites (TexComp-12), Raleigh USA, May 26-29, 2015.
Available from: 2016-01-29 Created: 2016-01-29 Last updated: 2018-04-18Bibliographically approved
Skrifvars, M., Esmaeili, N., Bakare, F. O., Afshar, S. & Åkesson, D. (2015). Mechanical properties for bio-based thermoset composites made from lactic acid, glycerol and viscose fibers. Cellulose (London), 22(1), 603-613
Open this publication in new window or tab >>Mechanical properties for bio-based thermoset composites made from lactic acid, glycerol and viscose fibers
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2015 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, no 1, p. 603-613Article in journal (Refereed) Published
National Category
Polymer Technologies
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-3981 (URN)10.1007/s10570-014-0500-3 (DOI)000350877100049 ()2-s2.0-84925463414 (Scopus ID)
Available from: 2015-12-11 Created: 2015-12-09 Last updated: 2018-11-30Bibliographically approved
Ramamoorthy, S. K., Bakare, F., Herrmann, R. & Skrifvars, M. (2015). Performance of biocomposites from surface modified regenerated cellulose fibers and lactic acid thermoset bioresin. Cellulose (London)
Open this publication in new window or tab >>Performance of biocomposites from surface modified regenerated cellulose fibers and lactic acid thermoset bioresin
2015 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882XArticle in journal (Refereed) Published
Abstract [en]

The effect of surface treatments, silane and alkali, on regenerated cellulose fibers was studied by using the treated fibers as reinforcement in lactic acid thermoset bioresin. The surface treatments were performed to improve the physico–chemical interactions at the fiber–matrix interface. Tensile, flexural and impact tests were used as indicator of the improvement of the interfacial strength. Furthermore, thermal conductivity, viscoelasticity measurements as well as microscopy images were made to characterize the fiber surface treatments and the effect on adhesion to the matrix. The results showed that silane treatment improved the mechanical properties of the composites as the silane molecule acts as link between the cellulose fiber and the resin (the fiber bonds with siloxane bridge while the resin bonds with organofunctional group of the bi-functional silane molecule) which gives molecular continuity in the interphase of the composite. Porosity volume decreased significantly on silane treatment due to improved interface and interlocking between fiber and matrix. Decrease in water absorption and increase in contact angle confirmed the change in the hydrophilicity of the composites. The storage modulus increased when the reinforcements were treated with silane whereas the damping intensity decreased for the same composites indicating a better adhesion between fiber and matrix on silane treatment. Thermogravimetric analysis indicated that the thermal stability of the reinforcement altered after treatments. The resin curing was followed using differential scanning calorimetry and the necessity for post-curing was recommended. Finite element analysis was used to predict the thermal behavior of the composites and a non-destructive resonance analysis was performed to ratify the modulus obtained from tensile testing. The changes were also seen on composites reinforced with alkali treated fiber. Microscopy images confirmed the good adhesion between the silane treated fibers and the resin at the interface.

Keywords
surface modification, cellulose fiber, mechanical properties, thermal conductivity, finite element analysis, resonance analysis
National Category
Polymer Technologies Composite Science and Engineering Textile, Rubber and Polymeric Materials Paper, Pulp and Fiber Technology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-70 (URN)10.1007/s10570-015-0643-x (DOI)000361003100029 ()2-s2.0-84937966648 (Scopus ID)
Funder
ÅForsk (Ångpanneföreningen's Foundation for Research and Development)
Available from: 2015-05-20 Created: 2015-05-20 Last updated: 2018-12-01Bibliographically approved
Skrifvars, M., Bakare, F., Åkesson, D., Bashir, T., Ingman, P. & Srivastava, R. (2015). Synthesis and characterisation of unsaturated lactic acid based thermoset bio-resins. European Polymer Journal, 67(June 2015), 570-582
Open this publication in new window or tab >>Synthesis and characterisation of unsaturated lactic acid based thermoset bio-resins
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2015 (English)In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 67, no June 2015, p. 570-582Article in journal (Refereed) Published
National Category
Polymer Technologies
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-3980 (URN)10.1016/j.eurpolymj.2014.11.045 (DOI)000357750900054 ()2-s2.0-84929071216 (Scopus ID)
Available from: 2015-12-11 Created: 2015-12-09 Last updated: 2018-12-01Bibliographically approved
Esmaeli, N., Bakare, F. O., Skrifvars, M., Afshar, S. J. & Åkesson, D. (2014). Mechanical properties for bio-based thermoset composites made from lactic acid, glycerol and viscose fibers. Cellulose (London), 22(1), 603-613
Open this publication in new window or tab >>Mechanical properties for bio-based thermoset composites made from lactic acid, glycerol and viscose fibers
Show others...
2014 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, no 1, p. 603-613Article in journal (Refereed) Published
Abstract [en]

Regenerated cellulose fibers were used to produce thermoset composites from a bio-based thermoset resin synthesized from lactic acid and glycerol. The resin was impregnated into the regenerated cellulose fiber and compression molded at elevated temperature to produce thermoset composites. Different fiber alignments (unidirectional and bidirectional), different reinforcement type (warp-knitted and non-woven) and varying fiber loading (65, 70 and 75 wt%) were investigated. The composites were characterized by flexural, tensile and Charpy impact testing and by dynamical mechanical thermal analysis. Water uptake and ageing properties in climate chamber were also characterized for the composites. The results showed that the composites had good mechanical properties. They can be produced with up to 70 wt% fiber content when using unidirectional (UD) and bidirectional fiber (BD) alignment, and with up to 65 wt% fiber content when using the non-woven (NW) reinforcement. The tensile modulus ranged between 11 and 14 GPa for UD composites, 7 and 8.5 GPa for BD composites and 5 and 7.5 GPa for NW composites. The flexural modulus ranged between 10 and 11.5 GPa for UD composites, 5 and 6.5 GPa for BD composites and 5 and 6 GPa for NW composites. The impact strength ranged between 130 and 150 kJ/m2 for UD composites, 98 and 110 kJ/m2 for BD composites and 17 and 20 kJ/m2 for NW composites. The result of the ageing test showed that the mechanical properties of the composites deteriorate with ageing but the addition of styrene somewhat counteracts the degradation, making the composite applicable for indoor use.

Place, publisher, year, edition, pages
Springer, 2014
Keywords
Composite, Regenerated cellulose fiber, Lactic acid, Thermoset, Reinforcement, Resource Recovery
National Category
Materials Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1942 (URN)10.1007/s10570-014-0500-3 (DOI)2320/14398 (Local ID)2320/14398 (Archive number)2320/14398 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-11-28Bibliographically approved
Bakare, F. O., Skrifvars, M., Wang, Y., Afshar, S. J., Esmaeli, N. & Åkesson, D. (2014). Morphological and mechanical properties of a biobased composite from a lactic acid based thermoset resin and viscose fiber reinforcement. Paper presented at SPE Automotive Composites Conference and Exhibitions (ACCE), 9th -11th September, 2014, Novi-Michigan, USA. Paper presented at SPE Automotive Composites Conference and Exhibitions (ACCE), 9th -11th September, 2014, Novi-Michigan, USA.
Open this publication in new window or tab >>Morphological and mechanical properties of a biobased composite from a lactic acid based thermoset resin and viscose fiber reinforcement
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2014 (English)Conference paper, Published paper (Refereed)
Keywords
Resource Recovery
National Category
Materials Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-7250 (URN)2320/14394 (Local ID)2320/14394 (Archive number)2320/14394 (OAI)
Conference
SPE Automotive Composites Conference and Exhibitions (ACCE), 9th -11th September, 2014, Novi-Michigan, USA
Available from: 2015-12-22 Created: 2015-12-22
Bakare, F. O., Skrifvars, M., Åkesson, D., Wang, Y., Afshar, S. J. & Esmaeili, N. (2014). Synthesis and Characterization of Bio-Based Thermosetting Resins from Lactic Acid and Glycerol. Journal of Applied Polymer Science, 131(12), 1-9
Open this publication in new window or tab >>Synthesis and Characterization of Bio-Based Thermosetting Resins from Lactic Acid and Glycerol
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2014 (English)In: Journal of Applied Polymer Science, E-ISSN 1097-4628, Vol. 131, no 12, p. 1-9Article in journal (Refereed) Published
Abstract [en]

A bio-based thermoset resin has been synthesized from glycerol reacted with lactic acid oligomers of three different chain lengths: n=3, 7 and 10. Lactic acid was first reacted with glycerol by direct condensation and the resulted branched molecule was then end-functionalized with methacrylic anhydride. The resins were characterized using FTIR, 13C-NMR spectroscopy to confirm the resins chemical structure and by DSC and DMTA to obtain the thermal properties. The resin flow viscosities were also measured using a Rheometer with different stress levels for each temperature used, as this is an important characteristic for resins which are intended to be used as a matrix in composite applications. The results showed that the resin with chain length n=3 have a better mechanical, thermal and rheological properties than resin with n=7 and 10. Also with its biobased content of 78% and glass transition temperature at 97°C makes it comparable with the commercial unsaturated polyester resins.

Place, publisher, year, edition, pages
Wiley, 2014
Keywords
Biopolymer and Renewable polymers, Composites, Crosslinking, Resins, Thermosets, Resource Recovery
National Category
Engineering and Technology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1866 (URN)10.1002/app.40488 (DOI)000334600500034 ()2320/13743 (Local ID)2320/13743 (Archive number)2320/13743 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-03-01Bibliographically approved
Bakare, F., Åkesson, D., Skrifvars, M., Bashir, T., Ingman, P. & Srivastava, R. (2014). Synthesis and characterization of unsaturated lactic acid based thermoset bio-resins. European Polymer Journal, 67, 570-582
Open this publication in new window or tab >>Synthesis and characterization of unsaturated lactic acid based thermoset bio-resins
Show others...
2014 (English)In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 67, p. 570-582Article in journal (Refereed) Published
Abstract [en]

Bio-based thermoset resins have been synthesized using lactic acid oligomers, which were functionalized with carbon–carbon double bonds, in order to allow their crosslinking by a free radical mechanism. Two different resin structures were synthesized. One resin was composed of an allyl alcohol terminated lactic acid oligomer, which was end-functionalized with methacrylic anhydride (MLA resin). The second resin was a mixture of the same allyl alcohol-lactic acid oligomer, and penthaerythritol. This mixture was end-functionalized with methacrylic anhydride, in order to get a methacrylate functionalized lactic acid oligomer, and methacrylate functionalized penthaerythritol (PMLA resin). The synthesized resins were characterized using FT-IR, 1H NMR and 13C NMR spectroscopy, differential scanning calorimetry as well as dynamic mechanical analysis to confirm the resin structure and reactivity. The flow viscosities were also measured in order to evaluate the suitability of the resins to be used as a matrix in composite applications. The results showed that the PMLA resin has better mechanical, thermal and rheological properties than the MLA resin, and both had properties which were comparable with a commercial unsaturated polyester resin. The high biobased content of 90% and the high glass transition temperature at 100 °C for the PMLA resin makes it an attractive candidate for composite applications where crude oil based unsaturated polyester resins are normally used.

Place, publisher, year, edition, pages
Pergamon Press, 2014
Keywords
Bioresin, Lactic acid, Resursåtervinning
National Category
Polymer Chemistry Materials Chemistry
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1996 (URN)10.1016/j.eurpolymj.2014.11.045 (DOI)2320/14546 (Local ID)2320/14546 (Archive number)2320/14546 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-11-02Bibliographically approved
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