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  • 1.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Bakare, Fatimat
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Bio-based thermoset resins from soybean and linseed oils for structural composites2011Konferensbidrag (Refereegranskat)
  • 2.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Biobased Composites Prepared by Compression Molding with a Novel Thermoset Resin from Soybean Oil and a Natural-Fiber Reinforcement2010Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 116, nr 3, s. 1759-1765Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biobased composites were manufactured with a compression-molding technique. Novel thermoset resins from soybean oil were used as a matrix, and flax fibers were used as reinforcements. The air-laid fibers were stacked randomly, the woven fabrics were stacked crosswise (0/90 ), and impregnation was performed manually. The fiber/resin ratio was 60 : 40. The prepared biobased composites were characterized by impact and flexural testing. Scanning electron microscopy of knife-cut cross sections of the specimens was also done to investigate the fiber–matrix interface. Thermogravimetric analysis of the composites was carried out to provide indications of thermal stability. Three resins from soybean oil [methacrylated soybean oil, methacrylic anhydride modified soybean oil (MMSO), and acetic anhydride modified soybean oil] were used as matrices. The impact strength of the composites with MMSO resin reinforced with air-laid flax fibers was 24 kJ/m2, whereas that of the MMSO resin reinforced with woven flax fabric was between 24 and 29 kJ/m2. The flexural strength of the MMSO resin reinforced with air-laid flax fibers was between 83 and 118 MPa, and the flexural modulus was between 4 and 6 GPa, whereas the flexural strength of the MMSO resin reinforced with woven fabric was between 90 and 110 MPa, and the flexural modulus was between 4.87 and 6.1 GPa.

  • 3.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Biobased Composites Prepared by Compression Moulding using a Novel Thermoset Resin from Soybean oil and a Natural Fibre Reinforcement2009Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Biobased composites were manufactured by using a compression moulding technique. Novel thermoset resins from soybean oil were used as matrix while flax fibres were used as reinforcement. The airlaid fibres were stacked randomly while woven fabrics were stacked crosswisely (90°) and impregnation was done manually. The fibre/ resin ratio was 60% to 40%.

  • 4.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Preparation of biobased composites using novel thermoset polymers from soybean oil and a natural fibre reinforcement2009Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Health related issues, stringent environmental protection policies, search for cost effective and alternative materials, crave for renewability and sustainability and quest for high performance materials for structural applications give the motivation for research in polymer composites and material science. Due to the health, safety and environmental concerns over the conventional synthetic materials and the legislation against their usage both in domestic and industrial applications, alternatives sources that will be comparable in properties are being sought. There is an emerging market for biodegradable polymers which is expected to increase substantially in the coming years.[1] Preparation of Composites Airlaid and woven flax fibre mats were first treated with 4% sodium hydroxide solution for one hour and then washed with plenty of water. This was done in order to remove any residual impurities. The fibres were dried at room temperature for 24 hr and then dried in a vacuum oven for 1hr at a temperature of 105°С. The 8 sheets of the fibre were hand laid cross- wisely and the impregnation was done manually. The fibre/ resin ratio was about 60% to 40%. Methacrylated soybean oil, methacrylic anhydride and acetic anhydride modified soybean oil were the synthesized matrices used. The compression moulding was done at a temperature of 170°С for 5 min at 40bar. Characterisations The tensile testing was performed based on an ISO-test method for tensile tests on plastic materials. The Charpy impact strength of unnotched specimens was evaluated in accordance with ISO 179 using a Zwick test instrument and scanning electron microscopy analysis was done on the fractured specimens. The composites showed various mechanical properties, having impact strengths between 24 and 63 kJ/m² and tensile strength up to 51MPa.

  • 5.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthesis of reactive soybean oils for use as a biobased thermoset resins in structural natural fiber composites2009Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 115, nr 6, s. 3137-3145Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biobased thermosets resins were synthesized by functionalizing the triglycerides of epoxidized soybean oil with methacrylic acid, acetyl anhydride, and methacrylic anhydride. The obtained resins were characterized with FTIR, 1H-NMR, and 13C-NMR spectroscopy to confirm the functionalization reactions and the extent of epoxy conversion. The viscosities of the methacrylated soybean oil resins were also measured for the purpose of being used as a matrix in composite applications. The cross-linking capability was estimated by UV and thermally initiated curing experiments, and by DSC analysis regarding the degree of crosslinking. The modifications were successful because up to 97% conversion of epoxy group were achieved leaving only 2.2% of unreacted epoxy groups, which was confirmed by 1H-NMR. The 13C-NMR confirms the ratio of acetate to methacrylate methyl group to be 1 : 1. The viscosities of the methacrylated soybean oil (MSO) and methacrylic anhydride modified soybean oil (MMSO) were 0.2 and 0.48 Pas, respectively, which indicates that they can be used in resin transfer molding process.

  • 6.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthesis of reactive soybean oils for use as biobased thermoset resins in structural natural fibre composites2008Konferensbidrag (Refereegranskat)
  • 7.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthetic modification of reactive soybean oils for use as biobased thermoset resins in structural natural fiber composites2008Konferensbidrag (Övrigt vetenskapligt)
  • 8.
    Adekunle, Kayode
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthetic modification of reactive soybean oils for use as biobased thermoset resins in structural natural fiber composites2008Ingår i: Polymer Preprints, ISSN 0551-4657, Vol. 49, nr 1, s. 279-Artikel i tidskrift (Refereegranskat)
  • 9.
    Bakare, Fatimat O.
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ramamoorthy, Sunil Kumar
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Thermomechanical properties of bio-based composites made from a lactic acid thermoset resin and flax and flax/basalt fibre reinforcements2016Ingår i: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 83, s. 176-184Artikel i tidskrift (Refereegranskat)
    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.

  • 10.
    Bakare, Fatimat Oluwatoyin
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wang, Yanfei
    Afshar, Shahrzad Javanshir
    Esmaeli, Nima
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Morphological and mechanical properties of a biobased composite from a lactic acid based thermoset resin and viscose fiber reinforcement2014Konferensbidrag (Refereegranskat)
  • 11.
    Bakare, Fatimat Oluwatoyin
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wang, Yanfei
    Afshar, Shahrzad Javanshir
    Esmaeli, Nima
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Synthesis and Preparation of Biobased Composites with A Novel Thermoset Resin from Lactic Acid2014Konferensbidrag (Refereegranskat)
  • 12.
    Bakare, Fatimat Oluwatoyin
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wang, Yanfei
    Afshar, Shahrzad Javanshir
    Esmaeili, Nima
    Synthesis and Characterization of Bio-Based Thermosetting Resins from Lactic Acid and Glycerol2014Ingår i: Journal of Applied Polymer Science, E-ISSN 1097-4628, Vol. 131, nr 12, s. 1-9Artikel i tidskrift (Refereegranskat)
    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.

  • 13.
    Bakare, Fatimat Oluwatoyin
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wang, Yanfei
    Esmaeili, Nima
    Afshar, Shahrzad Javanshir
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Biobased Composites Prepared From a Lactic Acid Based Thermoset Resin and Natural-Fiber Reinforcement2013Konferensbidrag (Refereegranskat)
  • 14.
    Bakare, Fatimat Oluwatoyin
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wang, Yanfei
    Esmaeili, Nima
    Afshar, Shahrzad Javanshir
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    The Effect of Glycerol in the Synthesis of a Lactic Acid Based Thermoset Resin2013Konferensbidrag (Övrigt vetenskapligt)
  • 15.
    Bakare, Fatimat Oluwatoyin
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wang, Yanfei
    Esmaeili, Nima
    Afshar, Shahrzad Javanshir
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    The Effect of Glycerol in the Synthesis of a Lactic Acid Based Thermoset Resin2013Konferensbidrag (Refereegranskat)
  • 16.
    Bakare, Fatimat
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Bashir, Tariq
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Ingman, Petri
    Srivastava, Rajiv
    Synthesis and characterization of unsaturated lactic acid based thermoset bio-resins2014Ingår i: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 67, s. 570-582Artikel i tidskrift (Refereegranskat)
    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.

  • 17.
    Bátori, Veronika
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Jabbari, Mostafa
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lennartsson, Patrik R.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Production of Pectin-Cellulose Biofilms: A New Approach for Citrus Waste Recycling2017Ingår i: International Journal of Polymer Science, ISSN 1687-9422, E-ISSN 1687-9430, Vol. 2017, s. 1-9, artikel-id 9732329Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    While citrus waste is abundantly generated, the disposal methods used today remain unsatisfactory: they can be deleterious for ruminants, can cause soil salinity, or are not economically feasible; yet citrus waste consists of various valuable polymers. This paper introduces a novel environmentally safe approach that utilizes citrus waste polymers as a biobased and biodegradable film, for example, for food packaging. Orange waste has been investigated for biofilm production, using the gelling ability of pectin and the strength of cellulosic fibres. A casting method was used to form a film from the previously washed, dried, and milled orange waste. Two film-drying methods, a laboratory oven and an incubator shaker, were compared. FE-SEM images confirmed a smoother film morphology when the incubator shaker was used for drying. The tensile strength of the films was 31.67 ± 4.21 and 34.76 ± 2.64 MPa, respectively, for the oven-dried and incubator-dried films, which is within the range of different commodity plastics. Additionally, biodegradability of the films was confirmed under anaerobic conditions. Films showed an opaque appearance with yellowish colour.

  • 18.
    Bátori, Veronika
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lundin, Magnus
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lennartsson, Patrik R.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    The effect of glycerol, sugar and maleic anhydride on pectin-cellulose biofilms prepared from orange wasteIngår i: Artikel i tidskrift (Refereegranskat)
  • 19.
    Bátori, Veronika
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lundin, Magnus
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lennartsson, Patrik R.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    The Effect of Glycerol, Sugar, and Maleic Anhydride on Pectin-Cellulose Thin Films Prepared from Orange Waste2019Ingår i: POLYMERS, Vol. 11, nr 3Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study was conducted to improve the properties of thin films prepared from orange waste by the solution casting method. The main focus was the elimination of holes in the film structure by establishing better cohesion between the major cellulosic and pectin fractions. For this, a previously developed method was improved first by the addition of sugar to promote pectin gelling, then by the addition of maleic anhydride. Principally, maleic anhydride was introduced to the films to induce cross-linking within the film structure. The effects of concentrations of sugar and glycerol as plasticizers and maleic anhydride as a cross-linking agent on the film characteristics were studied. Maleic anhydride improved the structure, resulting in a uniform film, and morphology studies showed better adhesion between components. However, it did not act as a cross-linking agent, but rather as a compatibilizer. The middle level (0.78%) of maleic anhydride content resulted in the highest tensile strength (26.65 +/- 3.20 MPa) at low (7%) glycerol and high (14%) sugar levels and the highest elongation (28.48% +/- 4.34%) at high sugar and glycerol levels. To achieve a uniform film surface with no holes present, only the lowest (0.39%) level of maleic anhydride was necessary.

  • 20.
    Bátori, Veronika
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mostafa, Jabbari
    Srivastava, Rajiv K.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lennartsson, Patrik R
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Synthesis and characterization of maleic anhydride-grafted orange waste for potential use in biocomposites2018Ingår i: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 13, nr 3, s. 4986-4997Artikel i tidskrift (Refereegranskat)
  • 21.
    Bátori, Veronika
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Pectin-based Composites2017Ingår i: Handbook of Composites from Renewable Materials: Biodegradable Materials, John Wiley & Sons, 2017, s. 487-518Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    One third of the cell wall of vascular plants is composed of pectin, which serves as the cementing material for the cellulosic network, behaving as a stabilized gel. Industrially, pectin is produced from juice and sugar production waste. Different sources and extraction conditions result in diversity in characteristics and applications of pectin. Most commonly, pectin is used in the food industry as a gelling and thickening agent and it is favored in the pharmaceutical industry as a carrier for colon-specific drugs. Pectin has good potential to be utilized as a matrix in production of environmentally friendly film packaging as well as biocomposite materials. Pectin is sensitive to chemical reactions and promotes the homogeneous immobilization of cells, genes, and proteins. However, due to limited mechanical properties pectin is not used for structural applications but instead rather for composites in which its biodegradable properties can be utilized. Pectin is often reinforced with hydroxyapatite and biphasic calcium phosphate for bone regeneration and tissue engineering applications. It can also be used as a biosorbent for copper removal from aqueous solutions. Active packaging of nanohybrids composed of pectin and halloysite nanotubes that are loaded with rosemary essential oil is another application of pectin-based composites.

  • 22.
    Bátori, Veronika
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Sárvári Horváth, Ilona
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Anaerobic degradation of bioplastics: A review2018Ingår i: Waste Management, Vol. 80, s. 406-413Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW), leading to renewableenergy production in the form of methane, is a preferable method for dealing with the increasing amountof waste. Food waste is separated at the source in many countries for anaerobic digestion. However, thepresence of plastic bags is a major challenge for such processes. This study investigated the anaerobicdegradability of different bioplastics, aiming at potential use as collecting bags for the OFMSW. Thechemical composition of the bioplastics and the microbial community structure in the AD processaffected the biodegradation of the bioplastics. Some biopolymers can be degraded at hydraulic retentiontimes usually applied at the biogas plants, such as poly(hydroxyalkanoate)s, starch, cellulose and pectin,so no possible contamination would occur. In the future, updated standardization of collecting bags forthe OFMSW will be required to meet the requirements of effective operation of a biogas plant.

  • 23.
    Esmaeili, Nima
    et al.
    University of Bolton.
    Jahandideh, Arash
    South Dakota State University.
    Muthukumarappan, Kasiviswanathan
    South Dakota State University.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Synthesis and characterization of methacrylated star-shaped poly(lactic acid) emplying core moilecules with different hydroxyl groups2017Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 134, nr 39, artikel-id 45341Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A set of novel bio-based star-shaped thermoset resins was synthesized via ring-opening polymerization of lactide and employing different multi-hydroxyl core molecules, including ethylene glycol, glycerol, and erythritol. The branches were end-functionalized with methacrylic anhydride. The effect of the core molecule on the melt viscosity, the curing behavior of the thermosets and also, the thermomechanical properties of the cured resins were investigated. Resins were characterized by Fourier-transform infrared spectroscopy, 13C-NMR, and 1H-NMR to confirm the chemical structure. Rheological analysis and differential scanning calorimetry analysis were performed to obtain the melt viscosity and the curing behavior of the studied star-shaped resins. Thermomechanical properties of the cured resins were also measured by dynamic mechanical analysis. The erythritol-based resin had superior thermomechanical properties compared to the other resins and also, lower melt viscosity compared to the glycerol-based resin. These are of desired characteristics for a resin, intended to be used as a matrix for the structural composites. Thermomechanical properties of the cured resins were also compared to a commercial unsaturated polyester resin and the experimental results indicated that erythritol-based resin with 82% bio-based content has superior thermomechanical properties, compared to the commercial polyester resin. Results of this study indicated that although core molecule with higher number of hydroxyl groups results in resins with better thermomechanical properties, number of hydroxyl groups is not the only governing factor for average molecular weight and melt viscosity of the uncured S-LA resins.

  • 24. Esmaeli, Nima
    et al.
    Bakare, Fatimat Oluwatoyin
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Afshar, Shahrzad Javanshir
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Mechanical properties for bio-based thermoset composites made from lactic acid, glycerol and viscose fibers2014Ingår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, nr 1, s. 603-613Artikel i tidskrift (Refereegranskat)
    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.

  • 25.
    Fazelinejad, Samaneh
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Mechanical Recycling of Polylactic Acid Reinforced with Calcium Carbonate2014Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Biopolymers are becoming increasingly popular and may help reduce oil dependency. As a result, industries’ attentions have been directed towards polylactic acid (PLA) which combines the advantages of being renewable and biodegradable resources at the same time. The upward trend of the bioplastics and biocomposites usage among consumers could have great consequence for the recycled plastics industry in the next few decades. While the mechanical recycling of many of the traditional, petro-based polymers have been studied in detail, bio-based polymers still need to be better characterized. The mechanical recycling of neat PLA has previously studied and tests show that it is possible to process PLA several times without significant loss of mechanical properties. However, commercial plastics are often used with some kind of filler. Due to the low production cost of chalk (mainly consisting of CaCO3) it is often added to commercial polymers. PLA can be filled with chalk and other fillers in order to improve the toughness and lowering the cost. The purpose of this project was to investigate the mechanical recycling of PLA compounded with chalk. PLA was compounded with 30 wt-% chalk and 5 wt-% plasticizer using a twin screw extruder. The mechanical recycling was simulated by multiple extrusion. Samples for mechanical testing were prepared by compress molding. The prepared compound was recycled up to 6 times by multiple extrusion. The mechanical and thermal properties were characterized after each cycle by TGA, DSC, DMTA, FTIR and tensile tests.

  • 26. Fazelinejad, Samaneh
    et al.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Recycling of Poly Lactic Acid Reinforced with Calcium Carbonate by Multiple Processing2014Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The upward trend of the bioplastics and biocomposites usage among consumers could have great consequence for the recycled plastics industry in the next few decades. As a result,industries’ attentions have been directed towards Poly Lactic Acid (PLA) which combines the advantages of renewable and biodegradable resources at the same time. Since PLA is more environmentally friendly compared to traditional petroleum-based commodity polymers, it has benefited from an upturned trend of interest in different markets, like the packaging, textile, and automotive industries. However, it is not applicable in many fields due to its inherent brittleness; even though it is very beneficial as the result of high strength and high modulus. Due to the low production cost of Nano calcium carbonate (nano-CaCO3) (NCC) which is useful to improve the toughness of PLA, it has reached a wide market in such industries as plastics, paints, and inks. By adding Nano calcium carbonate to polymer, thermal,crystallization, mechanical, biodegradability and melt rheological properties will be improved. The mechanical recycling of neat PLA has previously studied as well as some research on blend PLA/NCC by Sabzi et al. However, the purpose of this project is to investigate the characterization of PLA blend with Chalk (CaCo3) and Plasticizer by focusing on thermaland mechanical properties. The filler, which is 30% calcium carbonate, and 5% plasticizer compound with PLA in a two screws extruder. Plasticizer is added to composite to make it softer and it is consider constant in all samples. Multiple extrusions and compress molding are methods which can help in studying the recyclability of polymeric materials containing bioplastic and its derivatives and in figuring out the stability or service life respectively. In addition, these methods make it possible to determine the impacts of thermal and thermo mechanical degradation. Bio composite was recycled up to 6 times by using extruder equipment and crushing. The mechanical and thermal properties were characterized after each cycle by TGA, DSC,DMTA, FTIR, tensile machine and flexural test. The study represents that by introducing 30% calcium carbonate to PLA, it can be recycled up to 6 times without meeting any significant change in the mechanical and thermal properties.

  • 27.
    Fazelinejad, Samaneh
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Repeated mechanical recycling of polylactic acid filled with chalk2017Ingår i: Progress in Rubber, Plastics and Recycling Technology, ISSN 0266-7320, E-ISSN 1478-2413, s. 1-16Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polylactic acid (PLA) was compounded with 30 wt% chalk and 5 wt% of a biobased plasticiser on a twin screw extruder. Mechanical recycling of the obtained compound was studied by multiple extrusions up to six cycles. The degradation was monitored by mechanical and thermal tests. Tensile and flexural tests did not reveal any major degradation after six cycles of processing. Characterising the material with differential scanning calorimetry (DSC) did not detect any significant change of the thermal properties. The material was also characterised by FTIR and, again, no significant change was detected. The material was finally characterised by melt flow index and by proton nuclear magnetic resonance (1H-NMR). Both tests revealed that some degradation had occurred. The 1H-NMR clearly showed that the chain length had been reduced. Also, the MFI test showed that degradation had occurred. However, the study reveals that PLA filled with chalk can be recycled by repeated extrusion for up to 6 cycles, without severe degradation. This should be of relevance when considering the end-of-life treatment of polymer products made from PLA.

  • 28. Foltynowicz, Zenon
    et al.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Christéen, Jonas
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Microwave pyrolysis as a method to glass fibre recovery from used blades of wind turbines2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wind turbine blades made of composite materials at the end of their life cycle become the waste very difficult for final utilization. There are three possible routes for dismantled wind mill wings: landfill, incineration or recycling. In the paper the method of recycling of waste glass fiber reinforced plastic, coming from used wind turbine blades with microwave pyrolysis is described. Microwave pyrolysis of the fragmented blade from a wind mill blades were carried out at 300 to 600ºC in nitrogen atmosphere in special reactor at Stena AG facilities. The pyrolysis generated gas, oil and recovered glass fibres. The hydrocarbon pyrolysis products were analysed in terms of chemical composition and energy content while the recovered glass fibres were used to produce new thermoset composites. Further developments on pilot plants are in progress.

  • 29. George, Gejo
    et al.
    Tomlal Jose, E.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Nagarajan, E.R.
    Kuruvilla, Joseph
    Viscoelastic behaviour of novel commingled biocomposites based on polypropylene/jute yarns2012Ingår i: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 43, nr 6, s. 893-902Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Jute yarn reinforced polypropylene commingled composites were prepared by an environmentally benign technique called commingling method in which the matrix fibres and reinforcing fibres are intermingled together with good alignment. The dynamic mechanical properties or viscoelastic behaviour of these commingled composites were studied with reference to fibre content and various chemical treatments. The storage and loss modulus increased with fibre content where as tan δ decreased. KMnO4 and MAPP treated composites showed much higher storage and loss modulus values at all temperatures compared to untreated one. The glass transition temperature showed a marginal increasing tendency with fibre content and chemical treatments. The surface treatment mechanisms were supported by FT-IR spectra and the increase in interfacial adhesion after chemical treatments were supported by SEM images. Theoretical modelling was used to predict the values of storage modulus and tan δ and was found to be comparable with that of experimentally obtained results.

  • 30. Gustafsson, Jesper
    et al.
    Landberg, Mikael
    Bátori, Veronika
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zamani, Akram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Development of Bio-Based Films and 3D Objects from Apple Pomace2019Ingår i: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 11, nr 2, artikel-id 289Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Extensive quantities of apple pomace are generated annually but its disposal is still challenging. This study addresses this issue by introducing a new, environmentally-friendly approach for the production of sustainable biomaterials from apple pomace, containing 55.47% free sugars and a water insoluble fraction, containing 29.42 ± 0.44% hemicelluloses, 38.99 ± 0.42% cellulose, and 22.94 ± 0.12% lignin. Solution casting and compression molding were applied to form bio-based films and 3D objects (i.e., fiberboards), respectively. Using glycerol as plasticizer resulted in highly compact films with high tensile strength and low elongation (16.49 ± 2.54 MPa and 10.78 ± 3.19%, respectively). In contrast, naturally occurring sugars in the apple pomace showed stronger plasticizing effect in the films and resulted in a fluffier and connected structure with significantly higher elongation (37.39 ± 10.38% and 55.41 ± 5.38%, respectively). Benefiting from the self-binding capacity of polysaccharides, fiberboards were prepared by compression molding at 100 °C using glycerol or naturally occurring sugars, such as plasticizer. The obtained fiberboards exhibited tensile strength of 3.02–5.79 MPa and elongation of 0.93%–1.56%. Possible applications for apple pomace biomaterials are edible/disposable tableware or food packaging. 

  • 31.
    Jabbari, Mostafa
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Introducing all-polyamide composite coated fabrics: A method to produce fully recyclable single-polymer composite coated fabrics2016Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 133, nr 7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Novel all-polyamide composite (APC) has been developed to replace traditional coated fabrics with good interfacial adhesionand enhanced recyclability. The composite is fully recyclable since it contains no other materials except polyamide. APC was preparedby partially dissolving a polyamide fabric by treatment with a film-forming polyamide solution. The effect of the polyamidesolution concentration and gelling time on tensile and viscoelastic properties of APCs was investigated to explore the optimum processingparameters for balancing the good interfacial adhesion. The composite properties were studied by dynamic mechanical thermalanalysis (DMTA), tensile testing and scanning electron microscopy (SEM). The results showed a good adhesion between the coatingand the fabric. A new method was introduced to convert a low value added textile waste to a high value-added product. The compositeis tunable, in terms of having a dense or a porous top-layer depending on the end-use requirements.

  • 32.
    Jabbari, Mostafa
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    New Solvent for Polyamide 66 and Its Use for Preparing a Single-Polymer Composite-Coated Fabric2018Ingår i: International Journal of Polymer Science, ISSN 1687-9422, E-ISSN 1687-9430Artikel i tidskrift (Refereegranskat)
    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.

  • 33.
    Jabbari, Mostafa
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Taherzadeh, Mohammad J
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Novel lightweight and highly thermally insulative silica aerogel-doped poly (vinyl chloride)-coated fabric composite2015Ingår i: Journal of reinforced plastics and composites (Print), ISSN 0731-6844, E-ISSN 1530-7964, Vol. 34, nr 19, s. 1581-1592Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Novel lightweight and highly thermal insulative aerogel-doped poly(vinyl chloride)-coated fabric composites wereprepared on woven fabrics made of polyester fibres using knife coating method, and their performances were comparedwith neat composite. The composites were prepared by incorporating a commercial aerogel to a ‘green’ poly(vinylchloride) (PVC) plastisol. The effect of aerogel-content, thermal insulating property, thermal degradation, surface characteristics,tensile and physical properties of the composites were investigated. Results revealed that aerogel couldreduce thermal conductivity, density and hydrophilicity of the composites dramatically without significant decrease inother properties. Experimental results showed that thermal insulation properties were enhanced by 26% (from 205 to152 mW/m-K), density decreased by 17% (from 1.132 to 0.941 g/cm3) and hydrophobicity increased by 16.4% (from76.02 to 88.671.48) with respect to the unmodified coated fabric. Analyses proved that composite with 3% aerogel isthe lightest by weight, while 4% showed the highest thermal insulation. The results showed that 4% is the criticalpercentage, and preparation of composites with aerogel content higher than 4% has limitations with the given formulationdue to high viscosity of plastisol. The prepared composite has potential applications in many fields such asdevelopment of textile bioreactors for ethanol/biogas production from waste materials, temporary houses and tents,facade coverings, container linings and tarpaulins. The prepared composite can be considered ‘green’ due to usage of anon-phthalate environment-friendly plasticiser.

  • 34.
    Kalantar Mehrjerdi, Adib
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Abebe Mengistu, Bemnet
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Effects of a titanate coupling agent on the mechanical and thermo-physical properties of talc-reinforced polyethylene compounds2014Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 131, nr 13, s. 40449-40449Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An experimental study was carried out to investigate the effects of a titanate coupling agent on the mechanical properties, moisture absorption, and thermal conductivity of talc-filled high-density polyethylene (HDPE). Talc (0–35 wt %) was used as reinforcement particulate filler in an HDPE matrix and samples were prepared in a micro-compounder and an injection molding machine. Isopropyl tri(dioctyl)phosphate titanate (0.5 wt %) was used as coupling agent. Composites with and without coupling agent were evaluated for changes in mechanical and thermo-physical properties, morphology, and void content. Addition of the titanate coupling agent most often resulted in an increase in stiffness and tensile strength. Furthermore, both the void content and the elongation at break of composites were reduced. Results also showed that the coupling agent had no effects on the thermal conductivity, thermal diffusivity, and specific heat capacity of the composites. In addition, it was observed that the coupling agent was more effective at low concentrations of filler. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40449.

  • 35.
    Kumar Ramamoorthy, Sunil
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Kuzhanthaivelu, Gauthaman
    Bohlén, Martin
    Research Institutes of Sweden.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Waste Management Option for Bioplastics Alongside Conventional Plastics2019Ingår i: IRC 2019 International Research Conference Proceedings, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Bioplastics can be defined as polymers derived partly or completely from biomass. Bioplastics can be biodegradable such as polylactic acid (PLA) and polyhydroxyalkonoates (PHA); or non-biodegradable (biobased polyethylene (bio-PE), polypropylene (bio-PP), polyethylene terephthalate (bio-PET)). The usage of such bioplastics is expected to increase in the future due to new found interest in sustainable materials. At the same time, these plastics become a new type of waste in the recycling stream. Most countries do not have separate bioplastics collection for it to be recycled or composted. After a brief introduction of bioplastics such as PLA in UK, these plastics are once again replaced by conventional plastics by many establishments due to lack of commercial composting. Recycling companies fear the contamination of conventional plastic in the recycling stream and they said they would have to invest in expensive new equipment to separate bioplastics and recycle it separately. Bioplastics are seen as a threat to the recycling industry as bioplastics may degrade during the mechanical recycling process and the properties of the recycled plastics are seriously impacted. This project studies what happens when bioplastics contaminate conventional plastics.

    Three commonly used conventional plastics were selected for this study: polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET). In order to simulate contamination, two biopolymers, either polyhydroxyalkanoate (PHA) or thermoplastic starch (TPS) were blended with the conventional polymers. The amount of bioplastics in conventional plastics was either 1% or 5%. The blended plastics were processed again to see the effect of degradation. Mechanical, thermal and morphological properties of these plastics were characterized.

     

    The results from contamination showed that the tensile strength and the modulus of PE was almost unaffected whereas the elongation is clearly reduced indicating the increase in brittleness of the plastic. Generally, it can be said that PP is slightly more sensitive to the contamination than PE. This can be explained by the fact that the melting point of PP is higher than for PE and as a consequence, the biopolymer will degrade more quickly. However, the reduction of the tensile properties for PP is relatively modest. It is also important to notice that when plastics are recovered, there will always be a contamination that will reduce the material properties. The reduction of the tensile properties is not necessary larger than if a non-biodegradable polymer would have contaminated PE or PP. The Charpy impact strength is generally a more sensitive test method towards contamination. Again, PE is relatively unaffected by the contamination but for PP there is a relatively large reduction of the impact properties already at 1% contamination.

    PET is polyester and it is by its very nature more sensitive to degradation than PE and PP. PET also have a much higher melting point than PE and PP and as a consequence the biopolymer will quickly degrade at the processing temperature of PET. As for the tensile strength, PET can tolerate 1% contamination without any reduction of the tensile strength. However, when the impact strength is examined, it is clear that already at 1% contamination, there is a strong reduction of the properties. It can also be seen that presence of TPS is more detrimental to PET than PHA is. This can be explained by the fact that TPS contain reactive hydroxyl groups that can react with the ester bond of PET. This will in other words lead to degradation of PET.

    The thermal properties show the change in the crystallinity. As a general conclusion, it can be said that the plastics become less crystalline when contaminated. The blends were also characterized by SEM. Biphasic morphology can be seen as the two polymers are not truly blendable which also contributes to reduced mechanical properties. Recycling of the contaminated polymer shows an increase in crystallinity. This means that when the polymers are processed, polymer degradation occur causing the polymer chains to gradually become shorter which will enhance the crystallization process.

    The study shows that PE is relatively robust againt contamination, while polypropylene (PP) is somewhat more sensitive and polyethylene terephthalate (PET) can be quite sensitive towards contamination.

  • 36.
    Kumar Ramamoorthy, Sunil
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Rajan, Rathish
    Tampere University.
    Periyasamy, Aravin Prince
    Technical University of Liberec.
    Mechanical performance of biofibers and their corresponding composites2019Ingår i: Mechanical and Physical Testing of Biocomposites, Fibre-Reinforced Composites and Hybrid Composites / [ed] Mohammad Jawaid, Mohamed Thariq, Naheed Saba, Woodhead Publishing Limited, 2019Kapitel i bok, del av antologi (Refereegranskat)
    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.

  • 37.
    Persson, Nils-Krister
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Baghaei, Behnaz
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Bashir, Tariq
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Brorström, Björn
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Hedegård, Lars
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Carlson Ingdahl, Tina
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Larsson, Jonas
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lindberg, Ulla
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Löfström, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Oudhuis, Margaretha
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Pal, Rudrajeet
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Pettersson, Anita
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Påhlsson, Birgitta
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Kumar Ramamoorthy, Sunil
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Richards, Tobias
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Worbin, Linda
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Re: en ny samhällssektor spirar2016Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Resurser och hållbarhet är nära förknippade. Hållbarhet innebär att hushålla med resurser - materiella, miljömässiga och mänskliga. Och hushållning är per definition kärnan i ekonomi. Man börjar alltmer se framväxten av en hel arsenal av verktyg och förhållnings- och angreppssätt för att bygga hållbarhet. Detta förenas av ett synsätt att det som hitintills setts  om avfall och värdelöst, och rent utav besvärligt att ta hand om, nu blir en värdefull resurs. Det glömda och gömda kommer åter. Faktum är att många ord och begrepp kring detta börjar på just åter- eller re- . Internationellt talar man om Redesign, Recycling, Remake, Recycle, Recraft, Reuse, Recreate, Reclaim, Reduce, Repair, Refashion.

    Vad är då allt detta? Ja, vill man dra det långt, är det inte mindre än framväxten av ett nyvunnet sätt att tänka, ja av en ny samhällssektor, en bransch och en industri,  sammanbundet av filosofin att återanvändningen, spillminskningen, vidarebruket, efterlivet anses som viktiga faktorer för ett miljömedvetet samhälle. Re: blir paraplytermen för detta. I denna antologi av forskare från skilda discipliner vid Högskolan i Borås lyfts ett antal av dessa begrepp inom Re: fram.

  • 38. Pettersson, Carina
    et al.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Återvinning av komposit med mikrovågspyrolys2010Konferensbidrag (Övrigt vetenskapligt)
  • 39. Rahimiashtiyani, Samaneh
    et al.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Preparation and characterization of bio-nanocomposites from biobased thermoset resin, montmorillonite and natural fiber2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In this study bio-nanocomposites were manufactured, using a thermoset resin based on lactic acid and nanoclay (montmorillonite) as a matrix for flax fibers. The obtained composites were characterized by dynamic-mechanical thermal analysis (DMTA) and flexural testing. The aim of this study was to evaluate the mechanical properties of bio-nanocomposites without any surface treatment of the nanoclay and to use the resin/clay blend as a matrix for natural fiber composite. Results showed the nanoclay improved the mechanical properties.

  • 40. Rahimiashtiyani, Samaneh
    et al.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Preparation and characterization of bio-nanocomposites from biobased thermoset resin and montmorillonite2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Bio-nanocomposites are a new class of particle-based composites that have attracted much attention due to their environmental and economic advantages these years [1, 2]. In this study a biobased thermoset resin based on lactic acid was used and reinforced with montmorillonite (MMT). This resin consists of star-shaped oligomers of lactic acid, end-capped with methacrylate groups [3]. Thus, the resin can be cross-linked by a free radical polymerization. MMT consists of 1 nm thick aluminosilicate layers. Due to the high surface area, MMT has been evaluated as a reinforcement for several commercial polymers. While most commercial resins are non-polar, MMT is intrinsically polar. Therefore, MMT is usually surface treated in order to make it less polar. However, the resin used in this study is relatively polar and the purpose of this study was to evaluate if untreated MMT could be used to reinforce this resin. The curing was studied with isothermal differential scanning calorimetry (DSC) and the obtained composite were characterized by dynamic-mechanical thermal analysis (DMTA). Also transmission electronic spectroscopy (TEM) was used to characterize the structure. The result showed some improvements in mechanical properties. The DMTA results showed that the storage modulus and also loss modulus of the nanocomposite improved with respect to neat resin. Intercalated structures could be seen from the TEM micrographs.

  • 41.
    Ramamoorthy, Sunil Kumar
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Baghaei, Behnaz
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Preparation and Characterization of Biobased Thermoset Polymers from Renewable Resources and Their Use in Composites2017Ingår i: Handbook of Composites from Renewable Materials, Physico-Chemical and Mechanical Characterization / [ed] Vijay Kumar Thakur, Manju Kumari Thakur, Michael R. Kessler, Hoboken, New Jersey, USA: John Wiley & Sons, 2017, s. 425-457Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    This chapter focuses on physicochemical and mechanical characterization of compositesmade from renewable materials. Most common renewable materials used in composites arenatural fibers and polymers based on starch or vegetable oil. The extent of using renewablematerials in biocomposites has increased during the past decade due to extensive research oncellulosic fibers and biobased polymers. Earlier, the research was focused on using the naturalfibers as reinforcement in crude oil-based polymers such as polypropylene. Later, the emphasisshifted to increase the amount of renewable components in the biocomposites which led tothe introductionof biobased resins in the composites. The properties of some biocompositesare today comparable to the properties for commercially available nonrenewable composites.Several plant biofibers have been used as reinforcement in biobased thermoplastics or thermosetsto manufacture biocomposites. Material characterization is important to understand theperformance of these composites under specific environment. Detailed discussion about themechanical and physicochemical characterization is provided in this chapter. Physicochemicalcharacterization includes chemical composition, density, viscosity, molecular weight, meltingtemperature, crystallinity,morphology, wettability, surface tension, water binding capacity,electricalconductivity, flammability, thermal stability, and swelling. Mechanical characterizationincludes tensile, flexural, impact, compressive, shear, toughness, hardness, brittleness, ductility,creep, fatigue, and dynamic mechanical analysis.

  • 42.
    Skrifvars, Mikael
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Bakare, Fatimat
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Bashir, Tariq
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Ingman, Petri
    University of Turku.
    Srivastava, Rajiv
    Indian Institute of Technology Delhi.
    Synthesis and characterisation of unsaturated lactic acid based thermoset bio-resins2015Ingår i: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 67, nr June 2015, s. 570-582Artikel i tidskrift (Refereegranskat)
  • 43.
    Skrifvars, Mikael
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Dhakal, Hom
    Advanced Polymer and Composites (APC) Research Group, University of Portsmouth, Portsmouth, UK.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Zhang, Z
    Advanced Polymer and Composites (APC) Research Group, University of Portsmouth, Portsmouth, UK.
    Hybrid composites and biocomposites: concepts, opportunities and research challenges2016Konferensbidrag (Refereegranskat)
  • 44.
    Skrifvars, Mikael
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Esmaeili, Nima
    Bakare, Fatimat Oluwatoyin
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Afshar, Shahrzad
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mechanical properties for bio-based thermoset composites made from lactic acid, glycerol and viscose fibers2015Ingår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, nr 1, s. 603-613Artikel i tidskrift (Refereegranskat)
  • 45.
    Skrifvars, Mikael
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mabille, Colinne
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Wojno, Sylvia
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Dhakal, Hom
    University of Portsmouth.
    Zhang, Zhongyi
    University of Portsmouth.
    Resin transfer moulding processing of biocomposites from warp knitted and carded cellulose reinforcements2015Konferensbidrag (Refereegranskat)
  • 46.
    Skrifvars, Mikael
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mabille, Coline
    Wojno, Sylwia
    Zhang, Zhongyi
    University of Portsmouth.
    Dhakal, Hom
    University of Portsmouth.
    Warp knitted and carded regenerated cellulose reinforced biocomposites2015Konferensbidrag (Övrigt vetenskapligt)
  • 47.
    Skrifvars, Mikael
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Pettersson, C.
    Andreassson, S.
    Återvinning av kompositer genom mikrovågspyrolys2010Konferensbidrag (Övrigt vetenskapligt)
  • 48.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mekanisk återvinning av biopolymerer och deras blandningar och kompositer2015Övrigt (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Mekanisk återvinning av biopolymerer och deras blandningar och kompositer

    Biopolymerer blir allt vanligare på marknaden. Det är därför viktigt att utveckla återvinningssystem för att ta hand om dessa nya plaster. I ett pågående projekt, ’Hållbar återvinning av ”gröna” plaster och industriellt avfall’ studeras mekanisk återvinning av bioplaster. Återvinning av polymjölksyra (PLA) samt blandningar och kompositer av PLA har studerats genom upprepad bearbetning. Delar av dessa resultat kommer att presenteras.

  • 49.
    Åkesson, Dan
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Mekanisk återvinning av PLA förstärkt med cellulosafibrer2015Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 50.
    Åkesson, Dan
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Preparation and Characterization of UV-cured Nano Reinforced Biobased Coatings2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Polymers are typically produced from crude oil which is a non-renewable resource. With the fast depletion of the petroleum resources, the development of materials based on renewable resources is becoming important. Polymers prepared from renewable resources are under development, but has mainly focused on thermoplastic polymers such as polylactic acid. For some applications, such as composites and coatings, thermoset polymers are often preferred. Consequently, it is important to develop thermoset resins from renewable resources as well. Plant oils, such as soybean oil and linseed oil, have been utilized by mankind for a long time. Soybean oil is produced in large quantities and soybean oil is an excellent starting material for the synthesis of thermoset resins. A possible strategy to prepare thermoset resins from plant oils is to introduce pendant methacrylate groups in the structure. Thus, the resins can be cured by a free radical polymerization. Such a resin is very susceptible to photopolymerization when exposed to ultraviolet (UV) radiation, which is a common technique to cure coatings. In the present study, three different thermoset resins were studied. Two of the resins were based on soybean oil while the third resin was based on lactic acid. The latter resin was prepared by a direct condensation of lactic acid and pentaerythritol and was finally end-capped with methacrylate groups. Several authors have studied the addition of nano-reinforcements to thermoset resins. One of the most promising nano-reinforcements is layered silicate which has shown to improve several properties. Layered silicate has been used to reinforce conventional resins with good results. The addition of layered silicates to the biobased resins can be used to improve the properties and to broaden the applications. The resins used in this study were therefore reinforced with layered silicate and UV-cured. The cured resins were characterized by Soxhlet extraction, photo-FTIR, DMTA and tensile tests which will be presented during the presentation.

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