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  • 51.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Naeem, Jawad
    Persson, Nils-Krister
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    FUNCTIONAL TEXTILES: Micro-porous Conductive Membranes for Bio-fuel Cell and Anti-static Air Filter Applications2013Conference paper (Refereed)
    Abstract [en]

    Conductive membranes are the highly demanding materials in the field of bio-fuel generation, bio-electrodes, sensors and anti-static air filter systems. The conductive membranes can effectively be utilized for above mentioned applications if they have better conductivity, lower weight, flexibility and cost effectiveness. Textile materials are extremely versatile in nature because their synergic combinations with other functional materials could be used for a wide range of applications, such as medical, sports, defence, energy generation and chemical industry. The non-woven micro-porous textile substrates can effectively be functionalized by coating them with conjugated polymers, such as PEDOT and polypyrrole. Coating with conjugated polymers not only gives better conductivity values but also maintain the lower molecular weight of the substrate material. In our research, we have prepared micro-porous conductive membranes by coating cellulosic non-woven fabrics with conductive polymer PEDOT. For coating purpose, we utilized most effective deposition technique, which is called chemical vapour deposition (CVD) process. The deposition of PEDOT by CVD process showed advantages over other conventionally used methods, such as the micro-pores were not blocked even after PEDOT deposition. The electrical characterization on produced conductive membranes was performed by using Kiethely 6000 picoammeter. The surface morphology was examined by scanning electron microscopy and structural properties were determined by ATR-FTIR analysis. In order to see the behaviour of these conductive membranes, electrochemical impedance scanning (EIS) was performed in different electrolyte solutions. The produced conductive membranes might have potential to be utilized as active electrode in bio-fuel cells and also can be used in anti-static air filter systems.

  • 52.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Naeem, Jawad
    Persson, Nils-Krister
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Functionalization of Textile Materials by Coating with Conjugated Polymers2013Conference paper (Refereed)
    Abstract [en]

    During the last decade, smart textiles have attracted an enormous attention of researchers and found extraordinary applications in biomedical, sports, defense, energy, and fashion industry. These textiles are able to accept the physical signals from external stimuli and then generate a reaction in the form of thermal, electrical, chemical and magnetic signals. They should be in the form of functionalized fabric or electro-active fibers. A numerous techniques for the production of electrically conductive fibers have already been developed. In this study, we have prepared relatively highly conductive fibers with better mechanical properties. For this purpose, we have functionalized the commercially available textile fibers by coating with intrinsically conductive polymer (ICP), poly(3,4-ethylenedioxythiophene) (PEDOT). An efficient coating technique, so called oxidative chemical vapor deposition (CVD) was utilized for making uniform, thin and highly conductive polymer layers on the surface of textile fibers. For our initial experiments, we used viscose and polyester fibers as substrate materials. After performing a series of experiments, we have optimized a number of reaction parameters at which good electro-mechanical properties of conductive fibers can be achieved. At specific reaction conditions, the conductivity level which we have attained is approximately 15 S/cm. The PEDOT coated viscose and polyester fibers were compared in order to find out the best suitable substrate material. For increasing the service life of obtained conductive fibers, a thin layer of silicon resin was applied on the surface of PEDOT coated fibers.

  • 53.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Naeem, Jawad
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    Synthesis of electro-active membranes by chemical vapor deposition (CVD) process2014In: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 25, no 12, p. 1501-1508Article in journal (Refereed)
    Abstract [en]

    In the past two decades, many research is being carried out on coating of textile membranes with conductive polymers. In order to functionalize the textile membranes, coating of different intrinsically conductive polymers can be applied on these membranes through appropriate coating techniques like electrochemical polymerization, wet chemical oxidation and chemical vapor deposition(CVD. Noticeably, CVD process is one of the most suitable and environment friendly technique. In this research, microporous polyester and polytetrafluoroethylene (PTFE) membranes were coated with conductive poly(3,4-ethylenedioxythiophene) (PEDOT) by CVD process in the presence of ferric(III)chloride (FeCl3) used as an oxidant. Polymerization of PEDOT on the surface of membranes and pore size was examined by optical microscope and scanning electron microscopy (SEM). Structural analysis investigated with ATR-FTIR, which revealed the successful deposition of PEDOT on membranes without damaging their parent structures. The amount of PEDOT in PEDOT-coated polyester and PTFE membranes was explored with the help of thermogravimeteric analysis. Electrical resistance values of PEDOT-coated membranes were measured by two probe method. The effect of different electrolyte solutions such as, distilled H2O, Na2SO4, HCl, and H2SO4 on electrical properties of produced conductive membranes was investigated after dipping for certain period of time. It was found that membranes dipped in H2SO4 show very low electrical resistance values, i.e. 0.85 kΩ for polyester membrane and 1.17 kΩ for PTFE membrane. The obtained PEDOT-coated electro-active membranes may find their possible utility in fuel cells, enzymatic fuel cells, and antistatic air filter applications.

  • 54.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Smart Textiles: A novel concept of functionalizing textile materials2013Conference paper (Refereed)
    Abstract [en]

    Electrically conductive textile materials are the key components in smart and interactive textile applications. In our research, we introduced functionalities in commercially available textile substrates (fibers and fabrics) by coating them with conjugated polymer, such as poly (3,4-ethylenedioxythiophene) (PEDOT) [1-2]. In order to get conductivities that are of use, an efficient technique, chemical vapor deposition (CVD), was used. The obtained coated fibers and fabrics exhibited good electro-mechanical properties and can be utilized for a number of electronic applications, such as stretch sensors, anti-static air filters and electrodes for bio-fuel cells.

  • 55.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, M.
    University of Borås, School of Engineering.
    Persson, N-K.
    [external].
    Functionalization of textile yarns by coating with conjugated polymer (PEDOT) for smart textile applications2012Conference paper (Other academic)
  • 56.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    Electroactive textile fibers produced by coating commercially available textile fibers with conductive polymer2010In: Nordic Textile Journal, ISSN 1404-2487Article in journal (Refereed)
    Abstract [en]

    The development of electrically conductive fibers, exhibiting higher mechanical properties and their integration in smart and interactive textiles, has become a prominent research area throughout the world. Smart textiles have increasingly been used in medical, sports and military applications. In other words, we can say, smart textiles are going to shape our future. This paper describes our ongoing research in which, we have produced relatively highly conductive fibers by coating commercially available textile fibers (viscose, polyester) with conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT). A novel coating technique, called oxidative chemical vapor deposition (OCVD), was used for this purpose. Different testing and characterization techniques were then employed to investigate electrical, mechanical, thermal, and surface properties of PEDOT coated fibers. The surface modification of electrically conductive textile fibers with silicone resins is also discussed and an analysis is given to show how silicone coating enhances the mechanical as well as hydrophobic properties of coated textile fibers. The obtained PEDOT coated textile fibers showed good electrical as well as mechanical properties. From this research, we can easily select the most appropriate type of fiber according to the specific electronic application, exhibiting the required end-used properties. These conductive fibers could also be used as substrates for heat generation devices, such as solar cells, and organic fuel cells.

  • 57.
    Bashir, Tariq
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    High-strength electrically conductive fibers: functionalization of polyamide, aramid and polyester fibers with PEDOT polymer2017In: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 29, no 1, p. 310-318, article id 10.1002/pat.4116Article in journal (Refereed)
    Abstract [en]

    In this work, high-performance fibers such as aramid (Twaron), polyamide (PA6), polyester (PET), and hybrid Twaron/PA6 fibers were transformed into electroactive fibers by coating them with conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) through vapor phase polymerization (VPP) method. The VPP is considered as an efficient technique for depositing CPs on different substrates regardless of their lower solubility in various solvents. In this paper, PEDOT-coated high-performance fibers were prepared under already optimized reaction conditions, and then a comparison between electrical, thermal, and mechanical properties of different fibers, before and after coating, was made. The obtained coated fibers were characterized through scanning electron microscope (SEM), thermogravimetric analysis (TGA), 2-probe electrical resistance measurement method, and tensile testing. It was revealed that at particular reaction conditions, all high performance textile substrates were successfully converted into electroactive fibers. The voltage-current (V-I) characteristics showed that PEDOT-coated polyester fibers exhibited highest conductivity value among all other substrate fibers. The active PEDOT layers on high performance fibers could behave as an antistatic coating to minimize the risks associated with static charges at work places. Also, the obtained fibers have potential to be used as smart materials for various medical, sports, and military applications.

    Download full text (pdf)
    fulltext
  • 58.
    Bashir, Tariq
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    High-strengthelectrically conductive fibers: Functionalization of polyamide, aramid andpolyester fibers with PEDOT polymer2017In: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581Article in journal (Refereed)
    Abstract [en]

    In this work, high-performance fibers such as aramid (Twaron), polyamide (PA6), polyester (PET), and hybrid Twaron/PA6 fibers were transformed into electroactive fibers by coating them with conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) through vapor phase polymerization (VPP) method. The VPP is considered as an efficient technique for depositing CPs on different substrates regardless of their lower solubility in various solvents. In this paper, PEDOT-coated high-performance fibers were prepared under already optimized reaction conditions, and then a comparison between electrical, thermal, and mechanical properties of different fibers, before and after coating, was made. The obtained coated fibers were characterized through scanning electron microscope (SEM), thermogravimetric analysis (TGA), 2-probe electrical resistance measurement method, and tensile testing. It was revealed that at particular reaction conditions, all high performance textile substrates were successfully converted into electroactive fibers. The voltage-current (V-I) characteristics showed that PEDOT-coated polyester fibers exhibited highest conductivity value among all other substrate fibers. The active PEDOT layers on high performance fibers could behave as an antistatic coating to minimize the risks associated with static charges at work places. Also, the obtained fibers have potential to be used as smart materials for various medical, sports, and military applications.

    Download full text (pdf)
    fulltext
  • 59.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    University of Borås, School of Engineering.
    Oxidative Chemical Vapour Deposition Polymerization of Poly (3,4-ethylenedioxythiophene) on Viscose Yarns: A Route to Conductive Textile Structures2010Conference paper (Refereed)
  • 60.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    University of Borås, School of Engineering.
    Production of conductive yarns by chemical vapour deposition technique of PEDOT viscose fibres2010Conference paper (Refereed)
  • 61.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    Production of Highly Conductive Textile Viscose Yarns by Chemical Vapor Deposition Technique: A Route to Continuous Process2010In: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 22, no 12, p. 2214-2221Article in journal (Refereed)
    Abstract [en]

    An oxidative chemical vapor deposition (OCVD) process was used to coat flexible textile fiber (viscose) with highly conductive polymer, poly (3,4-ethylenedioxythiophene) (PEDOT) in resence of ferric (III) chloride (FeCl3) oxidant. OCVD is a solvent free process used to get uniform, thin, and highly conductive polymer layer on different substrates. In this paper, PEDOT coated viscose fibers, prepared under specific conditions, exhibited high conductivity 14.2 S/cm. The effects of polymerization conditions, such as polymerization time, oxidant concentration, dipping time of viscose fiber in oxidant solution, and drying time of oxidant treated viscose fiber, were carefully investigated. Scanning electron microscopy (SEM) and FT-IR analysis revealed that polymerization of PEDOT on surface of viscose fiber has been taken place and structural analysis showed strong interactions between PEDOT and viscose fiber. Thermogravimetric analysis (TGA) was employed to investigate the amount of PEDOT in PEDOT coated viscose fiber and interaction of PEDOT with viscose fiber. The effect of PEDOT coating on the mechanical properties of the viscose fiber was evaluated by tensile strength testing of the coated fibers. The obtained PEDOT coated viscose fiber having high conductivity, could be used in smart clothing for medical and military applications, heat generation, and solar cell demonstrators.

  • 62.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    [external].
    Production of PEDOT Coated Conductive Fibers for Smart & Interactive Textile Applications2012Conference paper (Refereed)
  • 63.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    Surface Modification of Conductive PEDOT Coated Textile Yarns with Silicone Resin2011In: Materials technology (New York, N.Y.), ISSN 1066-7857, E-ISSN 1753-5557, Vol. 26, no 3, p. 135-139Article in journal (Refereed)
    Abstract [en]

    Electroactive textile fibres and fabrics have been used in smart and interactive clothing for medical,military and sports applications. The improved surface properties of conductive textiles are required for their successful integration in all of the above mentioned applications. This paper presents the production of conductive poly(3,4-ethylenedioxythiophene) (PEDOT) coated viscose yarns in longer length, i.e. 5 m, and the surface modification of the coated yarns by treating with silicone solution. The structural properties of silicone coated conductive yarns were then investigated by Fourier transform infrared spectroscopy and thermogravimetric analysis. The effect of silicone coating on the mechanical, electrical and hydrophobic properties was also evaluated and then compared with the PEDOT coated viscose yarns without surface treatment. Results show that the mechanical and hydrophobic properties of conductive yarns were improved by surface modification with silicone without affecting their structural properties. The surface modified PEDOT coated yarns could be used as pressure and stretch sensors in health care applications.

  • 64.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Persson, Nils-Krister
    Synthesis of High Performance, Conductive PEDOT-coated Polyester Yarns by OCVD Technique2012In: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 23, no 3, p. 611-617Article in journal (Refereed)
    Abstract [en]

    Production of high performance conductive textile yarn fibers for different electronic applications has become a prominent area of many research groups throughout the world. We have used oxidative chemical vapor deposition (OCVD) technique to coat flexible and high strength polyester yarns with conjugated polymer, poly(3,4- ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl3) oxidant. OCVD is an efficient solvent free technique used to get uniform, thin, and highly conductive polymer layers on different substrates. In this paper, PEDOT-coated polyester (PET) yarns were prepared under specific reaction conditions, and the electrical, mechanical and thermal properties were compared to previously studied PEDOT-coated viscose yarns. Scanning electron microscopy (SEM) and FT-IR analysis revealed that polymerization of PEDOT on the surface of the polyester yarns has been taken place successfully and structural analysis showed that PEDOT has strong interactions with viscose yarns as compared to PET yarns. The voltage–current (V–I) characteristics showed that PET yarns are more conductive than PEDOT-coated viscose yarns. The variation in the conductivity of PEDOT-coated yarns and the heat generation properties during the flow of current through coated yarns for longer period of time, was studied by time–current (t–I) characteristics. Thermogravimeteric analysis (TGA) was employed to investigate the thermal properties and the amount of PEDOT in PEDOT-coated PET yarns compared to PEDOT-coated viscose. The effect of PEDOT coating and ferric (III) chloride concentration on the mechanical properties of coated yarns was evaluated by tensile testing. The obtained PEDOT-coated conductive polyester yarns could be used in smart clothing for medical and military applications.

  • 65.
    Bashir, Tariq
    et al.
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Ramamoorthy, Sunil Kumar
    Persson, Nils-Krister
    University of Borås, School of Engineering.
    All-organic conductive fibers for smart and interactive textile applications2013Conference paper (Other academic)
  • 66.
    Björk, Hans
    et al.
    University of Borås, School of Engineering.
    Lindecrantz, Kaj
    University of Borås, School of Engineering.
    Ericsson, Dag
    University of Borås, School of Engineering.
    Sarv, Hans
    University of Borås, School of Engineering.
    Bolton, Kim
    University of Borås, School of Engineering.
    Börjesson, Anders
    University of Borås, School of Engineering.
    Bazooyar, Faranak
    University of Borås, School of Engineering.
    Ahlström, Peter
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Andersson, Bengt-Åke
    University of Borås, School of Engineering.
    Johansson, Andreas
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    20 år med Institutionen Ingenjörshögskolan: historik, nuläge och framtid2009Report (Other academic)
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    COVER01
  • 67.
    Bohlén, Martin
    et al.
    University of Borås, School of Engineering.
    Yaghooby, Haleh
    Airola, Karri
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Film Extrusion of Hydroxyapapatite and β-Tricalciumphosphate Functionalized Polyactide Polymers for Biomedical Implants2010Conference paper (Other academic)
  • 68. Chalapati, Sachin
    et al.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Toluene mediated fluid catalytic cracking of low density polyethylene using ionic liquids2014Conference paper (Other academic)
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    FULLTEXT01
  • 69.
    Cho, Sung-Woo
    et al.
    University of Borås, School of Engineering.
    Adekunle, Kayode
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Mechanical properties of renewable thermoset composites reinforced with natural fibers2010Conference paper (Other academic)
    Abstract [en]

    The focus in this presentation has been to evaluate whether natural fibers can be used as reinforcement in composites based on renewable thermoset resin. Thermoset resins made from renewable resources as alternatives to crude oils are a relatively unexplored and important research area and could be used for a broad range of applications including coatings, inks, adhesives and composites. The common raw materials used in the preparation of biobased thermoset resins are vegetable oils such as soybean oil, rapeseed oil and linseed oil, which are low cost and abundant. Natural fibers as reinforcement have many advantages compared to synthetic fibers, for instance they are biodegradable, low weight and cost, nontoxic and recyclable. In the previous study, a novel thermoset resin [methacrylic anhydride modified soybean oil (MMSO)] was synthesized through the reaction of epoxidized soybean oil with methacrylic acid and used here as matrices. The studied composites based on the neat MMSO resin and the reisn blended with 30 wt.% styrene reinforced with non-woven flax fiber and woven flax fiber mats in different orientations [0°(warp direction), 45°, 90°(weft direction)] were manufactured using compression molding technique. The glass fiber reinforced composite was also prepared for the comparison purpose. The results show that it was possible to produce composite with high mechanical properties when the load is especially applied along the fiber direction, which implies that the structural composites having several plies of natural fiber mats in different orientations could be interesting candidates for use in technical applications.

  • 70.
    Cho, Sung-Woo
    et al.
    University of Borås, School of Engineering.
    Gällstedt, Mikael
    Ullsten, Henrik
    Wretfors, Christer
    Johansson, Eva
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Hedenqvist, Mikael S.
    Characteristics of wheat gluten bioplastics in relation to processing methods2010Conference paper (Other academic)
  • 71.
    Cho, Sung-Woo
    et al.
    University of Borås, School of Engineering.
    Gällstedt, Mikael
    Ullsten, Henrik
    Wretfors, Christer
    Johansson, Eva
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Hedenqvist, Mikael S.
    Protein-based bioplastics and nanocomposites from a processing perspective2010Conference paper (Other academic)
  • 72.
    Cho, Sung-Woo
    et al.
    University of Borås, School of Engineering.
    Persson, Maria
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Melt spun fibres of poly(lactic acid) and hydroxyapatite nanoparticles for use as tissue engineering scaffolds2011Conference paper (Refereed)
  • 73.
    Cho, Sung-Woo
    et al.
    University of Borås, School of Engineering.
    Persson, Maria
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Three dimensional woven bone tissue engineering scaffolds of melt-spun poly(lactic acid) fibres2011Conference paper (Refereed)
  • 74. Cho, Sung-Woo
    et al.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Hemanathan, Kumar
    Mahimaisenan, Pirabasenan
    Adekunle, Kayode
    University of Borås, School of Engineering.
    Regenerated cellulose fibre reinforced casein films: Effect of plasticizer and fibres on the film properties2014In: Macromolecular Research, ISSN 1598-5032, E-ISSN 2092-7673, Vol. 22, no 7, p. 701-709Article in journal (Refereed)
    Abstract [en]

    The idea of using man-made cellulosic fibres as reinforcement for casein films in this study was inspired by their well defined fibre diameter and availability in large quantity, eventually leading to a homogeneous high quality composite at low cost. The casein biofilms were fabricated by solution casting from an aqueous alkaline solution of the bovine milk protein casein in the presence of glycerol as a plasticizer, and the fibre-reinforced biocomposites were prepared by the addition of regenerated cellulose fibre to the casein casting solution with various amounts of glycerol. The effects of glycerol content and cellulose fibre reinforcements on the mechanical, thermal and physiological properties were characterized. The results showed that increasing glycerol content decreased the film strength, Young’s modulus and thermal stability with a gradual increase in the elongation. However, the tensile properties were noticeably improved when reinforced with cellulose fibre. The composite with 20 wt% glycerol and 20 wt% cellulose fibre showed the maximum tensile strength of 23.5 MPa and Young’s modulus of 1.5 GPa. The corresponding values for the composite with 30 wt% glycerol and the same fibre content were 15.1 MPa and 0.9 GPa, which were 2.3- and 3.2-fold higher compared to 30 wt% glycerol plasticized film. The thermal analysis revealed that the glass transition temperature and the thermal stability were decreased when the glycerol content was increased. Addition of cellulose fibres increased the glass transition temperature as well as the thermal stability. The gel electrophoresis (SDS-PAGE) analysis indicated that there was no significant decrease in the molecular weight of the casein protein during sample preparation. Scanning electron microscopy showed that the obtained composites with low glycerol content had adequate interfacial bonding, and Fourier transform IR spectroscopy confirmed the formation of molecular interactions between the cellulose fibres and the casein.

  • 75. Damadzadeh, B
    et al.
    Jabari, H
    Airola, Karri
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Effect of level of ceramic nanofillers on the mechanical and thermal behaviour of PLA and PLGA composite materials for medical implants2009Conference paper (Other academic)
  • 76. Damadzadeh, B.
    et al.
    Jabari, H.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Airola, K.
    Moritz, N.
    Vallittu, P.
    Effect of ceramic filler content on the mechanical and thermal behaviour of poly-L-lactic acid and poly-L-lactic-co-glycolic acid composites for medical applications2010In: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 21, no 9, p. 2523-2531Article in journal (Refereed)
    Abstract [en]

    One main application of resorbable poly-Llactic acid (PLLA) and poly-L-lactic-co-glycolic acid (PLGA) based materials is in medical implants. In this study composites were made from PLLA and PLGA with hydroxyapatite (HAp) respective b-tricalcium phosphate (b-TCP) fillers. The filler content and particle size were varied, and the thermal properties as well as the mechanical strength of the composites were investigated. The composites were made by an extrusion compounding process giving 2–2.5 mm diameter sized profiles. The results verified that the thermal stability of the composites was reasonable during the optimized compounding conditions. Scanning electron microscopy revealed that the fillers were well dispersed in the polymer matrices. The mechanical properties were improved by the addition of the fillers. The optimum mechanical properties for the extruded profiles were obtained with the HAp fillers. The E-modulus was increased from 3.3 to 4.6 GPa by addition of filler particles (30 wt%) whereas the flexural strength was reduced from 133 to 106 MPa.

  • 77.
    Darabi, Sozan
    et al.
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Göteborg, Sweden.
    Hummel, Michael
    Department of Bioproducts and Biosystems, Aalto University, 02150 Espoo, Finland.
    Rantasalo, Sami
    Department of Bioproducts and Biosystems, Aalto University, 02150 Espoo, Finland.
    Rissanen, Marja
    Department of Bioproducts and Biosystems, Aalto University, 02150 Espoo, Finland.
    Månsson, Ingrid Öberg
    Department of Bioproducts and Biosystems, Aalto University, 02150 Espoo, Finland.
    Hilke, Haike
    University of Borås, Faculty of Textiles, Engineering and Business.
    Hwang, Byungil
    School of Integrative Engineering, Chung-Ang University, 06974 Seoul, Republic of Korea.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Hamedi, Mahiar M.
    Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 11428 Stockholm, Sweden.
    Sixta, Herbert
    Department of Bioproducts and Biosystems, Aalto University, 02150 Espoo, Finland.
    Lund, Anja
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Göteborg, Sweden.
    Müller, Christian
    Anja Lund Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Göteborg, Sweden.
    Green Conducting Cellulose Yarns for Machine-Sewn Electronic Textiles2020In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 12, no 50, p. 56403-56412Article in journal (Refereed)
    Abstract [en]

    The emergence of “green” electronics is a response to the pressing global situation where conventional electronics contribute to resource depletion and a global build-up of waste. For wearable applications, green electronic textile (e-textile) materials present an opportunity to unobtrusively incorporate sensing, energy harvesting, and other functionality into the clothes we wear. Here, we demonstrate electrically conducting wood-based yarns produced by a roll-to-roll coating process with an ink based on the biocompatible polymer:polyelectrolyte complex poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The developed e-textile yarns display a, for cellulose yarns, record-high bulk conductivity of 36 Scm(-)(1), which could be further increased to 181 Scm(-)(1) by adding silver nanowires. The PEDOT:PSS-coated yarn could be machine washed at least five times without loss in conductivity. We demonstrate the electrochemical functionality of the yarn through incorporation into organic electrochemical transistors (OECTs). Moreover, by using a household sewing machine, we have manufactured an out-of-plane thermoelectric textile device, which can produce 0.2 mu W at a temperature gradient of 37 K.

  • 78.
    de Sousa, Giulia Simão
    et al.
    Department of Chemical and Materials Engineering Pontifical Catholic University of Rio de Janeiro Rio de Janeiro Brazil.
    Kalantar Mehrjerdi, Adib
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery, Faculty of Textiles, Engineering and Business University of Borås Borås Sweden;R&D Manager MuoviTech International Group MuoviTech AB Brämhult Sweden.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery, Faculty of Textiles, Engineering and Business University of Borås Borås Sweden.
    d'Almeida, José Roberto Moraes
    Department of Chemical and Materials Engineering Pontifical Catholic University of Rio de Janeiro Rio de Janeiro Brazil.
    Thermo‐mechanical properties of polyethylene composites filled with soapstone waste2023In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, article id e55017Article in journal (Refereed)
    Abstract [en]

    In this study, soapstone waste originated from craftsmanship activities was used as an alternative filler (0–30 wt%) for a high-density polyethylene (PE) matrix. The aim of this paper is to understand the effect of the filler particles on crystallinity, thermal stability and thermo-mechanical properties of this newly developed composite material. Physico-chemical characterization was performed by x-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. Thermogravimetric analysis (TGA), oxidation induction time (OIT) and dynamic mechanical thermal analysis (DMA) were performed to assess the effect of the filler on the themo-mechanical properties of PE. Thermal stability, measured by TGA, was enhanced, while OIT values reduced with filler content. A significant increase on the storage modulus of the composites (up to 148% in comparison with unfilled PE) was observed and this reinforcing effect was even more prominent at higher temperatures. XRD analysis revealed that the degree of crystallinity improved significantly with soapstone loading, which explains the substantial increase in stiffness observed. Increased crystallinity is also associated with higher strength, reduced residual stress, and better dimensional stability of end products, which can be particularly attractive for pressure pipe applications. 

  • 79. Dhakal, Hom N
    et al.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Adekunle, Kayode
    University of Borås, School of Engineering.
    Zhang, Z Y
    Falling weight impact response of jute/methacrylated soybean oil bio-composites under low velocity impact loading2014In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 92, p. 134-141Article in journal (Refereed)
    Abstract [en]

    In this study, impact performance of bio-composites fabricated from jute/methacrylated soybean oil (MSO) subjected to low-velocity impact loading is presented. The composite laminates were fabricated using compression moulding technique and their thickness and weave architectures effect on the impact response were investigated and the experimental observations are reported. From the results obtained, it was observed that fibre orientation and thickness variation have a significant influence on the impact resistance of jute/MSO composite material. The results show that the total absorbed energy and maximum peak load increase linearly with an increase in the thickness. Among the composite samples investigated where thickness comprised of: 1, 1.5, 2, 2.5 and 3 mm, a composite reinforced with 46 yarns per 10 cm weft and 50 warp (W2-3 mm thick) is found to have highest resistance to impact damage compared to 32 and 15 yarn per 10 cm weft samples. This was attributed to the improved fibre/matrix interface as a result of surface treatment of jute fibres and the fibre architectures effect which create the cross-over points which act as stress distributors.

  • 80. Ding, Xiangyu
    et al.
    Liu, Hewen
    Shi, Wenfang
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Form-fill-seal methodology for controlled encapsulation of small silver particles in hyperbranched polygycidol2009In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 112, no 3, p. 1209-1214Article in journal (Refereed)
  • 81. Dural Erem, A.
    et al.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Demirpek, U.
    Özcan, G.
    The Antimicrobial Efficiency of Polyamide 6/Silver Nanocomposites2010Conference paper (Other academic)
  • 82. Dural Erem, Aysin
    et al.
    Ozcan, G
    Erem, H H
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Antimicrobial activity of poly(l-lactide acid)/silver nanocomposite fibers2013In: Textile research journal, ISSN 0040-5175, E-ISSN 1746-7748, Vol. 83, no 20, p. 2111-2117Article in journal (Refereed)
    Abstract [en]

    Silver (Ag) nanoparticles (NP) and poly(lactide acid) (PLA) granules were microcompounded to form a nanocomposite. A series of PLA nanocomposite fibers containing, respectively, 0, 0.5, 1, 3 or 5 wt% Ag were produced and their antimicrobial activity against Gram-negative and Gram-positive bacteria evaluated. It was found that the PLA/Ag nanocomposite fibers exhibited increased antimicrobial activity, depending on the filler content. On the other hand, mechanical and thermal characterization tests, including thermogravimetric analysis, differential scanning calorimetry and tensile testing, showed that increasing concentrations of Ag hindered the mechanical properties of Nanocomposites due to partial agglomeration, leading to the generation of flaws. The crystallinity of the fibers was found to decrease by about 23% if the Ag content was increased to 5%. This could be attributed to a more rapid cooling rate resulting from the high thermal conductivity of the Ag particles.

  • 83. Dural Erem, Aysin
    et al.
    Ozcan, G
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Bacteriostatic PLA/Chitosan Composite Fİlms2012Conference paper (Refereed)
  • 84. Dural Erem, Aysin
    et al.
    Ozcan, G
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Cakmak, M
    Antimicrobial Activity of PP/TiO2 Fi2012Conference paper (Refereed)
  • 85. Dural Erem, Aysin
    et al.
    Ozcan, G
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Erem, H H
    The production of Chitosan and Polypropylene/Chitosan Composites2010Conference paper (Refereed)
  • 86. Dural Erem, Aysin
    et al.
    Ozcan, Gulay
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    In vitro assessment of antimicrobial polypropylene/zinc oxide nanocomposite fibers2013In: Textile research journal, ISSN 0040-5175, E-ISSN 1746-7748, Vol. 83, no 20, p. 2152-2163Article in journal (Refereed)
    Abstract [en]

    A series of polypropylene (PP) nanocomposite fibres containing respectively 0, 0.5, 1, 3, and 5 wt% ZnO nanoparticles (NPs) were prepared by melt spinning. The antimicrobial activity of these fibers against Staphylococcus aureus (ATCC 6538) as a Gram-positive bacterium and Klebsiella pneumoniae (ATCC 4352) as a Gram-negative bacterium was evaluated. It was confirmed by scanning electron microscopy that the dispersion of the NPs within the PP matrix was homogeneous. Although such homogeneity the fibers are unable to exhibit antimicrobial activity. The absorption properties of the fibers was then investigated and found to be inadequate, so cold plasma and chemical finishing were applied to improve their absorptivity. After this treatment the PP/ZnO nanocomposite fibers exhibited increasing antimicrobial effectiveness with filler content. In addition, mechanical and thermal characterization tests showed that increasing concentration of ZnO–NPs improved the mechanical properties of the fiber due to the interface between the matrix and the nanoparticles sharing the stress. The crystallinity of the fibers was found to decrease by about 7% as the level of ZnO increased to 5%. This was attributed to the more rapid cooling experienced in the presence of ZnO particles of high thermal conductivity.

  • 87. Dural-Erem, Aysin
    et al.
    Erem, Hasan
    Ozcan, Gulay
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Anatase titanium dioxide loaded polylactide membranous films: preparation, characterization, and antibacterial activity assessment2015In: Journal of the Textile Institute, ISSN 0040-5000, E-ISSN 1754-2340, Vol. 106, no 6Article in journal (Refereed)
    Abstract [en]

    In this study, the preparation method and characteristics of anatase titanium dioxide (TiO2) nanoparticle-loaded polylactide (PLA) films and their antibacterial efficacy against Klebsiella pneumoniae (ATCC 4352) and Staphylococcus aureus (ATCC 6538) bacterium were studied. A series of PLA nanocomposites containing, respectively, 0, 1, and 5% (wt.) titanium dioxide (TiO2) nanoparticles were prepared by melt intercalation method. The effect of TiO2 nanoparticles on the thermal and mechanical characteristics of the films was determined. Thermal analysis showed that the glass transition temperature, crystallization temperature, melting temperature, and decomposition temperatures (Td0.5 and Td0.05) decreased with the filler content. The results obtained from tensile tests showed that TiO2 nanoparticles reduced the mechanical properties and moduli of the PLA films. On the other hand, the water absorption properties of the nanocomposite films increased with the addition of nanoparticles and nanocomposite films exhibited bacteriostatic and limited bactericidal efficacy according to AATCC 147. Consequently, nanocomposite films may be good materials for medical applications due to their membranous properties.

  • 88.
    Ehsanimehr, S.
    et al.
    Université de Lorraine, CNRS, LPCT, 54000, Nancy, France.
    Sonnier, R.
    IMT – Mines Ales, Polymers Hybrids and Composites (PCH), 6 Avenue De Clavières, 30319, Alès Cedex, France.
    Badawi, M.
    Université de Lorraine, CNRS, LPCT, 54000, Nancy, France.
    Ducos, F.
    Université de Lorraine, CentraleSupélec, LMOPS, 57000, Metz, France.
    Kadi, Nawar
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery.
    Saeb, M. R.
    Department of Polymer Technology, Faculty of Chemistry, Gdańsk University of Technology, G. Narutowicza 11/12, 80-233, Gdańsk, Poland.
    Vahabi, H.
    Université de Lorraine, CentraleSupélec, LMOPS, 57000, Metz, France.
    Sustainable Flame-Retardant Flax Fabrics by Engineered Layer-by-Layer Surface Functionalization with Phytic Acid and Polyethylenimine2023In: Fire technology, ISSN 0015-2684, E-ISSN 1572-8099Article in journal (Refereed)
    Abstract [en]

    New generation of mission-oriented fabrics meets advanced requirements; such as electrical conductivity, flame retardancy, and anti-bacterial properties. However, sustainability concerns still are on-demand in fabrication of multi-functional fabrics. In this work, we used a bio-based phosphorus molecule (phytic acid, PA) to reinforce flax fabrics against flame via layer-by-layer consecutive surface modification. First, the flax fabric was treated with PA. Then, polyethylenimine (PEI) was localized above it to create negative charges, and finally PA was deposited as top-layer. Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and inductively-coupled plasma atomic emission spectrometry (ICP-AES) proved successful chemical treatment. Pyrolysis-combustion flow calorimetry (PCFC) showed significant drop by about 77% in the peak of heat release rate (pHRR) from 215 W/g for untreated to 50 W/g for treated flax fabric. Likewise, the total heat release (THR) decreased by more than three times from 11 to 3.2 kJ/g. Mechanical behavior of the treated flax fabric was completely different from untreated flax fabrics, changing from almost highly-strengthened behavior with short elongation at break to a rubber-like behavior with significantly higher elongation at break. Surface friction resistance was also improved, such that the abrasion resistance of the modified fabrics increased up to 30,000 rub cycles without rupture.   

  • 89. Erem, Aysin Dural
    et al.
    Ozcan, Gulay
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Cakmak, Mukerrem
    In vitro assesment of antimicrobial activity and characteristics of polyamide 6/silver nanocomposite fibers2013In: Fibers And Polymers, ISSN 1229-9197, E-ISSN 1875-0052, Vol. 14, no 9, p. 1415-1421Article in journal (Refereed)
    Abstract [en]

    In this study, the preparation method and characteristics of silver (Ag) nanoparticle (NP) loaded polyamide 6 (PA6) nanocomposite and its antimicrobial activity against Klebsiella pneumonia and Staphylococcus aureus were investigated. The melt intercalation method was used to prepare a series of PA 6 nanocomposite fibers containing, 0; 1; 3; 5 % (wt.) Ag. PA6/Ag nanocomposite fibers exhibit increased antimicrobial efficiency with the increase of nanoparticle contents. On the other hand, thermal characterization tests show that the increased concentration of Ag nanoparticles reduces the mechanical properties due to their partial agglomeration leading to flaw generation. The crystallinity of the fibers was found to decrease about 10 % with increase of Ag to 5 %. This was attributed to faster cooling rate experienced in the presence of high thermal conductivity Ag particles.

  • 90. Erem, Aysin
    et al.
    Ozcan, Gulay
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Cakmak, Mukerrem
    In vitro assesment of antimicrobial activity and characteristics of polyamide 6/silver nanocomposite fibers2013In: Fibers And Polymers, ISSN 1229-9197, E-ISSN 1875-0052, Vol. 14, no 9, p. 1415-1421Article in journal (Refereed)
    Abstract [en]

    In this study, the preparation method and characteristics of silver (Ag) nanoparticle (NP) loaded polyamide 6 (PA6) nanocomposite and its antimicrobial activity against Klebsiella pneumonia and Staphylococcus aureus were investigated. The melt intercalation method was used to prepare a series of PA 6 nanocomposite fibers containing, 0; 1; 3; 5 % (wt.) Ag. PA6/Ag nanocomposite fibers exhibit increased antimicrobial efficiency with the increase of nanoparticle contents. On the other hand, thermal characterization tests show that the increased concentration of Ag nanoparticles reduces the mechanical properties due to their partial agglomeration leading to flaw generation. The crystallinity of the fibers was found to decrease about 10 % with increase of Ag to 5 %. This was attributed to faster cooling rate experienced in the presence of high thermal conductivity Ag particles.

  • 91. Erem Dural, A.
    et al.
    Ozcan, G.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Antibacterial activity of PA6/ZnO nanocomposites fibers2011In: Textile research journal, ISSN 0040-5175, E-ISSN 1746-7748, Vol. 81, no 16, p. 1638-1646Article in journal (Refereed)
    Abstract [en]

    In this study, ZnO-loaded PA6 nanocomposite preparation and its antibacterial activity are investigated. This work aims to study the effect of the sizes and amount of the ZnO nanofiller on the antibacterial, mechanical, and thermal properties of the PA6/ZnO nanocomposites. The melt intercalation method is applied to prepare polyamide 6 (PA6) nanocomposite fibers, including 0, 0.5, 1, 3, 5 wt % zinc oxide (ZnO), using a laboratory-scale compounder. The antibacterial activity of the fibers against Staphylococcus aureus (ATCC 6538) as a gram positive bacterium and Klebsiella pneumoniae (ATCC 4352) as a gram negative bacterium is determined according to ASTM E 2149-0. Mechanical and thermal characterization tests are performed according to relevant standards (ASTM D7426-08, ASTM E1131-08, ASTM D3822-07; DSC, TGA, tensile tests). It is found that the dispersion of the ZnO particles within the PA6 matrix is homogenous according to scanning electron microscopy results. Antibacterial activity tests show that PA6/ZnO nanocomposite fibers exhibit antibacterial efficiency related to their nanoparticle contents. An increase in the amount of nanoparticles causes an increase of the antibacterial activity of the fibers. On the other hand, mechanical and thermal characterization tests show that the addition of ZnO nanoparticles does not affect the strength and thermal properties of the nanocomposites for these loadings.

  • 92.
    Esmaeili, Nima
    et al.
    University of Bolton.
    Jahandideh, Arash
    South Dakota State University.
    Muthukumarappan, Kasiviswanathan
    South Dakota State University.
    Åkesson, Dan
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Synthesis and characterization of methacrylated star-shaped poly(lactic acid) emplying core moilecules with different hydroxyl groups2017In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 134, no 39, article id 45341Article in journal (Refereed)
    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.

  • 93. Esmaeli, Nima
    et al.
    Bakare, Fatimat Oluwatoyin
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Afshar, Shahrzad Javanshir
    Åkesson, Dan
    University of Borås, School of Engineering.
    Mechanical properties for bio-based thermoset composites made from lactic acid, glycerol and viscose fibers2014In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, no 1, p. 603-613Article in journal (Refereed)
    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.

  • 94. Fatarella, Enrico
    et al.
    Mylläri, Ville
    Ruzzante, Marco
    Pogni, Rathish
    Baratto, Maria
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Syrjälä, Seppo
    Järvelä, Pentti
    Sulfonated polyetheretherketone/polypropylene polymer blends for the production of photoactive materials2014In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 132, no 8Article in journal (Refereed)
    Abstract [en]

    Sulfonated polyetheretherketone (SPEEK) was synthesized via a mono-substitution reaction of PEEK in concentrated sulphuric acid and was blended with polypropylene (PP) in 2–10%w/w concentration to be used for the production of photoactive thermoplastic products. SPEEK and SPEEK/PP blends were characterized using FTIR, DSC, TGA, NMR, rheology, SEM, and EPR. Under UV-Vis irradiation, stable benzophenone ketyl (BPK) radicals were generated by hydrogen extraction from PP. By increasing the amount of SPEEK in the polymer blend a linear increase in the BPK radicals was achieved according to the EPR data. DSC and TGA tests indicated weaknesses in the thermal stability of SPEEK but according to the rheological tests this should not have a major effect on processabililty. The optimal amount of SPEEK in the blend was obtained at 5%w/w. This concentration provided a good compromise between radical concentration, material processability, and cost

  • 95.
    Fatarella, Enrico
    et al.
    Next Technology Tecnotessile Società Nazionale di Ricerca s.r.l.
    Mylläri, Ville
    Tampere University of Technology.
    Ruzzante, Marco
    Next Technology Tecnotessile Società Nazionale di Ricerca s.r.l.
    Pogni, Rebecca
    Department of Biotechnology, Chemistry and Pharmacy, University of Siena.
    Baratto, Maria
    Department of Biotechnology, Chemistry and Pharmacy, University of Siena.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Syrjälä, Seppo
    Tampere University of Technology.
    Järvelä, Pentti
    Tampere University of Technology.
    Sulfonated polyetheretherketone/polypropylene polymer blends for the production of photoactive materials2015In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 132, no 8Article in journal (Refereed)
  • 96.
    Fazelinejad, Samaneh
    et al.
    University of Borås, School of Engineering.
    Åkesson, Dan
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Mechanical Recycling of Polylactic Acid Reinforced with Calcium Carbonate2014Conference paper (Other academic)
    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.

  • 97. Fazelinejad, Samaneh
    et al.
    Åkesson, Dan
    University of Borås, School of Engineering.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Recycling of Poly Lactic Acid Reinforced with Calcium Carbonate by Multiple Processing2014Conference paper (Other academic)
    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.

  • 98.
    Fazelinejad, Samaneh
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Åkesson, Dan
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Repeated mechanical recycling of polylactic acid filled with chalk2017In: Progress in Rubber, Plastics and Recycling Technology, ISSN 0266-7320, E-ISSN 1478-2413, p. 1-16Article in journal (Refereed)
    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.

  • 99. Foltynowicz, Zenon
    et al.
    Åkesson, Dan
    University of Borås, School of Engineering.
    Christéen, Jonas
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Microwave pyrolysis as a method to glass fibre recovery from used blades of wind turbines2012Conference paper (Refereed)
    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.

  • 100. George, G.
    et al.
    Jose, E.T.
    Jayanarayanan, K.
    Nagarajan, E.R.
    Skrifvars, Mikael
    University of Borås, School of Engineering.
    Joseph, K.
    Novel bio-commingled composites based on jute/polypylene yarns: Effect of chemical treatment on the mechanical properties2012In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 43, no 1, p. 219-230Article in journal (Refereed)
    Abstract [en]

    This paper mainly investigates the fabrication process of jute yarn reinforced, bidirectional thermoplastic commingled composites (both untreated and treated). Commingling method was used to prepare the composites wherein the Polypropylene yarn (PP yarn) and jute yarn were wound together onto a metal plate in a particular configuration and then compression moulded. The mechanical properties of the composites prepared from chemically treated jute yarn were found to increase substantially compared to those of untreated ones. The surface morphologies of the fracture surfaces of the composites were recorded using scanning electron microscope (SEM). The SEM micrographs reveal that interfacial bonding between the treated jute yarn and the matrix has improved significantly by chemical treatments. The various chemical treatment mechanisms have been supported by FT-IR spectra. Theoretical modelling was used to predict the tensile properties and was found to be in accordance with the experimental results.

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