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  • 251.
    Feng, Shizhen
    et al.
    South China University of Technology, Peoples R China.
    Liu, Chang
    South China University of Technology, Peoples R China.
    Xu, Xiaofeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Chalmers University of Technology, Sweden.
    Liu, Xuncheng
    South China University of Technology, Peoples R China.
    Zhang, Lianjie
    South China University of Technology, Peoples R China.
    Nian, Yaowen
    South China University of Technology, Peoples R China.
    Cao, Yong
    South China University of Technology, Peoples R China.
    Chen, Junwu
    South China University of Technology, Peoples R China.
    Siloxane-Terminated Side Chain Engineering of Acceptor Polymers Leading to Over 7% Power Conversion Efficiencies in All-Polymer Solar Cells2017In: ACS Macro Letters, E-ISSN 2161-1653, Vol. 6, no 11, p. 1310-1314Article in journal (Refereed)
    Abstract [en]

    To investigate the influence of functional pendent groups on acceptor polymers and photovoltaic properties of all-polymer solar cells (all-PSCs), two novel acceptor polymers containing siloxane-terminated side chains are synthesized and characterized. Increasing the content of siloxane-terminated side chains can reduce pi-pi stacking distance and improve crystalline behavior, yet lead to poorer solubility of the acceptor polymers. By modulating the proper loadings of siloxane-terminated side chains on the acceptor polymers, the PBDB-T:PNDI-Si25 all-PSC attains a maximal power conversion efficiency (PCE) of 7.4% with an outstanding fill factor of 0.68. The results provide, new insights for developing high-performance all-PSCs through functional group engineering on the acceptor polymers, to achieve good solubility, polymer miscibility, and blend morphology.

  • 252.
    Feng, Zhaoxuan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Odelius, Karin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Tunable chitosan hydrogels for adsorption: Property control by biobased modifiers2018In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 196, p. 135-145Article in journal (Refereed)
    Abstract [en]

    A sustainable strategy to fabricate chitosan-based composite hydrogels with tunable properties and controllable adsorption capacity of trace pharmaceuticals was demonstrated. Two biobased modifiers were utilized to tune the properties, nano-graphene oxide (nGO) derived from chitosan via microwave-assisted carbonization and oxidation, and genipin as the crosslinking agent. An increase in genipin content facilitated an increase in the degree of crosslinking as shown by improved storage modulus and decreased swelling ratio. Increasing nGO content changed the surface microtopography of the hydrogel which correlated with the surface wettability. nGO also catalyzed the genipin-crosslinking reaction. The hydrogel was further shown to be an effective adsorbent for a common anti-inflammatory drug, diclofenac sodium (DCF), with the removal efficiency ranging from 91 to 100% after 48 h. DCF adsorption efficiency could be tuned through simple alteration of nGO and genipin concentration, which provides promising potential for this environmental-friendly adsorbent in removal of DCF from pharmaceutical waste water.

  • 253.
    Feng, Zhaoxuan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Odelius, Karin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Rajarao, Gunaratna Kuttuva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Hakkarainen, Minna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Microwave carbonized cellulose for trace pharmaceutical adsorption2018In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 346, p. 557-566Article in journal (Refereed)
    Abstract [en]

    A promising sustainable strategy to valorize cellulose to high-value adsorbents for trace pharmaceuticals, like diclofenac sodium (DCF), in the water is demonstrated. Carbon nanospheres (CN) as the DCF adsorbent were derived from cellulose through a one-pot microwave-assisted hydrothermal carbonization method. CN exhibited efficient DCF removal (100% removal of 0.001 mg/mL DCF in 30 s and 59% removal of 0.01 mg/mL DCF in 1 h). The adsorption kinetics and isotherm data were well-fitted with the pseudo-second-order kinetic model and Langmuir model, respectively. The adsorption process was endothermic and spontaneous as confirmed by the thermodynamic parameters. Multiple characterization techniques including SEM/EDS, FTIR, FTIR-imaging and zeta potential were applied to qualitatively investigate the adsorption process. π-π stacking and hydrogen bonding were proposed as the dominant adsorption interactions. CN also demonstrated effective adsorption capacity towards three other commonly-detected contaminants in the wastewater including ketoprofen (KP), benzophenone (BZP), and diphenylamine (DPA), each bearing partial structural similarity with DCF. The affinity of the contaminants towards CN followed the order DPA > BZP > DCF > KP, which could be explained by the different configurations and chemical units. It was speculated that for DCF and KP, the steric hindrance and electrostatic repulsion produced by dissociated carboxyl groups can impede the adsorption process as compared to DPA and BZP. This methodology could offer further insights into the drug adsorption on the cellulose-derived carbon adsorbents and the use of bioderived carbons for treatment of wastewaters contaminated with pharmaceuticals.

  • 254.
    Feng, Zhaoxuan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Simeone, Antonio
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Odelius, Karin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Biobased Nanographene Oxide Creates Stronger Chitosan Hydrogels with Improved Adsorption Capacity for Trace Pharmaceuticals2017In: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 5, no 12, p. 11525-11535Article in journal (Refereed)
    Abstract [en]

    A promising green strategy for the fabrication of fully biobased chitosan adsorbents for wastewater purification is presented. Nanographene oxide (nGO)-type carbon dots were derived from chitosan (nGOCS) or from cellulose (nGOCL) through a two-step process including microwave-assisted hydrothermal carbonization and oxidation. Finally, nGO were evaluated as biobased property enhancers in chitosan hydrogel adsorbents. Macroporous chitosan hydrogels were synthesized by cross-linking with genipin, and the incorporation of nGO into these hydrogels was shown to facilitate the cross-linking reaction leading to more robust 3D cross-linked networks. This was evidenced by the increased storage modulus and by the swelling ratio that decreased from 5.7 for pristine chitosan hydrogel to 2.6 for hydrogel with 5 mg/mL nGOCS and 3.3 for hydrogel with 5 mg/mL nGOCL. As a further proof of the concept the hydrogels were shown to be effective adsorbent for the common anti-inflammatory drug diclofenac sodium (DCF). Here, the addition of nGO promoted the DCF adsorption process leading to 100% removal of DCF after only 5 h. The synergistic effect of electrostatic interactions, hydrogen bonding, and pi-pi stacking could explain the high adsorption of DCF on the hydrogels. The developed biobased CS/nGO hydrogels are thus promising adsorbents with great potential for purification of trace pharmaceuticals from wastewater.

  • 255. Ferrero, B.
    et al.
    Boronat, T.
    Moriana, Rosana
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Fenollar, O.
    Balart, R.
    Green composites based on wheat gluten matrix and posidonia oceanica waste fibers as reinforcements2013In: Polymer Composites, ISSN 0272-8397, E-ISSN 1548-0569, Vol. 34, no 10, p. 1663-1669Article in journal (Refereed)
    Abstract [en]

    In this work, green composites from renewable resources were manufactured and characterized. A fibrous material derived from Posidonia oceanica wastes with high cellulose content (close to 90 wt% of the total organic component) was used as reinforcing material. The polymeric matrix to bind the fibers was a protein (wheat gluten) type material. Composites were made by hot-press molding by varying the gluten content on composites in the 10-40 wt% range. Mechanical properties were evaluated by standardized flexural tests. Thermo-mechanical behavior of composites was evaluated with dynamic mechanical analysis (torsion DMA) and determination of heat deflection temperature. Morphology of samples was studied by scanning electronic microscopy and the water uptake in terms of the water submerged time was evaluated to determine the maximum water uptake of the fibers in the composites. Composites with 10-40 wt% gluten show interesting mechanical performance, similar or even higher to many commodity and technical plastics, such as polypropylene. Water resistance of these composites increases with the amount of gluten. Therefore, the sensitiveness to the water of the composites can be tailored with the amount of gluten in their formulation.

  • 256.
    Ferrero, B.
    et al.
    Universitat Politècnica de València (UPV), Alcoy (Alicante), Spain.
    Boronat, T.
    Universitat Politècnica de València (UPV), Alcoy (Alicante), Spain.
    Moriana, Rosana
    KTH Royal Institute of Technology.
    Fenollar, O.
    Universitat Politècnica de València (UPV), Alcoy (Alicante), Spain.
    Balart, R.
    Universitat Politècnica de València (UPV), Alcoy (Alicante), Spain.
    Green composites based on wheat gluten matrix and posidonia oceanica waste fibers as reinforcements2013In: Polymer Composites, ISSN 0272-8397, E-ISSN 1548-0569, Vol. 34, no 10, p. 1663-1669Article in journal (Refereed)
    Abstract [en]

    In this work, green composites from renewable resources were manufactured and characterized. A fibrous material derived from Posidonia oceanica wastes with high cellulose content (close to 90 wt% of the total organic component) was used as reinforcing material. The polymeric matrix to bind the fibers was a protein (wheat gluten) type material. Composites were made by hot-press molding by varying the gluten content on composites in the 10-40 wt% range. Mechanical properties were evaluated by standardized flexural tests. Thermo-mechanical behavior of composites was evaluated with dynamic mechanical analysis (torsion DMA) and determination of heat deflection temperature. Morphology of samples was studied by scanning electronic microscopy and the water uptake in terms of the water submerged time was evaluated to determine the maximum water uptake of the fibers in the composites. Composites with 10-40 wt% gluten show interesting mechanical performance, similar or even higher to many commodity and technical plastics, such as polypropylene. Water resistance of these composites increases with the amount of gluten. Therefore, the sensitiveness to the water of the composites can be tailored with the amount of gluten in their formulation.

  • 257.
    Finne Wistrand, Anna
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Polylactide:  2011In: Handbook of Engineering and Speciality Thermoplastics: Polyethers and Polyesters / [ed] S. Thomas and V. P.M., Hoboken, NJ, USA: John Wiley & Sons, 2011, p. 349-376Chapter in book (Other academic)
    Abstract [en]

    The production of durable functional products without using petroleumbased raw materials is a focus of much academic research today but it is also prioritized by many industries. Many questions still remain concerning the use, production and properties of bio-based and/or degradable polymers and whether or not they are more environmentally friendly than oil-based products. Polylactide is a bio-based compostable thermoplastic that is considered as one of the most promising materials for replacement of traditional volume plastics. The properties of polylactide can be tuned to resemble polystyrene, poly(ethylene terephthalate) or polyolefins by controlling the stereochemistry by copolymerization or blending. This chapter reviews the life-cycle of polylactide based materials as well as the properties and applications. The recent trends in the area are also discussed.

  • 258. Finnveden, G
    et al.
    Albertsson, A-C.
    Berendson, J.
    Eriksson, E.
    Höglund, L-O.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Sundquist, J-O.
    Solid waste treatment within the framework of life-cycle assessment1995In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 3, p. 189-Article in journal (Refereed)
  • 259. Flink, Johannes
    et al.
    Ek, Monica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    The effects of lignin structure from treatment of pulp with activated 1-hydroxybenzotrazole.1997In: Proceedings 9th Int. Symp. Wood Pulp Chem., 1997Conference paper (Refereed)
  • 260.
    Flock, Sofia
    KTH, School of Chemical Science and Engineering (CHE).
    Comparison of enzymatic and refining treatment of pulp fibres for strength improvement2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today, in pulp and paper industry, refining is used for strength improvement. This process requires energy and therefore, alternative methods with less energy consumption are of interest for the industry. In tissue production, only small energy consumption is used for refining and an enzymatic treatment could possibly replace the refining process. Therefore, a quantitative comparison between refining and enzymatic treated pulp as a function of grammage was done in this study. To find out if it was possible to replace refining by enzymes, a bleached kraft softwood pulp from pine and spruce was used. The pulp was subjected to enzymatic treatments of two different monocomponent endoglucanases and by mechanical treatment by a Voith laboratory refiner for comparison. To investigate different properties of the samples, tensile test, stretch at break and Schopper-Riegler was performed. The experiments in this study demonstrated that the enzymatic treatment did not give any effect on strength or dewatering. Therefore, enzymes cannot replace refining by the method used in this study.

  • 261.
    Flodberg, Göran
    et al.
    RISE, Innventia.
    Helland, Irene
    Norner Innovation AS, Norway.
    Thomson, Lars
    RISE, Innventia.
    Bodil Fredriksen, Siw
    Norner Innovation AS, Norway.
    Barrier properties of polypropylene carbonate and poly(lactic acid) cast films2015In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 63, p. 217-226Article in journal (Refereed)
    Abstract [en]

    A comparative study of the barrier properties of cast film of polypropylene carbonate (PPC) and cast film of poly(lactic acid) (PLA) has been made in this paper. Dynamic transmission measurements were conducted to obtain the barrier properties for oxygen transmission and for water vapour transmission. A special algorithm fminsearch in Matlab was used to adapt an exponential expression to the measured values. In this way the time needed to reach a 95% level of steady state was made possible to identify. The oxygen permeability was lower for PPC compared to PLA and this could be explained by a much higher positive enthalpy of solution for oxygen in PPC. The enthalpy of diffusion was close to similar for both PPC and PLA and was higher than for enthalpy of solution. The enthalpy of water vapour permeability was higher for PPC compared to PLA and this resulted in substantially higher water vapour permeability for PLA. The uptake of water vapour was also higher for PLA compared to PPC as shown by dynamic vapour sorption measurements. Differential scanning calorimetry confirmed that PPC is an amorphous polymer and that the PLA used in this study had a minimum of crystallinity which made it comparable to PPC.

  • 262.
    Flores Ituarte, Iñigo
    et al.
    Department of Materials and Production, Section of Sustainable Production, Faculty of Engineering and Science, Aalborg University, Copenhagen, Denmark.
    Wiikinkoski, Olli
    Department of Mechanical Engineering, School of Engineering, Aalto University, Espoo, Finland.
    Jansson, Anton
    Örebro University, School of Science and Technology. Department of Mechanical Engineering.
    Additive Manufacturing of Polypropylene: A Screening Design of Experiment Using Laser-Based Powder Bed Fusion2018In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 10, no 12, article id 1293Article in journal (Refereed)
    Abstract [en]

    The use of commodity polymers such as polypropylene (PP) is key to open new market segments and applications for the additive manufacturing industry. Technologies such as powder-bed fusion (PBF) can process PP powder; however, much is still to learn concerning process parameters for reliable manufacturing. This study focusses in the process–property relationships of PP using laser-based PBF. The research presents an overview of the intrinsic and the extrinsic characteristic of a commercial PP powder as well as fabrication of tensile specimens with varying process parameters to characterize tensile, elongation at break, and porosity properties. The impact of key process parameters, such as power and scanning speed, are systematically modified in a controlled design of experiment. The results were compared to the existing body of knowledge; the outcome is to present a process window and optimal process parameters for industrial use of PP. The computer tomography data revealed a highly porous structure inside specimens ranging between 8.46% and 10.08%, with porosity concentrated in the interlayer planes in the build direction. The results of the design of experiment for this commercial material show a narrow window of 0.122 > Ev > 0.138 J/mm3 led to increased mechanical properties while maintaining geometrical stability.

  • 263.
    Fogelström, Linda
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hansson, Susanne
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Linear vs. Hyperbranched Polymers in the Preparation of Polymer/Clay NanocompositesManuscript (preprint) (Other academic)
  • 264. Fonseca, R. D.
    et al.
    Correa, D. S.
    Paris, E. C.
    Tribuzi, V.
    Dev, Apurba
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Voss, T.
    Aoki, P. H. B.
    Constantino, C. J. L.
    Mendonca, C. R.
    Fabrication of zinc oxide nanowires/polymer composites by two-photon polymerization2014In: Journal of Polymer Science Part B: Polymer Physics, ISSN 0887-6266, E-ISSN 1099-0488, Vol. 52, no 4, p. 333-337Article in journal (Refereed)
    Abstract [en]

    We present an approach to fabricate ZnO nanowires/polymer composite into three-dimensional microstructures, based on two-photon polymerization direct laser writing, a fabrication method that allows submicrometric spatial resolution. The structural integrity of the structures was inferred by scanning electron microscopy, while the presence and distribution of ZnO nanowires was investigated by energy dispersive X-ray, Raman spectroscopy, and X-ray diffraction. The optical properties of the produced composite microstructures were verified by imaging the characteristic ZnO emission using a fluorescence microscope. Hence, such approach can be used to develop composite microstructures containing ZnO nanowires aiming at technological applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014, 52, 333-337 Zinc oxide (ZnO) has proven to be a promising material for optoelectronic devices operating in the blue to near-UV spectral region. While ZnO/polymer composite films have been readily produced via cast and spin coating, these standard approaches do not allow the fabrication of three-dimensional (3D) microstructures due to the lack of spatial resolution. In this work, 3D microstructures of composites made up of acrylic resin and ZnO nanowires are created by using two-photon polymerization.

  • 265.
    Forcyde, Ness
    KTH, School of Chemical Science and Engineering (CHE).
    Removal of Residual Monomers from Polymer Suspensions2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    One of the challenges with suspension polymerization is the removal of residual monomers. Environmental regulations and market preferences are the main driving forces behind the development of novel methods and improvement of current methods. In this work, the removal of monomers has been studied using two types of chemistries: post-polymerization with radical initiators, and aza-Michael addition. Two radical initiators with different degrees of hydrophobicity were used to polymerize residual monomers in polymer particle dispersions. Results show that both initiators succeeded in removing residual monomers, but the hydrophilic initiator is more efficient than the hydrophobic initiator. Two different substrates have been amine-functionalized and reacted with methyl acrylate (monomer) in water. The functionalized substrates were characterized using Kaiser test and UV/Vis spectroscopy. The heterogeneous nature of one of the substrates seems to affect the reproducibility of the analysis results. Data suggest that the amine-functionalized substrates react with methyl acrylate at 60 °C in water and full conversion may be achieved using stoichiometric ratios. However, the amount of results was limited and more experiments are needed.

  • 266.
    Forsberg, Viviane
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Green materials for inkjet printing of 2D materials and transparent electronics2018Conference paper (Other (popular science, discussion, etc.))
  • 267.
    Forsling, Josefine
    KTH, School of Chemical Science and Engineering (CHE).
    Zwitterjoniska homo- och blocksampolymer framställda med RAFT-polymerisation och dessas adsorption till cellulosaytor2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Thermo-responsive polymers were directly polymerized from the zwitterionic monomer sulfobetaine methacrylate (SBMA). The polymerizations were performed under homogenous aqueous conditions employing the controlled radical polymerization reversible-addition fragmentation chain transfer (RAFT). 4-Cyano-4-(phenylcarbonothioylthio)pentanoic acid (CTP) was employed as RAFT agent in polymerization of homopolymers poly (sulfobetaine methacrylate) (PSBMA) The target molar-mass for the homopolymers extended from 10.0 kDa to 200 kDa. The reactions were carried out in a salt solution (0.50 M NaCl) where the salt operated as screening agents for the attractive charges within the zwitterionic system according to the anti-polyelectrolyte effect, meaning that added salt enhanced the solubility. The phase transition of the polymers was investigated with UV-Vis spectroscopy where an upper critical solution temperature (UCST) was observed for the systems investigated, except for the two smallest polymers possessing targeted molar masses of 10.0 kDa and 25.0 kDa, respectively. The UCSTs for these polymers were probably below the temperature investigated due to the low molar-mass. The UCSTs for the polymers in this study were found to depend on both the molar-mass and the concentration of polymer in the solution investigated.

    An end-functionalized biopolymer (BP) ,was employed as a macroRAFT from which SBMA was polymerized. This resulted in a new type of block copolymer: BP-b-PSBMA. The reactions for the block copolymer were carried out under same conditions as for the homopolymers.

    Besides the investigation of the UCST for both homopolymers PSBMA and block copolymers PB-b-PSBMA, an investigation regarding the adsorption of selected polymers on cellulose were performed by quartz crystal microbalance with dissipation (QCM-D) measurements. The QCM-D crystals employed were modified which resulted in a negatively charged cellulose model surface. Besides QCM-D measurements, cellulose filter papers composed of uncharged cellulose fibers were also employed in the investigation of adsorption for the selected polymers. FT-IR measurements were performed on the filter papers for detection of carbonyl peaks that could indicate a successful adsorption of the polymers.

    Proton nuclear magnetic resonance (1H NMR) analyses were performed to determine the conversion and the kinetics of the polymerizations. The majority of the polymers possessed pseudo-first order kinetics and additionally exhibited low molar-mass dispersity ĐM (ĐM = Mw/Mn). ĐM values were obtained from size exclusion chromatography (SEC) and were a further verification of a successfully controlled radical polymerization. The surface structures of the cellulose model surface after the adsorption were further evaluated by atomic force microscopy (AFM) micrographs taken of the surfaces. The micrographs revealed a significant difference between the virgin cellulose model surfaces in comparison to the surface with adsorbed BP-b-PSBMA200.

  • 268. Frostell, Claes
    et al.
    Bjorling, Gunilla
    Strömberg, Emma
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Karlsson, Sigbritt
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Aune, Ragnhild E.
    Tracheal implants revisited2017In: The Lancet, ISSN 0140-6736, E-ISSN 1474-547X, Vol. 389, no 10075, p. 1191-1191Article in journal (Refereed)
  • 269.
    Fu, Qiliang
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Berglund, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Honeycomb like templates prepared from balsa wood2015In: ICCM International Conferences on Composite Materials, International Committee on Composite Materials , 2015Conference paper (Refereed)
    Abstract [en]

    In the current study, we have used sodium chlorite and sodium hydroxide as extraction solutions, to remove lignin and hemicelluloses from the Balsa (Ochroma Lagopus) wood tissues, without damaging the wood honeycomb architecture. Surface morphologies are studied using scanning electron microscopy (SEM). In addition, sugars analysis of the chemically extracted wood is reported. 

  • 270.
    Fuoco, Tiziana
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Mathisen, T.
    Finne Wistrand, Anna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Minimizing the time gap between service lifetime and complete resorption of degradable melt-spun multifilament fibers2019In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 163, p. 43-51Article in journal (Refereed)
    Abstract [en]

    We have succeeded to modulated the degradation rate of poly(L-lactide) (PLLA) melt-spun multifilament fibers to extend the service lifetime and increase the resorption rate by using random copolymers of L-lactide and trimethylene carbonate (TMC). The presence of TMC units enabled an overall longer service lifetime but faster degradation kinetics than PLLA. By increasing the amount of TMC up to 18 mol%, multifilament fibers characterized by a homogenous degradation profile could be achieved. Such composition allowed, once the mechanical integrity was lost, a much longer retention of mechanical integrity and a faster rate of mass loss than samples containing less TMC. The degradation profile of multifilament fibers consisting of (co)polymers containing 0, 5, 10 and 18 mol% of TMC has been identified during 45 weeks in vitro hydrolysis following the molecular weight decrease, mass loss and changes in microstructure, crystallinity and mechanical properties. The fibers degraded by a two-step, autocatalyzed bulk hydrolysis mechanism. A high rate of molecular weight decrease and negligible mass loss, with a consequent drop of the mechanical properties, was observed in the early stage of degradation for fibers having TMC content up to 10 mol%. The later stage of degradation was, for these samples, characterized by a slight increase in the mass loss and a negligible molecular weight decrease. Fibers prepared with the 18 mol% TMC copolymer showed instead a more homogenous molecular weight decrease ensuring mechanical integrity for longer time and faster mass loss during the later stage of degradation.

  • 271.
    Fuoco, Tiziana
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Pappalardo, Daniela
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Aluminum Alkyl Complexes Bearing Salicylaldiminato Ligands: Versatile Initiators in the Ring-Opening Polymerization of Cyclic Esters2017In: CATALYSTS, ISSN 2073-4344, Vol. 7, no 2, article id 64Article, review/survey (Refereed)
    Abstract [en]

    Linear aliphatic polyesters are degradable thermoplastic polymers, which can be obtained by ring-opening polymerization (ROP) of cyclic esters through a coordination-insertion mechanism. Aluminum based organometallic complexes have a leading position as efficient catalysts for this polymerization process. Aluminumalkyl complexes bearing salicylaldiminato ligands, although less explored, have been shown to be efficient and versatile catalysts for the ROP of various cyclic esters. These species have the potential to function as active catalysts in the ROP because of their less coordinatively saturated nature with respect to analogous SALEN-type complexes. They have been used as efficient catalysts in the ROP of commercially available cyclic esters, such as epsilon-caprolactone, L-lactide, rac-lactide, and glycolide. Moreover, they resulted in efficient catalysts for the ROP of cyclic esters with large ring-size and for the ROP of functionalized lactide. Furthermore, they have been used in the co- and ter-polymerization of various cyclic esters affording well controlled polymerization and a plethora of microstructural architectures, ranging from random to block to multiblock.

  • 272.
    Gabrielsson, Erik O.
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Armgarth, Astrid
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Hammarström, Per
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Nilsson, K. Peter N.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Controlled Microscopic Formation of Amyloid-Like Aβ Aggregates Using an Organic Electronic DeviceManuscript (preprint) (Other academic)
    Abstract [en]

    Alzheimer’s disease (AD), primarily associated with formation of fibrillar amyloid-beta peptide (Aβ) aggregates in the brain, is one of the most common old-age diseases. It is therefore crucial with an elevated scientific interest in Aβ, and its fundamental properties in a wide sense, to develop efficient methods for early detection and to combat AD. For the development of new techniques, both for AD detection and prevention, researchers are dependent on either tissue samples from deceased patients, animal models or in vitro systems. In vitro systems, such as producing protein aggregates of the Aβ-peptide in a test tube by incubation under denaturing conditions, offers us a simple but rather blunt tool for evaluating aggregation inhibition caused by compounds or to investigate new detection methods. We recently introduced the organic electronic ion pump (OEIP) as a method for creating amyloid-like aggregates at high spatiotemporal control as compared to the resulting aggregates manufactured using regular test tube-conditions. Combined with a fluorescent probe that is specific for the fibrillar aggregated form of misfolded peptides commonly seen in AD, this allowed us to control and to monitor the aggregation of a model peptide system in a highly confined space.

    To further elaborate the functionality of the OEIP together with amyloid-specific probes, we here present experiments demonstrating electronically controlled micron sized formation of Aβ-aggregates with morphologies ranging from fine fibers, to bundles of fibers, and thick mesh-like fiber structures. We foresee that the methodology can be implemented in multi array systems that can be utilized for studies of protein aggregation in confined spaces or together with cultured cells, as well as for the development of screening platforms for assessment of molecules influencing the Aβ-aggregation process.

  • 273.
    Gabrielsson, Erik O.
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Janson, Per
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Simon, Daniel T.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    A Four-Diode Full-Wave Ionic Current Rectifier Based on Bipolar Membranes: Overcoming the Limit of Electrode Capacity2014In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 26, no 30, p. 5143-5147Article in journal (Refereed)
    Abstract [en]

    Full-wave rectification of ionic currents is obtained by constructing the typical four-diode bridge out of ion conducting bipolar membranes. Together with conjugated polymer electrodes addressed with alternating current, the bridge allows for generation of a controlled ionic direct current for extended periods of time without the production of toxic species or gas typically arising from electrode side-reactions.

  • 274.
    Galland, Sylvain
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Cellulose network materials - compression molding and magnetic functionalization2012Licentiate thesis, comprehensive summary (Other academic)
  • 275.
    Galland, Sylvain
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Olsson, Richard T.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Ström, Valter
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Cellulose nanofibrils decorated by inorganic nanoparticles and used in magnetic nanocomposite membranes of high toughnessManuscript (preprint) (Other academic)
  • 276. Gallet, G.
    et al.
    Lämpiänen, R.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Characterisation by SPME-GC-MS of matrix changes of poly(L-lactide) exposed to outdoor soil environment2001In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 71, p. 147-Article in journal (Refereed)
  • 277. Gallstedt, M.
    et al.
    Hedenqvist, Mikael S.
    KTH, Superseded Departments, Polymer Technology.
    Packaging-related properties of alkyd-coated, wax-coated, and buffered chitosan and whey protein films2004In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 91, no 1, p. 60-67Article in journal (Refereed)
    Abstract [en]

    Packaging-related properties of coated films of chitosan-acetic acid salt and whey protein concentrate (WPC) were studied. Chitosan (84.7% degree of deacetylation) and WPC (65-67% protein) were solution cast to films. These films are potential oxygen barriers for use in packaging. Coatings of wax or alkyds were used to enhance the water-barrier properties. The packaging-related properties of chitosan films treated in a buffering solution, with a pH of 7.8, were also investigated. The coated films were characterized with respect to Cobb absorbency, overall migration to water, water vapor transmission rate, and oxygen permeability. The creasability and bending toughness were determined. The wax was a more efficient barrier to liquid water and 90-95% relative humidity than the alkyd. However, the alkyd-coated material had superior packaging-converting properties. The alkyd-coated WPC and chitosan-salt films were readily folded through 180degrees without any visible cracks or delamination. The overall migration from the alkyd-coated materials was below the safety limit, provided the coat weight was higher than 7.5 mg/cm(2) on WPC and 2.1 mg/cm(2) on chitosan-salt. The barrier properties of chitosan film under moist conditions were improved by the buffer treatment. However, the buffering also resulted in shrinkage of the film.

  • 278. Gallstedt, Mikael
    et al.
    Pettersson, Henrik
    Johansson, Therese
    Newson, William R.
    Johansson, Eva
    Hedenqvist, Mikael S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Film Extrusion of Crambe abyssinica/Wheat Gluten Blends2017In: Journal of Visualized Experiments, ISSN 1940-087X, E-ISSN 1940-087X, no 119, article id e54770Article in journal (Refereed)
    Abstract [en]

    Crambe abyssinica is a plant with potential for use in industrial (non-food) plant oil production. The side stream from this oil production is a high-protein crambe meal that has limited value, as it is not fit for food or feed use. However, it contains proteins that could potentially make it a suitable raw material for higher-value products. The purpose of this study was to find methods of making this side stream into extruded films, showing that products with a higher value can be produced. The study mainly considered the development of material compositions and methods of preparing and extruding the material. Wheat gluten was added as a supportive protein matrix material, together with glycerol as a plasticizer and urea as a denaturant. The extrudate was evaluated with respect to mechanical (tensile testing) and oxygen barrier properties, and the extrudate structure was revealed visually and by scanning electron microscopy. A denser, more homogeneous material had a lower oxygen transmission rate, higher strength, and higher extensibility. The most homogeneous films were made at an extruder die temperature of 125-130 degrees C. It is shown here that a film can be extruded with promising mechanical and oxygen barrier properties, the latter especially after a final compression molding step.

  • 279. Gan, Zhixing
    et al.
    Xu, Hao
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cellular Biophysics. KTH, Centres, Science for Life Laboratory, SciLifeLab. Ningbo University, China.
    Photoluminescence of Diphenylalanine Peptide Nano/Microstructures: From Mechanisms to Applications2017In: Macromolecular rapid communications, ISSN 1022-1336, E-ISSN 1521-3927, Vol. 38, no 22, article id 1700370Article, review/survey (Refereed)
    Abstract [en]

    Diphenylalanine (Phe-Phe, FF) molecules, which can self-assemble into highly ordered nano/microstructures, have increasingly aroused intense interests due to their special optical properties. In this review, recent advances in photoluminescence (PL) of supramolecular architectures of FF-based peptide and the underlying mechanisms are highlighted. Mainly deep ultraviolet emission at around 285 nm and/or blue emission at approximate to 450 nm are observed in various FF peptide structures and its derivatives, which are primarily interpreted by quantum confinement effects, shallow radiative traps, and electron delocalization via hydrogen bonds in beta-sheet structures. Furthermore, current applications of such fluorescent peptide nano/microstructures are also reviewed here, e.g., probing the number of water molecules confined in FF, temperature sensing, and visualization of deep ultraviolet beam. Yet, the PL mechanism is still under fierce debate and the application based on fluorescence is constantly under exploration. Thus, this review is endeavored to boost future explorations on the PL of the bioinspired FF peptide nano/microstructures.

  • 280.
    Garcia-Garcia, Daniel
    et al.
    UPV, ITM, Plaza Ferrandiz y Carbonell 1, Alicante 03801, Spain..
    Balart, Rafael
    UPV, ITM, Plaza Ferrandiz y Carbonell 1, Alicante 03801, Spain..
    Lopez-Martinez, Juan
    UPV, ITM, Plaza Ferrandiz y Carbonell 1, Alicante 03801, Spain..
    Ek, Monica
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Moriana, Rosana
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Optimizing the yield and physico-chemical properties of pine cone cellulose nanocrystals by different hydrolysis time2018In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 5, p. 2925-2938Article in journal (Refereed)
    Abstract [en]

    Cellulose nanocrystals (CNCs) were isolated for the first time from pine cones (PC) by alkali and bleaching treatments and subsequent sulfuric acid hydrolysis (64%) at 45 degrees C. The influence of the hydrolytic reaction time (30, 45, and 90 min) on the yield, chemical composition and structure, and thermal stability of CNCs was evaluated. The removal of non-cellulosic constituents during the alkaline and bleaching treatment resulted in high pure cellulosic fibres. The isolation of CNCs from these cellulosic fibres at different reaction times was verified by the nano-dimensions of the individual crystals (< 3 and < 335 nm of average diameter and length, respectively). The highest yield (15%) and the optimum CNCs properties in terms of aspect ratio, thermal stability and crystallinity were obtained for an extraction time of 45 min. PC appeared to be a new promising source of cellulose fibres and CNCs with potential to be applied as reinforcement in composites and for food-packaging.

  • 281.
    García-García, Daniel
    et al.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Alicante, Spain.
    Balart, Rafael
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Alicante, Spain.
    Lopez-Martinez, Juan
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Alicante, Spain.
    Ek, Monica
    School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Fibre and Polymer Technology, KTH-Royal Institute of Technology, Stockholm, Sweden.
    Moriana, Rosana
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Fibre and Polymer Technology, KTH-Royal Institute of Technology, Stockholm, Sweden.
    Optimizing the yield and physico-chemical properties of pine cone cellulose nanocrystals by different hydrolysis time2018In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 5, p. 2925-2938Article in journal (Refereed)
    Abstract [en]

    Cellulose nanocrystals (CNCs) were isolated for the first time from pine cones (PC) by alkali and bleaching treatments and subsequent sulfuric acid hydrolysis (64%) at 45 degrees C. The influence of the hydrolytic reaction time (30, 45, and 90 min) on the yield, chemical composition and structure, and thermal stability of CNCs was evaluated. The removal of non-cellulosic constituents during the alkaline and bleaching treatment resulted in high pure cellulosic fibres. The isolation of CNCs from these cellulosic fibres at different reaction times was verified by the nano-dimensions of the individual crystals (< 3 and < 335 nm of average diameter and length, respectively). The highest yield (15%) and the optimum CNCs properties in terms of aspect ratio, thermal stability and crystallinity were obtained for an extraction time of 45 min. PC appeared to be a new promising source of cellulose fibres and CNCs with potential to be applied as reinforcement in composites and for food-packaging.

  • 282.
    García-García, Daniel
    et al.
    Instituto de Tecnología de Materiales-ITM, Universitat Politècnica de València, Alicante, Spain.
    Lopez-Martínez, Juan
    Instituto de Tecnología de Materiales-ITM, Universitat Politècnica de València, Alicante, Spain.
    Rafael, Balart
    Instituto de Tecnología de Materiales-ITM, Universitat Politècnica de València, Alicante, Spain.
    Strömberg, Emma
    School of Engineering Science in Chemistry, Biotechnology and Health, Department of Fibre and Polymer Technology, KTH-Royal Institute of Technology, Stockholm, Sweden.
    Moriana, Rosana
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. School of Engineering Science in Chemistry, Biotechnology and Health, Department of Fibre and Polymer Technology, KTH-Royal Institute of Technology, Stockholm, Sweden.
    Reinforcing capability of cellulose nanocrystals obtained from pine cones in a biodegradable poly(3-hydroxybutyrate)/poly(ε-caprolactone) (PHB/PCL) thermoplastic blend2018In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 104, p. 10-18Article in journal (Refereed)
    Abstract [en]

    In this work, different loads (3, 5 and 7 wt%) of pine cone cellulose nanocrystals (CNCs) were added to films ofpoly(3-hydroxybutyrate)/poly(ε-caprolactone) (PHB/PCL) blends with a composition of 75 wt% PHB and 25 wt% PCL (PHB75/PCL25). The films were obtained after solvent casting followed by melt compounding in anextruder and finally subjected to a thermocompression process. The influence of different CNCs loadings on themechanical, thermal, optical, wettability and disintegration in controlled compost properties of the PHB75/PCL25blend was discussed. Field emission scanning electron microscopy (FESEM) revealed the best dispersion of CNCson the polymeric matrix was at a load of 3 wt%. Over this loading, CNCs aggregates were formed enhancing thefilms fragilization due to stress concentration phenomena. However, the addition of CNCs improved the opticalproperties of the PHB75/PCL25films by increasing their transparency and accelerated the film disintegration incontrolled soil conditions. In general, the blend with 3 wt% CNCs offers the best balanced properties in terms ofmechanical, thermal, optical and wettability

  • 283.
    Gard Timmerfors, Jessica
    KTH, School of Chemical Science and Engineering (CHE).
    Material analysis of a self-reinforced poly (ethyleneterephthalate) composite2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Methods as infrared spectroscopy, X-ray, birefringence and DSC are often used on polymer

    fibres or films to detect changes in crystallinity, chain orientation and other microstructural

    changes in the material.

    In this study a self-reinforced Poly(ethylene Terephthalate) (PET) composite is processed

    with different degree of shrinkage or elongation during heating and forming. Normal spun

    PET fibre can be cold drawn to increase the crystallinity and mechanical properties. This

    study investigates whether this phenomenon is detectable for fibres in composites and can

    explain the change in mechanical properties at different elongations during processing.

    Furthermore, this study investigates if these common analysis methods for fibre or films can

    be used to analyse a PET self-reinforced composite.

    X -ray indicates no difference in the theoretical size of the crystals.

    All samples were birefringence, which indicate an anisotropic material, crystals, however due

    to a lack of equipment the changes in the crystal orientation could not be fully investigated.

    Reflective IR-analysis did not work on the composite and transmission appears to work.

    Interpretation models as a common baseline or baseline of each peak do not work. Lack of

    expertise and information of matrix make batch peak analyse not viable, but this

    interpretation model might work.

  • 284.
    Gedde, Ulf
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Hjertberg, Thomas
    Borealis.
    Costa, Francis
    Borealis/Linz.
    Oderkerk, Jeroen
    Borealis.
    Polyolefin composition with increased resistance against degradation caused by chlorine dioxide2011Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The present invention relates to a polyolefin composition with increased resistance to degradation caused by ClO2-containing water and to an article made of such a polyolefin composition. The polyolefin composition comprises a polyolefin base resin (A), at least one antioxidant (B) having an initial oxygen induction time (OIT190°C) of more than 35 min., determined according to the OIT190°C test described herein and having a slope of the curve, when OIT190°C, in minutes, is recorded as a function of exposure time, in minutes, in a chlorine dioxide degradation test as described herein, of at least -0.07, and c) at least one antioxidant (C) having an initial oxygen induction time (OIT190°C) of not more than 35 min., determined according to the OIT190°C test described herein and having a slope of the curve, when OIT190°C, in minutes, is recorded as a function of exposure time, in minutes, in a chlorine dioxide degradation test as described herein, of less than -0.07, wherein said polyolefin composition shows a resistance against water containing 10 ppm chlorine dioxide at 70 °C and a pH of 6.8 ± 0.1 of at least 450 min., expressed as the time to reach 50% of the initial oxygen induction time at 210 °C (OIT(210°C),50%), determined according to the chlorine dioxide degradation test as described herein. The present invention further relates to the use of the polyolefin composition for the production of an article, e.g. a pipe, a fitting or a storage container and to the use of the polyolefin composition for increasing the resistance of an article against degradation caused by contact with ClO2-containing water.

  • 285.
    Gedde, Ulf W
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Untitled2016In: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 55, p. A2-A2Article in journal (Other academic)
  • 286.
    Gemeda, Aveke Elias
    KTH, School of Chemical Science and Engineering (CHE).
    Depletion of antioxidants and polymer degradation in polyethylene pipes distributing chlorinated water2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Tap water disinfected by chlorine dioxide is oxidizing polymers and influences the properties of distributing pipes that usually made in polyethylene. Though it kills bacteria in drinking water, chlorine dioxide and its byproducts potentially shorten the polyethylene pipes service time.

    Squalane, which is a liquid hydrocarbon, is used in the squalane test. The chlorinated water and squalane forms dual-phase which makes easier for sampling from the squalane phase. The samples for tape test were pressed by Fontune press and were suspended in ClO2 water. In both tests ClO2 water was changed every 30 min to keep the concentration of chlorine constant.

    The oxidation induction time (OIT), which proportional to the concentration of the antioxidants, was used to analyze the depletion time of the antioxidants. Increasing chlorinated water bath temperature did not increase the degradation rate of the antioxidants in squalane test. However the OIT results from tape test showed a temperature-dependence manner.

    Tensile test on the materials that exposed to chlorinated water at concentration of 10 ppm of chlorine dioxide until depletion of antioxidants showed the depletion of antioxidants did not significantly affect the mechanical properties of the host material. There was a small decrease in tensile strain at break and tensile strain at tensile strength.

    Scanning electron microscopy (SEM) images showed there were micro-cracks formed on the surface of solid specimen after exposed to water containing chlorine dioxide and tensile test. However, the same sample without expose

  • 287. Geng, Lihong
    et al.
    Mittal, Nitesh
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Zhan, Chengbo
    Ansari, Farhan
    Sharma, Priyanka R.
    Peng, Xiangfang
    Hsiao, Benjamin S.
    Söderberg, Daniel
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Understanding the Mechanistic Behavior of Highly Charged Cellulose Nanofibers in Aqueous Systems2018In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 51, no 4, p. 1498-1506Article in journal (Refereed)
    Abstract [en]

    Mechanistic behavior and flow properties of cellulose nanofibers (CNFs) in aqueous systems can be described by the crowding factor and the concept of contact points, which are functions of the aspect ratio and concentration of CNF in the suspension. In this study, CNFs with a range of aspect ratio and surface charge density (380-1360 mu mol/g) were used to demonstrate this methodology. It was shown that the critical networking point of the CNF suspension, determined by rheological measurements, was consistent with the gel crowding factor, which was 16. Correlated to the crowding factor, both viscosity and modulus of the systems were found to decrease by increasing the charge density of CNF, which also affected the flocculation behavior. Interestingly, an anomalous rheological behavior was observed near the overlap concentration (0.05 wt %) of CNF, at which the crowding factor was below the gel crowding factor, and the storage modulus (G') decreased dramatically at a given frequency threshold. This behavior is discussed in relation to the breakup of the entangled flocs and network in the suspension. The analysis of the mechanistic behavior of CNF aqueous suspensions by the crowding factor provides useful insight for fabricating high-performance nanocellulose-based materials.

  • 288. Ghirardello, Mattia
    et al.
    Öberg, Kim
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Staderini, Samuele
    Renaudet, Olivier
    Berthet, Nathalie
    Dumy, Pascal
    Hed, Yvonne
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Marra, Alberto
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Dondoni, Alessandro
    Thiol-Ene and Thiol-Yne-Based Synthesis of Glycodendrimers as Nanomolar Inhibitors of Wheat Germ Agglutinin2014In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 52, no 17, p. 2422-2433Article in journal (Refereed)
    Abstract [en]

    Alkene and alkyne functional polyester-based dendrimers of generation 1 to 4 have been prepared and reacted under free-radical conditions with 2-acetamido-2-deoxy-1-thio--D-glucose (GlcNAc-SH). As the alkene-dendrimers underwent the addition of one thiyl radical per ene group whereas each yne group of alkyne-dendrimers was saturated by two thiyl radicals, a collection of glycodendrimers with glycan density ranging from six to ninety-six GlcNAc per dendrimer was obtained. The recognition properties of the prepared glycodendrimers toward the wheat germ agglutinin (WGA) were evaluated by enzyme-linked lectin assay (ELLA). The eight glycodendrimers were excellent ligands showing IC50 values in the nanomolar range and relative potencies per sugar unit up to 2.27 e(6) when compared to monosaccharidic GlcNAc used as monovalent reference.

  • 289.
    Gil-Castell, O.
    et al.
    Instituto de Tecnología de Materiales (ITM), Universidad Politecnica de Valencia (UPV), Valencia, Spain.
    Badia, J. D.
    Instituto de Tecnología de Materiales (ITM), Universidad Politecnica de Valencia (UPV), Valencia, Spain / Departament d'Enginyeria Química, Escola Tecnica Superior d'Enginyeria, Universitat de Valencia, Burjassot, Spain.
    Kittikorn, T.
    School of Chemical Science and Engineering, Fibre and Polymer Technology, KTH e Royal Institute of Technology, Stockholm, Sweden / Department of Materials Science and Technology, Faculty of Science, Prince of Songkla University, Songkhla, Thailand.
    Strömberg, E.
    School of Chemical Science and Engineering, Fibre and Polymer Technology, KTH e Royal Institute of Technology, Stockholm, Sweden.
    Ek, M.
    School of Chemical Science and Engineering, Fibre and Polymer Technology, KTH e Royal Institute of Technology, Stockholm, Sweden.
    Karlsson, Sigbritt
    University of Skövde. School of Chemical Science and Engineering, Fibre and Polymer Technology, KTH e Royal Institute of Technology, Stockholm, Sweden.
    Ribes-Greus, A.
    Instituto de Tecnología de Materiales (ITM), Universidad Politecnica de Valencia (UPV), Valencia, Spain.
    Impact of hydrothermal ageing on the thermal stability, morphology and viscoelastic performance of PLA/sisal biocomposites2016In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 132, p. 87-96Article in journal (Refereed)
    Abstract [en]

    The influence of the combined exposure to water and temperature on the behaviour of polylactide/sisal biocomposites coupled with maleic acid anhydride was assessed through accelerated hydrothermal ageing. The biocomposites were immersed in water at temperatures from 65 to 85 degrees C, between the glass transition and cold crystallisation of the PLA matrix. The results showed that the most influent factor for water absorption was the percentage of fibres, followed by the presence of coupling agent, whereas the effect of the temperature was not significant. Deep assessment was devoted to biocomposites subjected to hydrothermal ageing at 85 degrees C, since it represents the extreme degrading condition. The morphology and crystallinity of the biocomposites were evaluated by means of X-Ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The viscoelastic and thermal performance were assessed by means of dynamic mechanic thermal analysis (DMTA) and thermogravimetry (TGA). The presence of sisal generally diminished the thermal stability of the biocomposites, which was mitigated by the addition of the coupling agent. After composite preparation, the effectiveness of the sisal fibre was improved by the crystallisation of PLA around sisal, which increased the storage modulus and reduced the dampening factor. The presence of the coupling agent strengthened this effect. After hydrothermal ageing, crystallisation was promoted in all biocomposites therefore showing more fragile behaviour evidencing pores and cracks. However, the addition of coupling agent in the formulation of biocomposites contributed in all cases to minimise the effects of hydrothermal ageing. 

  • 290.
    Gil-Castell, O.
    et al.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València, Valencia, Spain.
    Badia, J. D.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València, Valencia, Spain / Departament de Química Orgànica i Analítica, Universitat Rovira i Virgili, Tarragona, Spain / Departament d’Enginyeria Química, Escola Tècnica Superior d’Enginyeria, Universitat de València, Burjassot, Spain.
    Strömberg, E.
    KTH Royal Institute of Technology, School of Chemical Science and Engineering, Fibre and Polymer Technology, Stockholm, Sweden.
    Karlsson, Sigbritt
    University of Skövde. KTH Royal Institute of Technology, School of Chemical Science and Engineering, Fibre and Polymer Technology, Stockholm, Sweden.
    Ribes-Greus, A.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València, Valencia, Spain.
    Effect of the dissolution time into an acid hydrolytic solvent to taylor electrospun nanofibrous polycaprolactone scaffolds2017In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 87, p. 174-187Article in journal (Refereed)
    Abstract [en]

    The hydrolysis of the polycaprolactone (PCL) as a function of the dissolution time in a formic/acetic acid mixture was considered as a method for tailoring the morphology of nanofibrous PCL scaffolds. Hence the aim of this research was to establish a correlation between the dissolution time of the polymer in the acid solvent with the physicochemical properties of the electrospun nanofibrous scaffolds and their further service life behaviour. The physico-chemical properties of the scaffolds were assessed in terms of fibre morphology molar mass and thermal behaviour. A reduction of the molar mass and the lamellar thickness as well as an increase of the crystallinity degree were observed as a function of dissolution time. Bead-free fibres were found after 24 and 48 h of dissolution time with similar diameter distributions. The decrease of the fibre diameter distributions along with the apparition of beads was especially significant for scaffolds prepared after 72 h and 120 h of dissolution time in the acid mixture. The service life of the obtained devices was evaluated by means of in vitro validation under abiotic physiological conditions. All the scaffolds maintained the nanofibrous structure after 100 days of immersion in water and PBS. The molar mass was barely affected and the crystallinity degree and the lamellar thickness increased along immersion preventing scaffolds from degradation. Scaffolds prepared after 24 h and 48 h kept their fibre diameters whereas those prepared after 72 h and 120 h showed a significant reduction. This PCL tailoring procedure to obtain scaffolds that maintain the nanoscaled structure after such long in vitro evaluation will bring new opportunities in the design of long-term biomedical patches. 

  • 291. Gil-Castell, O.
    et al.
    Badia, J. D.
    Strömberg, Emma
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Karlsson, Sigbritt
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. Skövde University, Sweden.
    Ribes-Greus, A.
    Effect of the dissolution time into an acid hydrolytic solvent to taylor electrospun nanofibrous polycaprolactone scaffolds2017In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 87, p. 174-187Article in journal (Refereed)
    Abstract [en]

    The hydrolysis of the polycaprolactone (PCL) as a function of the dissolution time in a formic/acetic acid mixture was considered as a method for tailoring the morphology of nanofibrous PCL scaffolds. Hence, the aim of this research was to establish a correlation between the dissolution time of the polymer in the acid solvent with the physico-chemical properties of the electrospun nanofibrous scaffolds and their further service life behaviour. The physico-chemical properties of the scaffolds were assessed in terms of fibre morphology, molar mass and thermal behaviour. A reduction of the molar mass and the lamellar thickness as well as an increase of the crystallinity degree were observed as a function of dissolution time. Bead-free fibres were found after 24 and 48 h of dissolution time, with similar diameter distributions. The decrease of the fibre diameter distributions along with the apparition of beads was especially significant for scaffolds prepared after 72 h and 120 h of dissolution time in the acid mixture. The service life of the obtained devices was evaluated by means of in vitro validation under abiotic physiological conditions. All the scaffolds maintained the nanofibrous structure after 100 days of immersion in water and PBS. The molar mass was barely affected and the crystallinity degree and the lamellar thickness increased along immersion, preventing scaffolds from degradation. Scaffolds prepared after 24 h and 48 h kept their fibre diameters, whereas those prepared after 72 h and 120 h showed a significant reduction. This PCL tailoring procedure to obtain scaffolds that maintain the nanoscaled structure after such long in vitro evaluation will bring new opportunities in the design of long-term biomedical patches.

  • 292.
    Gil-Castell, Oscar
    et al.
    Instituto de Tecnología de Materiales (ITM), Universitat Politecnica de Valencia (UPV), Valencia, Spain.
    Badia, J. D.
    Instituto de Tecnología de Materiales (ITM), Universitat Politecnica de Valencia (UPV), Valencia, Spain / Departament d'Enginyeria Química, Escola Tecnica Superior d'Enginyeria, Universitat de Valencia, Burjassot, Spain.
    Kittikorn, Thorsak
    Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Stockholm, Sweden / Department of Materials Science and Technology, Faculty of Science, Prince of Songkla University Songkhla, Thailand.
    Strömberg, Emma
    Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Martínez-Felipe, Alfonso
    Instituto de Tecnología de Materiales (ITM), Universitat Politecnica de Valencia (UPV), Valencia, Spain / Departamento de Química Organica, Facultad de Ciencias, Instituto de Ciencia de Materiales de Aragon (ICMA), Universidad de Zaragoza-CSIC, Spain.
    Ek, M.
    Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Karlsson, Sigbritt
    University of Skövde. Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Ribes-Greus, Amparo
    Instituto de Tecnología de Materiales (ITM), Universitat Politecnica de Valencia (UPV), Spain.
    Hydrothermal ageing of polylactide/sisal biocomposites: Studies of water absorption behaviour and Physico-Chemical performance2014In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 108, no special issue, p. 212-222Article in journal (Refereed)
    Abstract [en]

    An accelerated hydrothermal degrading test was designed in order to analyse the synergic effect of water and temperature on PLA/sisal biocomposites with and without coupling agent. As well, the physicochemical properties of biocomposites were monitored along the hydrothermal test by means of Scanning Electron Microscopy, Size Exclusion Chromatography and Differential Scanning Calorimetry. The addition of fibre induced higher water absorption capability and promoted physical degradation, as observed in the surface topography. During the processing of biocomposites and throughout the hydrothermal ageing, a reduction of molecular weight due to chain scission was found. As a consequence, a faster formation of crystalline domains in the PIA matrix occurred the higher the amount of fibre was, which acted as a nucleating agent. Higher crystallinity was considered as a barrier against the advance of penetrant and a reduction in the diffusion coefficient was shown. The addition of coupling agent presented a different influence depending on the composition, showing an inflection point around 20% of sisal fibre. (C) 2014 Elsevier Ltd. All rights reserved.

  • 293.
    Gimåker, Magnus
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Nygårds, Mikael
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.). KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Östlund, Sören
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.). KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Shear strength development between couched papers during dryingManuscript (preprint) (Other (popular science, discussion, etc.))
    Abstract [en]

    The out-of-plane properties (e.g., out-of-plane shear strength) of paper materials are very important for their performance during converting and end use. There is, however, a lack of published data on how shear strength develops throughout the stages of paper manufacturing. The present study investigates how the shear strength developed between couched sheets during drying in a Rapid-Köthen laboratory sheet drier. The shear strength of sheets was measured, starting from sheets with a solids content of approximately 35% all the way to fully dry sheets. Shear strength development was examined between both never-dried and rewetted sheets made of unbeaten and beaten pulp. The results indicate that the shear strength increased with increasing solids content at all solids contents investigated. The shear strength was low (<120 kPa) up to a solids content of approximately 60–70%, after which it increased rapidly with increasing solids content, suggesting that interactions important for the shear strength of dry paper start to develop at this particular dry content.

  • 294.
    Glauser, T
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Johansson, M
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, A
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Electron-beam curing of thick thermoset composite matrices1999In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 40, p. 5297-5302Article in journal (Refereed)
    Abstract [en]

    Electron-beam (EB) curing of two epoxy resins, one acrylated and one methacrylated, has been investigated. The change in thermomechanical properties, such as T-g, and the change of residual unsaturation have been studied as a function of dose. These results, in combination with in situ measurements of the temperature during cure, have shown the importance of sample geometry for the final properties of the thermoset. The thermal history of the sample during cure greatly affects the properties of the cured resin. (C) 1999 Elsevier Science Ltd. All rights reserved.

  • 295. Glauser, T
    et al.
    Johansson, Mats
    Hult, Anders
    Electron-beam curing of thick thermoset composite matrices1999In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 40Article in journal (Refereed)
  • 296.
    Glavas, Lidija
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Odelius, Karin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Albertsson, Ann-Christine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Redox responsiveness and electroactivity for preparation of smart micelles2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Article in journal (Other academic)
  • 297.
    Glavas, Lidija
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Olsén, Peter
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Odelius, Karin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Albertsson, Ann-Christine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Achieving Micelle Control through Core Crystallinity2013In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 14, no 11, p. 4150-4156Article in journal (Refereed)
    Abstract [en]

    We have designed a pathway for controlling the critical micelle concentration and micelle size of polyester-based systems. This was achieved by creating an array of different copolymers with semicrystalline or amorphous hydrophobic blocks. The hydrophobic block was constructed through ring-opening polymerization of epsilon-caprolactone, L-lactide, and epsilon-decalactone, either as homopolymers or random copolymers, using PEG as both the initiator and the hydrophilic block. Micelles formed with amorphous cores exhibited considerably higher critical micelle concentrations than those with semicrystalline cores. Micelles with amorphous cores also became larger in size with an increased molecular weight of the hydrophobic bock, in contrast to micelles with semicrystalline cores, which displayed the opposite behavior. Hence, core crystallinity was found to be a potent tool for tailoring micelle properties and thereby facilitating the optimization of drug delivery systems. The introduction of PEG-P epsilon DL also proved to be a valuable asset in the tuning of micelle properties.

  • 298.
    Golabi, Mohsen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Tuning the surface properties of polypyrrole films for modulating bacterial adhesion.2016In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 217, no 10, p. 1128-1135Article in journal (Refereed)
    Abstract [en]

    Tuning the physical–chemical properties of polypyrrole (PPy) opens up potentially exciting new applications, especially in the area of bacterial adhesion. Polypyrrole is electrochemically synthesized under various conditions and the physical properties of the films and their effects on bacterial adhesion are characterized. Five types of dopants—chloride (Cl), perchlorate (ClO4), p-toluene-sulfonate (ToS), dodecylbenzene sulfonate (DBS), and poly sodium styrene sulfonate (PSS)—are used to fabricate PPy films at two different constant potentials (0.500 and 0.850 V) with and without Fe3+. Their thickness, roughness, and wettability are measured. The adhesion tendency of Escherichia coli, as a model bacterium, to the four polymers is studied. E. coli shows greater adhesion tendency to the hydrophobic, rough surface of PPy-DBS, and less adhesion tendency to the smooth and hydrophilic surface of PPy-PSS. The results facilitate the choice of appropriate electropolymerization conditions to modulate bacterial adhesion.

  • 299. Golda-Cepa, M.
    et al.
    Brzychczy-Wloch, M.
    Engvall, Klas
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Aminlashgari, Nina
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Kotarba, A.
    Microbiological investigations of oxygen plasma treated parylene C surfaces for metal implant coating2015In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 52, p. 273-281Article in journal (Refereed)
    Abstract [en]

    Parylene C surface was modified by the use of oxygen plasma treatment and characterized by microscopic and surface-sensitive techniques (E-SEM, AFM, XPS, LDI-TOF-MS, contact angle). The influence of the treatment on surface properties was investigated by calculations of surface free energy (Owens-Wendt method). Moreover, early adhesion (Culture Plate Method, Optical Microscopy Test) and biofilm formation ability (Cristal Violet Assay) on the parylene C surface was investigated. The bacteria strains which are common causative agents of medical device-associated infections (Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa - reference strains and clinical isolates) were used. It was concluded that chemical (oxygen insertion) and physical (nanotopography generation) changes, have a significant impact on the biocompatibility in terms of increased hydrophilicity (θw of unmodified sample = 88° ± 2°, θw of 60 min modified sample = 17.6° ± 0.8°) and surface free energy (SFE of unmodified sample = 42.4 mJ/m2, and for 60 min modified sample = 70.1 mJ/m2). At the same time, no statistical effect on biofilm production and bacteria attachment to the modified surface of any of the tested strains was observed.

  • 300. González-Ausejo, J.
    et al.
    Sanchez-Safont, E.
    Lagaron, J. M.
    Olsson, Richard T.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gamez-Perez, J.
    Cabedo, L.
    Assessing the thermoformability of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(acid lactic) blends compatibilized with diisocyanates2017In: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 62, p. 235-245Article in journal (Refereed)
    Abstract [en]

    Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a renewable alternative to conventional barrier packaging polymers due to its thermoplastic properties, biodegradability and gas barrier performance but its potential industrial applications are limited by its high price and difficult processability. A thorough study concerning the thermoforming ability of PHBV, and blends with poly(lactic acid) (PLA) incorporating three different diisocyanates as compatibilizers (hexamethylene diisocyanate, poly(hexamethylene) diisocyanate and 1,4-phenylene diisocyanate) is herein presented after component melt blending. A straightforward universal qualitative method is proposed to assess the thermoformability, based on a visual inspection of a thermoformed specimen and the ability to reproduce the mold shape, and the thermoforming window of the material. The results reveal a significant improvement in the thermoforming capacity and a widening of the thermoforming windows as the correct amounts of diisocyanates are incorporated. The barrier properties and the biodisintegrability of the blends was also studied, confirming a predictable slight decrease of the barrier performance when PLA is added, but without negatively affecting the disintegrability under composting conditions with respect to pristine PHBV.

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