his.sePublications
Change search
Refine search result
1 - 23 of 23
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Atarijabarzadeh, Sevil
    et al.
    KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden.
    Nilsson, Fritjof
    KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden / ABB, Corp Res, Västerås, Sweden.
    Hillborg, Henrik
    KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden / ABB, Corp Res, Västerås, Sweden.
    Karlsson, Sigbritt
    University of Skövde. KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden.
    Strömberg, Emma
    KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden.
    Image Analysis Determination of the Influence of Surface Structure of Silicone Rubbers on Biofouling2015In: International Journal of Polymer Science, ISSN 1687-9422, E-ISSN 1687-9430, article id 390292Article in journal (Refereed)
    Abstract [en]

    This study focuses on how the texture of the silicone rubber material affects the distribution of microbial growth on the surface of materials used for high voltage insulation. The analysis of surface wetting properties showed that the textured surfaces provide higher receding contact angles and therefore lower contact angle hysteresis. The textured surfaces decrease the risk for dry band formation and thus preserve the electrical properties of the material due to a more homogeneous distribution of water on the surface, which, however, promotes the formation of more extensive biofilms. The samples were inoculated with fungal suspension and incubated in a microenvironment chamber simulating authentic conditions in the field. The extent and distribution of microbial growth on the textured and plane surface samples representing the different parts of the insulator housing that is shank and shed were determined by visual inspection and image analysis methods. The results showed that the microbial growth was evenly distributed on the surface of the textured samples but restricted to limited areas on the plane samples. More intensive microbial growth was determined on the textured samples representing sheds. It would therefore be preferable to use the textured surface silicone rubber for the shank of the insulator.

  • 2.
    Badia, J. D.
    et al.
    a Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), València, Spain / Departament d’Enginyeria Química, Escola Tècnica Superior d’Enginyeria, Universitat de València, Burjassot, Spain.
    Kittikorn, T.
    KTH, School of Chemical Science and Engineering, Fibre and Polymer Technology, Stockholm, Sweden / Department of Materials Science and Technology, Faculty of Science, Prince of Songkla University, Thailand.
    Strömberg, E.
    KTH/ School of Chemical Science and Engineering, Fibre and Polymer Technology, Stockholm.
    Santonja-Blasco, L.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Spain / Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, United States.
    Martínez-Felipe, A.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Spain / Departamento de Química Orgánica, Facultad de Ciencias, Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, Spain.
    Ribes-Greus, A.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Spain.
    Ek, M.
    Departament d’Enginyeria Química, Escola Tècnica Superior d’Enginyeria, Universitat de València, Burjassot, Spain.
    Karlsson, Sigbritt
    University of Skövde. KTH, School of Chemical Science and Engineering, Fibre and Polymer Technology, Stockholm.
    Water absorption and hydrothermal performance of PHBV/sisal biocomposites2014In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 108, p. 166-174Article in journal (Refereed)
    Abstract [en]

    The performance of biocomposites of poly(hydroxybutyrate-co-valerate) (PHBV) and sisal fibre subjected to hydrothermal tests at different temperatures above the glass transition of PHBV (T-H = 26, 36 and 46 degrees C) was evaluated in this study. The influences of both the fibre content and presence of coupling agent were focused. The water absorption capability and water diffusion rate were considered for a statistical factorial analysis. Afterwards, the physico-chemical properties of water-saturated biocomposites were assessed by Fourier-Transform Infrared Analysis, Size Exclusion Chromatography, Differential Scanning Calorimetry and Scanning Electron Microscopy. It was found that the water diffusion rate increased with both temperature and percentage of fibre, whereas the amount of absorbed water was only influenced by fibre content. The use of coupling agent was only relevant at the initial stages of the hydrothermal test, giving an increase in the diffusion rate. Although the chemical structure and thermal properties of water-saturated biocomposites remained practically intact, the physical performance was considerably affected, due to the swelling of fibres, which internally blew-up the PHBV matrix, provoking cracks and fibre detachment. (C) 2014 Elsevier Ltd. All rights reserved.

  • 3.
    Badía, J. D.
    et al.
    Universidad Politécnica de Valencia, Spain.
    Moriana, Rosana
    Universidad Politécnica de Valencia, Spain.
    Santonja-Blasco, L.
    Universidad Politécnica de Valencia, Spain.
    Ribes-Greus, A.
    Universidad Politécnica de Valencia, Spain.
    A thermogravimetric approach to study the influence of a biodegradation in soil test to a Poly(lactic acid)2008In: Macromolecular Symposia, ISSN 1022-1360, E-ISSN 1521-3900, Vol. 272, no 1, p. 93-99Article in journal (Refereed)
    Abstract [en]

    An amorphous grade Poly (lactic acid) (PLA) was selected for an accelerated burial in soil test during 450 days. Thermogravimetric analyses were carried out to study the effects of degradation in soil on the thermal stability and the thermal decomposition kinetics. A single stage decomposition process is observed for all degradation times. It is shown that the thermal stability of PLA is slightly affected by degradation in soil. Concerning the study of the thermal decomposition kinetics, Criado master curves were plotted from experimental data to focus the study of the thermodegradation kinetic model.The kinetic methods proposed by Broido and Chang were used to calculate the apparent activation energies (Ea) of the degradation mechanism. These results were compared to the Ea values obtained by the method developed by Coats and Redfern in order to prove the applicability of the former methods to the kinetic study. As expected, non-linear tendency is found out for Ea variation along the degradation times, which can be explained as an evolution by stages. Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.

  • 4.
    Badía, José David
    et al.
    Instituto de Investigación en Tecnología de Materiales, Universidad Politécnica de Valencia, Spain.
    Santonja-Blasco, Laura
    Instituto de Investigación en Tecnología de Materiales, Universidad Politécnica de Valencia, Spain.
    Moriana, Rosana
    Instituto de Investigación en Tecnología de Materiales, Universidad Politécnica de Valencia, Spain.
    Ribes-Greus, Amparo
    Instituto de Investigación en Tecnología de Materiales, Universidad Politécnica de Valencia, Spain.
    Thermal analysis applied to the characterization of degradation in soil of polylactide: II. on the thermal stability and thermal decomposition kinetics2010In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 95, no 11, p. 2192-2199Article in journal (Refereed)
    Abstract [en]

    The disposal stage of polylactide (PLA) was assessed by burying it in active soil following an international standard. Degradation in soil promotes physical and chemical changes in the polylactide properties. The characterization of the extent of degradation underwent by PLA was carried out by using Thermal Analysis techniques. In this paper, studies on the thermal stability and the thermal decomposition kinetics were performed in order to assess the degradation process of a commercial PLA submitted to an accelerated soil burial test by means of multi-linear-non-isothermal thermogravimetric analyses. Results have been correlated to changes in molecular weight, showing the same evolution as that described by the parameters of thermal stability temperatures and apparent activation energies. The decomposition reactions can be described by two competitive different mechanisms: Nucleation model (A2) and Reaction Contracting Volume model (R3). The changes in the kinetic parameters and kinetic models are in agreement with the calorimetric and dynamic-mechanical-thermal results, presented in the Part I of the study [1]. © 2010 Elsevier Ltd. All rights reserved.

  • 5.
    España, J. M.
    et al.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Alcoy (Alicante), Spain.
    Fages, E.
    Textile Research Institute (AITEX), Alcoy (Alicante), Spain.
    Moriana, Rosana
    Textile Research Institute (AITEX), Alcoy (Alicante), Spain.
    Boronat, T.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Alcoy (Alicante), Spain.
    Balart, R.
    Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Alcoy (Alicante), Spain.
    Antioxidant and antibacterial effects of natural phenolic compounds on green composite materials2012In: Polymer Composites, ISSN 0272-8397, E-ISSN 1548-0569, Vol. 33, no 8, p. 1288-1294Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to establish the thermal performance of a biocomposite (Arbofill kokos®), stabilized with different natural phenolic additives, to check the antioxidant capacity of the resulting compounds. Different phenolic compounds (thymol, carvacrol, α-tocopherol, and tannic acid) were used as biobased additives and the concentrations ranged between 0.5 wt% and 2 wt%. The results obtained were compared with formulations containing a typical industrial petroleum-based antioxidant agent (octadecyl-3-(3,5-di-tert- butyl-4-hydroxyphenyl) propionate). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize the antioxidant performance of the selected natural additives. The antimicrobial effect of these natural phenolic compounds was also studied by analyzing the growth of bacterial colonies. The comparison between the natural phenolic compounds and the petroleum-based antioxidant compound showed good antioxidant action for natural phenolic compounds; in all the mixtures of biocomposite and antioxidant agent the oxidation onset temperature (OOT) increased in a remarkable way, but the highest stabilization effect was achieved with α-tocopherol with provides a % increase on OOT of about 45%. With regard to antibacterial activity of the different natural phenolic compounds, thymol, and carvacrol showed interesting antibacterial properties against Staphylococcus aureus. Copyright © 2012 Society of Plastics Engineers.

  • 6.
    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.

  • 7.
    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.

  • 8.
    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

  • 9.
    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. 

  • 10.
    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. 

  • 11.
    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.

  • 12.
    Kittikorn, Thorsak
    et al.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Strömberg, Emma
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Ek, Monica
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Karlsson, Sigbritt
    University of Skövde. KTH Royal Institute of Technology, Stockholm, Sweden.
    Comparison of water uptake as function of surface modification of empty fruit bunch oil palm fibres in PP biocomposites2013In: BioResources, ISSN 1930-2126, Vol. 8, no 2, p. 2998-3016Article in journal (Refereed)
    Abstract [en]

    Empty fruit bunch oil palm (EFBOP) fibres were surface modified by four different methods, propionylation, vinyltrimethoxy silanization, PPgMA dissolution modification, and PPgMA blending, and integrated into a polypropylene (PP) matrix. The designed biocomposites were subjected to an absorption process at different temperatures. Their water uptake behaviour was compared with the unmodified fibre biocomposites. An increased fibre content and temperature resulted in increased water uptake for all of the biocomposites. The biocomposites containing modified fibres showed a reduction in water uptake, rate of diffusion, sorption, and permeation in comparison with unmodified fibre composites. Comparing the 20 wt% fibre composites at ambient temperature, the performance in water absorption followed the sequence silanization < propionylation < PPgMA dissolution modification < PPgMA blending < no modification. Furthermore, the lowest water absorption was obtained from the silanized fibre/PP composite with 40% fibre content at ambient temperature. Dissolution or blending of PPgMA gave similar water uptake results. The reduction of diffusion, sorption, and permeation confirmed that the modification of fibres was potentially effective at resisting water penetration into the composites.

  • 13.
    Le Normand, Myriam
    et al.
    KTH Royal Institute of Technology.
    Moriana, Rosana
    KTH Royal Institute of Technology.
    Ek, Monica
    KTH Royal Institute of Technology.
    Isolation and characterization of cellulose nanocrystals from spruce bark in a biorefinery perspective2014In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 111, p. 979-987Article in journal (Refereed)
    Abstract [en]

    The present study reports for the first time the isolation of cellulose fibers and cellulose nanocrystals (CNCs) from the bark of Norway spruce. The upgrading of bark cellulose to value-added products, such as CNCs, is part of the "bark biorefinery" concept. The removal of non-cellulosic constituents was monitored throughout the isolation process by detailed chemical composition analyses. The morphological investigation of the CNCs was performed using AFM and showed the presence of nanocrystals with an average length of 175.3 nm and a diameter of 2.8 nm, giving an aspect ratio of around 63. X-ray diffraction (XRD) analyses showed that the crystallinity index increased with successive treatments to reach a final value greater than 80% for CNCs. The thermal degradation of the isolated bark CNCs started at 190 degrees C Spruce bark appeared to be a new promising industrial source of cellulose fibers and CNCs.

  • 14.
    Le Normand, Myriam
    et al.
    KTH Royal Institute of Technology.
    Moriana, Rosana
    KTH Royal Institute of Technology.
    Ek, Monica
    KTH Royal Institute of Technology.
    The bark biorefinery: a side-stream of the forest industry converted into nanocomposites with high oxygen-barrier properties2014In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 21, no 6, p. 4583-4594Article in journal (Refereed)
    Abstract [en]

    The purpose of the bark biorefinery concept is to upgrade the different constituents present in bark to multiple value-added bio-based products. Non-cellulosic polysaccharides (NCP) and cellulose nanocrystals (CNC) sequentially isolated from the inner bark of Norway spruce were used as raw materials for the formulation of renewable nanocomposites. The film formation abilities of NCP/CNC formulations prepared with different proportions of CNC were studied. Homogeneous transparent films with a glossy appearance were obtained when more than 30 wt% CNC was incorporated. The influence of the CNC content on the NCP/CNC films was assessed in terms of structural, thermal, mechanical and oxygen-barrier properties. All the films showed better performances with increasing CNC content, which was explained by the strong interactions between the two components. The effect on the film performances of adding sorbitol as a plasticizer was also evaluated. The presence of sorbitol decreased the thermal stability, the stiffness and the oxygen permeability of the films at 80 % RH. However, the addition of sorbitol enhanced the elongation of the films and further improved their oxygen-barrier properties at 50 % RH. The composite properties could thus be tailored by adding different amounts of sorbitol and CNC, resulting in all-carbohydrate materials with performances similar to or even better than the conventional barrier materials used in packaging.

  • 15.
    Moriana, Rosana
    et al.
    KTH Royal Institute of Technology, School of Chemical Science and Engineering, Fibre and Polymer Technology, Stockholm, Sweden / Materials Technology Institute (ITM), School of Design Engineering (ETSID), Polytechnic University of Valencia, Spain.
    Strömberg, Emma
    KTH Royal Institute of Technology, School of Chemical Science and Engineering, Fibre and Polymer Technology, Stockholm, Sweden.
    Ribes, Amparo
    Materials Technology Institute (ITM), School of Design Engineering (ETSID), Polytechnic University of Valencia, Spain.
    Karlsson, Sigbritt
    KTH Royal Institute of Technology, School of Chemical Science and Engineering, Fibre and Polymer Technology, Stockholm, Sweden.
    Degradation behaviour of natural fibre reinforced starch-based composites under different environmental conditions2014In: Journal of Renewable Materials, ISSN 2164-6325, E-ISSN 2164-6341, Vol. 2, no 2, p. 145-156Article in journal (Refereed)
    Abstract [en]

    The purpose of this work was to study the effect of hydrothermal, biological and photo degradation on natural fibres reinforced biodegradable starch-based (Mater-BiKE) composites to characterize the structural changes occurring under exposure to different environments. The composites water-uptake rate was hindered by the interfacial interactions between matrix and fibres. Thermal, structural and morphological analysis provided useful information about the irreversible changes in the properties of the composites caused by degradation in soil and photodegradation, and their synergetic effects. The effects due to the photo-oxidation and degradation in soil on the composites depended on the different chemical composition of each fibre. The composite with more hemicellulose and lignin in its formulation was more affected by both types of degradation, but still the end result properties were better than the ones shown for the degraded Mater-BiKE. The photo-oxidation of all the studied materials achieved enhanced degradation rate in soil. The Mater-BiKE/ kenaf was shown to have the slowest water-uptake rate and better thermal properties once photo-oxidized, indicating better service life conditions. At the same time, the Mater-BiKE/kenaf was affected to a major extent by the synergetic effects of both photo-oxidation and soil burial test, showing a faster degradative rate and better disposal conditions. © 2014 Scrivener Publishing LLC.

  • 16.
    Moriana, Rosana
    et al.
    KTH Royal Institute of Technology.
    Vilaplana, Francisco
    KTH Royal Institute of Technology.
    Ek, Monica
    KTH Royal Institute of Technology.
    Forest residues as renewable resources for bio-based polymeric materials and bioenergy: chemical composition, structure and thermal properties2015In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, no 5, p. 3409-3423Article in journal (Refereed)
    Abstract [en]

    The potential of three different logging residues (woody chips, branches and pine needles) as renewable resources to produce environmentally friendly polymeric materials and/or biofuel has been critically evaluated in terms of their structure, chemical composition and thermal properties. Woody chips constitute the most attractive forest residue to be processed into polymeric materials in terms of their highest cellulose content, crystallinity and thermal stability. In contrast, pine needles and branches offer higher heating values and optimum product distribution for solid fuel applications due to their higher lignin content. In general, forest residual biomass has great potential for conversion into new added value products, such as composites or solid biofuel, thus constituting a sustainable waste management procedure from a biorefinery perspective. The correlation between the chemical and structural properties with the thermal/pyrolytic behavior of residual biomass offers valuable insights to assess their sustainable exploitation.

  • 17.
    Moriana, Rosana
    et al.
    KTH Royal Institute of Technology / Universidad Politécnica de Valencia, Spain.
    Vilaplana, Francisco
    KTH Royal Institute of Technology / Wallenberg Wood Science Centre (WWSC).
    Karlsson, Sigbritt
    University of Skövde. KTH Royal Institute of Technology.
    Ribes, Amparo
    Universidad Politécnica de Valencia, Spain.
    Correlation of chemical, structural and thermal properties of natural fibres for their sustainable exploitation2014In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 112, p. 422-431Article in journal (Refereed)
    Abstract [en]

    The potential of lignocellulosic natural fibres as renewable resources for thermal conversion and material reinforcement is largely dependent on the correlation between their chemical composition, crystalline structure and thermal decomposition properties. Significant differences were observed in the chemical composition of cotton, flax, hemp, kenaf and jute natural fibres in terms of cellulose, hemicellulose and lignin content, which influence their morphology, thermal properties and pyrolysis product distribution. A suitable methodology to study the kinetics of the thermal decomposition process of lignocellulosic fibres is proposed combining different models (Friedman, Flynn-Wall-Ozawa, Criado and Coats-Redfern). Cellulose pyrolysis can be modelled with similar kinetic parameters for all the natural fibres whereas the kinetic parameters for hemicellulose pyrolysis show intrinsic differences that can be assigned to the heterogeneous hemicellulose sugar composition in each natural fibre. This study provides the ground to critically select the most promising fibres to be used either for biofuel or material applications.

  • 18.
    Moriana-Torró, Rosana
    et al.
    Instituto de Tecnología de Materiales, Escuela Técnica Superior de Ingeniería del Diseño, Universidad Politécnica de Valencia, Spain.
    Contat-Rodrigo, L.
    Instituto de Tecnología de Materiales, Escuela Técnica Superior de Ingeniería del Diseño, Universidad Politécnica de Valencia, Spain.
    Santonja-Blasco, L.
    Instituto de Tecnología de Materiales, Escuela Técnica Superior de Ingeniería del Diseño, Universidad Politécnica de Valencia, Spain.
    Ribes-Greus, A.
    Instituto de Tecnología de Materiales, Escuela Técnica Superior de Ingeniería del Diseño, Universidad Politécnica de Valencia, Spain.
    Thermal characterisation of photo-oxidized HDPE/Mater-Bi and LDPE/Mater-Bi blends buried in soil2008In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 109, no 2, p. 1177-1188Article in journal (Refereed)
    Abstract [en]

    Blends of high and low density polyethylene with a commercial biodegradable material (Mater-Bi) were subjected to an accelerated soil burial test. A set of samples was previously photo-oxidized to evaluate the effects of UV-irradiation on the degradation in soil process of these blends. Thermogravimetric as well as calorimetric analysis were performed to study the biodegradation, photo-degradation and their synergetic effects. Differential scanning calorimetry was carried out to analyze the morphological changes as a consequence of the photo-oxidation process. UV-irradiation slightly modifies the crystalline content of HDPE/Mater-Bi blends, increasing the heterogeneity of this blend. Criado master curves were plotted to analyses the degradation kinetic model. Broido and Coats-Redfern methods have been used for calculating the Ea of the thermal decomposition mechanisms. Thermogravimetric results reveal that noncomplexed starch is more affected by biodegradation than the polyethylene matrix and the starch/EVPH complexes chains from Mater-Bi. However, the effects of both photo-oxidation and biodegradation processes on the thermal decomposition of Mater-Bi is influenced by the polymeric matrix used. Previous photo-oxidation finds to slow down the degradative effects caused by the soil burial test on the HDPE/Mater-Bi blends. © 2008 Wiley Periodicals, Inc.

  • 19.
    Oinonen, Petri
    et al.
    KTH Royal Institute of Technology.
    Krawczyk, Holger
    Lund University.
    Ek, Monica
    KTH Royal Institute of Technology.
    Henriksson, Gunnar
    KTH Royal Institute of Technology.
    Moriana, Rosana
    KTH Royal Institute of Technology.
    Bioinspired composites from cross-linked galactoglucomannan and microfibrillated cellulose: Thermal, mechanical and oxygen barrier properties2016In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 136, p. 146-153Article in journal (Refereed)
    Abstract [en]

    In this study, new wood-inspired films were developed from microfibrillated cellulose and galactoglucomannan-lignin networks isolated from chemothermomechanical pulping side streams and cross-linked using laccase enzymes. To the best of our knowledge, this is the first time that cross-linked galactoglucomannan-lignin networks have been used for the potential development of composite films inspired by woody-cell wall formation. Their capability as polymeric matrices was assessed based on thermal, structural, mechanical and oxygen permeability analyses. The addition of different amounts of microfibrillated cellulose as a reinforcing agent and glycerol as a plasticizer on the film performances was evaluated. In general, an increase in microfibrillated cellulose resulted in a film with better thermal, mechanical and oxygen barrier performance. However, the presence of glycerol decreased the thermal stability, stiffness and oxygen barrier properties of the films but improved their elongation. Therefore, depending on the application, the film properties can be tailored by adjusting the amounts of reinforcing agent and plasticizer in the film formulation.

  • 20.
    Santonja-Blasco, L.
    et al.
    Instituto de Tecnología de Materiales, Universidad Politécnica de Valencia, Spain.
    Moriana, Rosana
    Instituto de Investigación en Tecnología de Materiales, Universidad Politécnica de Valencia, Spain.
    Badía, J. D.
    Instituto de Tecnología de Materiales, Universidad Politécnica de Valencia, Spain.
    Ribes-Greus, A.
    Instituto de Tecnología de Materiales, Universidad Politécnica de Valencia, Spain.
    Thermal analysis applied to the characterization of degradation in soil of polylactide: I. Calorimetric and viscoelastic analyses2010In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 95, no 11, p. 2185-2191Article in journal (Refereed)
    Abstract [en]

    An accelerated soil burial test has been performed on a commercial polylactide (PLA) for simulating non-controlled disposal. Degradation in soil promotes physical and chemical changes in polylactide properties, which can be characterized by Thermal Analysis techniques. Physical changes occurred in polylactide due to the degradation in soil were evaluated by correlating their calorimetric and viscoelastic properties. It is highly remarkable that each calorimetric scan offers specific and enlightening information. Degradation in soil affects the polylactide chains reorganization. A multimodal melting behavior is observed for buried PLA, degradation in soil also promotes the enlarging the lamellar thickness distribution of the population with bigger average size. Morphological changes due to degradation in soil lead to an increase in the free volume of the polylactide chains in the amorphous phase that highly affected the bulk properties. Thermal Analysis techniques provide reliable indicators of the degradation stage of polylactide induced by degradation in soil, as corroborated by molecular weight analysis. © 2010 Elsevier Ltd. All rights reserved.

  • 21.
    Santonja-Blasco, Laura
    et al.
    Instituto de Tecnología de Materiales, Escuela Técnica Superior de Ingeniería del Diseño,Universidad Politécnica de Valencia, Spain.
    Contat-Rodrigo, Laura
    Instituto de Tecnología de Materiales, Escuela Técnica Superior de Ingeniería del Diseño,Universidad Politécnica de Valencia, Spain.
    Moriana-Torró, Rosana
    Instituto de Tecnología de Materiales, Escuela Técnica Superior de Ingeniería del Diseño,Universidad Politécnica de Valencia, Spain.
    Ribes-Greus, A.
    Instituto de Tecnología de Materiales, Escuela Técnica Superior de Ingeniería del Diseño,Universidad Politécnica de Valencia, Spain.
    Thermal characterization of polyethylene blends with a biodegradable masterbatch subjected to thermo-oxidative treatment and subsequent soil burial test2007In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 106, no 4, p. 2218-2230Article in journal (Refereed)
    Abstract [en]

    The viability of producing environment-friendly blends of HDPE and LDPE with a commercial biodegradable masterbatch containing starch and polyethylene was studied. The service life of these blends was simulated by means of a thermo-oxidative treatment, and their further disposal in landfill was modeled using an accelerated soil burial test. Characterization was carried out in terms of their calorimetric and thermogravimetric properties. Thermo-oxidative treatment causes an increase in the crystalline content of both components of the blends, and promotes a segregation of the crystallite sizes of polyethylene. The soil burial test leads to changes in the crystalline content of the biodegradable material, which is influenced by the polyolefinic matrix used. The kinetics of the thermal decomposition of these blends was studied using the Hirata and the Broido models. Thermogravimetric results reveal that the thermo-oxidative treatment causes a decrease in the activation energy of the thermal decomposition process of both components in the blends, regardless of the type of polyethylene used. The thermooxidative treatment mainly modifies the thermal properties of starch during the degradation process in soil, especially in the LDPE blends. Synergetic degradation of these blends is a complex process that is dependent on the polyolefinic matrix used and mainly causes morphological changes.

  • 22.
    Svärd, Antonia
    et al.
    Fiber 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. Fiber and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden.
    Brännvall, Elisabet
    RISE Bioeconomy, Stockholm, Sweden.
    Edlund, Ulrica
    Fiber and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden.
    Rapeseed Straw Biorefinery Process2019In: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 7, no 1, p. 790-801Article in journal (Refereed)
    Abstract [en]

    A rapeseed straw biorefinery process was demonstrated with more than 50% of the straw recovered as products. Xylan with a weight-average molecular weight of 56 760 g/mol was extracted in an alkaline step. The straw residue was subjected to soda pulping, resulting in cellulose-rich fibers and a lignin-rich liquid fraction. The lignin contained syringyl and guaiacyl aromatic structural units in a 1/0.75 ratio. The cellulose pulp was bleached, resulting in a cellulose fraction of 85% purity and a crystallinity index (CI) of 83%. Two grades of nanocellulose, CNF and CNC, were isolated from the bleached pulp. The CNF was very heterogeneous in size with an average diameter of 4 nm and an average length of 1177 nm. The CNC had an average diameter of 6 nm and an average particle length of 193 nm. CNF and CNC had good thermal stability and an aspect ratio of 294 and 32, respectively.

  • 23.
    Tagami, Ayumu
    et al.
    KTH Royal Institute of Technology, Department of Fibre and Polymer Technology, Stockholm, Sweden / Nippon Paper Industries Co., Ltd., Research Laboratory, Oji, Kita-ku, Tokyo, Japan.
    Gioia, Claudio
    KTH Royal Institute of Technology, WWSC-Wallenberg Wood Science Centre, Stockholm, Sweden / University of Bologna, Department of Civil, Chemical, Environmental, and Materials Engineering, Bologna, Italy.
    Lauberts, Maris
    Latvian State Institute of Wood Chemistry, Riga, Latvia.
    Budnyak, Tetyana
    KTH Royal Institute of Technology, Department of Fibre and Polymer Technology, Stockholm, Sweden.
    Moriana, Rosana
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. KTH Royal Institute of Technology, Department of Fibre and Polymer Technology, Stockholm, Sweden / SLU-Swedish University of Agricultural Sciences, Molecular Sciences, Uppsala, Sweden.
    Lindström, Mikael E.
    KTH Royal Institute of Technology, Department of Fibre and Polymer Technology, Stockholm, Sweden.
    Sevastyanova, Olena
    KTH Royal Institute of Technology, Department of Fibre and Polymer Technology, Stockholm, Sweden / KTH Royal Institute of Technology, WWSC-Wallenberg Wood Science Centre, Stockholm, Sweden.
    Solvent fractionation of softwood and hardwood kraft lignins for more efficient uses: Compositional, structural, thermal, antioxidant and adsorption properties2019In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 129, p. 123-134Article in journal (Refereed)
    Abstract [en]

    This work summarizes the impact of solvent fractionation on the chemical structure, antioxidant activity, heating values, and thermal and adsorption properties of industrial hardwood and softwood kraft lignins. The aim of the research was to develop a simple approach for obtaining lignin fractions with tailored properties for applications in certain materials. Four common industrial solvents, namely, ethyl acetate, ethanol, methanol and acetone, in various combinations, were found to be efficient for separating spruce and eucalyptus kraft lignins into fractions with low polydispersities. The ethanol fraction of spruce and the ethyl acetate fraction of eucalyptus afforded the highest yields. Gel-permeation chromatography analysis was used to evaluate the efficiency of the chosen solvent combination for lignin fractionation. The composition and structure of the lignin material was characterized by elemental analysis, analytical pyrolysis (Py-GC/MS/FID) and 31P NMR spectroscopy. The thermal properties of the lignin samples were studied using thermogravimetric analysis. Proximate analysis data (ash, volatile components, organic matter and fixed carbon) was obtained through the direct measurement of weight changes in each experimental curve, and the high heating values (in MJ/kg) were calculated according to equations suggested in the literature. The adsorption properties of fractionated kraft lignins were studied using methylene blue dye. The correlations observed between molecular weight, composition and functionality and the thermal, radical scavenging and adsorption properties of the lignin fractions provides useful information for selecting the appropriate solvent combinations for specific applications of lignin raw materials (including their use as antioxidants, biofuels or sorbents in water treatment processes). © 2018

1 - 23 of 23
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf