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  • 1.
    Lopez-Rubio, A.
    et al.
    Institute of Agrochemistry and Food Technology, CSIC.
    Lagaron, J. M.
    Institute of Agrochemistry and Food Technology, CSIC.
    Ankerfors, M.
    STFI-Packforsk.
    Lindström, T.
    STFI-Packforsk.
    Nordqvist, David
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Mattozzi, Alessandro
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Enhanced film forming and film properties of amylopectin using micro-fibrillated cellulose Carbohydr. Polym. 68 (2007) 718-7272008Inngår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 71, nr 3, s. 482-482Artikkel i tidsskrift (Fagfellevurdert)
  • 2.
    Lôpez-Rubio, A.
    et al.
    Institute of Agrochemistry and Food Technology, CSIC.
    Lagaron, J. M.
    Institute of Agrochemistry and Food Technology, CSIC.
    Ankerfors, M.
    STFI-Packforsk.
    Lindström, T.
    STFI-Packforsk.
    Nordqvist, David
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Mattozzi, Alessandro
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Enhanced film forming and film properties of amylopectin using micro-fibrillated cellulose2007Inngår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 68, nr 4, s. 718-727Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work describes a novel approach to produce amylopectin films with enhanced properties by the addition of micro fibrillated cellulose (MFC). Aqueous dispersions of gelatinized amylopectin, glycerol (0-38 wt%) and MFC (0-10 wt%) were cast at ambient temperature and 50% relative humidity and, after 10 days of storage, the tensile properties were investigated. The structure of the composite films was revealed by optical, atomic force and transmission electron microscopy. The moisture content was determined by thermogravimetry and the temperature-dependent film rigidity was measured by thermal mechanical analysis. Synchrotron simultaneous small- and wide-angle X-ray measurements revealed that the solutions had to be heated to above 85 degrees C in order to achieve complete gelatinization. Optical microscopy and atomic force microscopy revealed uniformly distributed MFC aggregates in the films, with a length of 10-90 mu m and a width spanning from a few hundred nanometers to several microns. Transmission electron microscopy showed that, in addition to aggregates, single MFC microfibrils were also embedded in the amylopectin matrix. It was impossible to cast antylopectin films of sufficient quality with less than 38 wt% glycerol. However, when MFC was added it was possible to produce high quality films even without glycerol. The film without glycerol was stiff and strong but not brittle. It was suggested that this remarkable effect was due to its comparatively high moisture content. Consequently MFC acted both as a "conventional" reinforcement because of its fibrous structure and also indirectly as a plasticiser because its presence led to an increase in film moisture content.

  • 3.
    Nordqvist, David
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Biodegradable Blends and Nanocomposite Films with Amylopectin, Poly(lactic acid) and Chitosan Matrices2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [sv]

    Användningan av engångsförpackningar har ökat kraftigt de senaste åren. Den absolut största delen av dessa förpackningar tillverkars av oljebaserade plaster såsom polyetylen (PE) och polypropylen (PP). Dessa har även en oerhört lång nedbrytningstid, vilket gör det viktigt att finna mer miljövänliga alternativ. Exempel på förnyelsebara och bionedbrytbara material är amylopektin (AP), kitosan och polymjölksyra (PLA). I denna avhandling presenteras arbete med att utveckla dessa material för att öka deras chanser att i framtiden användas som, förslagsvis, förpackningsmaterial. Nanokompositer baserade på AP och kitosan tillverkas genom att montmorillonitlera (MMT) och/eller mikrofibrillär cellulosa (MFC) inkorporeras i matrisen. En metod där en vattenlöslig reaktiv kompatibilisator används för att öka adhesionen mellan MMT och AP-matrisen presenteras. Mekanisk prövning visar på ökad styvhet and styrka när kompatibilisatorn används. Påverkan av olika värmebehandlingar innan, under och efter filmbildning redovisas. Med infraröd strålning (IR) och absorbtionsmätningar följs rektionen mellan fyllmedel och matris. Studier på MFC/AP visar att användningen av MFC leder till en anmärkningsvärd effect, det vanligen spröda amylopektinmaterialet blir en böjbar komposit utan att använda mjukgörare. Detta är möjligt tack vare att MFC är mycket hydroskopisk och, som de termiska mätningarna visar, binder vatten väldigt hart. Även mekaniska prövning av fiberkompositerna har studerats. Fiberkompositer baserade på kitosan har studerats tillsammans med en allmänt vedertagen buffringsmetod. De mekaniska egenskaperna i vått och torrt tillstånd har genom detta kunna förbättrats. Fiber och lerdistributionen i samtliga nanokompositer har även analyserats med X-ray, transmissions electron mikroskop (TEM), skanning electron mikroskop (SEM) och optiskt mikroskop (OM). Slutligen har PLA blandningar med AP producerats genom smältblandning. För att öka affiniteten mellan de två komponenterna har en nedbrytbar sort av polyetylenvinylalkohol (EVOH), med hög halt vinyl alkohol, använts som kompatibilisator. Den morphologiska stukturen har studerats genom SEM, OM, och Raman spektroskopi. En bra mixing erhölls även om en visss fasseparation kunde ses. När även glycerol ingick i systemet kunde en lite bättre dispersion fås.

  • 4.
    Nordqvist, David
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Biodegradable nanocomposite films based on amylopectin and chitosan2006Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The use of disposable material is rapidly increasing, today the absolute majority of the material used for these application, i.e. food packages, are oil-based plastics such as polyethylene and polypropylene. Therefore it is of great importance to find alternative biodegradable materials made from renewable resources for this huge growing market. In the present thesis, work and research to develop and improve such materials are presented. Amylopectin and chiotsan are two interesting material choises for these applications. In this thesis serveral ways of improving amylopectin (AP) and chitosan films are presented, using either Na+-montmorillonite (MMT) or microfibrillated cellulose (MFC). A novel approach of using a water-soluble coupling agent to enchance the strength and stiffness of MMT/AP-composites by increasing the adhesion beween the matrix and the filler. The results from IR, mechanical and moisture absorption tests show that the coupling agent indeed improve the properties of the composite films. Studies on MFC/AP show that the MFC have a remarkable effect of acting as a reinforcing plasticiser creating a flexible material without the use of a plasticiser. Thermal measurements show that the MFC have a ability to bound water very tightly. This was further investigated with thermal analysis. Chitosan, another interesting “green material”, and the effect of using MFC and/or a well-known buffer treatment, to enhace the mechanical properties of chitosan films in dry and wet conditions have here been investigated. The addition of MFC prevented extensive shrinkage in the wet condition due to increased wet stiffness.

  • 5.
    Nordqvist, David
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Dolares Sanchez, M.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Lagaron, Jose M.
    Melt blends of PLA and amylopectin using EVOH as a compatibilizer: Part I: Morpological characterizationManuskript (Annet vitenskapelig)
  • 6.
    Nordqvist, David
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Properties of amylopectin/montmorillonite composite films containing a coupling agent2007Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 104, nr 6, s. 4160-4167Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The addition of clay to polymers has the combined effects of enhancing both the strength / stiffness and the barrier properties. This investigation presents a novel approach to further enhance the strength / stiffness of cast plasticized amylopectin (AP)/Na+-montmorillonite clay films using a water-soluble coupling agent, poly[(isobutylene-alt-maleic acid, ammonium salt)-co-(isobutylene-alt-maleic anhydride)], between the filler and the matrix. The addition of clay increased the strength and stiffness of the film and the addition of 0.4 parts of a coupling agent per 1 part clay further increased these properties. The trends were the same after each treatment, and there were always significant differences in stiffness and strength between the films without clay and with clay with 0.4 parts of the coupling agent. The increase in stiffness / strength in the presence of a small amount of the coupling agent suggested that it had a bridging effect, presumably through strong secondary bonds to the clay and to the matrix. Infrared spectroscopy and moisture swelling experiments indicated that ester bonds were formed between the coupling agent and AP. X-ray spectroscopy and transmission electron microscopy revealed that the clay-particle / polymer structure was qualitatively independent of the presence of the coupling agent showing a mixture of intercalated clay stacks and exfoliated platelets.

  • 7.
    Nordqvist, David
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Transport Properties of Nanocomposites Based on Polymers and Layered Inorganic Fillers2009Inngår i: Packaging Nanotechnology / [ed] Amar K Mohanty; Manjusri Misra; Hari Singh Nalwa, Stevenson Ranch, Calif.: American Scientific Publishers , 2009Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 8.
    Nordqvist, David
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Idermark, Johan
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Gällstedt, M.
    STFI-Packforsk.
    Ankerfors, M.
    STFI-Packforsk.
    Lindström, T.
    STFI-Packforsk.
    Enhancement of the wet properties of transparent chitosan-acetic-acid-salt films using microfibrillated cellulose2007Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 8, nr 8, s. 2398-2403Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This report presents a new route to enhance the wet properties of chitosan-acetic-acid-salt films using microfibrillated cellulose (MFC). The enhancement makes it easier to form chitosan-acetic-acid-salt films into various shapes at room temperature in the wet state. Chitosan with MFC was compared with the well-known buffer treatment. It was observed that films containing 5 wt % MFC were visually identical to the buffered/unbuffered films without MFC. Field-emission scanning electron microscopy indicated that MFC formed a network with uniformly distributed fibrils and fibril bundles in the chitosan matrix. The addition of MFC reduced the risk of creases and deformation in the wet state because of a greater wet stiffness. The wet films containing MFC were also extensible. Although the stiffness, strength and extensibility were highest for the buffered films, the wet strength of the MFC-containing unbuffered films was sufficient for wet forming operations. The effects of MFC on the mechanical properties of the dry chitosan films were small or absent. It was concluded that the addition of MFC is an acceptable alternative to buffering for shaping chitosan films/products in the wet state. The advantages are that the "extra" processing step associated with buffering is unnecessary and that the film matrix remains more water-soluble.

  • 9.
    Nordqvist, David
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Sico, G.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Nanocomposites based on amylopectin, microfibrillated cellulose and montmorilloniteInngår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344Artikkel i tidsskrift (Annet vitenskapelig)
  • 10.
    Nyström, Daniel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Antoni, Per
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Östmark, Emma
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Nordqvist, David
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Örtegren, Jonas
    Fogelström, Linda
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Malmström, Eva E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Lindgren, Mikael
    Hult, Anders
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Honeycomb Patterned Membranes from Polymer Modified Silica NanoparticlesManuskript (Annet vitenskapelig)
  • 11. Sanchez-Garcia, M. D.
    et al.
    Nordqvist, David
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Hedenqvist, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Lagaron, J. M.
    Incorporating Amylopectin in Poly(lactic acid) by Melt Blending Using Poly(ethylene-co-vinyl alcohol) as a Thermoplastic Carrier. II. Physical Properties2011Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 119, nr 6, s. 3708-3716Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study adds to a previous morphological work (paper I) with further characterization of the developed poly(lactic acid) (PLA) blends containing amylopectin, which made use of an ethylene-vinyl alcohol copolymer (EVOH) as a melt-compoundable carrier for the polysaccharide in the biopolyester. The effect of using glycerol as compatibilizer was also characterized. Water and oxygen transport parameters, mechanical properties, and comparative biodegradability tests were evaluated for the blends. From the results, the barrier properties to oxygen were only seen to improve at 0% RH and mostly for the PLA-EVOH blends, which furthermore showed a positive deviation from the rule of mixtures. At high relative humidity, the blends showed somewhat poorer barrier performance due to the comparatively higher improvement in barrier of the neat PLA at 80% RH. Interestingly, room temperature biodegradability testing suggested that low additions of the blending elements seemed to facilitate the biodegradability of the biopolyester. Despite the fact that properties were not so dramatically improved, incorporating renewable resources within PLA seems as a potentially viable route to reduce PLA supply dependency, retain good optical properties and to overcome some drawbacks associated to the use of this biopolyester. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 3708-3716, 2011

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