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Wood Hydrolysate for Renewable Products
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Renewable biomass has been used by mankind for a long time for different purposes, from simply food to industrial products. Among a large family of polysaccharides, hemicellulose is non-edible but has shown a potential in many industrial fields such as medicine, agriculture and packaging. However, a complicated process is usually required to extract highly purified hemicellulose for further applications, which makes it not practical and economical for real industrial applications.

This thesis presents the utilization of a wood hydrolysate which was simply upgraded and recovered instead of being highly purified from the liquid by-product in the pulp industry. This softwood hydrolysate is rich in hemicellulose, O-acetyl galactoglucomannan (AcGGM), and also contains some lignin.

Films and coatings were produced based on this wood hydrolysate by blending with two other polysaccharide co-components, carboxymethyl cellulose (CMC) and chitosan. Different recipes with a variety of concentrations and compositions were prepared. For comparison, highly purified AcGGM-based films and coatings were also produced.

Mechanical properties and water vapor and oxygen barrier properties of the films and coatings were investigated. It was found that as a co-component, chitosan improved the mechanical properties best, and CMC gave better oxygen barrier properties at both 50% and 80% relative humidity. The wood-hydrolysate-based films gave much lower oxygen permeability (OP) values than AcGGM-based films.

In order to reveal why the less purified wood hydrolysate gave a better oxygen barrier, both theoretical and experimental studies were carried out. A group calculation based on Hansen’s Solubility parameter theory (HSP) showed that there were strong interactions between lignin and AcGGM in the wood hydrolysate and also that CMC was more compatible with wood hydrolysate/AcGGM than chitosan. These led to an affinity between components and gave a more compact molecular structure, and thus a smaller free volume in the matrix. This interpretation was in agreement with the Positron annihilation lifetime spectra (PALS) data, which showed that wood-hydrolysate-based films had a smaller free volume (hole size) and narrower distribution than AcGGM-based films. It also showed that CMC-co-component films had smaller hole radii in the matrix than chitosan-co-component films. Thermal properties and FTIR also shed light on the influence and nature of these interactions.


Abstract [sv]


Förnyelsebar biomassa har använts under lång tid för olika ändamål, från mat till industriprodukter. En stor familj av heteropolysackarider är hemicellulosa som har visat en potential i många applikationer, t. ex, inom medicin, jordbruket och förpackning industrin. För att utvinna renad hemicellulosa, krävs komplicerade processer, vilket är opraktiskt och för kostsant för många industriella tillämpningar. I detta arbete har vi använt ett hydrolysat som utvinns utan omfattande upprening från en flytande sidoström i massaindustrin. Detta barrveds hydrolysat är rikt på hemicellulosan, O-acetylerad galactoglucomannan (AcGGM) och innehåller även en del lignin.

Filmer och beläggningar skapades genom blandning av detta hydrolysat med två andra polysackarider samkomponenter; karboximetylcellulosa (CMC) och kitosan. Olika formuleringar med varierade koncentrationer och kompositioner utvecklades. Dessutom framställdes motsvarande formuleringar av AcGGM. Filmerna och beläggningarna analyserades med avseende på mekaniska egenskaper, kemisk struktur, vattenånga- och syrebarriäregenskaper. Kitosan, som samkomponent, förbättrade de mekaniska egenskaperna bäst medan CMC gav bäst syrebarriäregenskaper vid såväl 50% som 80% relativ fuktighet. Hydrolysat-baserade filmer hade betydligt lägre syrepermeabilitet (OP) än AcGGM-baserade filmer. För att förstå varför mindre renat hydrolysat gav bättre syrebarriäregenskaper än upprenad AcGGM, utvecklades en kombinerat teoretisk-analytisk modell. Beräkningar baserade på Hansens löslighetsparametersteori (HSP) visade att det finns starka interaktioner mellan lignin och hemicellulosorna i hydrolysatet, och även att CMC var mer kompatibel med hydrolysat/AcGGM än kitosan, vilket ger en starkare affinitet mellan komponenterna och en mer kompakt molekylstuktur, och därmed mindre fri volym i matrisen. Denna tolkning verifieras av positron annihilation lifetime spectra (PALS), som visar att hydrolysat-baserade filmer har en mindre fri volym (hålstorlek) och högre homogenitet än AcGGM-baserade filmer. Även termiska analyser och FTIR verifierade inflytandet och arten av dessa interaktioner.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology , 2011. , 49 p.
Trita-CHE-Report, ISSN 1654-1081 ; 2011:20
Keyword [en]
wood hydrolysate, hemicellulose, oxygen permeability, PALS, film, coating, CMC, chitosan, HSP
National Category
Polymer Chemistry
URN: urn:nbn:se:kth:diva-31134ISBN: 978-91-7415-879-3OAI: diva2:402820
2011-04-04, D32, KTH, Lindstedtsv 5, Entreplan, 100 44 Stockholm, 09:00 (English)

QC 20110311

Available from: 2011-03-11 Created: 2011-03-09 Last updated: 2012-12-18Bibliographically approved
List of papers
1. Barrier Films from Renewable Forestry Waste
Open this publication in new window or tab >>Barrier Films from Renewable Forestry Waste
2010 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 11, no 9, 2532-2538 p.Article in journal (Refereed) Published
Abstract [en]

Biobased free-standing films and coatings with low oxygen permeability were designed from a wood hydrolysate according to a recovery and formulation procedure that provides added value to wood converting industrial processes. Wood components released to the wastewater in the hydrothermal treatment of spruce wood were recovered and converted to an oligo- and polysaccharide-rich, noncellulosic fraction that was utilized in film formulations in a range of concentrations and compositions. Free-standing smooth and transparent films as well as coatings on thin PET were prepared and characterized with respect to oxygen permeability, tensile properties, structure, and water vapor transmission. With oxygen permeabilities as low as below I cm(3) mu m m(-2) day(-1) kPa(-1) and with adequate mechanical properties, the films and coatings show promising property profiles for renewable packaging applications.

Added values, Barrier films, Bio-based, Films and coatings, Freestanding films, Hydrothermal treatments, Industrial processs, Low oxygen, Oxygen permeability, Packaging applications, Property profiles, Spruce wood, Transparent films, Water vapor transmission, Wood components, Agriculture, Coatings, Mechanical properties, Oxygen, Oxygen permeable membranes, Wastewater, Wastewater treatment, Water vapor, Wood
National Category
Polymer Chemistry
urn:nbn:se:kth:diva-26701 (URN)10.1021/bm100767g (DOI)000281629600045 ()2-s2.0-77956536494 (ScopusID)
QC 20101129Available from: 2010-11-29 Created: 2010-11-26 Last updated: 2013-05-15Bibliographically approved
2. Conceptual approach to renewable barrier film design based on wood hydrolysate
Open this publication in new window or tab >>Conceptual approach to renewable barrier film design based on wood hydrolysate
2011 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 12, no 4, 1355-1362 p.Article in journal (Refereed) Published
Abstract [en]

Biomass is converted to oxygen barriers through a conceptually unconventional approach involving the preservation of the biomass native interactions and macromolecular components and enhancing the effect by created interactions With a co-component. A combined calculation/assessment model is elaborated to understand, quantify, and predict which compositions that provide an intermolecular affinity high enough to mediate the molecular packing needed to create a functioning barrier. The biomass used is a wood hydrolysate, a polysaccharide-rich but not highly refined mixture where a fair amount of the native intermolecular and intramolecular hernicelluloses-lignin interactions are purposely preserved, resulting in barriers with very low oxygen permeabilities (OP) both at 50 and 80% relative humidity and, considerably lower OPs than coatings based on the corresponding highly purified spruce hemicellulose, O-acetyl galactoglucomannan (AcGGM). The component interactions and, mutual affinities effectively mediate an immobilization of the chain segments in a dense disordered structure, modeled through the Hansen's solubility parameter concept and quantified on the nanolength scale by positron annihilation lifetime spectrum (PALS).

National Category
Polymer Chemistry
urn:nbn:se:kth:diva-31287 (URN)10.1021/bm200128s (DOI)000289223500058 ()21366288 (PubMedID)2-s2.0-79953872797 (ScopusID)
Uppdaterad från submitted till published 20110506 QC 20110311Available from: 2011-03-11 Created: 2011-03-11 Last updated: 2013-05-15Bibliographically approved

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