Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Lipase Catalyzed Co-polymerization of the Suberin Monomercis-9,10-Epoxy-18-hydroxyoctadecanoic Acid with Lactones
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
(engelsk)Manuskript (preprint) (Annet vitenskapelig)
Identifikatorer
URN: urn:nbn:se:kth:diva-25678OAI: oai:DiVA.org:kth-25678DiVA, id: diva2:359322
Merknad
QC 20101027Tilgjengelig fra: 2010-10-27 Laget: 2010-10-27 Sist oppdatert: 2010-10-27bibliografisk kontrollert
Inngår i avhandling
1. Suberin based polyesters
Åpne denne publikasjonen i ny fane eller vindu >>Suberin based polyesters
2009 (engelsk)Licentiatavhandling, med artikler (Annet vitenskapelig)
Abstract [en]

In the wish to replace oil-based chemicals and materials with such based on biodegradable and renewable resources, this work has been performed. In a biorefinary concept, waste birch bark from paper pulp mills and timber production has been evaluated as a potential source for polyesters. 

In the present thesis investigations are made on synthesis of epoxy-functionalized polyesters from the birch outer bark aliphatic suberin ω-hydroxy fatty acid, cis-9,10-epoxy-18-hydroxyoctadecanoic acid. Studies of accessibility and reactivity of cellulose have been performed as a first step to enable covalent attachment or grafting of the epoxy-functionalized polyesters to cellulose. 

Candida antarctica lipase B (Novozym 435) is reported to be an efficient catalyst for condensation polymerization of cis-9,10-epoxy-18-hydroxyoctadecanoic acid to form poly(9,10-epoxy-18-hydroxyoctadecanoic acid) with high molecular weight (Mw). Performed in toluene in the presence of molecular sieves a Mw of 20000 (reaction time 68 h, Mw/Mn 2.2) was obtained. Performed in bulk without any drying agent a Mw of 15000  was obtained at a much shorter reaction time (reaction time 3h, Mw/Mn 2.2). Further the same lipase has been used for succesful co-polymerizations of cis-9,10-epoxy-18-hydroxyoctadecanoic acid with lactones. By combining condensation and ring-opening polymerization, epoxy-functionalized linear polyesters and cyclic oligomers have been synthesized. For example, co-polymerization of cis-9,10-epoxy-18-hydroxy-octadecanoic acid and ε-caprolactone performed in toluene in the presence of molecular sieves gave mainly cyclic oligomers, especially at shorter reaction times. Co-polymerization performed in bulk gave linear polyesters with a Mw of 35000 (reaction time 24 h, Mw/Mn 6), irrespective molecular sieves were added or not. 

The epoxy-functionalized polyesters could be used for surface modification of pulp fibres and cellulose fibrils, which further can be used for production of new valuable composite materials with improved features. Knowledge of how different processing conditions affect the structure of cellulose is an important tool in the work to achieve successful grafting of produced polyesters to cellulose fibres/fibrils. CP/MAS 13C-NMR spectroscopy has been used to study structural changes caused by the dissolving pulp process. An irreversible increase in average fibril aggregate width from raw pulp to final pulp during the process is shown. This increase in aggregate width could negatively influence the reactivity of the cellulose.

 

 

sted, utgiver, år, opplag, sider
Stockholm: KTH, 2009. s. 37
Serie
Trita-CHE-Report, ISSN 1654-1081 ; 2009:21
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-10528 (URN)978-91-7415-311-8 (ISBN)
Presentation
2009-05-15, K1, KTH, Teknikringen 56, Stockholm, 10:00 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2009-05-25 Laget: 2009-05-25 Sist oppdatert: 2010-10-27bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Søk i DiVA

Av forfatter/redaktør
Olsson, AnnAreskogh, DimitriIversen, Tommy
Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric

urn-nbn
Totalt: 135 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf