Change search
CiteExportLink to record
Permanent link

Direct 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
Enhancing UV protection of clear coated exterior wood by reactive UV absorber and epoxy functional vegetable oil
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Since ancient times wood has played a large role in human activities, both in terms of fuel and for construction purposes. A drawback with wood in exterior applications is, however, its susceptibility to photo-initiated degradation, caused by radiation from the sun. Hence, wood needs to be protected against ageing by means of different surface treatments. The work presented in this thesis describes a possible method for protecting wood against photo-initiated degradation. The system comprises the UV absorber, 2-hydroxy-4(2,3-epoxypropoxy)-benzo-phenone (HEPBP), which has a primary epoxy group with the ability to react covalently with hydroxyl groups, enabling reaction with hydroxyl groups of the wood (preferably phenolic hydroxyls in lignin). The epoxy functional vegetable oils (soybean and linseed oil) contain secondary epoxy groups which theoretically also enables reaction with the hydroxyl groups of the wood. This ability and a possible reaction with wood could result in a more long term protection since it prevents leaching of the protective substances. The study includes evaluation of several reaction parameters of the pretreatment, such as temperature, time, the influence of the oil, and also the photo protective ability of the sole pretreatment. The results show that a reaction temperature of 102 °C or higher results in presence of the reactants on the surface even after extraction, indicating grafting. Two different reaction procedures imply that reaction for 16 h results in slightly better results compared to a 1 h dipping procedure with 2 h subsequent drying in an oven. However, in terms of time and energy consumption the difference is considered too small to defend using the longer reaction procedure. Colour measurements of samples before, during and after ageing indicate a better performance of the pretreated samples compared to the untreated, and an effect of the oil is also noticed, giving the colour change a more stable increase that levels off instead of continuing to increase. The study also takes into account the use of a clear coating together with the pretreatment to study the performance of a complete coating system, in terms of photo protection. Coating of the pretreated samples is shown to work, with uncompromised adhesion as a result. Evaluations of natural and accelerated weathering of the full systems indicate only minor degradation after 1400 h of accelerated ageing or 14 months of natural exposure. After 4000 h of accelerated ageing, visible signs of degradation are detected, but the pretreated samples perform slightly better than the untreated. After 26 months of natural exposure the samples had too much mould in order to perform a reliable evaluation of the photo induced degradation. Overall the pretreatment is concluded to have a photostabilising effect of the wood.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. , 87 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2014:46
National Category
Polymer Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-156085ISBN: 978-91-7595-318-2 (print)OAI: oai:DiVA.org:kth-156085DiVA: diva2:764819
Public defence
2014-12-12, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Formas, 2008-1447
Note

Resarch funder: Lantmännens Forskningsstiftelse. QC 20141121

Available from: 2014-11-21 Created: 2014-11-20 Last updated: 2014-11-21Bibliographically approved
List of papers
1. Grafting of 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone and epoxidized soybean oil to wood: Reaction conditions and effects on the color stability of Scots pine
Open this publication in new window or tab >>Grafting of 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone and epoxidized soybean oil to wood: Reaction conditions and effects on the color stability of Scots pine
2012 (English)In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 97, no 9, 1779-1786 p.Article in journal (Refereed) Published
Abstract [en]

This study investigates the photostabilizing effect of the reactive UV-absorber 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone (HEPBP) when used as a primer for wood. The present work further includes a study on the effect of HEPBP used in combination with an epoxy functionalized vegetable oil as a primer system. The study is based on reactions performed on pine veneers using 3-pentanone as a solvent and 4-(dimethylamino)pyridine (DMAP) as a catalyst, varying the reaction time and temperature. Results from FTIR and SEC measurements indicate that a desired reaction between HEPBP and wood does occur and that there are synergetic effects when HEPBP and oil are combined. Color measurements also indicate that the use of HEPBP and epoxidized soybean oil as pretreatment for wood results in a lower color change after 400 h of artificial weathering. We conclude that using HEPBP in combination with epoxy functionalized soybean oil does improve photostability of wood exposed to artificial weathering.

Keyword
UV-protection, 2-Hydroxy-4(2, 3-epoxypropoxy)-benzophenone (HEPBP), Wood, Epoxy functionalized soybean oil, Grafting
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-92248 (URN)10.1016/j.polymdegradstab.2012.06.006 (DOI)000308051500027 ()2-s2.0-84864606912 (Scopus ID)
Note

QC 20121009. Updated from submitted to published.

Available from: 2012-03-30 Created: 2012-03-30 Last updated: 2017-12-07Bibliographically approved
2. Reactive UV-absorber and epoxy functionalized soybean oil for enhanced UV-protection of clear coated wood
Open this publication in new window or tab >>Reactive UV-absorber and epoxy functionalized soybean oil for enhanced UV-protection of clear coated wood
2014 (English)In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 110, 405-414 p.Article in journal (Refereed) Published
Abstract [en]

The present work investigates the photostabilising effect of a pretreatment consisting of 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone (HEPBP) and epoxy functionalized soybean oil (ESBO), reacted on to Scots pine veneers coated with two different acrylic top coats. Two different pretreatment procedures were used, varying in reaction time and temperature. Results from FTIR and SEC analysis indicate that a large amount of reactant was present on the veneers after treatment with either of the two reaction procedures. Furthermore, coating of the pretreated surfaces was possible and the pretreatment does not seem to affect the adhesion between the coating and the wood substrate. Both accelerated ageing and natural exposure was used to study the resistance to photodegradation, and the results were analysed using colour measurements, FTIR and SEM. These analyses all show that 1400 h of accelerated ageing degrades neither the wood nor the coating to any larger extent. However, after 4000 h of UV exposure some signs of degradation are visible but to a lesser extent for pretreated samples. For the samples exposed to natural weathering during 14 months the performance was good in terms of photostabilisation, however all samples suffer from mould to different extents. Pretreated samples show smaller and more evenly distributed areas of mould compared to the references, which show slightly more mould. The combined coating/pretreatment system is thus assumed to have an effect in terms of photostabilization of the coated wood.

Keyword
2-Hydroxy-4(2, 3-epoxypropoxy)-benzophenone, Epoxy functional vegetable oil, Photodegradation, Soybean oil, UV-protection, Weathering
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-92251 (URN)10.1016/j.polymdegradstab.2014.09.017 (DOI)000347495700047 ()2-s2.0-84949117531 (Scopus ID)
Funder
Swedish Research Council Formas, 2008-1447
Note

Updated from "Manuscript" to "Article". QC 20141121

Available from: 2012-03-30 Created: 2012-03-30 Last updated: 2017-12-07Bibliographically approved
3. Effect of lignin structures on the reactions with epoxidized vegetable oils
Open this publication in new window or tab >>Effect of lignin structures on the reactions with epoxidized vegetable oils
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-156093 (URN)
Note

QS 2014

Available from: 2014-11-21 Created: 2014-11-21 Last updated: 2014-11-21Bibliographically approved
4. A SEM study on the use of epoxy functional vegetable oil and reactive UV-absorber as UV-protecting pretreatment for wood
Open this publication in new window or tab >>A SEM study on the use of epoxy functional vegetable oil and reactive UV-absorber as UV-protecting pretreatment for wood
Show others...
2015 (English)In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 113, no SI, 40-45 p.Article in journal (Refereed) Published
Abstract [en]

The present study investigates the ageing performance of a UV protective system for wood, comprising the reactive UV absorber 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone (HEPBP) and epoxy functional vegetable oils (linseed and soybean oil). Scots pine samples of radial or cross-sectional surfaces were treated using a combination of the two components, or using only one of the oils. The treated samples were then aged in a Weather-Ometer for 2 x 60 h and analysed using VPSEM to follow the degradation of the wood substrate in the exact same spot before, during and after ageing. The results of the radial surfaces show slightly less degradation of samples treated with a combination of HEPBP and oil, and for the cross-sectional surfaces an even stronger protective effect is visible. For samples treated with only one of the two oils, no improvement was detectable. The radial surfaces were also analysed using FTIR where the results indicate presence of the protective treatment even after 120 h of exposure. Overall the combined pretreatment of HEPBP and epoxy functional linseed oil was concluded to have a photo-stabilising effect of the wood substrate.

Keyword
UV-absorber, Epoxy functional vegetable oil, Linseed oil, 2-Hydroxy-4(2, 3-epoxypropoxy)-benzophenone (HEPBP)
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-156094 (URN)10.1016/j.polymdegradstab.2015.01.005 (DOI)000353078100005 ()2-s2.0-84922584471 (Scopus ID)
Note

QC 20150609. Updated from manuscript to article in journal.

Available from: 2014-11-21 Created: 2014-11-21 Last updated: 2017-12-05Bibliographically approved

Open Access in DiVA

Thesis(3255 kB)1986 downloads
File information
File name FULLTEXT01.pdfFile size 3255 kBChecksum SHA-512
eaa8acb37a2a4865b0e737316f1efd1cd57bf94a60c27f0a4d2a1ab7c82700fd4f417aa739507b43cce752d4462509e2f6f5ad6f9042ef10d0ade1601d8cf19b
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Olsson, Sara
By organisation
Coating Technology
Polymer Chemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 1986 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 450 hits
CiteExportLink to record
Permanent link

Direct 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