Wood Science and Technology

, Volume 52, Issue 6, pp 1607–1620 | Cite as

Highly effective impregnation and modification of spruce wood with epoxy-functional siloxane using supercritical carbon dioxide solvent

  • Tillmann Meints
  • Christian HansmannEmail author
  • Marcus Müller
  • Falk Liebner
  • Wolfgang Gindl-Altmutter


Chemical modification of wood is an established approach to improve its biological durability, water repellence, dimensional stability, and UV resistance. Norway spruce wood (Picea abies) in dry state, however, has an extraordinarily high recalcitrance towards impregnation with liquid modification reagents as drying triggers the irreversible closure of pits, i.e. the cell-to-cell valves in softwood. In the present study, it is shown that supercritical carbon dioxide is a highly suitable impregnation medium to overcome the recalcitrance of dry spruce wood. This has been exemplarily demonstrated for deca(dimethylsiloxane)-α,ω-diglycidylether (D8M 2 OG ), a linear oligosiloxane with terminal epoxy-functionalities, which could be loaded into respective wood samples affording a weight gain of up to 63%. The thermally assisted reaction of the epoxy-functional siloxane with the wood polymers was catalysed with ring-opening Tin (II) octoate. The effort resulted in a remarkably reduced wettability with water, as evident from contact angle measurements (~ 140°), and in a significant decrease (≤ 20%) of the sample’s sensitivity towards moisture-induced dimensional changes.



The authors gratefully thank Prof. Dr. Martin Wendland from the Institute for Chemical and Energy Engineering of BOKU University Vienna, Austria, who enabled the use of the scCO2 plant and Markus Hauptmann who operated the scCO2 plant.

Compliance with Ethical Standards

Conflict of interest

The authors declare no conflict of interest.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Wood K plus – Competence Centre for Wood Composites and Wood ChemistryLinzAustria
  2. 2.University of Applied Forest Sciences RottenburgRottenburg a.N.Germany
  3. 3.Department of ChemistryBOKU - University of Natural Resources and Life Science ViennaTullnAustria
  4. 4.Department of Materials Science and Process EngineeringBOKU - University of Natural Resources and Life Science ViennaTullnAustria

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