University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Doctoral Thesis:
Stefan Veigel
(2012):
Mechanische Charakterisierung cellulosefaserverstärkter Holz-Klebeverbindungen.
Doctoral Thesis - Holzforschung und Holztechnologien (WST),
BOKU-Universität für Bodenkultur,
pp 135.
UB BOKU
obvsg
- Abstract:
- The present study investigates the possibility of improving the bonding performance of aminoplastic wood adhesives by the addition of small amounts of cellulose nanofibrils. For this purpose, nanofibrils were prepared from wood pulp and mechanically characterised as thin films. The results showed that the oxidation of cellulose using the catalyst 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) facilitates the fibrillation of pulp fibres and leads to significantly enhanced strength and stiffness of the corresponding cellulose films. Cellulose nanofibrils were added to industrially applied urea-formaldehyde and melamine-urea-formaldehyde adhesives in concentrations of up to 5% based on solid resin. Wood adhesive bonds were prepared and mechanically characterised. Lap joint testing according to EN 302-1 revealed more than 30% higher strength values for cellulose-reinforced bonds compared to pure UF-bonds. The effect of cellulose addition on the specific fracture energy of solid wood adhesive bonds was investigated using the double cantilever beam test. Again, significant performance improvements could be observed. Despite the higher strength of TEMPO-oxidised cellulose, untreated nanofibrils showed the best results in this case. Furthermore, the fibre reinforced adhesives were used to prepare particle board and oriented strand board on a laboratory scale. For both panel types, mechanical board properties, especially the fracture toughness, were enhanced.
- Betreuer: Gindl-Altmutter Wolfgang
- 1. Berater: Müller Ulrich
- 2. Berater: Konnerth Johannes