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Gewählte Master / Diploma Thesis:

Lorenz Pfungen (2015): Lignin Phenol Formaldehyde Wood Adhesives.
Master / Diploma Thesis - Institut für Holztechnologie und Nachwachsende Rohstoffe, BOKU-Universität für Bodenkultur, pp 75. UB BOKU obvsg FullText

Data Source: ZID Abstracts
Due to its phenolic structure and the huge available quantities of lignin a lot of efforts to substitute phenol with lignin in phenolic adhesives were already made. The goal of this master thesis was to develop a production procedure for lignin-phenol-formaldehyde resins of which the amount of phenol is replaced up to 40% by lignin. The hypothesis was that it is possible to produce adhesives with equal properties compared to pure phenol-formaldehyde resins. Therefore adhesives with 5, 10, 20, 30 and 40% lignin based on the total mass of phenol were produced as well as a reference resin with 0%. For the tests Sarkanda grass Soda lignin and pine Kraft lignin Indulin AT™ were used. To determine an appropriate synthesis temperature screening tests were performed at the beginning. Subsequently reproducibility tests were conducted. During these tests the procedure and the used equipment were changed to optimize the resin synthesis. The optimized procedure was used to synthesize adhesives which were characterized. The resins were characterized in terms of viscosity, solid content (ISO 3251), B-time (DIN 16916-2) as a value for curing time, water miscibility (ISO 8989) and free formaldehyde content (ISO 11402). The curing development was determined with differential scanning calorimetry. To determine the influence of the used amount of lignin on the bonding strength the longitudinal tensile shear strength according ÖNORM EN 302-1 was determined. The specimens were stored in different climates (treatment A1+ and A2) and tested afterwards. The results of the tests showed no substantial differences. An exception was the free formaldehyde content which increases linearly with increasing amount of lignin. An increased amount of lignin led to a delayed curing of a resin. The statistical analysis of the tensile shear test showed that for both climates the average tensile shear strength of the groups differ from each other.

Beurteilende(r): Konnerth Johannes
1.Mitwirkender: Liebner Falk
2.Mitwirkender: Van Herwijnen Hendrikus

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