Supercritical carbon dioxide impregnation of technical veneers with high-performance P/N flame retardants

Project "Flame retardant treatment of wood using supercritical carbon dioxide" (FFG, Bridge-1 program, project number FO999903628) is a network project between BOKU, Kompetenzzentrum Wood KPlus and the companies NATEX (Austria) and Fritz Kohl GmbH & Co. KG. The impregnation of technical veneers with high-performance flame retardants using supercritical CO2 as a carrier medium is to be investigated with the aim of using these veneers in aircraft, automobile and shipbuilding. In the 3-year's project, R&D work is carried out in 4 central work packages (in addition to the APs Management and Dissemination). Based on a comprehensive literature study (WP 2) on P- and N-containing high-performance flame retardants, accompanying experiments investigating their dissolution and transport behavior in scCO2 as well as experiments targeting the introduction of functional groups for improved solubility or chemical fixation in wood, a selection of promising flame retardants for further work in WP 3-5 will be made. For these compounds, investigations into the solubility and transport behavior in scCO2 will be carried out in AP 3. This work allows the identification of particularly promising FSM and impregnation conditions (p, T, relaxation regime). Subsequently, tests are carried out to impregnate wood veneers, technical veneers and small solid wood samples in order to evaluate the loading success qualitatively and quantitatively. Accordingly, these tests are accompanied by comprehensive analysis, which serves to demonstrate the homogeneity of the loading, the degree of loading and the influence of the treatment on essential material properties. Data from these experiments can be used to draw important conclusions about improving process control. Finally, in WP 5, flame protection-relevant, mechanical, olfactory, morphological and colorimetric parameters will be collected for selected samples in order to finally evaluate the practical suitability of scCO2-supported impregnation of wood veneers and its transfer to solid wood. .