Complex chemical interactions on thermo hydrolytic degradation of urea formaldehyde resins (UF-resins) in recycling UF-bonded boards

• Published in: European journal of wood and wood products Vol. 70; no. 4; pp. 401 - 405
• Main Authors: Roffael, E., Hüster, H.-G.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-07-2012; Springer Nature B.V
• Subjects: Acetic acid; Acids; Biomedical and Life Sciences; Ceramics; Chemical interactions; Composites; Deacetylation; Degradation; Formic acid; Glass; Life Sciences; Machines; Manufacturing; Natural Materials; Originals Originalarbeiten; Polymers; Processes; Resins; Urea; Urea formaldehyde resins; Wood Science & Technology; Urea Formaldehyde Resin; Urea Formaldehyde; Volatile Acid; Wood Particle; Reaction Period
• ISSN: 0018-3768; 1436-736X
• DOI: 10.1007/s00107-011-0574-7

Thermohydrolytic treatment of chips from UF-bonded particleboards using the flask method technique at temperatures of about 103°C resulted in a notable increase in the pH-value of aqueous absorption medium after a reaction period of 24 h, most likely due to degradation of the UF-resin. This leads to neutralisation of the stronger formic acid to a much higher extent than acetic acid. Accordingly, the release of formic acid using the flask technique decreases to a much higher extent compared to that of acetic acid under the same conditions. The release of acetic acid could also be enhanced by possible deacetylation of the wood material induced by the hardener usually present in recovered UF-boards. This indicates that inextricably intertwined reactions unfold on hydrothermic degradation of UF-bonded particleboards.