13C-NMR Spectroscopy of Urea-Formaldehyde Resin Adhesives with Different Formaldehyde/Urea Mole Ratios

  • Park, Byung-Dae (Department of Wood Science and Technology, Kyungpook National University) ;
  • Lee, Sang M. (Division of Environmental Wooden Material Engineering, Korea Forest Research Institute) ;
  • Park, Jong-Young (Division of Environmental Wooden Material Engineering, Korea Forest Research Institute)
  • Received : 2007.09.19
  • Accepted : 2007.11.16
  • Published : 2008.03.25

Abstract

As a part of abating formaldehyde emission of urea-formaldehyde (UF) resin adhesive, this study was conducted to investigate chemical structures of UF resin adhesives with different formaldehyde/urea (F/U) mole ratios, using carbon-13 nuclear magnetic resonance ($^{13}C$-NMR) spectroscopy. UF resin adhesives were synthesized at four different F/U mole ratios such as 1.6, 1.4, 1.2, and 1.0 for the analysis. The analysis $^{13}C$-NMR spectroscopy showed that UF resin adhesives with higher F/U mole ratios (i.e., 1.6 and 1.4) had two distinctive peaks, indicating the presence of dimethylene ether linkages and methylene glycols, a dissolved form of free formaldehyde. But, these peaks were not detected at the UF resins with lower F/U mole ratios (i.e., 1.2 and 1.0). These chemical structures present at the UF resins with higher F/U mole ratios indicated that UF resin adhesive with higher F/U mole ratio had a greater contribution to the formaldehyde emission than that of lower F/U mole ratio. Uronic species were detected for all UF resins regardless of F/U mole ratios.

Keywords

Acknowledgement

Supported by : The Agricultural Research and Planning Center (ARPC)

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