Journal of the Korean Wood Science and Technology

The Korean Society of Wood Science & Technology (한국목재공학회)
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Effects of Formaldehyde to Urea Mole Ratio on Thermomechanical Curing of Urea-Formaldehyde Resin Adhesives

  • Park, Byung-Dae (Department of Wood Science and Technology, Kyungpook National University) ;
  • Kim, Jae-Woo (Tennessee Forest Products Center, University of Tennessee)
  • Received : 2007.01.29
  • Accepted : 2007.04.27
  • Published : 2007.09.25
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Abstract

This study was conducted to investigate the effects of formaldehyde to urea (F/U) mole ratio on thermomechanical curing of UF resin adhesives with different F/U mole ratios. Thermomechanical curing of these UF resin adhesives was characterized using parameters of dynamic mechanical analysis (DMA) such as the gel temperature, maximum storage modulus, and peak temperatures of storage and loss modulus. As the F/U mole ratio decreased, the gel temperature of UF resin adhesives increased. The maximum storage modulus as an indicator of the rigidity of UF resin adhesives decreased with decreasing F/U mole ratio. The peak temperature of tan $\delta$ increased with decreasing F/U mole ratio, indicating that the vitrification occurred faster for high F/U mole ratio of UF resin adhesives than for the one of lower F/U mole ratio. These results partially explained the reason why UF resin adhesives with lower F/U mole ratio resulted in relatively poor adhesion performance when they were applied.

Keywords

References

  1. Christiansen, A., W. R. A. Follensbee, R. A. Geimer, J. A. Koutsky, and G. E. Myers. 1993. Phenol-formaldehyde resin curing and bonding in steam-injection pressing. Part II. Differences between rates of chemical and mechanical responses to resin cure. Holzforschung. 47: 76-82 https://doi.org/10.1515/hfsg.1993.47.1.76
  2. Christjanson, P., K. Siimer, T. Pehk, and I. Lasn. 2002. Structural changes in urea-formaldehyde resins during storage. Holz als Roh-und Werkstoff. 60(6): 379-384 https://doi.org/10.1007/s00107-002-0326-9
  3. Chow, S. and P. R. Steiner. 1975. Catalytic, exothermic reactions of urea-formaldehyde resin. Holzforschung. 29(1): 4-10 https://doi.org/10.1515/hfsg.1975.29.1.4
  4. Dunky, M. 1983. Urea-formaldehyde (UF) adhesive resins for wood. Int. J Adhesion & Adhesives. 18: 95-107
  5. Ebewele, R. O. 1995. Differential scanning calorimetry and dynamic mechanical analysis of amine-modified urea-formaldehyde adhesives. J Appl. Polym. Sci. 58(10): 1689-1700 https://doi.org/10.1002/app.1995.070581005
  6. Follensbee, R. A., J. A. Koutsky, A. W. Christiansen, G. E. Myers, and R. L. Geimer. 1993. Development of dynamic mechanical methods to characterize the cure state of phenolic resins. J Appl. Polym. Sci. 47: 1481-1496 https://doi.org/10.1002/app.1993.070470820
  7. Gu, J. Y., M. Higuchi, M. Morita, and C. Y. Hse. 1995. Synthetic conditions and chemical structures of urea-formaldehyde resins I. Properties of the resins synthesized three different procedures. Mokkuzai Gakkaishi. 41(12): 1115-1121
  8. Hse, C. Y., Z. Y. Xia, and B. Tomita. 1994. Effects of reaction pH on properties and performance of urea-formaldehyde resins. Holzforschung. 48(6): 527-534 https://doi.org/10.1515/hfsg.1994.48.6.527
  9. Kim, M. G., W. L.-S. Nieh, and R. M. Meacham. 1991. Study on the curing of phenol-formaldehyde resol resins by dynamic mechanical analysis. Ind. Eng. Chem. Res. 30: 798-803 https://doi.org/10.1021/ie00052a027
  10. Marutzky, R. In: Wood Adhesives: Chemistry and Technology, Vol. 2. A. Pizzi, Ed., Marcel Dekker Inc., 1986. pp. 307-387
  11. Myers, G. E. 1983. Formaldehyde emission from particleboard and plywood paneling: measurement, mechanism, and product standards. For. Prod. J. 33(5): 27-37
  12. Myers, G. E. 1984. How mole ratio of UF resin affects formaldehyde emission and other properties: A literature critique. For. Prod. J. 34(5): 35-41
  13. Myers, G. E. and K. A. Koutsky. 1987. Procedure for measuring formaldehyde liberation from formaldehyde-based resins. For. Prod. J. 37(9): 56-60
  14. Myers, G. E. and K. A. Koutsky. 1990. Formaldehyde liberation and cure behavior of ureaformaldehyde resins. Holzforschung. 44(2): 117-126 https://doi.org/10.1515/hfsg.1990.44.2.117
  15. Myers, G. E. In: Formaldehyde Release from Wood Products, B. Meyer. B. A. K. Andrews, R. M. Reinhardt. Ed., American Chemical Society, 1986, pp. 8-14
  16. No, B. and M. G. Kim. 2005. Curing of low level melamine-modified urea-formaldehyde particleboard binder resin studied with dynamic mechanical analysis (DMA). J Appl. Polym. Sci. 97: 377-389 https://doi.org/10.1002/app.21759
  17. Onic, L., V. Bucur, M. P. Ansell, A. Pizzi, X. Deglise, and A. Merlin. 1988. Dynamic thermomechanical analysis as control technique for thermoset bonding of wood joints. Int. J Adhesion and Adhesives. 18: 89-94 https://doi.org/10.1016/S0143-7496(97)00049-3
  18. Park, B.-D., E. C. Kang, and J. Y. Park. 2006, Effects of formaldehyde to urea mole ratio on thermal curing behavior of urea-formaldehyde resin and properties of particleboard. J of Appl. Polym. Sci. 101(3): 1787-1792 https://doi.org/10.1002/app.23538
  19. Pizzi, A., L. Lipschitz, and J. Valenzuela. 1994. Theory and practice of the preparation of low formaldehyde emission UF adhesives. Holzforschung. 48(3): 254-261 https://doi.org/10.1515/hfsg.1994.48.3.254
  20. Que, Z., T. Furuno, S. Katoh, and Y. Nishino. 2007. Effects of urea-formaldehyde resin mole ratio on the properties of particleboard. Building & Environment. 42: 1257-1263 https://doi.org/10.1016/j.buildenv.2005.11.028
  21. Siimer, K., T. Kaljuvee, and P. Christjanson. 2003. Thermal behaviour of urea-formaldehyde resins during curing. J. Thermal Anal. Calorimetry. 72(2): 607-617 https://doi.org/10.1023/A:1024590019244
  22. Sundin, B. and P. Hanetho. 1978. Formaldehyde emission from particleboard and other building materials. In: Proc. of 12th International Particleboard Symposium, Washington State University, Pullman, WA, USA. pp. 251-286
  23. Umemura, K., S. Kawai, Y. Mizuno, and H. Sasaki. 1996. Dynamic mechanical properties of thermosetting resin adhesives II: urea resin. Mokuzai Gakkaishi. 42(5): 489-496
  24. Young, R. H. 1986. Adhesive cure as determined by dynamic mechanical analysis and its effect on wood composite performance. In: Christiansen, A.W., R. H. Gillespie, G. E. Myers and B. H. Rivers, eds. Wood Adhesives in 1985: status and needs, Proc. of a conference, 1985, May 14-16, Madison, WI USA, Forest Products Research Society, pp. 267-276
  25. Zeman, S. and L. Tokarova. 1992. Thermogravimetric analysis of urea-formaldehyde polycondensates. Thermochemica Acta. 202: 181-189 https://doi.org/10.1016/0040-6031(92)85162-O