Skip to main content

Official Journal of the Japan Wood Research Society

Journal of Wood Science Cover Image

Improvement mechanism of bondability in UF-bonded reed and wheat straw boards by silane coupling agent and extraction treatments

Abstract

The effects of silane coupling agents and extractives on the wettability of reed and wheat straws were investigated. The inherent wettability of these materials was low but could be significantly improved by treating with silane coupling agents. The degree of improvement achieved by each silane coupling agent was different: Vinyl silane had almost no effect on wettability, epoxide silane was found to be more effective for reed straw, and amino silane was better for wheat straw. The wettability of these materials could also be improved by ethanol-benzene extraction, which resulted in more improvement in wheat straw than reed straw. The analyses of untreated reed and wheat straws by electron spectroscopy for chemical analysis (ESCA) revealed that there was much silicon on both the outer and inner surfaces of the former but only on the outer surface of the latter. The influence of hot-water extractives and silane coupling agents on the gelation time and pH of urea formaldehyde (UF) resin was also examined. The addition of extractives was found to increase the gelation time. Amino silane greatly retarded the gelation of OF resin, whereas epoxide and vinyl silanes had no influence on resin gelation. This retardation was found to be due to an increase in the pH of the resin.

References

  1. 1.

    Sauter S (1996) Developing composites from wheat straw. In: Proceedings of the 30th international particleboard/composite material symposium, Washington State University, Pullman, WA, pp 197–214

    Google Scholar 

  2. 2.

    Dalen H, Shorma T (1996) The manufacture of particleboard from wheat straw. In: Proceedings of the 30th international particleboard/composite material Symposium, Washington State University, Pullman, WA, pp 191–196

    Google Scholar 

  3. 3.

    Han G, Zhang C, Zhang D, Umemura K, Kawai S (1998) Upgrading of UF-bonded reed and wheat straw particleboard using silane coupling agents. J Wood Sci 44:282–286

    CAS  Article  Google Scholar 

  4. 4.

    Loxton C, Hague J (1996) Utilization of agricultural crop materials in panel products. In: Proceedings no. 7286: the use of recycled wood and paper in building applications. Madison, WI, Forest Products Society, pp 190–192

    Google Scholar 

  5. 5.

    Hse C, Choong E (1997) Bonding of rice-husk/wood composites. Presented at the (IUFRO) forest products for sustainable forestry, July 7-12, Washington State University, Pullman, WA, USA

    Google Scholar 

  6. 6.

    Young RA (1976) Wettability of wood pulp fiber. Wood Fiber Sci 8:120–128

    CAS  Google Scholar 

  7. 7.

    Nguyen T, Johns WE (1979) The effects of aging and extractives on the surface free energy of Douglas-fir and red wood. Wood Sci Technol 13:29–40

    CAS  Article  Google Scholar 

  8. 8.

    Browning BL (1967) Methods of wood chemistry, vol I. Wiley, New York, p 79

    Google Scholar 

  9. 9.

    William Russell C (1996) The straw resource: a new fiber basket. In: Proceedings of the 30th international particleboard/composite material Symposium, Washington State University, Pullman, WA, pp 183–190

    Google Scholar 

  10. 10.

    Kanazawa H, Nakagami T, Nobashi K, Yokota T (1978) The effects of teak wood extractives on the curing reaction and the hydrolysis rate of urea resin adhesive. Mokuzai Gakkashi 20:55–59

    Google Scholar 

  11. 11.

    Akaike Y, Nakagami T, Yokota T (1974) The inhibitory effect of kapur wood extracts on the gelation of the urea resin adhesive. Mokuzai Gakkashi 20:224–229

    CAS  Google Scholar 

  12. 12.

    Johns WE, Niazi KA (1980) Effect of pH and buffering capacity of wood on the gelation time of urea-formaldehyde resin. Wood Fiber 12:255–263

    CAS  Google Scholar 

  13. 13.

    Freeman H (1959) Properties of wood and adhesive. For Prod J 9:451–458

    Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Guangping Han.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Han, G., Umemura, K., Kawai, S. et al. Improvement mechanism of bondability in UF-bonded reed and wheat straw boards by silane coupling agent and extraction treatments. J Wood Sci 45, 299–305 (1999). https://doi.org/10.1007/BF00833494

Download citation

Key words

  • Reed straw
  • Wheat straw
  • Urea formaldehyde resin
  • Bondability
  • Silane coupling agent