How Overdrying Wood Reduces Its Bonding to Phenol-Formaldehyde Adhesives: A Critical Review of the Literature. Part II. Chemical Reactions
Keywords:Drying, inactivation, adhesive, bonding, review, extractives, mechanism, wettability, oxidation, acidity
AbstractLiterature dealing with the effect of excessive drying (overdrying) on wood surface inactivation to bonding is reviewed in two parts and critically evaluated, primarily for phenolic adhesives. Part I of the review, published earlier, covers physical mechanisms that could contribute to surface inactivation. The principal physical mechanism is the migration to the surface of extractives that decrease wettability. Part II of the review considers mechanisms involving chemical reactions: reduction of wood surface strength, oxidation and pyrolysis of wood bonding sites, and chemical interference with resin cure or bonding. In those cases where extractives are not the primary cause of inactivation, oxidation or pyrolysis probably is the major cause of inactivation. Inactivation of oak and of some Southeast Asian hardwoods may be due to the acidity of extractives, but the importance of decreased wettability caused by extractives cannot be dismissed.
APA. 1983. U.S. product standard PS 1-83 for construction and industrial plywood with typical APA trademarks. American Plywood Association, Tacoma, WA. 44 pp.nBack, E. L. 1987. The bonding mechanism in hardboard manufacture. Holzforsch. 41(4):247-258.nBack, E. L., and L. O. Klinga. 1963. Reactions in dimensional stabilization of paper and fibre building board by heat treatment. Sven. Papperstidn. 66(19):745-753.nBeall, F. C. 1969. Thermogravimetric analysis of wood lignin and hemicelluloses. Wood Fiber 1(3):215-226.nBrushwood, D. E. 1988. Effects of heating on chemical and physical properties and processing quality of cotton. Text. Res. J. 58(6):309-317.nBurkill, I. H. 1966. A dictionary of the economic products of the Malay Peninsula. Ministry of Agriculture and Co-operatives, Governments of Malaysia and Singapore. Kuala Lampur, Malaysia: Pp. 851-855, 876-881.nChow, S. 1975. Minimizing wood surface inactivation at high temperatures by boron compounds. Forest Prod. J. 25(5):41-48.nChow, S. 1979. Wood treatment for preserving wood bondability. U.S. patent 4 145 242. March 20. 4 pp.nChow, S.-Z. 1971a. Infrared spectral characteristic and surface inactivation of wood at high temperatures. Wood Sci. Technol. 5:27-39.nChow, S.-Z. 1971b. Determining veneer surface inactivation by a reflectance colorimeter. Forest Prod. J. 21(2):19-24.nChow, S.-Z., and H. N. Mukai. 1972. Effect of thermal degradation of cellulose on wood-polymer bonding. Wood Sci. 4(4):202-208.nChristiansen, A. W. 1990. How overdrying wood reduces its bonding to phenol-formaldehyde adhesives: A critical review of the literature. Part I. Physical responses. Wood Fiber Sci. 22:(4):441-459.nCollett, B. M. 1973. Oxidative mechanisms for polymerization of lignocellulosic materials: Nitric acid and nitrogen oxides. Ph.D. thesis, University of California, Berkeley. 295 pp.nDavis, W. H., and W. S. Thompson. 1964. Influence of thermal treatment of short duration on the toughness and chemical composition of wood. Forest Prod. J. 14(8):350-356.nDe Bruyne, N. A. 1939. The nature of adhesion. Flight 18 (12, Supplement): 534a-534d (28 December).nFinar, I. L. 1973. Chemistry, vol. 1, 6th ed. Longman, London. Pp. 177.nGardner, D. J., and T. J. Elder. 1988. Surface activation treatment of wood and its effect on the gel time of phenol-formaldehyde resin. Wood Fiber Sci. 20(3):378-385.nHancock, W. V. 1964. The influence of native fatty acids on the formation of glue bonds with heat-treated wood. Ph.D. thesis, University of British Columbia, Vancouver, Canada. 176 pp.nHare, D. 1973. Effect of drying methods in the adhesive bonding of eastern spruce veneer. M.S. thesis, University of Maine, Orono, ME. 132 pp.nHernadi, A. 1977. Change of functional groups and optical properties of cellulose during thermal ageing. Paperi ja puu. 59(9):566-568, 571-573.nHernadi, A., and J. Domotor. 1981. Water take-up and swelling of the cellulose fibres after thermal treatment. Cellul. Chem. Technol. 15(1):63-75.nHillis, W. E. 1984. High temperature and chemical effects on wood stability. Part 1: General considerations. Wood Sci. Technol. 18:281-293.nJordan, D. L., and J. D. Wellons. 1977. Wettability of Dipterocarp veneers. Wood Sci. 10(1):22-27.nKuo, M.-L., D. Dicarlo, and C.-Y. Hse. 1984. Influence of extractives on bonding properties of white oak and southern red oak. J. Adhes. 16:257-278.nMitchell, P. H. 1988. Irreversible property changes of small loblolly pine specimens heated in air, nitrogen, or oxygen. Wood Fiber Sci. 20(3):320-335.nNguyen, D. 1975. Effect of wood extractives on cure of phenolic resin. M.S. thesis, Oregon State University, Corvallis, OR. 108 pp.nNorthcott, P. L. 1957. The effect of dryer temperatures upon the gluing properties of Douglas-fir veneer. Forest Prod. J. 7(1):10-16.nNorthcott, P. L., and H. G. M. Colbeck. 1959. Effect of dryer temperatures on bending strength of Douglas-fir veneer. Forest Prod. J. 9(9):292-297.nNorthcott, P. L., W. V. Hancock, and K. C. Shen. 1959. Undercure … casehardening in plywood. Forest Prod. J. 9(12):442-451.nPhilippou, J. L., and Zavarin, E. 1984. Differential scanning calorimetric and infra-red spectroscopic studies of interactions between lignocellulosic materials, hydrogen peroxide, and furfuryl alcohol. Holzforschung. 38(3):119-126.nPlagemann, W. L., E. W. Price, and W. E. Johns. 1984. The response of hardwood flakes and flakeboard to high temperature drying. J. Adhes. 16:311-338.nPlomley, K. F., W. E. Hillis, and K. Hirst. 1976. The influence of wood extractives on the glue-wood bond. I. The effect of kind and amount of commercial tannins and crude wood extracts on phenolic bonding. Holzforsch. 30(1):14-19.nRammon, R. M., S. S. Kelley, R. A. Young, and R. H. Gillespie. 1982. Bond formation by wood surface reactions. Part II. Chemical mechanisms of nitric acid activation. J. Adhesion. 14:257-282.nRoffael, E. 1987. Drying of pine chips and the effect on the strength of particleboard. Proceedings, 21st International Particleboard/Composite Materials Symposium; 1987 March 24-26; Pullman, WA. Washington State University, Pullman, WA. Pp. 361-381.nRoffael, E., and W. Rauch. 1974. Extraktstoffe in Eiche und ihr Einfluss auf die Verleimbarkeit mit alkalisch Phenol-Formaldehydharzen. (Extracts of oak and their influence on bonding with alkaline phenol-formaldehyde resins.) Holz. Roh Werkst. 32(5):182-187.nSeborg, R. M., H. Tarkow, and A. J. Stamm. 1953. Effect of heat upon the dimensional stabilization of wood. J. Forest Prod. Res. Soc. 3(3):59-67.nSellers, T., Jr., J. R. McSween, and W. T. Nearn. 1988. Gluing of eastern hardwoods: A review. Gen. Tech. Rep. SO-71. U.S. Department of Agriculture, Forest Service, Southern Forest Service Experiment Station, New Orleans, LA. 30 pp.nStamm, A. J. 1956. Thermal degradation of wood and cellulose. Ind. Eng. Chem. 48(3):413-417.nStamm, A. J. 1975. Solid modified woods. Page 120 in F. Kollmann, E. W. Kuenzi, and A. J. Stamm, eds. Principles of wood science and technology, vol. 2. Springer-Verlag, Berlin, New York.nStamm, A. J., H. K. Burr, and A. A. Kline. 1946. STAYBWOOD … heat-stabilized wood. Ind. Eng. Chem. 38(6):630-634.nStamm, A. J., and L. A. Hansen. 1937. Minimizing wood shrinkage and swelling. Effect of heating in various gases. Ind. Eng. Chem. 29(7):831-833.nStockman, L., and A. Teder. 1963. The effect of drying on the properties of papermaking pulps. Part 2. The effect of heat-treatment on the mechanical properties. Sven. Papperstidn. 66(20):822-832.nSuchsland, O., and R. R. Stevens. 1968. Gluability of southern pine veneer dried at high temperatures. Forest Prod. J. 18(1):38-42.nTroughton, G. E., and S. Chow. 1973. Heat-induced color-intensity changes in coastal Douglas-fir and white spruce. Wood Fiber 4(4):259-263.nTroughton, G. E., and L. R. Rozon. 1974. Heat effects on tensile properties of Douglas-fir and white spruce thin sections. Wood Sci. 7(2):116-122.nWellons, J. D. 1977. Adhesion to wood surfaces. Pages 150-168 in I. G. Goldstein, ed. Wood technology: Chemical aspects. American Chemical Society, Washington, DC.nWellons, J. D., and R. L. Krahmer. 1973. Project F-918 report. Characteristics of delaminated exterior hardwood plywood. Oregon State University, Forest Research Laboratory, Corvallis, OR. 20 pp.n
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