Chemical Modification of Wood
Keywords:Chemical modification, resin-impregnated wood, etherification, acetals, esterification, oligo-esterification, slow release biocides, dimensional stability, decay resistance, termite resistance, fire resistance
Wood is, perhaps, nature's most wonderful gift to humanity, its versatile character providing unlimited scope for property manipulation and product development to suit diverse applications. Progress in the field of polymer chemistry led to the development of a new class of wood products with substantially improved physical, chemical, mechanical, and biological properties. Aesthetic superiority, uniform finish, property enhancement, and reduced maintenance made modified wood attractive for large-scale application in many industrial uses as substitutes for costly metals and alloys.
Chemical modification of the cell wall achieved significant success during the last two decades. A wide variety of wood modification reactions have been studied, of which acetylation holds great potential. Improved dimensional stability and resistance to biological degradation have made it attractive for use in high-value panels and joinery products. The high resistance to biodegradation, especially with bonded biocides, holds a bright future for its use in wood protection in view of increasing environmental controls to limit pollution of the planet Earth.
Improvement in dynamic mechanical properties of wood, resulting from bulking of the cell wall, shows promise for its utilization in the manufacture of improved musical instruments.
Agrawal, S. C., K. Kohli, N. K. Shukla, and S. Kumar. 1985. Mechanical properties of wood acetylated with thioacetic acid. J. Ind. Acad. Wood Sci. 16(2):61-67.nAkitsu, H., M. Norimoto, and T. Morooka. 1991. Vibrational properties of chemically modified wood. Mokuzai Gakkaishi 37(7):590-597.nAkitsu, H., M. Norimoto, T. Morooka, and R. M. Rowell. 1993. Effect of humidity on vibrational properties of chemically modified wood. Wood Fiber Sci. 25(3):250-260.nAktiebolag, M. D. 1965. Wood impregnation with gaseous ethylene oxide. French Pat. 1 408 170.nAmerican Society for Testing and Materials. 1991. Standard specification for modified woods. Annual Book of ASTM Standards. ASTM Designation: D:1324-83. Philadelphia, PA.nAnand, A. S. 1981. Densified wood laminates. J. Timb. Dev. Assoc. (India) 27(2):5-16.nANON. 1987. Wood handbook: Wood as an engineering material. USDA Forest Serv. Forest Prod. Lab. Agriculture Handbook No. 72, Madison, WI.nArora, M., and M. S. Rajawat. 1982. Wettability related to gluability of acetylated timbers. J. Timb. Dev. Assoc. (India) 28(4):17-21.nChen, G. C. 1992a. Fungal resistance of loblolly pine reacted with methyl or phenyl isocyanates. Holzforschung 46(1):77-80.nChen, G. C. 1992b. Fungal resistance of loblolly pine reacted with para-toluene sulfonyl chloride or isocyanate. Wood Fiber Sci. 24(2):161-167.nChen, G. C., and R. M. Rowell. 1987. Approaches to the improvement of biological resistance of wood through controlled release technology. Am. Paint Coatings J. 72(16):37-41.nChen, G. C., R. M. Rowell, and W. D. Ellis. 1990. Fungal resistance of southern pine impregnated with methyl fluorophenyl carbamates or reacted with fluorophenyl isocyanates. Wood Fiber Sci. 22(2):165-172.nCodd, P., W. B. Banks, J. A. Cornfield, and G. R. Williams. 1992. The biological effectiveness of wood modified with heptadecenylsuccinic anhydride against two brown rot fungi: Coniofora puteana and Gloephyllum trabeum. Intl. Res. Group on Wood Preservation Doc. No. IRG/WP 3705.nCorden, M. E., and J. J. Morrell. 1988. Evaluating potential decay control agents with a small block test. Wood Fiber Sci. 20(4):477-486.nDev, I., and S. Kumar. 1989. A note on the acetylation of wood with acetic acid. J. Timb. Dev. Assoc. (India) 35(4):33-36.nDunningham, E. A., D. V. Plackett, and A. P. Singh. 1992. Weathering of chemically modified wood—Natural weathering of acetylated radiata pine: Preliminary results. Holz Roh-Werkst. 50(11):429-432.nEllis, W. D., and R. M. Rowell. 1984. Reactions of isocyanates with southern pine wood to improve dimensional stability and decay resistance. Wood Fiber Sci. 16(3):349-356.nFeist, W. C., and R. M. Rowell. 1982. UV degradation and accelerated weathering of chemically modified wood. In David N. S. Hon, ed. Graft copolymerization of lignocellulosic fibers. ACS Symp. Series 187, Am. Chem. Soc., Washington, DC.nFeist, W. C., R. M. Rowell, and W. D. Ellis. 1991. Moisture sorption and accelerated weathering of acetylated and methacrylated aspen. Wood Fiber Sci. 23(1):128-136.nFuruno, T., T. Uehara, and S. Jodai. 1992. The role of wall polymer in decay durability of wood-polymer composites. Mokuzai Gakkaishi 38(3):285-293.nGoldstein, I. S., W. A. Dreher, and E. B. Jeroski. 1959. Wood processing inhibition against swelling and decay. Ind. Eng. Chem. 51(10):1313-1317.nGoldstein, I. S., E. B. Jeroski, A. E. Lund, J. F. Nielson, and J. W. Weaver. 1961. Acetylation of wood in lumber thickness. Forest Prod. J. 11(8):363-370.nGurvich, J. C. 1957. The past developments and future prospects for Compreg. Forest Prod. J. 7(9):16A-17A.nImamura, Y., and K. Nishimoto. 1986. Resistance of acetylated wood to attack by subterranean termites. Wood Res. 72:37-44.nImamura, Y., and K. Nishimoto. 1987. Some aspects on the resistance of acetylated wood against biodeterioration. Wood Res. 74:33-4.nInoue, M., M. Norimoto, Y. Otsuka, and T. Yamada. 1990. Surface compression of coniferous wood lumber. I. A new technique to compress the surface layer. Mokuzai Gakkaishi 36(11):969-975.nInoue, M., M. Norimoto, Y. Otsuka, and T. Yamada. 1991. Surface compression of coniferous wood lumber II. Permanent set of compression wood by low molecular weight phenolic resins and some physical properties of the products. Mokuzai Gakkaishi 37(3):227-233.nInoue, M., S. Ogata, M. Nishikawa, Y. Otsuka, S. Kawai, and M. Norimoto. 1993. Dimensional stability, mechanical properties, and color changes of a low molecular weight melamine-formaldehyde resin impregnated wood. Mokuzai Gakkaishi 39(2):181-189.nIS. 1966. Indian standard specification for high and medium density wood based laminates (Compreg) Part I-Part IV. Bureau of Indian Standards, Manak Bhavan, New Delhi, India.nJohnson, B. R., and R. M. Rowell. 1988. Resistance of chemically modified wood to marine borers. Mater. Org. 23(2):147-156.nKalnins, M. A. 1984. Chemical modification of wood for improved decay resistance. Wood Sci. 15(2):81-89.nKoppers. 1961. Dimensionally stabilized wood. New Materials Tech. Inf. No. RDW-400 E-106.nKumar, S., and S. C. Agrawal. 1982. Chemical modification of wood with thioacetic acid. In David N. S. Hon, ed. Graft copolymerization of lignocellulosic fibers. ACS Symp. Series 187, Am. Chem. Soc., Washington, DC.nKumar, S., and K. Kohli. 1986. Chemical modification of wood: Reaction with thioacetic acid and its effect on physical and mechanical properties and biological resistance. In E. E. Carraher and L. H. Sperling, eds. Renewable resource materials—New polymer sources. Polymer Sci. Tech., Plenum Press, New York, NY.nKumar, S., Indra Dev, and S. P. Singh. 1991. Hygroscopicity and dimensional stability of wood acetylated with thioacetic acid and acetyl chloride. J. Timb. Dev. Assoc. (India) 37(1):25-32.nLehinger, A. L. 1970. Biochemistry. Worth Publishers Inc., New York, NY.nLiu, C., and C. W. McMillin. 1965. Treatment of wood with ethylene oxide gas or propylene oxide gas. U.S. Pat. 3 183 114.nMackay, J. F. G. 1972. The occurrence, development and control of checking in Tasmanian Eucalyptus obliqua. Holzforschung 26(4):121-124.nMartins, V. A., and W. C. B. Banks. 1991. Sorptive properties of chemically modified wood. Wood Protect. 1(2):69-75.nMatsuda, H., M. Ueda, and K. Murakami. 1988a. Oligoesterified woods based on anhydride and epoxide. I. Preparation and dimensional stability of oligoesterified woods by stepwise addition reactions. Mokuzai Gakkaishi 34(2):140-148.nMatsuda, H., M. Ueda, and K. Murakami. 1988b. Oligoesterified woods based on anhydride and epoxide. II. Preparation and dimensional stability of oligoesterified woods by heating wood immersed in anhydride-epoxide solution. Mokuzai Gakkaishi 34(7):587-603.nMatsuda, H., M. Ueda, and K. Murakami. 1988c. Oligoesterified woods based on anhydride and epoxide. IV. Preparation and dimensional stability of oligoesterified woods by heating-suction of wood impregnated with reactant solution. Mokuzai Gakkaishi 34(12):1004-1011.nMeyer, J. A. 1982. Industrial use of wood-polymer materials: State of the art. Forest Prod. J. 32(1):24-29.nMilitz, H. 1991. Improvement of shrinking and swelling behavior and durability of wood by treatment with non-catalyzed acetic anhydride. Holz Roh-Werkst. 49(4):147-152.nMilitz, H. 1993. Treatment of timber with water soluble dimethylol resins to improve their dimensional stability and durability. Wood Sci. Technol. 27(3):347-355.nMinato, K., and H. Yano. 1990. Improvement of dimensional stability and acoustic properties of wood for musical instruments by sulfur dioxide catalyzed for-malization. Mokuzai Gakkaishi 36(5):362-367.nMinato, K., R. Yasuda, and H. Yano. 1990. Improvement of dimensional stability and acoustic properties of wood for musical instruments with cyclic oxymethylenes. II. Formalization with tetraoxane. Mokuzai Gakkaishi 36(11):990-996.nMurakami, K., and H. Matsuda. 1990a. Oligoesterified woods based on anhydride and epoxide. VII. Dynamic mechanical properties of oligoesterified woods. Mokuzai Gakkaishi 36(1):49-56.nMurakami, K., and H. Matsuda. 1990b. Oligoesterified woods based on anhydride and epoxide. VIII. Resistance of oligoesterified woods against weathering and biodeterioration. Mokuzai Gakkaishi 36(7):538-544.nMurakami, K., H. Matsuda, and M. Ueda. 1989. Oligoesterified woods based on anhydride and epoxide. V. Properties of oligoesterified woods obtained by heating-suction of wood impregnated with reactant solution. Mokuzai Gakkaishi 35(4):328-335.nMurakami, K., H. Matsuda, and M. Ueda, J. Y. Ryu, Y. Imamura, and M. Takahashi. 1993. Oligoesterified woods based on anhydride and epoxide IX. Decay and termite resistance of oligoesterified woods. Mokuzai Gakkaishi 39(4):436-445.nNarayanamurthi, D., and B. K. Handa. 1953. Acetylated woods. Das Papier 7:87-92.nNicholas, D. D., and A. D. Williams. 1987. Dimensional stabilization of wood with dimethylol compounds. Intl. Res. Group on Wood Preservation Doc. No. IRG/WP/3412.nNorimoto, M., J. Gril, K. Minato, K. Okamura, J. Mukudai, and R. M. Rowell. 1987. Suppression of creep of wood under humidity changes through chemical modification. Moku. Kogyo 42:504-508.nNorimoto, M., J. Gril, and R. M. Rowell. 1992. Rheological properties of chemically modified wood: Relationship between dimensions and creep stability. Wood Fiber Sci. 24(1):25-35.nOtlesnov, Y., and N. Nikiton. 1977. Trial operations of a commercial installation for modification of wood by acetylation. Proc. Lativ. Agr. Acad. (LSKhA) 130:50-53.nPlackett, D. V., E. A. Dunningham, and A. P. Singh. 1992. Weathering of chemically modified wood: Accelerated weathering of acetylated radiata pine. Holz Roh-Werkst. 50(4):135-140.nRaff, R. A., I. W. Herrick, and M. F. Adams. 1966. Flame retardant wood by in situ radiation polymerization of organophosphorus monomers. Forest Prod. J. 16(2):43-47.nRowell, R. M. 1975. Chemical modification of wood. Advantages and disadvantages. Am. Wood Preservers' Assoc. 71:41-51.nRowell, R. M. 1982. Wood preservation and stabilization by chemical modification of the wood substance. Chemical aspects of wood technology. Maddel. Svens. Traforsknings Inst. A. 772:32-49.nRowell, R. M. 1983a. Bioactive polymer wood composites. In J. J. Roseman and S. Z. Mansford, eds. Controlled release delivery systems. Marcel Dekker Inc., New York, NY and Basel, Switzerland.nRowell, R. M. 1983b. Chemical modification of wood. Forest Prod. Abs. 6(12):363-381. Commonwealth Forestry Bureau, Oxford, UK.nRowell, R. M. 1984. Bonding of toxic chemicals to wood. Appl. Biochem. Biotechnol. 9:447-453.nRowell, R. M., and W. D. Ellis. 1979. Chemical modification of wood: Reaction of methyl isocyanate with southern pine. Wood Sci. 12(1):52-58.nRowell, R. M., W. D. Ellis. 1981. Bonding of isocyanates to wood. ACS Symposium Series 172:263-284.nRowell, R. M., and W. D. Ellis. 1984. Reaction of epoxides with wood. USDA Forest Serv. Forest Prod. Lab. Res. Paper 451. Madison, WI.nRowell, R. M., and D. I. Gutzmer. 1976. Treatment of wood with butylene oxide. U.S. Pat. 3 985 921.nRowell, R. M., S. V. Hart, and G. R. Esenther. 1979. Resistance of alkylene-oxide modified southern pine to attack by subterranean termites. Wood Sci. 11(4):271-274.nRowell, R. M., R. A. Sosott, W. F. DeGroot, and F. Shafizadeh. 1984. Bonding fire retardants to wood. Part I. Thermal behavior of chemical bonding agents. Wood Fiber Sci. 16(2):214-223.nRudkin, A. W. 1950. The role of hydroxyl group in the gluing of wood. Austral. J. Appl. Sci. 1:270-283.nRugevitsa, A. A., and A. E. Embreksha. 1988. Modification of wood with acetylation agents and polyethylene glycol. Trudy Lativ. Sel. Akad. 253:39-44.nRyu, J-Y., M. Takahashi, Y. Imamura, and T. Sato. 1991. Biological resistance of phenol-resin treated wood. Mokuzai Gakkaishi 37(9):852-858.nRyu, J-Y., Y. Imamura, M. Takahashi, and H. Kajita. 1993. Effect of molecular weight of resin in the biological resistance of phenol resin-treated wood. Mokuzai Gakkaishi 39(4):486-492.nSadzhaya, D. N., L. S. Murlguliya, Z. S. Dzvelaya, and R. A. Tsotseliya. 1987. Furniture from alder modified by thermochemical method. Derev. Prom. 9:26-27.nSasaki, T., M. Norimito, T. Yamada, and R. M. Rowell. 1988. Effect of moisture on the acoustical properties of wood. Mokuzai Gakkaishi 34(10):794-803.nShukla, K. S., and R. C. Bhatnagar. 1989. A note on the effect of compression on strength properties of Populus deltoides and Populus ciliata. J. Timb. Dev. Assoc. (India) 35(1):17-20.nShvalbe, K. P. 1988. The problem of freeing acetylated wood from byproducts of the treatment and ways of solving it. Trudy Lativ. Sel. Adak. 253:45-51.nSingh, D., I. Dev, and S. Kumar. 1992. Chemical modification of wood with acetic anhydride. J. Timb. Dev. Assoc. (India) 38(1):5-8.nSingh, S. P., I. Dev, and S. Kumar. 1979. Chemical modification of wood: Vapor phase acetylation with thioacetic acid. Wood Sci. 11(4):268-270.nSingh, S. P., I. Dev, and S. Kumar. 1981. Chemical modification of wood. II. Vapor phase acetylation with acetyl chloride. Intl. J. Wood Preserv. 1(4):169-171.nStamm, A. J., and R. H. Baechler. 1960. Decay resistance and dimensional stability of five modified woods. Forest Prod. J. 10(1):22-26.nStamm, A. J., and R. M. Seborg. 1943. Resin treated wood (Impreg). USDA Forest Serv. Forest Prod. Lab. Rep. No. 1380, Madison, WI.nStamm, A. J., and R. M. Seborg. 1944. Resin treated laminated compressed wood (Compreg). USDA Forest Serv. Forest Prod. Lab. Rep. No. 1381, Madison, WI.nStamm, A. J., H. K. Burr, and A. A. Kline. 1946. Staybwood: Heat stabilized wood. Ind. Eng. Chem. 38(6):630-637.nSubramanian, R. V. 1984. Bioactive wood-polymer composites. In R. M. Rowell, ed. The chemistry of solid wood. ACS Advances in Chemistry Series 207, Am. Chem. Soc., Washington, DC.nSubramanian, R. V., J. A. Mendoza, and B. K. Garg. 1978. Application of organotin polymers to wood preservation. Proc. 5th Intl. Symp. on Controlled Release of Bioactive Materials. 6.8-6.24.nSubramanian, R. V., J. A. Mendoza, and B. K. Garg. 1981a. Wood preservation by organotin polymers. Part I. In situ polymerization of organotin monomers. Holzforschung 35(5):253-259.nSubramanian, R. V., J. A. Mendoza, and B. K. Garg. 1981b. Wood preservation by organotin polymers. Part II. Improvements in strength and decay resistance. Holzforschung 35(6):263-272.nSuida, H. 1930. Acetylating wood. Austrian Pat. 122 499.nTakahashi, M., and Y. Imamura. 1990. Biological resistance of phenol-resin treated wood. Intl. Res. Group on Wood Preservation Doc. No. IRG/WP 3602.nTakahashi, M., Y. Imamura, and M. Tanahashi. 1989. Effect of acetylation on decay resistance of wood against brown rot, white rot and soft-rot fungi. Intl. Res. Group on Wood Preservation Doc. No. IRG/WP 3540.nTarkow, H. 1945. Acetylation of wood with ketene. USDA Forest Serv. Forest Prod. Lab. Rep., Madison, WI.nTarkow, H., A. J. Stamm, and E. C. O. Erickson. 1950. Acetylated wood. USDA Forest Serv. Forest Prod. Lab. Rep. No. 1593, Madison, WI.nVasisht, R. C. 1983. Importance of depositing polymers in wood cell walls for wood treatment. Proc. Am. Wood Preservers' Assoc. 79:129-136.nVidelov, C. L. 1989. Biological degradation resistance of pine wood treated with dimethylol components. Intl. Res. Group on Wood Preservation Doc. No. IRG/WP 3528.nVidelov, Kh. 1986. The resistance of acetylated Scots pine wood to fungus pests. Nauch. Trud. Mekh. Tekh. Drves 30:177-182.nWakeling, A. N., D. V. Plackett, and D. R. Cronshaw. 1992. The susceptibility of acetylated Pinus radiata to mould and stain fungi. Intl. Res. Group on Wood Preservation Doc. No. IRG/WP 1548.nWang, W. H., S. C. Yin, and S. Y. Chen. 1982. A study on the decay resistance of acetylated wood. J. Nanjing Tech. Coll. For. Prod. Nanching Shih. China 4:64-72.nWest, H., and W. B. Banks. 1986. Topochemistry of the wood-isocyanate reaction: An analysis of reaction profiles. J. Wood Chem. Technol. 6(3):411-425.nWitt, A. E. 1980. Acrylic wood in the United States. Third International Meeting on Radiation Processing, Tokyo, Japan.nYano, H., and K. Minato. 1989. Improvement of acoustical properties of violin by the use of chemically modified wood. Proc. Intl. Cong. on Acoustics, Yugoslavia.nYano, H., and K. Minato. 1993. Controlling the timbre of wooden musical instruments by chemical modification. Wood Sci. Technol. 27:287-293.nYano, H., M. Norimoto, and T. Yamada. 1986. Changes in acoustical properties of Sitka spruce due to acetylation. Mokuzai Gakkaishi 32(12):990-995.nYano, H., N. Kanou, and J. Makudai. 1990. Changes in acoustic properties of Sitka spruce due to saligenin treatment. Mokuzai Gakkaishi 36(11):923-929.nYano, H., J. Makudai, and M. Norimoto. 1988. Improvements in the piano pin-blocks. Mokuzai Gakkaishi 34(2):94-99.nZhao, G. J., M. Norimoto, F. Tanaka, T. Yamada, and R. M. Rowell. 1989. Structure and properties of acetylated wood. I. Changes in the degree of crystallinity and dielectric properties by acetylation. Mokuzai Gakkaishi 33(2):136-142.nZhou, H. M., D. Z. Qian, and A. F. Wang. 1985. A study on the physical and mechanical properties of acetylated and untreated bamboo. J. Nanjing Inst. Forestry 3:13-34.n
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.