Technical Note: A Preliminary Study on the Bending Stiffness of Chemically Treated Wood Material for Structural Composite Lumber


  • T. Eric McConnell
  • Sheldon Q. Shi
  • Rubin Shmulsky


This research explored the effect of a chemical treatment on the stiffness of three southern hardwoods, yellow-poplar, sweetgum, and red oak, with the aim of broadening the potential feedstocks for structural composite lumber. Water-saturated 3 × 15 × 150 mm samples from each species were heated at 150° C for 30 min in three solutions: 1.0% H2SO4, water, and 1.0% NaOH. The specimens were nondestructively tested by static bending before and after treatment, and the reduction in modulus of elasticity (MOE) was determined. A significant interaction was present between the species and solutions. The trend in mean response for each species was generally a quadratic function of the solution. MOE was reduced the least for each species exposed to water. Sweetgum had a higher reduction in MOE in all three solutions, being significantly greater in the alkaline solution.


AWPA (2008) Accelerated method of evaluating wood preservatives in soil contact. E-23-07. American Wood Protection Association, Birmingham, AL.nBongers HPM, Beckers EPJ (2003) Mechanical properties of acetylated solid wood treated on pilot plant scale. Page 59 in Callum Hill wood modification—Chemical, thermal, and other processes. John Wiley & Sons, West Sussex, UK.nCaril CG (1996) Review of thickness swell in hardboard siding—Effect of processing variables. Gen Tech Rep FPL-GTR-96. USDA Forest Prod Lab, Madison, WI.nHagglund E (1951) Chemistry of wood. Academic Press, New York, NY. 631 pp.nHalligan AF (1970) A review of thickness swelling in particleboard. Wood Sci Technol 4(4):301-312.nHse CY (1975) Properties of flakeboards from hardwoods growing on southern pine sites. Forest Prod J 25(3):48-53.nLarmore FD (1959) Influence of specific gravity and resin content on properties of particleboard. Forest Prod J 9(4):131-134.nLarsson P, Simonson R (1994) A study of the strength, hardness, and deformation of acetylated Scandanavian softwoods. Page 59 in Callum Hill wood modification—Chemical, thermal, and other processes. John Wiley & Sons, West Sussex, UK.nMitchell PH (1988) Irreversible property changes of small loblolly pine specimens heated in air, nitrogen, or oxygen. Wood Fiber Sci 20(3):320-355.nParedes JJ, Mills R, Shaler SM, Gardner DJ, van Heiningen A (2009) Influence of hot water extraction on the physical and mechanical behavior of OSB. Forest Prod J 58 (12):56-62.nRowell RM, Tillman A-M, Simonson R (1986) A simplified procedure for the acetylation of hardwood and softwood flakes for flakeboard production. J Wood Chem 6(3):427-448.nSAS (2003) Version 9.1.3. SAS Institute, Cary, NC.nYoungquist JA, Krzysik A, Rowell RM (1986) Dimensional stability of acetylated aspen flakeboard. Wood Fiber Sci 18(1):90-98.n






Research Contributions