Reducing Moisture Swell of Densified Wood With Polycarboxylic Acid Resin
Keywords:
Dimensional stability, moisture, polycarboxylic acid, swelling, trimellitic anhydride, water, woodAbstract
A water-soluble polycarboxylic acid (PCA) resin was assessed for ability to limit moisture swelling of densified wood. Aspen flakes were treated in 0 (control), 1, 5, 10, and 20% PCA resin solutions and drained for 1, 10, and 20-min time periods. Following treatments, flakes were compressed to roughly 50% strain at 170°C. The PCA content of flakes significantly increased with increasing concentration and drain time. Water absorption and thickness swell of flakes decreased with increasing PCA content. Both water absorption and thickness swell of untreated flakes were over 100%; but for PCA-treated flakes, water absorption and thickness swell as low as 45% and 16%, respectively, were achieved. Irreversible thickness swell decreased with increasing PCA content, while reversible thickness swell remained relatively constant. The swelling coefficient decreased with increasing PCA content, a behavior that often is associated with bulking agents for treated, uncompressed wood. However, dynamic mechanical analysis further suggested that PCA resin acts as a cross-linking agent to stabilize the position of the collapsed cell walls.References
Anderson, R. L., W. W. Cattron, V. F. Smith, Jr., and D. J. Fenoglio. 1998. Polyanhydride cross-linked fibrous cellulosic products and manufacture thereof (Amoco Corp., USA). PCT Int. Appl. WO 9813545 A1 980402.nAnderson, R. L., W. W. Cattron, V. F. Smith, Jr., and D. J. Fenoglio. 1999. Polyanhydride cross-linked fibrous cellulosic products and process for their preparation (BP Amoco Corp., USA). U.S. patent 5981739.nChow, P., Z. Bao, J. A. Youngquist, R. M. Rowell, J. H. Muehl, and A. M. Krzysik. 1996. Properties of hardboards made from acetylated aspen and southern pine. Wood Fiber Sci. 28(2):252-258.nClemons, C., R. A. Young, and R. M. Rowell. 1992. Moisture sorption properties of composite boards from esterified aspen fiber. Wood Fiber Sci. 24(3):353-363.nHsu, W. E., W. Schwald, J. Schwald, and J. A. Shields. 1988. Chemical and physical changes required for producing dimensionally stable wood-based composites. Wood Sci. Technol. 11:281-289.nKelley, S. S., T. G. Rials, and W. G. Glasser. 1987. Relaxation behaviour of the amorphous components of wood. J. Mater. Sci. 22:617-624.nMenard, K. P. 1999. Dynamic mechanical analysis. CRC Press LLC, Boca Raton, FL. 208 pp.nRowell, R. M., S. Kawai, and M. Inoue. 1995. Dimensionally stabilized, very low density fiberboard. Wood Fiber Sci. 27(4):428-436.nStamm, A. J. 1964. Wood and cellulose science. The Ronald Press Company, New York, NY. 549 pp.n
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