Technical Note: Effect of Epoxy Embedment on Micromechanical Properties of Brown-Rot-Decayed Wood Cell Walls Assessed with Nanoindentation
Keywords:Brown-rot decay, softwood, nanoindentation, resin embedding
AbstractMechanical properties of brown-rot-decayed wood cell walls were evaluated using a nanoindentation technique. Epoxy resin is a typical medium for the sample embedding process in nanoindentation. It is assumed that the embedding process does not affect cell wall properties or that any effects are similar for different samples. As part of an investigation of microscale mechanical effects of brown-rot in wood, we applied nanoindentation to cell walls of decayed and nondecayed pine wood samples. For epoxy-embedded samples, there were no differences in modulus and hardness for control and decayed samples. However, for unembedded samples, significant differences were found between control and decayed samples. These results indicate that the epoxy-embedding process may confound micromechanical testing results. We speculate that in this case, epoxy resin penetrated and reinforced the cell wall of decayed samples.
Chirkova J, Irbe I, Andersons B, Andersone I (2006) Study of the structure of biodegraded wood using the water vapour sorption method. Int Biodeterior Biodegrad 58 (3-4):162-167.nCowling EB (1961) Comparative biochemistry of decay of sweetgum sapwood by white-rot and brown rot fungi. USDA Tech Bull No 1258. 75 pp.nCowling EB, Brown W (1969) Structural features of cellulosic materials in relation to enzymatic hydrolysis. Pages 152-187 in GJ Hajny and ET Reese, eds. Cellulases and their applications. Adv Chem Series 95. American Chemical Society, Washington, DC.nCurling SF, Clausen CA, Winandy JE (2002) Relationships between mechanical properties, weight loss and chemical composition of wood during incipient brown-rot decay. Forest Prod J 52(7/8):34-39.nFengel D (1967) Ultramicrotomy, its application in wood research. Wood Sci Technol 1(3):191-204.nFlournoy DS, Kirk TK, Highley TL (1991) Wood decay by brown-rot fungi: Changes in pore structure and cell wall volume. Holzforschung 45(5):383-388.nGindl W, Gupta HS (2002) Cell wall hardness and Young's modulus of melamine-modified spruce wood by nanoindentation. Compos Part A-Appl S 33(8):1141-1145.nGindl W, Gupta HS, Schöberl T, Lichtenegger HC, Fratzl P (2004a) Mechanical properties of spruce wood cell walls by nanoindentation. Appl Phys A-Mater 79 (8):2069-2073.nGindl W, Schöberl T, Jeronimidis G (2004b) The interphase in phenol formaldehyde and polymeric methylene diphenyl-di-isocyanate glue lines in wood. Int J Adhes Adhes 24(4):279-286.nGindl W, Schöberl T (2004) The significance of the elastic modulus of wood cell walls obtained from nanoindentation measurements. Compos Part A-Appl S 35(11):1345-1349.nGoodell B (2003) Brown-rot fungal degradation of wood: Our evolving view. Pages 97-118 in B Goodell, DD Nicholas, and TP Schultz, eds. Wood deterioration and preservation: Advances in Our Changing World. American Chemical Society Symposium Series 845, Washington, DC.nHowell C, Hastrup ACS, Goodell B, Jellison J (2009) Temporal changes in wood crystalline cellulose during degradation by brown rot fungi. Int Biodeterior Biodegrad 63(4):414-419.nJakes JE, Frihart CR, Beecher JF, Moon RJ, Stone DS (2008) Experimental method to account for structural compliance in nanoindentation measurements. J Mater Res 23(4):1113-1127.nJayme G, Fengel D (1961) Beitrag zur Kenntnis des Feinbaus der Frühholztracheiden Beobachtungen an Ultradünnschnitten von Fichtenholz. Holz Roh Werkst 19(2):50-55 [in German with summary in English].nKonnerth J, Gierlinger N, Keckes J, Gindl W (2009) Actual versus apparent within cell wall variability of nanoindentation results from wood cell walls related to cellulose microfibril angle. J Mater Sci 44 (16):4399-4406.nKonnerth J, Valla A, Gindl W (2007) Nanoindentation-mapping of a wood-adhesive bond. Appl Phys A-Mater 88(2):371-375.nMeng Y (2010)Methods for characterizing mechanical properties of wood cell walls via nanoindentation. MS thesis, University of Tennessee, Knoxville, TN. 141 pp.nOliver WC, Pharr GM (1992) An improved technique for determining hardness and elastic-modulus using load and displacement sensing indentation experiments. J Mater Res 7(6):1564-1583.nSchwarze FWMR, Engels J, Mattheck C, Linnard W (2000) Fungal strategies of wood decay in trees. Springer-Verlag, Berlin, Germany. 185 pp.nTze WTY, Wang S, Rials TG, Pharr GM, Kelley SS (2007) Nanoindentation of wood cell walls: Continuous stiffness and hardness measurements. Compos Part A-Appl S 38 (3):945-953.nWimmer R, Lucas BN, Oliver WC, Tsui TY (1997) Longitudinal hardness and Young's modulus of spruce tracheid secondary walls using nanoindentation technique. Wood Sci Technol 31(2):131-141.nWinandy JE, Morrell JJ (1993) Relationship between incipient decay, strength, and chemical composition of Douglas-fir heartwood. Wood Fiber Sci 25(3):278-288.nZimmermann T, Thommen V, Reimann P, Hug HJ (2006) Ultrastructural appearance of embedded and polished wood cell walls as revealed by atomic force microscopy. J Struct Biol 156(2):363-369.n
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