Mechanical Properties of Secondary Wall and Compound Corner Middle Lamella near the Phenol-Formaldehyde (PF) Adhesive Bond Line Measured by Nanoindentation

Abstract:

To find out the penetration of PF into the wood cell wall and its effects onthe mechanical properties in the cellular level, the elastic modulus and hardness of secondary wall (S₂ layer) and compound corner middle lamella (CCML) near PF bond line region were determined by nanoindentation. Compare to the reference cell walls (unaffected by PF), PF penetration into the wood tissues showed improved elastic modulus and hardness. And the mechanical properties decreased slowly with the increasing the distance from the bond line, which are attributed to the effects of PF penetration into S₂ layer and CCML. The reduced elastic modulus variations were from18.8 to 14.4 GPa for S₂ layer, and from10.1 to 7.65 GPa for CCML. The hardness was from 0.67 to 0.52 GPa for S₂ layer, and from 0.65 to 0.52 GPa for CCML. In each test viewpoint place, the average hardness of CCML was almost as high as that of S₂ layer, but the reduced elastic modulus was about 50% less than that of S₂ layer. But the increase ratio of mechanical properties was close. All the results showed PF penetrates into the CCML. The penetration behavior and penetration depth from bond line were similar in both S₂ layer and CCML.

• Periodical: Advanced Materials Research (Volumes 236-238)
• Pages: 1746-1751
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.236-238.1746
• Online since: May 2011
• Authors: Kun Liang, Guan Ben Du, Omid Hosseinaei, Si Qun Wang, Hui Wang
• Keywords: Compound Corner Middle Lamella, Nanoindentation, Phenol–Formaldehyde

References

[1] W.C. Oliver and G.M. Pharr: J. Mater. Sci. Vol. 7 (1992), p.1564

[2] W. Gindl, A. Sretenovic, A. Vincenti and U. Muller: Holzforschung. Vol. 59 (2005), p.307

[3] A.P. Singh, C.R. Anderson, J. M. Warnes and J. Matsumura: HolzRoh Werkst Vol. 60 (2002), p.333

[4] M. Dunky and P. Niemz: Holzwerkstoffe und Leime, Technologie und Einflussfaktoren (Springer-Verlag, Berlin 2002).

DOI: 10.1007/978-3-642-55938-9_2

[5] H. Saiki, T. Goto and T. Sakuno: Mokuzai Gakkaishi Vol. 21 (1975), p.283.

[6] M. Sernek, J. Resnik and F. A. Kamke: Wood Fiber Sci. Vol. 31 (1999), p.41

[7] C. J. Buckley, C. Phanopoulos, N. Khaleque , A. Engelen, M.E.J. Holwill and A.G. Michette: Holzforschung Vol. 56 (2002), p.215

DOI: 10.1515/hf.2002.035

[8] W. Gindl and H.S. Gupta, Compos. Sci. Technol. Vol. 33 (2002), p.1141

[9] W. Gindl, T. Schoberl and G. Jeronimidis: Int. J. Adhes. Adhes. Vol. 24 (2004a), p.279

[10] W. Gindl, T. Schoberl and G. Jeronimidis: Int. J. Adhes. Adhes. Vol. 24 (2004b), p.535

[11] J. Konnerth and W. Gindl: Holzforschung. Vol. 60 (2006), p.429

[12] J. Konnerth, A.Valla and W. Gindl: Applied Physics A Vol. 88 (2007), p.371

[13] R. Wimmer and B.N. .Lucas: IAWA Journal Vol. 18(1) (1997), p.77

[14] W.Gindl: Holz Roh Werkst. Vol. 59 (2001), p.211

[15] R.E. Mark: Cell wall mechanics of tracheids (Yale University Press, New Haven, London 1967).