Abstract
This paper reports a new method of detecting urea-formaldehyde (UF) resin penetration into the cell walls of radiata pine (Pinus radiata D. Don) by means of transmission electron microscopy (TEM) in combination with energy-dispersive X-ray spectroscopy (EDXS). The quantifications of penetrated UF resin in the ultrathin cuts of cell walls were realized by detecting nitrogen (N) element by TEM-EDXS. Both line scan and area mapping revealed N in cell walls in contact with resin-filled lumens but not in those in contact with empty lumens. Thus, UF resin had penetrated the cell walls from the lumen side.
Acknowledgments
This work was supported by the Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and Technology (2011-0022112). This work was also financially supported by the Ministry of Education Science and Technology (MEST) and The Korean Federation of Science and Technology Societies (KOFST).
References
Adamopoulos, S., Bastani, A., Gascón-Garrido, P., Militz, H., Mai, C. (2012) Adhesive bonding of beech wood modified with a phenol-formaldehyde compound. Eur. J. Wood Prod. 70: 897–901.10.1007/s00107-012-0620-0Search in Google Scholar
Bolton, A.J., Dinwoodie, J.M., Davies, D.A. (1988) The validity of the use of SEM/EDAX as a tool for the detection of UF resin penetration into wood cell walls in particleboard. Wood Sci. Technol. 22:345–356.10.1007/BF00353324Search in Google Scholar
Frihart, C.R. (2004) Adhesive interaction with wood. In: Fundamentals of Composite Processing. Proceedings of a Workshop, November 5–6, 2003, Madison, Wisconsin. Gen. Tech. Rep. FPL-GTR-149, USDA For. Serv., For. Prod. Lab., pp. 29–53.10.2737/FPL-GTR-149Search in Google Scholar
Gavrilović-Grmuša, I., Dunky, M., Miljković, J., Diporović-Momčilović, M. (2012) Influence of the viscosity of UF resins on the radial and tangential penetration into poplar wood and on the shear strength of adhesive joints. Holzforschung 66:849–856.10.1515/hf-2011-0177Search in Google Scholar
Gierlinger, N., Hansmann, C., Roder, T., Sixta, H., Gindl, W. Wimmer, R. (2005) Comparison of UV and confocal Raman microscopy to measure the melamine-formaldehyde resin content within cell walls of impregnated spruce wood. Holzforschung 59: 210–213.10.1515/HF.2005.033Search in Google Scholar
Gindl, W., Dessipri, E., Wimmer, R. (2002) Using UV-microscopy to study diffusion of melamine-urea-formaldehyde resin in cell walls of spruce wood. Holzforschung 56:103–107.10.1515/HF.2002.017Search in Google Scholar
Gindl, W., Zargar-Yaghubi, F., Wimmer, R. (2003) Impregnation of softwood cell walls with melamine-formaldehyde resin. Bioresource Technol. 87:325–330.10.1016/S0960-8524(02)00233-XSearch in Google Scholar
Hass, P., Wittel, F.K., Mendoza, M., Herrmann, H.J., Niemz, P. (2012) Adhesive penetration in beech wood: experiments. Wood Sci. Technol. 46:243–256.Search in Google Scholar
Hunt, C.G., Jakes, J.E., Grigsby, W. (2010) Evaluation of adhesive penetration of wood fibre by nanoindentation and microscopy. In: BIOCOMP 2010 – 10th Pacific Rim Bio-Based Composites Symposium. October 5–8, 2010. Banff, Alberta, Canada, pp. 216–226.Search in Google Scholar
Kamke, F.A., Lee, J.N. (2007) Adhesive penetration in wood – a review. Wood Fiber Sci. 39:205–220.Search in Google Scholar
Lang, Q., Chen, H.Y., Pu, J.W. (2013) Wood modification using a urea-formaldehyde prepolymer. Wood Fiber Sci. 45:1–8.Search in Google Scholar
Park, B.D., Jeong, H.W. (2011) Hydrolytic stability and crystallinity of cured urea-formaldehyde resin adhesives with different formaldehyde/urea mole ratios. Int. J. Adhes. Adhes. 31:524–529.10.1016/j.ijadhadh.2011.05.001Search in Google Scholar
Rapp, A.O., Bestgen, H., Adam, W., Peck, R.D. (1999) Electron energy loss spectroscopy (EELS) for quantification of cell wall penetration of a melamine resin. Holzforschung 53:111–117.10.1515/HF.1999.018Search in Google Scholar
Singh, A.P., Anderson, C.R., Warnes, J.M., Matsumura, J. (2002) The effect of planning on the microscopic structure of Pinus radiata wood cells in relation to penetration of PVA glue. Holz Roh. Wekst. 60:333–341.Search in Google Scholar
Singh, A.P., Dawson, B.S.W., Rickard, C., Bond, J., Singh, A. (2008) Light, confocal, and scanning electron microscopy of wood-adhesive interface. Microsc. Anal. 22:5–8.Search in Google Scholar
Singh, A.P., Nuryawan, A., Park, B.D. (2013) A novel sample preparation method that enables ultrathin sectioning of urea-formaldehyde resin for imaging by transmission electron microscopy. Microsc. Res. 1:1–6.Search in Google Scholar
Xing, C., Riedl, B., Cloutier, A., Shaler, S.M. (2005) Characterization of urea-formaldehyde resin penetration into medium density fiberboard fibers. Wood Sci. Technol. 39:374–384.Search in Google Scholar
©2015 by De Gruyter
