Comparison of UV and confocal Raman microscopy to measure the melamine-formaldehyde resin content within cell walls of impregnated spruce wood

摘要

The dimensional instability and susceptibility of wood to biological attack have put wood products under pressure in a number of markets. Therefore, improvement of these undesirable wood properties through chemical and thermal wood modification has been the subject of research for many years. For chemical wood modification a number of substances have been tested with varying success (e.g., Matsuda 1996). In addition to true chemical modification, in which wood is denatured, infiltration of wood with polymers is another possible way to improve certain properties. Melamine-formaldehyde (MF) is one of the hardest and stiffest isotropic polymeric materials (Hags-trand 1999) used in decorative laminates, moulding compounds, adhesives, coatings and other products. Impregnation of solid wood with water-soluble MF resin has led to a significant improvement in surface hardness and elasticity (MOE) (Inoue et al. 1993; Miroy et al. 1995; Deka and Saikia 2000; Deka et al. 2002). On the cellular level, an increase in the elastic modulus and longitudinal hardness of MF-infiltrated spruce cell walls was shown using nano-indentation (Gindl and Gupta 2002).