Glue-wood interaction

Still Open for debate [20, 21], The contents of water and hydroxyl groups are very high in EPI adhesive gluelines, hence the probability of reaction between isocyanate and hydroxyl groups in the wood is most likely very low. The adhesion between the glue and the wood will, however, he improved by ionic interactions and mechanical and chemical bonds, e.g., hydrogen bonds [4, 6]. 

It has been found that IR imaging enables visualizing the distribution of not only wood compounds but also wood particles in the polymer matrix within wood-plastic composites (Figure 6.17) [107]. The interaction at the interphase between wood and polymers, glue, or paint is often critical for product performance and can be investigated accurately using IR spectroscopy [99]. 

---