Effect of pH regulation on the properties of furfuryl alcohol-modified decorative veneer

Combining decorative and functional elements is an essential trend in the value-added nature of fast-growing wood, which can promote its commercial application in wood-based boards, interior decoration, and furnishings. This study introduces a convenient method for preparing modified veneers that can replace the predominant market colors by adjusting the pH value and furfuryl alcohol (FA) concentration. The physical, mechanical, anti-mildew, and sound insulation properties were systematically evaluated. The results revealed that pH significantly affected color, and the surface bonding strength of all modified veneers met standard requirements. The shear strength, sound insulation properties, and dimensional stability of the plywood made from 70% FA-modified veneer at strong acid conditions were significantly improved, but the bending strength was reduced. Analysis of Variance revealed that pH values and FA concentration significantly affected the color changes. Combined with scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), and Fourier-transform infrared spectroscopy (FTIR) results, it was shown that the distribution of the FA and the interaction between FA and cell wall chemical components were influenced by pH values and furfuryl alcohol concentration, which are likely responsible for the color and property changes.