Furfurylation as a post-treatment for thermally-treated wood

A Pinus elliottii wood was thermally modified at 200 °C for 2 h and then treated by in situ polymerization with furfuryl alcohol (FA) using a vacuum-pressure process to investigate the influence of furfurylation on a thermally treated wood. The presence of poly(furfuryl alcohol) (PFA) was confirmed by micrographs (SEM and CLSM), which also showed that it reached internal spaces between cracks originated in the previous heat treatment. Chemical changes from furfurylation were detected by infrared spectroscopy, especially in the previously thermally treated wood. The wood modified by the combined thermorretification/furfurylation treatment presented similar esthetic attributes compared to the furfurylated wood. Compared to the isolated treatments, the combined treatment caused an increase of 150–260% in the evaluated mechanical properties and 5–10% in thermal stability. The two-step treated pine wood also showed higher levels of surface and bulk hydrophobicity and resistance against white-rot fungus.