Properties of water steam-treated maple wood (Acer pseudoplatanus L.).

The hydrothermal treatment of maple (Acer pseudoplatanus L.) wood by steam represents the modification method with the effective heat transfer, which can improve industrially significant properties of wood, i.e. its color, hydrophobicity and subsequently dimensional stability. The maple wood was modified by steam at 125°C during 8 hours, and at pressure of 0.18 MPa. The water contact angle of steam-treated maple wood increased from 44.9° (for untreated maple wood) to 55.3° (for steam-treated maple wood), and the stability of water drop on steam-treated maple wood surface increased. FTIR spectra show an increase in C=O and glycoside bonds concentration on the surface of steam-treated maple wood, but the concentration of C-O-C groups decreased. SEM micro photos confirmed the deformation and shrinking of maple wood cells due to steam treatment. XPS measurements confirmed, that the concentration of oxygen as well as C=O and C-O-O groups on the surface of steam-treated maple wood showed a slight decrease in comparison with pristine wood sample.