Infrared Studies of “Hard” and “Soft” Woods

FT-IR spectra of 24 different woods have been studied with the use of whole wood pieces and a diffuse reflectance accessory. Three absorptions have been identified, the positions or relative intensities of which are characteristic of the holocellulose/lignin ratio or of the type of lignin present in the wood. These spectral features serve as useful indicators to distinguish between “soft” or “hard” woods.