Photodegradation of wood at elevated temperature: Infrared spectroscopic study

The purpose of this investigation was to evaluate the effect of elevated temperature on the photodegradation of solid wood. The work presented here, deals with the changes of infrared spectrum generated by the photodegradation process. Wood samples were irradiated with a mercury vapour lamp. The photodegradation behaviours of conifers and deciduous species were studied at elevated (80 °C) and at ambient (30 °C) temperatures. The infrared data were analysed using the difference spectrum method. The properly calculated difference spectrum gave much more information about the chemical changes than the visual comparison of the absorption spectra measured before and after the irradiation. The results showed considerably greater degradation at 80 °C than at 30 °C. The difference spectra revealed the absorption increase of tree different types of carbonyl groups. Remarkable differences were found between the photodegradation behaviours of softwoods and hardwoods. Poplar belongs anatomically to the hardwoods but its photodegradation properties were between that of hardwoods and softwoods.