Photodegradation of wood at elevated temperature: colour change.

The purpose of this investigation was to evaluate the effect of elevated temperature on the photodegradation of solid wood. The work presented here, dealt with the changes of colour during the degradation process. Wood samples were irradiated by mercury vapour lamp at 80°C and at 30°C to screen out the effect of thermal decomposition during photodegradation.

Thermal degradation of wood during photodegradation.

In this study, wood samples were exposed to light irradiations (direct sunlight, xenon lamp, mercury vapour lamp) and thermal treatments were carried out in dry- and in humid conditions at 90°C. One part of the samples was covered by an aluminium plate during light irradiation. The samples under the aluminium plate also suffered considerable chemical changes, monitored by infrared technique and colour measurement.