Exposure of Pinus elliottii wood treated with titanium dioxide to the fungus Postia placenta and photodegradation

Abstract

It was impregnated commercial titanium dioxide into Pinus elliottii wood, aiming to increase its durability against the attack of brown rot fungus Postia placenta and photodegradation caused by ultraviolet radiation. The samples were put under 8 bar pressure for 3 hours at different concentrations of TiO2 (0.5%, 0.25%, 0.124% and 0%-control). To evaluate the effect of the fungus on the wood, the test was carried out according to ASTM D2017-05 and UNE-EN 113:1996 with modifications. The photodegradation was performed by exposing a tangential section to ultraviolet radiation for 400 hours, and the colorimetric parameters were periodically evaluated. Statistically, the treatments with TiO2 did not differ among themselves, but were much lower than the control, showing the effectiveness of this product in protecting the wood against the attacks of degraders. As for the photodegradation, the treated wood remained practically unchanged, differently from the control that had a darkening accelerated mainly in the first 50 hours. With this information, it can be stated that TiO2 treated wood is able to hinder the fungus access to the cell wall, to inhibit its growth and to create a barrier that protects the polymers from photodegradation, increasing its durability and emerging as a potential alternative for wood treatment.