Abstract
The article presents preliminary results of the biological durability of oil heat treated (OHT) alder wood (Alnus glutinosa) against pure cultures of rot fungi (Postia placenta and Trametes versicolor) in lab condi- tions. The modifi cation was performed by heating of specimens immersed in soya oil. There were four heating regimes of different duration (6 and 10 hours) at fi nal temperature of 180 and 200 oC. The increase in mass (MI) caused by modifi cation and mass loss of wood caused by fungal decay (ML) were determined. In addition, the natural durability of alder wood was determined and compared to the natural durability of beech wood as the reference wood species. After modifi cation of alder wood at 200 °C, MI was lower than after treatment at 180 °C. MI was also lower after 10 hours of treatment than after 6 hours of treatment. The results showed signifi cantly increased biological dura- bility of modifi ed alder wood against both tested fungi. The effect of OHT on increasing the biological durability of alder wood was higher against the fungus P. placenta. It seems that the fungus T. versicolor favours the remained oil after modifi cation causing higher mass loss. The results showed that alder wood, thermally modifi ed in soya oil by testing regimens, is not suitable for applications in use classes 3-5.
Highlights
It is known that wood specimens lose their mass during thermal modification due to the evaporation of extractives and of volatile compounds formed during thermolysis mainly of hemicelluloses and partly of lignin (Hill, 2006 quoted Shafizadeh and Chin, 1977 and Sudo et al, 1985; Rapp and Sailer, 2001b quoted Sandermann and Augustin, 1963, Kollmann and Fengel, 1965, Topf, 1971 and Tjeerdsma et al 1998; Sidorova, 2009)
Mass increase during oil heat treated (OHT) process is the actual result of mass loss of wood and oil uptake in wood, many authors reported this mass increase as WPG
The increase in mass of modified specimens decreased by increasing the duration of oil heat treatment modification at both tested temperatures
Summary
Wood is a material that can be used for different purposes. It can be degraded by xylophagous microorganisms, xylophagous insects, UV rays, etc. (Hasan, 2010; Beyzar, 2012). It is flammable and hygroscopic, and its dimensions change depending on its moisture content. The above mentioned properties are undesirable and limit the application of wood in comparison to other new materials. There are many processes that can reduce/eliminate the undesired properties of wood. Hill (2006) mentioned some of the first scientists (Tiemann, 1915; Stamm and Hansen, 1937; Stamm et al, 1946; etc.) who have introduced various wood modification processes. Some chemical and thermal modifications have been the most investigated, but only some of them are commercialized
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
