Investigation of temperature effect on fixation of Celcure preservative (ACC) in beech (Fagus orientalis)
A Karimi, M Ghorbani
In this research, the fixation speed of Celcure 2% (ACC) preservative salt, under temperature of 17°C, 27°C and 50°C, on intact and stained wood specimens of beech was investigated. For this purpose, blocks of wood with 5x5x7 cm dimensions were prepared and saturated with 2% ACC concentration by full-cell process. The specimens were put in three incubators at the above-mentioned temperatures. For measuring the percentage of fixation through time, the specimens were extracted by using hydraulic pressure equipment, under 69 Mpa pressure. The pH of extraction was measured with the method of diphenyl Carbazid and by using spectrophotometer. This measurement was done continuously and the amount of 6- valence chromium concentration present in the extract was compared with the amount of chromium concentration in the primary solution and then the percentage of fixation was calculated. The results showed that the decrease in 6-valence chromium is accompanied with increase of pH, this is due to absorption of positive hydrogen ion by 6-valence chromium for reduction to 3-valence chromium and also ion-exchange of active components with wood during the primary phase of fixation. Also, the time necessary for reaching complete fixation in intact and stained wood in the fixation temperature conditions of 17, 27 and 50°C were 1075, 501, 109 hours, respectively. In general, the results showed that temperature has effective role in accelerating of fixation process and in this respect, intact and stained wood did not show significant statistical difference.