Studies on accelerated ageing procedures with TBTO-treated wood
J Jermer, M-L Edlund, B Henningsson, W Hintze
The efficacy of various procedures for accelerated ageing of organotin based wood preservatives in treated wood has been investigated. It was found that leaching of the treated wood samples in water according to the European Standard EN 84 was not satisfactory for organotin based preservatives and is probably also unsuitable even for other types of organic solvent preservatives. Keeping tributyltin oxide (TBTO) treated samples in a heating cabinet at 70°C for five weeks, however, had a considerable effect on the breakdown of TBTO and the subsequent decay test. Therefore, an ageing procedure involving a heating period should be considered for all organic solvent wood preservatives. The investigation also confirmed that elevated temperatures accelerate the degradation of TBTO and that there is a strong correlation between the percentage of TBTO in the wood and its resistance against decay.
Keywords: ACCELERATED AGEING; ORGANOTINS; PERMANENCE; LEACHING; STANDARDS; EVAPORATION; DECAY; TEMPERATURE; TEST METHODOLOGY; TBTO; EN 84