Copper leaching from copper-ethanolamine treated wood during exposure to terrestrial microorganisms
M Humar, N Thaler, B Lesar
Copper-ethanolamine based wood preservatives are still the most important solutions for protection of wood in ground applications in Europe. Wood in ground is exposed to variety of organisms, which can act synergistically. In order to simulate these conditions in laboratory, Scots pine (Pinus sylvestris) specimens impregnated with copper-ethanolamine preservative of three different concentrations (cCu = 0.125%; 0.25% and 0.5%) were exposed to three different soils according to the ENV 807 procedure for periods between 12 weeks and 32 weeks. After respective periods of exposure, samples were isolated and their mass loss, bending strength and modulus of elasticity were determined. In the final step remaining copper in the samples was determined. The results showed that in spite of the prominent copper leaching, tested copper-ethanolamine treated wood exhibited good performance in ground applications. Furthermore, it is evident, that there is a good correlation between mechanical properties and mass loss determined, regardless of the chemical treatment applied.