Boron compounds are effective biocide, even at low concentrations. In general, they do not have negative influence on human and environment. Unfortunately, boron does not react with wood; therefore, it is subsequently leached from wood in moist environment. To reduce leaching of boron from wood, the boron based solutions were combined with various concentrations of 2 types of the polyethylene wax (We1 and We6) produced by BASF. 10 different solutions of 0,1% or 0,5 % concentrations of boron and 25 % and 50 % concentrations of polyethylene wax emulsions were prepared. Spruce wood samples were impregnated with selected solutions according to the vacuum-pressure process. Samples were conditioned after impregnation under standard conditions, furthermore, part of the samples were dried at temperatures above the melting point of respective wax (135 °C). Leaching of the impregnated wood was performed according to 3 standards (SIST EN 84, SIST ENV 1250-2 and prCEN/TS 15119-1). The results show that the addition of wax emulsion reduces uptake of the preservative solution during leaching. According to the standard prCEN/TS 15119-1, the lowest boron ratios were leached; while at specimens leached according to the standard SIST EN 84, all boron was leached from the specimens, regardless to the presence of the wax emulsion. During leaching of the impregnated wood samples and the samples additionally exposed to drying at 13 °C.
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