Micro-distribution and fixation of a rosin-based micronized-copper preservative in poplar wood

Abstract

A new rosin-based micronized-copper preservative containing rosin sizing agent and copper sulfate was investigated. The effect of rosin sizing agent on the distribution and fixation of copper in treated wood was determined. Poplar wood samples that had been treated with the rosin-based micronized-copper preservatives were analyzed by a scanning electron microscope equipped with an energy dispersive X-ray analyzer (SEM-EDS). Copper was detected both in the lumens and the cell walls of the treated wood. The atomic absorption spectrophotometry (AAS) analysis showed that the leaching of copper from wood impregnated with rosin-based micronized-copper preservatives was significantly reduced. Moreover, SEM-EDS proved that most of the copper was still in the treated wood after leaching. The X-ray photoelectron spectrometer (XPS) analysis also indicated that copper in the treated wood was Cu(II). After leaching, treated wood blocks were exposed to the decay fungi Gloeophyllum trabeum and Trametes versicolor. Results showed that the use of rosin-based micronized copper to impregnate wood can protect wood against fungal attack as effectively as ammoniacal copper quaternary (ACQ).