• Journal of the Korean Wood Science and Technology
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• v.37 no.5
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• pp.421-425
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• 2009

This research investigates the effect of copper retention on copper leaching in wood treated with copper-based preservatives. Radiata pine (Pinus radiata D. Don) sapwood samples were ground in a Wiley mill equipped with a 20-mesh screen. The ground wood was vacuum-treated with various concentrations of alkaline copper quat (ACQ), bis-(N-cyclohexyl-diazeniumdioxy)-copper (CB-HDO), and copper azole (CUAZ). The treated samples were conditioned at $70^{\circ}C$ and 100% RH for 72 hours. The samples were leached by using the distilled water for four weeks, and the copper contents in each sample were measured by X-ray spectroscopy. As expected, the copper leaching was increased with increasing of copper retention. The copper leaching from the ACQ and CB-HDO treated samples were gradually decreased with increasing copper retention: however, the copper losses from the CUAZ treated samples appeared to be proportionally increased with the increase in copper retention in all retention levels tested. The results indicate that at the conditions of the same copper retention ACQ and CB-HDO treated wood have a better leaching resistance compared to CUAZ treated wood.

• Journal of the Korean Wood Science and Technology
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• v.38 no.5
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• pp.450-456
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• 2010

This research was performed to develop the simple techniques to predict the copper concentration in alkaline copper quat (ACQ), copper azole (CUAZ), and bis-(N-cyclohexyl-diazeniumdioxy)-copper (CB-HDO) solutions. Two simple methods measuring the color due to copper compounds were evaluated by using a spectrophotometer. One is to directly measure the color of the preservative solutions. The other is to measure the color developed on the surface of a treated sample with the preservatives. The $L^*$ of the measured color values appeared to be the most sensitive to the change of copper concentration. The $a^*$ values of the preservative solutions tended to be decreased at above a certain concentration condition, and the $b^*$ values showed no trend with the concentration of copper compounds in preservative solutions. The surface color of the treated samples were changed from bluish to greenish as time passed. Both methods showed the high $R^2$ values of the regression models determined by using the lightness, which suggested that the methods might be applicable in preservative-treatment mills for the easy and fast prediction of the copper concentration.