Treatment of scots pine wood with oil in water and water in oil emulsion systems: effects on boron leaching and water absorption

Abstract

The aim of this study was to investigate the water absorption and water repellent efficiency of oils and oil water emulsions [oil-in-water (O/W) and water-in-oil (W/O)] and possibilities of reducing the amount of boron leaching from treated wood. Scots pine wood samples treated with waste or sunflower oil and water formulations contained 3%BA. The level of water absorption and water repellent efficiency were determined with cyclical wetting tests, total of 14 days. The results show that emulsion systems could decrease water absorption of wood and improve water repellent efficiency compared to those of only boron treated and untreated control ones. Especially W/O emulsion systems showed almost equal water repellent efficiencies as with pure oil even though retentions of the emulsion in wood were lower than pure oil’s retentions. After leaching period, amount of boron remained in treated wood with W/O formulation gave some promising results to a degree of 35% based on the initial boron level whereas samples treated with O/W formulations did not show good performance to keep the boron in wood. The W/O emulsion systems might be a potential method to decrease boron leaching and increase water repellency of wood.