Water Repellent Efficiency of Organic Solvent Extractives from Aleppo Pine Leaves and Bark Applied to Wood

Abstract

Summary Natural wax-like materials were extracted from leaves and bark of Aleppo pine (Pinus halepensis Mill.) by using toluene as organic solvent. Experimental water repellent formulations (WRFs) were prepared using 10% gum rosin as the resin constituent and 0%, 1% and 2% paraffin wax, pine needle/bark extracts or mixtures of paraffin wax and needle/bark extracts in proportion 1 : 1 as hydrophobic substance. All experimental WRFs applied to small, cross-sectional wood specimens of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.). Wood specimens were impregnated by a simple immersion technique and the water repellent effectiveness (WRE) was assessed by using tangential swelling data. Toluene soluble extracts from needles and bark applied to wood provided hydrophobic properties to pine and beech wood specimens but to a lesser degree when compared to paraffin wax. Bark extracts appeared to be stronger hydrophobic materials than needle extracts. Both needle and bark extracts can be successful substitutes for paraffin wax in WRFs up to 50 %. The degree of protection provided by WRFs and the differences between treatments were smaller in pine heartwood and beech sapwood than in pine sapwood.