STUDIES TO IMPROVE SOME PROPERTIES OF POP LAR WOOD BY IMPREGNATION WITH WATER-SOLUBLE RESINS

Studies with popular (Populus spp.) were performed to elucidate whethe r some technological properties and the resistance against fungal atta ck could be improved by impregnation with water-soluble resins. The re sults showed that swelling and shrinkage of poplar wood may considerab ly be reduced by a treatment with resins. The anti-shrink-efficiency ( ASE) strongly depends upon the resin type. An air-curing acrylate-modi fied alkyd resin and an air-curing alkyd/polybutadiene oil system prod uced the best effects. Additions of wood preservatives to the resins f urther improved the ASE. Some disadvantages of the tested resins may b e seen in their leachability with consequent loss of the dimension-sta bilizing effects. The resins by themselves do not reveal fungistatic p roperties but an impregnation of poplar wood with these materials led in all cases to a better durability against Coniophora puteana and Cor iolus versicolor. Leaching procedures influenced the durability in var ious ways. With resin/fungicide combinations, a good resistance agains t C. versicolor could be reached even after leaching. SEM and EDAX met hods were used to localize the resins in the cell walls and lumina and to detect the growth of mycelium in the specimens.