The decrease of water sorption is one of objectives of wood acetylation (Ac) with acetic anhydride (AA). The water absorption in acetylated wood might be decreased with rapeseed (Brassica napus) oil (RSO). Besides RSO might be used as cheap alternative additive to AA to get similar to acetylated wood water anti-absorption property. Four modification schedules were used to modify aspen (Populus tremula L.) wood:
1) acetylation (Ac) with acetic anhydride (AA), 2) Ac with subsequent impregnation with rapeseed oil (Ac+RSO), 3) sequential impregnation with AA and RSO with heat treatment (AA+RSO), and 4) impregnation with RSO at elevated temperature (RSO). Modified and reference wood specimens were tested with cyclic hydrothermal treatment (CHT). Each CHT cycle had 3 treatment stages: wood swelling in hot water at 75 °C, following freezing at -20 °C and drying at 103 °C to evaluate each used modification mode. Duration of the each cycle’s stage was 3 days. Wood specimens were weighted and measured after swelling and drying stages. On the base of water absorption, and wood density alterations analysis the tested modification methods by their efficiency are ranged: Ac + RSO ³ AA + RSO > AC » RSO.
Keywords: acetylation, aspen wood, impregnation, rapeseed oil, water absorption
Authors
Morozovs A.
Department of Wood Processing, Latvia University of Agriculture, Jelgava
Keke A.
Department of Organic Chemistry, Faculty of Chemistry,Rīga
Fisere L
Laboratory assistant Department of Chemistry, Latvia University of Agriculture, Jelgava
Spulle U.
Department of Wood Processing, Latvia University of Agriculture, Jelgava
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