engleski

Selected Properties of Beech Wood Modified by Citric Acid

The Anti Swelling Efficiency (ASE) and biological durability against brown rot fungus Poria placenta of beech wood modified by Citric Acid (CA) was measured and results are presented. Modification was performed by impregnation with 7.0 % CA and 6.5 % sodium-hypophosphite water solution and 10 hours curing at 140 and 160 °C. In addition, the influence of leaching after modification on ASE and on durability was researched. Weight Percentage Gain (WPG) caused by modification, maximum swelling and mass loss of wood after fungal decay were measured. At increasing curing temperature WPG of modified beech wood decreases. Results showed increased dimensional stability of modified wood for more than 40 % and durability of modified wood to be more than 9 times greater than durability of non-modified wood. Improved durability remained unchanged after leaching, while dimensional stability decreased to 30 % after leaching. Results indicate modification by CA as a promising method, but further research on modification parameters optimisation is needed towards improvement of desired wood properties.

Anti Swelling Efficiency (ASE); Beech wood; Biological durability; Chemical modification of wood; Citric acid; Esterification; Poria placenta

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