Effect of chemical modification on water absorption, dimensional stability and biological durability of wood

Abstract

In this study, effect of chemical modification using with acetic, phthalic and propionic anhydrides on water absorption, dimensional stability and biological resistance of wood was studied. For this purpose, Scots pine (Pinus sylvestris L.) wood samples were treated with the anhydrides and heated at 120° C during 2, 4 and 8 hours after treatment. Chemical changes in wood were investigated with FT-IR. Dimensional stability and water absorption rates of samples were determined by weighting the samples and measuring the dimensions during 14 days in water submersion test. Decay test was performed using a brown rot fungus, Coniophora puteana for 3 months on both leached and unleached samples. According to results, water absorption rate of treated wood was lower than that of untreated controls. The best results for anti-shrink efficiency were found in propionic, acetic and phthalic anhydride treatments, respectively. The weight loss of samples exposed to C. puteana was found as 34% and 37% for unleached and leached controls, respectively. The weight loss values were in a range of 0-2.1% and 0.5-7.6% for unleached and leached modified samples, respectively. Propionic anhydride showed better decay resistance against decay fungus compared to other anhydrates.