Influence of wood modification with polyethylene glycol and various carboxylic acids on the dimensional stability of beech wood ( Fagus sylvatica )

The goal of this study was the fixation of water-soluble polyethylene glycol (PEG) into the wooden cell wall. The dimensional stability of beech wood (Fagus sylvatica) modified with PEG400 and various carboxylic acids (1,2,3,4-butanetetracarboxylic acid (BTCA), citric acid (CA), malic acid, pyromellitic acid, tartaric acid, L-glutamic acid hydrochloride, ethylene diamine tetraacetic acid disodium salt dihydrate, trans-aconitic acid, maleic acid and itaconic acid) was examined. Investigations of anti-swelling efficiency (ASE), weight-percent gain (WPG) and bulking effect were made. Both the highest dimensional stabilization (values of ASE at the end of examination between 37 and 40%) and the best fixation of the chemicals in the wood (total loss of WPG between 37 and 38%) were achieved with combinations of BTCA/PEG and CA/PEG. The variants impregnated without PEG had lower bulking values. Successful modification of wood seems to be possible with BTCA, CA and malic acid in combination with PEG400.