INFRARED SPECTROSCOPY OF WOOD OF PINE, BIRCH AND OAK, MODIFIED WITH MONOETHANOLA-MINE(N→B)THREEHYDROXYBORATE

Abstract

The article presents the results of IR-spectroscopic study of wood of pine, birch and oak, modified with 50% aqueous solution of monoethanolamine(N→B)threehydroxyborate. IR spectra of the samples of birch and oak, modified by monoethanolamine(N→B)threehydroxyborate havebeen obtained for the first time. It was found that the modifier chemically interacts at room temperature with the reactive groups of the tree species under study; the chemical bonds being formed are hydrolytically stable. It is revealed that the change in the supramolecular structure of the modified wood is associated with a change in the system of hydrogen bonds. It is shown that the in the case of modifyingwith monoethanolamine(N→B)threehydroxyborate, there is no destruction of the aromatic rings of lignin, and the main chains of the macromolecules of cellulose, i.e. modifying is in "soft" conditions. It was found that the modifier interacts with the primary hydroxyl groups of cellulose and carboxyl groups of lignin in the modification of pine wood; when modifying, the wood of birch and oak monoethanolamine(N→B)threehydroxyborate mainly interacts with the carboxyl groups of lignin. The density of the grafting modifier depends on the availability of reactive groups of wood composite, and it decreases with increasing the density of wood. Taking into account that surface grafted compounds determine many properties of wood (specific surface area, water absorption, swelling, bio- and fire-resistance), different grafting density and surface distribution of grafted molecules of modifiers on the surface of wood samples under study will lead to differences in the listed properties of the modified wood materials.