CHEMICAL COMPOSITION AND MECHANICAL PROPERTIES OF VARIOUS PARTS OF BIRCH WOOD

The article compares mechanical parameters, group chemical compositions, iron content, lipid compositions before and after saponification, moisture, bulk density in three parts of Betula pubescens Ehrh. birch wooden parts: sapwood, false heartwood, heartwood border. strength properties the are worse than those sapwood. border core is sometimes stronger that other parts. Evaluation carried out terms hardness, flexural compression strength. False even more so its border, contain extractives extracted by ethanol, water, alkali solution, methylene chloride less iron. content components: cellulose, lignin, polysaccharides differs, but significantly. heavier Moisture various decreases following order: composition different determined gas-liquid chromatography-mass spectrometry saponification esters. Differences sterols given. An increased monoterpene alcohols arylheptanoids observed at a tree explained amount extractives.