MODIFICATION OF WOOD MATERIALS IN ARTIFIC IAL HOT-SPRING WATER AND THEIR PROPERTIES

The modification of various wood materials has been carried out by soa king samples in the artificial hot spring water prepared by dissolutio n of Yubana (deposits of natural hot spring water from Matsukawa in Iw ate prefecture) in hot distilled water. The treated woods were found t o become lighter in weight and to have a higher porous state compared to those obtained by the same treatment using only hot distilled water . HPLC analysis indicates that the hot spring water after the treatmen t contained both arabinose and xylose in the case of needleleaf trees and only xylose in the case of broad leaf trees. Those saccharides wer e thought to form by the accelerated hydrolysis of wood hemicellulose in the hot spring water. In the treatment of Sugi for 100 hours, 22% o f hemicellulose was decomposed to saccharides in the hot spring water, while 18% of hemicellulose to saccharides in hot water. On the other hands, the amount of lignin in the modified woods was increased about 18 similar to 20% after the treatment, which indicates no dissolution of lignin occurred during the treatment. It was also confirmed that th e swelling property and dimensional stability in moisture atmosphere c an be improved with the decomposition of the non-crystalline parts of wood materials by the treatment using the hot spring water.