各種ケイ酸塩溶液系で調製した無機質複合化木材の無機成分分析
2004 年 53 巻 4 号 p. 388-395
詳細
2004 年 53 巻 4 号 p. 388-395
The presence and distribution particularly of boron compounds among inorganic substances are related greatly to the enhancement of performances such as decay, termite, and fire resistances in wood-mineral composites (WMCs). Regarding ashes obtained by removing an organic matter with heat-burning, the quantitative ratios of inorganic components like silicic acid, boron compounds, and others in composites made using various silicate solution system were investigated by means of the weighing method, X-ray fluorescence analysis, and ICP (inductivity coupled plasma) spectrometry. Also, the silicon concentration in leached solution from WMC specimens was determined by atomic absorption spectrometry. Further, we conducted the decay test to examine the relation between the presence of inorganic compounds and the performance enhancement. The WMCs were prepared by diffusion-penetrating the water glass-boron compound system (double treatment) and the colloidal silica solution system in the sapwood specimens of Sugi (Cryptomeria japonica) in addition to the new impregnating process of water glass-boron acid mixing solution (single treatment).
From the above analyses, the general tendency on the contents of silicic acid, sodium oxide, and boron became clear. There existed a considerable amount of sodium oxide in WMC specimens made with the water glass-boron compound system and the water glass-boric acid mixing solution. It decreased in quantity owing to exudation out of specimen by leaching procedure and hence the relative ratio of silicic acid increased greatly. Almost all of inorganic substances consisted of silicic acid in the colloidal silica solution system and it hardly leached out because of the tight fixation in the specimen. The content of boron could be determined by ICP spectrometry and it decreased considerably in quantity by leaching procedure. However, even a small amount of boron left proved to be very effective to the enhancement of decay resistance from the result of decay test.
