Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2005: ¥2,000,000 (Direct Cost: ¥2,000,000)
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Research Abstract |
This project concerns the application boron-based chemicals as environmentally friendly wood-preservatives. Boric acid in the solution of sodium hydroxyl sodium hydroxide was impregnated into wood samples {Cryptomeria japonica and Fagus crenata) and the distribution of boron in wood was visualized by using neutron radiography. This technique was found to be very effective for such purpose and different distribution of boron depending on the wood species was clearly observed. In samples of Cryptomeria japonica, the impregnated boron was located in the region close to the cross sections, whereas almost homogeneous distribution of boron was observed in samples of Fagus crenata. One of the disadvantages of boron-based preservatives is their low fixability in wood. Therefore, impregnation of boric acid with protein, such as whey protein isolate and pig blood serum, followed by the heat treatment was investigated to improve the fixability. The results showed the substantial reduction of leaching. Furthermore, the durability of the wood samples impregnated by the mixture boric acid and pig blood serum was estimated by exposing to white-and brown-rot fungi, Trametes versicolor and Fomitopsis palustris, respectively, for 12 weeks. The mass loss after exposing was less than 3% for white-rot and slightly higher than 3% for brown-rot, respectively, indicating that the combination of boric acid and protein can be one of the promising wood preservatives.
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