Improvement of electrical properties of wood by combination with ceramics

与陶瓷结合改善木材的电性能

• 批准号: 04660182
• 负责人: SOBUE Nobuo
• 金额: $ 1.34万
• 依托单位: Shizuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04660182/
• 关键词: Wood-ceramic composites; Metal alkoxides; Electrical properties; Carbonization; Addition of water glass; Resistivity; 熱伝導率; 焼成温度; セラミックスー木材複合化; チタン酸ナマリ; ジルコン酸ナマリ

This project deals with improvement of electrical properties of wood by forming wood-ceramics composites which have characteristic piezoelectricity and dielectricity and by carbonization of wood based materials which contain inorganic composites in order to control electrical and physical properties of the carbonized wood based material.A sol-gel process method was applied in order to form wood-inorganic composites. Metal alkoxides of Pb-Ti and Pb-Zr composites were impregnated in wet-sol state. Water glass and glassy balloon named shirasu balloon were added between 5 to 40 % in content to wood powder, and it was formed by using powder phenolic resin under pressure at 190ﾟC.The carbonization was made at 500 and 800ﾟC.The sedimentation of object ceramics was succeeded by the sol-gel method, but the desired improvement of electrical properties was not enough, because the temperature for aging of the gel was not enough to crystallize the object materials. However, the temperature 150ﾟC was the limit to prevent the thermal degradation of wood.The electrical resistivity of the carbonized materials depended on the temperature of carbonization. The resistivity was above 1 MOMEGA・cm by the treatment of 500ﾟC, and below 1 OMEGA・cm by the treatment of 800ﾟC.It increased remarkably by adding the small amount of the water glass, below 5% incontent. In the case of glass balloon, it increased above lMOMEGA・cm by adding 40% in content. Thermal conductivity was 0.1-0.2 W・m^<-1>・K^<-1>, which is almost equivalent to that of solid wood whose density is almost same. It was proved that the addition of inorganic substance was efficient to control resistivity of carbonized wood materials.As a future approach, the carbonization of the composites which are composed of wood powder and ceramics powder whose electrical and magnetic properties are characteristic will be efficient.

该项目通过形成具有压电和介电特性的木陶瓷复合材料，以及通过对含有无机复合材料的木基材料进行碳化，以控制碳化木基材料的电学和物理性能，来改善木材的电性能。采用溶胶-凝胶法制备木-无机复合材料。以湿溶胶方式浸渍Pb-Ti和Pb-Zr复合材料的金属醇氧化物。在木粉中加入5 ~ 40%含量的水玻璃和shirasu玻璃球，在190℃的压力下用粉状酚醛树脂制成。在500和800℃下进行炭化。溶胶-凝胶法成功地完成了物体陶瓷的沉积，但由于凝胶老化的温度不足以使物体材料结晶，因此电性能的改善不够理想。然而，150℃是防止木材热降解的极限温度。炭化材料的电阻率与炭化温度有关。500c处理的电阻率在1 ω·cm以上，800c处理的电阻率在1 ω·cm以下。加入少量水杯，含量在5%以下时，其含量显著增加。以玻璃球囊为例，通过添加40%的含量，它增加到1momega·cm以上。导热系数为0.1-0.2 W·m^<-1>·K^<-1>，与密度几乎相同的实木几乎相当。实验证明，无机物的加入对炭化木质材料的电阻率控制是有效的。木粉和陶瓷粉组成的复合材料具有良好的电、磁性能，其碳化是未来的发展方向。