二氧化硅/木材复合材料的微观结构与物理性能

为了明确二氧化硅/ 木材复合材料的微观结构与物理性能, 通过EDAX 及XRD 的测定分析了溶胶2凝胶法制备的二氧化硅/ 木材复合材料的微观结构, 通过应力松弛、介电性质、热重、表面显微硬度的测定分析了该材料的物理性能。结果表明: 生成的二氧化硅与增重率呈正相关, 在纤维饱和点以下, 生成的二氧化硅存在于细胞壁中。XRD 衍射峰位置没有改变, 增重率增大, 峰强减弱, 结晶度减小。应力松弛量变小, 材料内部的结合力增强, 分子间产生了交联结合。介电常数值增大, 介电损耗随着频率的增加呈先增加后减小的趋势, 室温下, 出现最大峰值的频率均在log f = 6. 5 Hz 附近。热失重过程中, 快速失重的起始温度提高, 残余质量增加, 表面显微硬度提高。 

Microstructure and physical properties of silicon dioxide/ wood composite

In order to completely know the microst ructure and physical characteristics of silicon dioxide/ wood composites , X-ray diff raction (XRD) and energy dispersive X-ray analyzer ( EDAX) are used for studying the microst ructure of silicon dioxide/ wood composites made by sol-gel. St ress relaxation , dielect ric properties , thermogravimet ry and surface microhardness mensurating methods are used for analyzing their physical properties. Theresult s show that silicon dioxide exist s in the cell wall of wood for silicon dioxide/ wood composites made by thewood of moisture content under the fibre saturation point . Crystallinity decreases , while the mole f raction of silicondioxide increases with the enhancement of mass gain. The position of XRD spect ra peak is the same as the unt reatment . The magnitude of st ress relaxation of silicon dioxide/ wood composites is less than the unt reatment . There isa cross-linking between wood molecule and silicon dioxide. The dielect ric constant decreases , while the dielect ricloss factor increases firstly , then decreases with increasing f requency. The f requency of the dielect ric loss factorreaching the maximum value is in the vicinity of log f = 6. 5 Hz at room temperature. The start temperature of fastthermogravimet ry of the silicon dioxide/ wood composites rises in the thermogravimet ry course , their remainder massincreases in the end , and their surface microhardness increases.