按照木质粉末高密度滑动轴承制备工艺(160℃,70 MPa,保温、保压30 min),对小于350μm的杨木粉末的三级抽提物纤维素-木质素-半纤维素复合体、纤维素-木质素复合体和纤维素实施无胶温压成形,分析温压前后各样粉的微观结构、物相、官能团、纤维素结晶度等的变化情况。结果表明,木质粉末中的纤维素、半纤维素、木质素在无胶温压成形过程中均发生了化学反应,产生了化学链接。温压成形可改善各级抽提物的化学结构,提高其化学结合程度与纤维素结晶度,使其一体化、致密化、塑化程度与热稳定性明显提高。综合温压成形工艺成本与温压材料特性表征,以杨木粉末为基材制备生物质功能材料(如滑动轴承)宜采用一级抽提物或原粉。
According to the preparation technology of woody powder high density sliding bearing(160 ℃ under 70 MPa for 30 min),self-bonding warm compaction was implemented on the three grade extractives of poplar powders in particle size small than 350 μm(cellulose-lignin-hemicellulose complex,cellulose-lignin complex and cellulose),the changes of microstructure,phase,functional groups,cellulose crystallinity etc of every sample powders were analyzed.The results show that all the cellulose,hemicellulose and lignin of woody powder occurre chemical reaction during the forming process,the chemical link formed.Self-bonding warm compaction process not only improves the chemical structures of all grades extractives,but also increases their chemical combined extent and cellulose crystallinity,the degree of integration,desification,plasticization and thermal stability are significantly strengthened.Synthetically analyzing the cost of warm compaction process and characterization of warm compaction materials,it is revealed that taking poplar powder as substrate,the biological functional materials(such as sliding bearing) are prepared by the first grade extractive or raw powder.