植物生物质是纤维素纤维的主要来源，所提取的不同尺度纤维广泛用于复合材料、纺织、造纸等领域。生物质非纤维素化学成分降解及部分细胞解构是化学法分离提取纤维的必经过程，对其化学成分在细胞水平上富集规律和降解行为的深入了解是设计不同尺度生物质纤维分离的关键因素。尽管生物质化学成分的降解特性已有长期深入的研究，但生物质纤维分离过程中不同尺度纤维内和纤维间化学成分分布和迁移规律，以及其降解特征尚不清晰，制约了生物质纤维精准分离技术的发展。本研究选取四种有代表性的生物质原料，对其进行不同尺度的纤维制备，使用FTIRM和TOP-SIMS等技术在微米尺度上对不同尺度的生物质纤维进行结构解析及化学成分分布研究，建立单纤维和束纤维化学成分分布模型；并获取纤维进一步分离时化学成分的分布变化参数，探索不同尺度纤维的化学成分降解规律，揭示纤维结构和化学分布影响化学成分降解行为的机制，为植物多尺度纤维开发提供指导信息。

Plant biomass is the main source of cellulose fibers. The extracted fibers of different sizes are widely used in composite materials, textiles, papermaking and other fields. Degradation of non-cellulosic chemical components of biomass and decomposition of some cells are the necessary process for chemical separation and extraction of fibers. A thorough understanding of the enrichment regularity and degradation behavior of the chemical components at the cellular level is the key factor for designing the separation of biomass fibers at different scales. Although the degradation characteristics of biomass chemical components have been studied for a long time, the distribution and migration of chemical components within and between fibers at different scales and their degradation characteristics are still unclear, which restricts the development of precise separation and extraction technology of biomass fibers. In this study, four representative biomass raw materials are selected to prepare fibers of different sizes. FTIRM and TOP-SIMS techniques are used to analyze the structure and chemical composition distribution of biomass fibers of different sizes at micron scale, and the chemical composition distribution models of single fibers and fiber bundles are established. Then further obtain the distribution parameters of chemical components when the fibers are separated, explore the degradation regularity of chemical composition of different scale fibers, reveal the mechanism of fiber structure and chemical composition distribution affecting the degradation behavior of chemical composition, and provide guidance information for the development of plant multi-scale fibers.