高含量炭增强超高分子量聚乙烯复合材料的界面结合机理

Wood charcoal and ultra high molecular weight polyethylene (UPE) could be used to prepare high strength composite materials. It's a new way to use wood charcoal in the field of new materials with high added value. Because of the poor interfacial bonding of the wood-plastic composites, charcoal powder is used instead of wood fiber as an enhanced phase of the composites. It was found that the charcoal powder has an excellent enhancement effect on UPE. This project is going to start from the micro and nano structure of charcoal powder and UPE, and study the morphology and properties of the two phases. And the effect rule of the structural characteristics of charcoal powder and UPE on the interfacial bonding of the composites is explored. The model theory of the "three dimensional penetrated and binding structure" is proposed. And its strong-toughening influence mechanism on composite materials is proposed. The principle of the high strength of the composites with high charcoal powder filling content (70%-80%) is explored. The effect of the structural characteristics of charcoal powder and UPE on the interfacial bonding is explored. The interfacial bonding mechanism of the wood charcoal/UPE composites (physical/chemical aspects) is revealed. The approach of interface control and its influence on the performance of the system is presented. The achievements of this project will provide a theoretical basis for further study of the structure and interface of the new composite materials. It will provide theoretical guidance for the preparation of composites with the aim of saving polymer resin, which will expand the application of wood charcoal in the field of new composite materials with high added value. Meanwhile, it will provide a scientific basis for expanding the application of wood charcoal in the field of advanced high strength engineering materials.

将木炭粉与超高分子量聚乙烯（UPE）复合制备高强材料，使木炭在高值化新材料领域找到了突破点。本项目针对木塑复合材料界面结合欠佳的问题，用木炭粉替代木纤维作为复合材料的增强相，前期研究发现木炭粉在高含量下对UPE具有极好的增强效果。本项目拟从木炭粉及UPE的微纳观结构切入，研究两相的形态结构及特性，探寻炭粉和UPE的结构特性对界面结合的作用规律。提出“三维穿入捆绑结构”模型理论及其对复合材料的强-韧化影响机制。探究木炭粉高含量下（70%～80%），木炭粉/UPE复合材料实现高强度的原理。揭示木炭粉/UPE复合材料的界面结合机制（物理/化学方面），并提出界面调控的途径及其对性能的影响。本项目研究成果可为深入研究生物质复合材料界面结构、界面结合机理提供理论依据，为提出以节约高聚物树脂为目标的复合材料制备技术提供理论指导，同时为拓展木炭在前沿高强工程材料中的应用领域提供科学依据。

针对木塑复合材料界面结合欠佳的问题，本项目利用生物炭粉替代木纤维作为复合材料的增强相，在炭粉高含量下，实现了复合材料高强度、高分散性。阐明了炭粉超微结构，表面化学状态，炭粉含量、粒径、种类与复合材料性能之间的关系。揭示了炭粉表界面特性、三维穿捆结构对复合材料的强-韧化影响机制。在微观尺度下研究利用物理/化学修饰实现对复合材料的界面调控，揭示了复合材料的界面结合机理。提出炭粉/UHMWPE复合材料可控制备的相关技术，并探究了炭塑复合材料的热稳定性、粘弹性及力学性能。结果表明：（1）炭粉与聚合物基体间有着良好的界面相容性、分散性良好；（2）炭粉和聚合物间形成三维穿捆结构，界面结合效果佳，强度大大提高；（3）采用生物炭改性超高分子量聚乙烯（UHMWPE），改善了UHMWPE的加工性能，可实现炭/UHMWPE复合型材连续加工成型。（4）高含量炭粉的添加显著了提升复合材料的力学性能和热稳定性，当炭粉含量高达70%～80%时，复合材料强度高达60-85MPa。本技术可为节约高聚物树脂为目标的复合材料制备技术提供指导，同时为拓展生物质炭在前沿高强工程材料、高附加值功能性材料的应用提供依据。因该复合材料具有高强度、防潮防虫，减塑固碳等优点，符合生态可持续发展要求，在建筑材料、工程材料、机械工业等领域都有广泛的应用前景。