植物纤维增强复合材料力学高性能化与多功能化研究

论文从植物纤维的微观结构、化学组成以及力学性能入手,针对植物纤维增强复合材料的界面性能,综述了国内外采用植物纤维表面处理方法来提升复合材料力学性能的研究进展,分析了所遇到的瓶颈,并进一步从复合材料结构设计的角度出发,充分利用植物纤维独特的多层次、多尺度的微观结构特点,通过揭示植物纤维增强复合材料多层次、多尺度的界面力学损伤破坏机制,实现了植物纤维增强复合材料的界面调控和力学高性能化.在此基础上,提出了植物纤维增强复合材料兼顾阻燃和声学性能的结构设计原则和特有的界面力学研究方法.此外,也介绍了相关基础研究成果在航空、轨道交通等领域的示范应用,并针对实现绿色复合材料的结构功能一体化的应用提出了未来研究方向.

High Mechanical Performance and Multi-functionalities of Plant-fiber-reinforced Composites

During the past decade, plant fibers have been thrust into the global spotlight as environment-friendly materials with attractive advantages of low cost, renewability and biodegradability, and have become promising alternatives to traditional synthetic fibers in making fiber-reinforced composites owing to their interesting mechanical and physical properties. However, the limited benefits of the mechanical properties of plant-fiber-reinforced composites (PFRCs) become the bottleneck for their large-scale industrial applications. As we all know, the mechanical performances of composite materials are largely dependent on their interfacial properties owing to the decisive role of the interface in composite structure design. The poor interfacial bonding between hydrophilic plant fibers and hydrophobic polymer matrices is one of the main reasons for the unsatisfactory mechanical properties of PFRCs. In this paper, the unique microstructure, chemical composition and mechanical properties of plant fibers were introduced, together with a review of the latest research progress in improving the interfacial mechanical properties of PFRCs by fiber surface modifications. The limitative effects of the reported improvements by ignoring the hierarchical structure of plant fibers were then analyzed and discussed. Furthermore, the distinct multi-layer and multi-scale microstructure characteristics of plant fibers were considered from the point of views of structural design and manufacturing of the composites. Hybrid technology and nano-modification techniques were employed to design and optimize the interfacial properties of PFRCs. The improved interfacial properties and high mechanical performances of PFRCs were achieved by fully taking advantages of their multi-layer and multi-scale interfacial failure behaviors and damage mechanisms. Based on this, the structural design principles focusing on the mechanical properties, flame-retardant properties and acoustic properties of PFRCs were proposed. In addition, the demonstration applications of the above fundamental research findings on the high mechanical performances and multi-functionality of PFRCs in aviation, railway transportation and automotive industries were introduced. Finally, some suggestions on future research were put forward for achieving the structural and functional integrated green eco-composite materials, so that the large-scale real applications of PFRCs in the fields of aerospace, railway transportation, automotive engineering, civil infrastructures, and so on could be fulfilled. At the same time, expansions of the theories on multi-scale mechanics of composite materials could be expected.