电晕法处理超高相对分子质量聚乙烯纤维

用电晕法对超高相对分子质量聚乙烯纤维进行了表面处理。利用DPPH检测纤维表面自由基的产生和变化，并用XPS表面元素分析、SEM等方法探讨了纤维表面性能处理前后的变化。实验发现，通过电晕处理后，纤维复合材料的抗剪切强度从未处理的5．98MPa提高到14．3MPa。     

超高分子量聚乙烯纤维表面处理的研究进展

详细介绍了超高分子量聚乙烯纤维的各种表面处理方法 ,如等离子体处理、电晕放电和化学氧化等 ,重点讨论了这些方法对纤维增强复合材料粘结性能和力学性能的影响 ,特别关注了近年来各种表面处理超高分子量聚乙烯纤维技术的进展。     

运用神经网络设计碳纤维织物/环氧复合材料界面性能

提出一种设计碳纤维织物／环氧复合材料界面性能的新方法。利用BP(back propagation)神经网络，建立起工艺参数与复合材料界面性能的关系模型，同时给出了实例用来验征此方法的有效性。     

Damage and permeability in tape-laid thermoplastic composite cryogenic tanks

This work presents a combined experimental and numerical approach to the design and analysis of tape-laid thermoplastic composite cryogenic tanks. A detailed material and defect characterisation of automated tape-laid CF/PEEK is undertaken using optical micrography and 3D X-ray CT (computed tomography) as well as cryogenic testing to investigate damage formation. Resulting material data is used as input for a novel XFEM (extended finite element method)–cohesive zone methodology which is used to predict intra- and inter-ply damage in an internally pressurised cryogenic tank. An optimised tank lay-up is presented and analysed using the numerical method to ensure resistance to microcrack formation and fuel leakage through the tank walls under operating loads.     

制备工艺对单向连续碳纤维增强聚醚砜复合材料层间结合强度的影响

采用溶液浸渍和热压成型制备了以聚醚酚为基体的单向连续碳纤维增强复合材料,研究了不同树脂浓度和热压工艺参数下复合材料的层间剪切强度。结果表明:成型温度高的复合材料具有较高的层间剪切强度,适当延长保温时间能够大幅度提高复合材料的性能。扫描电镜和热重分析表明树脂基体与碳纤维之间结合紧密,不同树脂含量的复合材料在热压成型过程中,界面处有不同的作用机理。     

γ-射线辐照对聚丙烯腈纤维结构和强度的影响

采用γ-射线辐照方法对在氮气介质中的聚丙烯腈纤维进行处理,探索辐照剂量对纤维单丝拉伸强度和复合材料界面性能的影响。研究结果表明：在辐照剂量10-1000kGy范围内,随着辐照剂量的增加纤维单丝拉伸强度逐渐降低,同时辐照使得复合材料的层间剪切强度降低。进而采用原子力显微镜（AFM）对纤维表面形貌进行观察,用红外光谱（FT-IR）表征纤维表面化学结构,用X射线衍射（XRD）分析结晶状态,用差示扫描量热仪（DSC）测定纤维的耐热性能。     

纤维铺放压紧力及预浸带加热温度对复合材料力学性能的影响

采用三因素四水平正交实验与单因素实验相结合, 通过力学性能测试及SEM和光学显微镜微观形貌观察研究了复合材料铺放过程中压紧力、 预浸带加热温度及芯模温度对复合材料力学性能的影响。实验结果表明: 压紧力与加热温度对层间剪切强度(ILSS)影响很大, 而芯模温度影响较小; 当压紧力为600 N、 预浸带加热温度为30℃、 芯模温度为18℃时, 复合材料综合力学性能达到最佳。微观形貌观察结果表明: 随着压紧力和预浸带加热温度升高, 纤维与树脂接触充分, 树脂与纤维分布均匀性较好, 层间富树脂区的厚度较小, ILSS逐渐增加; 但当预浸温度上升到40℃以后, 压紧力作用导致树脂与纤维的分布均匀性变差, 层间富树脂区的厚度较大, 从而导致ILSS下降。     

The Addition of Polyethylene-Polyamine Surface Treated Carbon Nanotube on the Interfacial Adhesion of Carbon Fiber-Reinforced Polyimide Composite

Carbon fiber reinforced polyimide (CF/PI) composites have been filled with polyethylene-polyamine-treated carbon nanotube to enhance the adhesion. According to the modification, the interlaminar shear strength (ILSS) of composites has been greatly improved. Dynamic wetting method, XPS and SEM are used to examine the microscopic properties of resultant composites. The enhanced ILSS is attributed to the CNT interlock, which improves the wetting between carbon fibers and resins.     

冷等离子体处理对涤纶纤维表面性能的影响

采用冷等离子体技术处理涂纶纤维,利用ESCA分析了冷等离子体处理前后的纤维表面元素组成,官能团类型的变化,通过比较处理前后浸润性,涂纶纤维／环氧复合材料的层间剪切强度,研究了冷等离子处理对涤纶纤维表面性质的影响,结果表明：绦纶纤维经冷等离子处理后表面含氧的极性基团增加,纤维表面的浸润性显著改善,涤纶纤维／环氧复合材料界面性能增强。     

A comparative study on mechanical properties of carbon fiber/PEEK composites

The aim of this work was to improve mechanical properties such as flexural strength and interlaminar shear strength (ILSS) of polyetheretherketone (PEEK) thermoplastic polymer which has very high processing temperature due to its high melting temperature. Carbon fiber (CF) surface was modified by two different methods: oxidative and non-oxidative. Piranha solution and chromate solution were used for chemical treatment (oxidative treatment), and silicone based polymers were used for polymer coating (non-oxidative). The changes on the surface structure and surface chemistry were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR), respectively. FTIR results indicate that coating fibers decreases carbon element content, whereas increases the oxygen and silicone content as well as their functional groups on the surface. Flexural strength and ILSS properties of CF/PEEK composites were measured according to ASTM D-790 and ASTM D2344, respectively.