Interfacial Properties Modification of Carbon Fiber/Polyarylacetylene Composites

This work was dedicated to performing surface oxidation and coating treatments on carbon fibers （CF） and investigating the changes of fiber surface properties after these treatments, including surface composition, relative volume of functional groups, and surface topography with X-ray photoelectron spectroscopy （XPS） and atom force microscopy （AFM） technology. The results show that, after oxidation treatments, interfacial properties between CF and non-polar polyarylacetylene （PAA） resin are remarkably modified by removing weak surface layers and increasing fiber surface roughness. Coating treatment by high char phenolic resin solution after oxidation makes interface of CF/PAA composites to be upgraded and the interfacial properties further bettered.

EXPERIMENTAL STUDY ON PEK -C MODIFIED EPOXIES AND THE CARBON FIBER COMPOSITES FOR AEROSPACE APPLICATION

The morphological structure of various epoxies toughened with a special amorphous thermoplastic PEK-C and their carbon fiber composites were studied by using SEM. For both cases, phase separation and inversion took place to form fine epoxy-rich globules dispersing in the PEK-C matrix, in which the epoxy-rich phase had the absolutely higher volume fraction. The phase structure and the interfacial properties were also studied by means of FTIR, DSC, and DMTA as well. An accompanying mechanical determination revealed that an improved toughness was achieved both in the blend casts and in the carbon fiber composites. A composite structural model was hence suggested.

Comparative study on the interface and mechanical properties of T700/Al and M40/Al composites

T700/Al and M40/Al composites were fabricated by squeeze casting technology, and their interface and mechanical properties were investigated comparatively. The results showed that both of the composites were dense, and the fibers were distributed uniformly in aluminum matrix. Aluminum carbide （Al4C3） was observed on the interface of the two carbon fiber-reinforced aluminum （Cf/Al） composites. There was little Al4C3 with a length of 300-500 nm and a width of 30-60 nm in the M40/Al composite, whereas there was a great deal of Al4C3 with a length of 200-400 nm and a width of 100-200 nm in the T700/Al composite, due to a higher graphitization of M40Cf than T700Cf. The M40/Al composite showed a much higher tensile strength than the TT00/Al composite, and it was related to interracial bonding between carbon fibers and aluminum matrices.

Interfacial Improvement of Carbon Fiber/Epoxy Composites by Incorporating Superior and Versatile Multiscale Gradient Modulus Intermediate Layer with Rigid-flexible Hierarchical Structure

In order to enhance the interfacial adhesion of carbon fiber(CF)and polymer matrix,a multiscale gradient modulus intermediate layer with rigid-flexible(GO-PA)hierarchical structure was designed and fabricated between CFs and matrix by a facile and businesslike strategy.The polarity,roughness and wettability of CFs surface as well as the thickness of intermediate layer in composite have been significantly increased after rigid-flexible hierarchical structure was constructed.The IFSS,ILSS,compression and impact toughness manifested that the hierarchical structure could bring about a fantastic improvement(76.8%,46.4%,40.7%and 37.8%)for the interfacial and mechanical properties than other previous reports.Consequently,the establishment of CF surface with gradient modulus rigid-flexible hierarchical structure via regulation of nanoparticles and polymer array would open a new,viable and promising route to obtaining high-performance composites.

Interconnected Ni(OH)_(2)and polyether amine on carbon fiber surface for simultaneously improving interfacial adhesion of epoxy composites and electrochemical properties

Interconnected Ni(OH)_(2)nanoflakes and polyether amine(PEA)were deposited on carbon fiber tows via a facial and effective process of chemical bath deposition and dip coating.Based on this,a win–win benefit of simultaneously improvements in interfacial shear strength(IFSS)of carbon fiber/epoxy composites and the electrochemical activity has been achieved.Compared with CF and CF-Ni(OH)_(2)composites,the IFSS of CF-Ni(OH)_(2)-PEA/epoxy composite respectively increased 7.9%and 45.4%,which was put down to the covalent bonding of Ni(OH)_(2)-PEA coating with fiber and epoxy matrix,as well as the effective stress transfer by the uniform honeycomb structure of Ni(OH)_(2).In aqueous KOH electrolyte,the CF-Ni(OH)_(2)-PEA electrode presented the maximum specific capacitance of 689.98 F·g^(-1)at 5 m V·s^(-1),572.28 F·g^(-1)at a current density of 0.5 A·g^(-1)due to the strong adhesion of carbon fiber with Ni(OH)_(2)by PEA,the reservation of the threedimensional hollow honeycomb structure of Ni(OH)_(2)for easy ion-transport and–NH_(2)functional groups from PEA for providing more active sites.The excellent performance of CF-Ni(OH)_(2)-PEA reinforcement demonstrates its promising potential for application in high performance composites with integrated structure and function,which shows great advantages in various fields of aerospace,energy,electronics,automobile,civil engineering,sports,etc.

TENSILE PROPERTIES AND INTERFACIAL FEATURE OF SiC COATED C/Al COMPOSITE WIRES UNDER ISOTHERMAL HEAT TREATMENT

The effect of different regimes of heat treatment on the tensile strength of SiC coated composite of C fibers reinforced Al wires has been investigated.Their tensile strength may increase under treatment either at 500℃ for 2h or 550℃ for 1h,but decrease over 600℃.After the strength tests of extracted fibers from composite wires,the SiC coating is an excellent protection to C fibers.EPMA and EDAX showed that the C/Al interface of the composite wires is stable under treatment below 600℃,but unstable at 650℃

Effect of coating thickness on microstructures and mechanical properties of C/Cu/Al composites

The different copper coatings with thickness varying from 0.3μm to 1.5μm were deposited on carbon fibers using either electroless plating or electroplating method. The coated fibers were chopped and composites were fabricated with melting aluminum at 700℃. The effect of the copper layer on the microstructure in the system was discussed. The results show that the copper layer has fully reacted with aluminum matrix, and the intermetallic compound CuAl2 forms through SEM observation and XRD, EDX analysis. The results of tensile tests indicate that composites fabricated using carbon fibers with 0.7-1.1μm copper coating perform best and the composites turn to more brittle as the thickness of copper coating increases. The fracture surface observation exhibits good interface bonding and ductility of the matrix alloy when the thickness of copper coating is about 0.7-1.1μm.

Facile preparation of a SiC@SiO_(2)nanowire-toughened ZrB_(2)-SiC/SiC bilayer coating with good interfacial bonding,high toughness,and excellent cyclic ablation resistance on C/CA composites

Preparing antioxidant coatings to address the inherent oxidation sensitivity of carbon fiber-reinforced carbon aerogel(C/CA)composites is a feasible way to promote their application in oxidizing environments as thermal insulation materials.However,preparing the coatings with excellent oxidation and ablation resistance while avoiding evident damage to the C/CA substrate still remains a challenge.Herein,a SiC@SiO_(2)nanowire-toughened ZrB2–SiC/SiC bilayer coating with a large thickness of 500μm was prepared on C/CA using a one-step low-temperature reaction sintering method,which simultaneously formed a sintered outer layer with even-distributed nanowires and a siliconized gradient inner layer.By courtesy of the synergic thermal response of the layers and the crack deflection induced by the nanowires,the resulting coating has moderate residual compressive stress of 0.08–1.22 GPa in the interface,high interfacial bonding strength of 6.02 MPa,and good fracture toughness of 4.36 MPa·m^(1/2).Benefited from the optimum components and improved structure,the coating shows excellent cyclic ablation resistance with linear ablation rates of 0.1μm/s at 1650℃for 1500 s(300 s×5 cycles)and 0.4μm/s at 1850℃for 900 s(300 s×3 cycles).The one-step preparation strategy contributes to little damage to the substrate,thus showing the well-preserved mechanical and thermal insulation properties.

碳纤维表面改性及其对热塑性复合材料界面性能影响的研究进展

基于复合材料界面作用机制,系统总结了碳纤维表面改性方法,分别讨论了不同碳纤维改性处理方法对热塑性复合材料界面性能的影响及相关研究进展。碳纤维表面进行改性处理是增强热塑性复合材料界面结合强度的有效途径。最后对碳纤维表面改性方法的未来发展方向进行了展望。

碳纤维增强树脂基复合材料界面改性及应用进展

轻质高强的碳纤维增强树脂基复合材料(CFRP)在碳达峰和碳中和的国家战略中展现出重要的研究价值,提高复合材料界面结合强度是重点和难点问题。针对碳纤维表面浸润性差和力学性能转化率低的问题,简述了CFRP界面增强理论和碳纤维表面处理方法,重点阐述了氧化法、化学接枝和涂层法,用物理或化学手段提高复合材料力学性能。此外,从热固性树脂和热塑性树脂两种基体材料的各自性能特点分析了碳纤维与树脂基体适配性的问题,提出了不同的解决方案。最后,介绍了CFRP在航空、风电叶片和新能源汽车领域的研究进展,提出了飞机轻量化、风机大型化和电车普及背景下材料研究的发展建议,如优化针对高强或高模等具有不同表面形态碳纤维的特定表面改性技术,开发针对不同树脂的改性方法,研发不同类别及应用场景下的碳纤维上浆剂,加强复合材料界面增强理论和界面表征技术研究,制定碳纤维复合材料标准化体系。

多巴胺对碳纤维增强聚苯硫醚复合材料界面性能的影响

碳纤维增强聚苯硫醚复合材料(CF/PPS)因其具有优异的综合性能被广泛关注,但实际应用中发现碳纤维与聚苯硫醚的界面结合并不理想,因此,改善CF/PPS界面结合强度来提升其宏观力学性能就有着深远的理论意义和应用价值。文中基于微球脱粘技术,将具有优良黏附性的多巴胺水溶液作为界面改性剂,对纤维进行表面改性,采用微球脱粘实验和宏观拉伸等实验测试探究了不同多巴胺浓度对CF/PPS界面性能的影响。结果表明,当多巴胺浓度为2 g/L时,聚多巴胺在碳纤维表面均匀黏附,形成较好的微纳结构,涂覆效果最佳,表观界面剪切强度最大为36.09 MPa,较未改性前增加13.50%;PDA-CF2/PPS拉伸试样的断面呈现凹凸不平的形态,拔出的碳纤维上残留树脂基体最多,具有良好的界面改性效果。

碳纤维/镁复合材料的显微组织与弯曲性能

为满足极端空天环境对轻质结构材料提出的要求,采用压力渗透法制备了T300、T700和M40碳纤维增强镁基复合材料(C_(f)/Mg)。研究了不同种类碳纤维对C_(f)/Mg复合材料界面显微组织和弯曲性能的影响。结果表明:T300/AZ91D和T700/AZ91D复合材料中均存在严重的界面反应产物Al_(4)C_(3)相,使复合材料在低应力下发生脆性断裂。然而,在M40/AZ91D复合材料中,界面处Al_(4)C_(3)相的量显著减少和尺寸显著减小,界面强度相对较高。因此,M40/AZ91D复合材料能够充分发挥出载荷传递效果,最终表现出1100 MPa的较高弯曲强度。

碳纤维复合材料高温界面性能研究进展

碳纤维复合材料以其强度高、耐腐蚀、质量轻、抗疲劳等优良特性被广泛应用于航空航天及国防军工领域。然而,航空航天用复合材料结构部件在高温、湿热环境中会发生界面损伤和失效。上浆剂是碳纤维复合材料界面相的重要组成部分,研制可以增强界面强度和耐高温的上浆剂对提高复合材料的热力学性能具有重要意义。文中从碳纤维表面上浆剂的角度出发,重点介绍了碳纤维复合材料界面特性、上浆剂的作用机理以及高温下复合材料界面的破坏机制。最后,针对环氧上浆剂耐热性差的缺点,阐述了碳纤维耐高温涂层改性和纳米粒子改性,重点介绍了聚酰亚胺、聚醚醚酮、生物活性多巴胺及氧化石墨烯、多面体低聚倍半硅氧烷(POSS)纳米粒子等类型改性上浆剂的研究进展。指出发展环境友好型上浆剂和POSS纳米粒子改性将是下一步工作的重点。

基于上浆处理的碳纤维/聚丙烯纤维毡复合材料的制备及性能研究

碳纤维/热塑性树脂基复合材料因其综合性能好、耐变形、可循环利用等优异性能在复合材料领域拥有良好前景,界面作为两相的过渡区域,起到应力传递作用,对复合材料的力学性能有重要影响。通常采用上浆剂使碳纤维表面改性,从而提高界面结合能力。本文针对一种碳纤维/聚丙烯混合毡进行上浆,采用模压成型制备复合材料。通过透气性、透光性测试分析了上浆均匀性和对混合毡结构的效果,通过拉伸、弯曲及冲击试验研究了上浆对复合材料力学性能的影响效果,并分析了上浆剂的作用机理。结果表明,上浆后,复合材料的拉伸强度提高了22.52%,弯曲强度提高了7.57%,冲击强度提高了39.07%。

碳纤维/乙烯基酯树脂复合材料界面性能研究

采用改性上浆剂对SCF-35S-48K碳纤维上浆,分析了上浆工艺对上浆碳纤维的表面形貌和碳纤维/乙烯基酯树脂复合材料界面性能影响。复合材料的微观结构和层间剪切性能结果表明:上浆层对碳纤维起到了一定的保护作用,碳纤维表面平整、可加工性好,与树脂基体的界面黏结性好,复合材料的层间剪切强度达到68.18 MPa,比未上浆碳纤维/乙烯基酯树脂复合材料高7.56%,满足复合材料应用要求。

碳纤维用于竞技体育器材的性能优势与改性优化研究

为改善竞技体育器材用碳纤维复合材料性能,以纳米改性材料为载体对碳纤维复合材料进行了改性处理,并对其力学性能进行了测试表征。结果发现,纳米改性材料可有效改善碳纤维复合材料整体性;随着纳米改性材料质量分数增加,碳纤维复合材料拉伸强度表现为先升高后降低的态势,抗弯强度呈现为先升高后降低再升高的波形趋势,裂纹扩展功、冲击形成功、总冲击功皆呈现出不同程度的逐渐增大趋势,界面剪切强度表现为先增大后减小的态势;表明纳米改性材料可有效增强健美操器材用碳纤维复合材料拉伸性能、弯曲性能冲击性能、界面剪切强度。

碳纤维增强树脂基复合材料的界面

从碳纤维、树脂基体、界面3个层次对碳纤维增强树脂基复合材料的界面研究进行了综述,重点介绍了碳纤维表面特性表征及改性方法、树脂基体特性及改性方法和界面分析表征手段,由此提出了纤维/树脂界面的研究路线,简要分析了复合材料界面研究的前景与趋势。为了实现纤维/树脂界面的良好匹配,充分发挥碳纤维复合材料的性能优势,需完善界面表征手段、明确界面微观性能与复合材料宏观性能的关系、深化研究界面对复合材料湿热性能及失效模式的影响等。

碳纤维表面处理及其对碳纤维/树脂界面影响的研究

碳纤维增强树脂/石墨复合材料是树脂/石墨双极板材料的一个主要研究内容,纤维与树脂间的界面结合是其中的关键问题。综述了碳纤维的氧化处理、偶联剂涂层处理和等离子体处理方法及各种处理方法对碳纤维/树脂界面的影响。对碳纤维的表面处理,可以提高碳纤维与树脂的界面粘接力,获得良好的界面层,达到对界面的优化处理。

碳纤维表面性质分析及其对复合材料界面性能的影响

研究了T300-3K和T300-6K碳纤维的表面物理和化学特性,并对其与环氧树脂复合材料体系的界面性能进行了测试与分析。结果表明T300-6K碳纤维表面的O/C比和活性碳原子比例均高于T300-3K碳纤维。T300-6K碳纤维表面沟槽深度、宽度和长度均大于T300-3K碳纤维但表面粗糙度较小。T300-6K碳纤维环氧树脂体系的界面剪切强度与相应的T300-3K体系基本相当。

碳纤维阳极氧化法处理对复合材料界面性能的影响

利用阳极氧化法对碳纤维进行表面改性处理 ,研究了碳纤维处理前后表面化学组成 ,纤维复丝拉伸强度和复合材料的层间剪切强度 ( IL SS)。结果表明 ,经阳极氧化处理碳纤维表面的含氧、含氮极性官能团数目增加 ,纤维复丝拉伸强度有所下降 ,复合材料的 ILSS值提高。同时通过实验结果分析 ,阐明阳极氧化处理使复合材料界面性能改善的机理。