芳纶纤维增强树脂基复合材料的界面粘结性能研究

为了改善芳纶纤维增强树脂基复合材料的界面粘结性能,从树脂基体入手,依据相似相容原理和芳纶的结构特点,合成出新型热固性树脂(AFR–T)用作芳纶复合材料的基体,以未经表面处理的芳纶作增强材料,采用热压成型法制备了AFR–T/芳纶纤维复合材料,并通过测定溶度参数、接触角、线膨胀系数、层间剪切强度(ILSS)和横向拉伸强度等方法研究了复合材料的界面粘结性能。结果表明,AFR–T树脂浇注体与芳纶的溶度参数相近,AFR–T树脂溶液在芳纶纸表面的接触角为36.9°,小于环氧树脂(EP)溶液与芳纶纸的接触角(53.2°),说明AFR–T树脂对芳纶的浸润性优于EP;AFR–T/芳纶纤维复合材料的ILSS和横向拉伸强度为73.0 MPa和25.3 MPa,分别比EP/芳纶纤维复合材料提高了25.9%和32.5%,这表明AFR–T树脂与芳纶纤维之间的浸润性和界面粘结性能较好。     

芳纶纤维/AFR树脂复合材料界面粘结性能的研究

为了改善芳纶纤维复合材料的界面粘结性能,合成了一种新型树脂(AFR)作为基体,以未经任何表面处理的芳纶纤维作增强材料,制备了芳纶纤维/AFR复合材料。采用测定表面能、接触角、层间剪切强度、横向拉伸性能和扫描电镜观察形貌等方法,从宏观和微观等方面研究了芳纶纤维/AFR复合材料的界面粘结性能。结果表明,AFR树脂与芳纶纤维有相近的表面能,AFR树脂溶液与芳纶纤维的接触角为42.8°,而环氧树脂(EP)与芳纶纤维的接触角为68°,说明AFR树脂对芳纶纤维的润湿性优于EP树脂;芳纶/AFR复合材料的层间剪切强度、横向拉伸强度和纵向拉伸强度分别为74.64MPa、25.34MPa和2256MPa,比芳纶/EP复合材料的相应强度分别提高了28.7%、32.5%和13.4%,其复合材料破坏面的形貌也说明芳纶纤维与AFR树脂之间的界面粘结性能较好。     

Surface modification of aramid fibers with γ‐ray radiation for improving interfacial bonding strength with epoxy resin

Co⁶⁰ γ‐ray radiation as a simple and convenient method for surface modification of Armos aramid fibers was introduced in this article. Two kinds of gas mediums, N₂ and air, were chosen to modify aramid fiber surface by γ‐ray irradiation. After fiber surface treatment, the interlaminar shear strength values of aramid/epoxy composites were enhanced by about 17.7 and 15.8%, respectively. Surface elements of aramid fibers were determined by XPS, the analysis of which showed that the ratio of oxygen/carbon was increased. The crystalline state of aramid fibers was determined by X‐ray diffraction instrument. The surface topography of fibers was analyzed by atomic force microscopy and scanning electron microscope. The degree of surface roughness and the wettability of fiber surface were both enhanced by γ‐ray radiation. The results indicated that γ‐ray irradiation technique, which is a suitable way of batch process for industrialization, can significantly improve the surface properties of aramid fibers reinforced epoxy resin matrix composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

RETRACTED ARTICLE: Surface modification of aramid fibers with novel chemical approach

Friedel–Crafts Reaction as a simple and convenient approach to the surface modification of aramid fiber was introduced in this paper. Epoxy chloropropane was chosen as the treatment reagent to modify aramid fibers surface via Graft reaction. After the modification, the interfacial properties of aramid/epoxy composites were investigated by the single fiber pull-out test (SFP), and the mechanical properties of aramid fibers were investigated by the tensile strength test. The results showed that the interfacial shear strength (IFSS) value of aramid/epoxy composites was enhanced by about 50%, and the tensile strength of aramid fibers had no obvious damage. The crystalline state of aramid fibers was determined by X-ray diffraction instrument (XRD), and the results showed that there were not any distinct crystal type varieties. The surface elements of aramid fibers were determined by X-ray photoelectron spectroscopy (XPS), the analysis of which showed that the oxygen/carbon ratio of aramid fiber surface increased obviously. The possible changes of the chemical structure of aramid fibers were investigated via Fourier transform infrared spectrum (FTIR), and the analysis of which showed that the epoxy functional groups were grafted into the molecule structure of aramid fibers. The surface morphology of aramid fibers was analyzed by Scanning electron microscope (SEM), and the SEM results showed that the physical structure of aramid fibers was not etched or damaged obviously. The surface energy of aramid fibers was investigated via the dynamic capillary method, and the results showed that the surface energy was enhanced by 31.5%, and then the wettability degree of aramid fiber surface was enhanced obviously too. All of the results indicated that this novel chemical modification approach not only can improve the interfacial bonding strength of aramid/epoxy composites remarkably, but also have no negative influence on the intrinsic tensile strength of aramid fibers.     

Adhesive joints between carbon fiber and aluminum foam reinforced by surface‐treated aramid fibers

Short aramid fibers have been successfully used to reinforce the interface adhesive property between carbon fiber/epoxy composites and aluminum foam, and to form aramid‐fiber “composite adhesive joints.” In this study, to further improve the reinforcing effect of the aramid‐fiber‐reinforced adhesive joints, aramid fibers were ultrasonic treated to conduct different surface conditions. Critical energy release rate of the carbon fiber/aluminum foam sandwich beams with as‐received and treated interfacial aramid fibers were measured to study the influence of the surface treatment on aramid fibers. It was found that reinforcements in critical energy release rate were achieved for all samples with treated aramid fiber as measured under double cantilever beam condition. The interfacial characteristics of the short aramid fibers with different surface condition were investigated and discussed based on scanning electron microscopy observations. It is suggested that advanced bonding between aramid fibers and epoxy resin was conducted after surface treatment, and more energy was therefore absorbed through fiber bridging during crack opening and extension process. POLYM. COMPOS., 36:192–197, 2015. © 2014 Society of Plastics Engineers     

Ultrasonic modification of aramid fiber–epoxy interface

An ultrasonic irradiation technique is used during the process of fabricating aramid fiber–epoxy resin reinforced composites to improve the interfacial adhesion performance. Under the ultrasonic treatment, the change of the resin viscosity is studied. The results of a microbond test show obvious improvement in the interfacial shear strength after ultrasonic treatment. The mechanical properties of the composites, such as the interlaminar shear strength and tensile strength, are measured. Combined with the SEM results, these show it is the mechanical properties that are improved and the fracture modes are varied from the interface between the fibers and resin to the fibrillation of fibers and resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2764–2768, 2001     

低温氨气等离子体对芳纶表面的改性

采用氨气等离子体对芳纶表面进行改性,用X-射线光电子能谱、场发射扫描电子显微镜、力学性能测试等手段对改性前后纤维表面的元素组成、形貌及其拉伸强度进行表征,并进一步通过微脱黏方法分析了等离子体处理条件对芳纶/环氧树脂复合材料界面黏结强度的影响。结果表明:芳纶经表面改性后,其表面极性官能团、表面粗糙度均有所增加,同时与环氧树脂基体的界面黏结强度明显增加。     

Interfacial studies on the surface modified aramid fiber reinforced epoxy composites

In this work, solutions of rare earth modifier (RES) and epoxy chloropropane (ECP) grafting modification method were used for the surface treatment of aramid fiber. The effect of chemical treatment on aramid fiber has been studied in a composite system. The surface characteristics of aramid fibers were characterized by Fourier transform infrared spectroscopy (FTIR). The interfacial properties of aramid/epoxy composites were investigated by means of the single fiber pull‐out tests. The mechanical properties of the aramid/epoxy composites were studied by interlaminar shear strength (ILSS). As a result, it was found that RES surface treatment is superior to ECP grafting treatment in promoting the interfacial adhesion between aramid fiber and epoxy matrix, resulting in the improved mechanical properties of the composites. Meanwhile, the tensile strengths of single fibers were almost not affected by RES treatment. This was probably due to the presence of reactive functional groups on the aramid fiber surface, leading to an increment of interfacial binding force between fibers and matrix in a composite system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4165–4170, 2006     

Surface modification of aramid fibers via ammonia‐plasma treatment

In this article, aramid fibers III were surface modified using an ammonia‐plasma treatment to improve the adhesive performance and surface wettability. The surface properties of fibers before and after plasma treatment were investigated by X‐ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, and water contact angle measurements. The interfacial shear strength of each aramid fibers III‐reinforced epoxy composites was studied by micro‐debonding test. The ammonia‐plasma treatment caused the significant chemical changes of aramid fibers III, introducing nitrogen‐containing polar functional groups, such as ? C? N? and ? CONH? , and improving their surface roughness, which contributed to the improvement of adhesive performance and surface wettability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40250.     

Surface ammonification of the mutual‐irradiated aramid fibers in 1,4‐dichlorobutane for improving interfacial properties with epoxy resin

The mutual irradiated aramid fibers in 1,4‐dichlorobutane was ammoniated by ammonia/alcohol solution, in an attempt to improve the interfacial properties between aramid fibers and epoxy matrix. Scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), dynamic contact angle analysis (DCA), interfacial shear strength (IFSS), and single fiber tensile testing were carried out to investigate the functionalization process of aramid fibers and the interfacial properties of the composites. Experimental results showed that the fiber surface elements content changed obviously as well as the roughness through the radiation and chemical reaction. The surface energy and IFSS of aramid fibers increased distinctly after the ammonification, respectively. The amino groups generated by ammonification enhanced the interfacial adhesion of composites effectively by participating in the epoxy resin curing. Moreover, benefited by the appropriate radiation, the tensile strength of aramid fibers was not affected at all. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44924.     

高能辐照对国产芳纶纤维/环氧复合材料界面性能影响

芳纶纤维因其表面惰性、光滑使其与树脂浸润性差,界面结合强度低。以环氧氯丙烷为介质1,采用60Coγ-射线辐照方法对国产芳纶纤维进行表面改性,以界面剪切强度（IFSS）和层间剪切强度（ILSS）表征芳纶/环氧复合材料界面结合性能。结果表明在400kGy辐照剂量下改性效果最好;经高能辐照处理的芳纶纤维表面能升高,并失去了原有的光滑表面,且纤维表面氧含量有大幅度提高,使得纤维表面活性增大。     

Effect of rare earth elements surface treatment on tensile properties of aramid fiber‐reinforced epoxy composites

Solutions of rare earth modifier (RES) and epoxy chloropropane (ECP) grafting modification method were used for the surface treatment of aramid fiber. Tensile properties of both the aramid/epoxy composites and single fibers were tested. The effects of RES concentration on tensile properties of aramid/epoxy composites were investigated in detail to explore an optimum amount of rare earth elements in solution for modifying aramid fiber. The fracture surface morphologies of tensile specimens were observed and analyzed with the aid of SEM. The experimental results show that rare earth treatment is superior to ECP grafting treatment in promoting interfacial adhesion between the aramid fiber and epoxy matrix. Meanwhile, the tensile strengths of single fibers were almost not affected by RES treatment. The optimum performance is obtained when the content of rare earth elements is 0.5 wt %. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1037–1041, 2004     

杂环芳纶表面ZnO纳米界面相的构筑及其界面强化作用

为了改善杂环芳纶(F3)与环氧树脂黏结性差以及不耐紫外辐射的缺点,首先对纤维进行功能化预处理,然后通过溶胶-凝胶法和水热法分别在芳纶表面生长了氧化锌纳米颗粒和氧化锌纳米线界面层。采用X成、形貌、与环氧树脂的黏结性以及抗紫外性能进行了研究。结果表明:纳米颗粒状和纳米线形态的ZnO纳米界面相能够显著提高纤维与树脂基体的黏结性能,与未处理的纤维相比,单纤维复合材料的界面剪切强度分别提高了14.1%和27.0%;同时ZnO的破坏,经过168 h紫外辐射试验后,纤维强度保持率从79.1%提高到96.7%。     

Modification of the carbon fiber surface with a copper coating for composite materials with epoxy

Surface treatment of carbon fibers is essential to provide adequate interfacial interaction, and strength in carbon fiber/epoxy composites. The electrodeposition of a metallic copper coating on the carbon fiber surface has been examined as an alternative method to improve carbon fiber-epoxy interfacial properties. The wettability of the carbon fiber by the epoxy resin was improved as a result of copper electrodeposition. As a consequence, the adhesion between the carbon fiber and epoxy was also greatly improved by the surface electrolytic treatment used. The electrodeposition conditions affected significantly both wettability and adhesion phenomena. The electrolytic current had a strong effect on the interface performance. It was found that there was an intermediate electrolytic current, within the range used, which promoted better wetting and composite strength, compared with conventionally surface-oxidized carbon fibers.     

左旋多巴胺处理对芳纶表面结构与性能的影响

利用L-3,4-二羟基苯丙氨酸(L-DOPA)的氧化自聚合,在杂环芳纶表面修饰聚L-3,4-二羟基苯丙氨酸(PDOPA)活性涂层来提高芳纶的表面活性及耐紫外辐照性能。结果表明:改性后芳纶表面粗糙度显著提高,同时,PDOPA涂层上大量的羧基、羟基等活性单元均有利于增强与环氧树脂的机械锁合力,改性后芳纶/环氧树脂复合材料的界面剪切强度提高了32.0%。此外,上述改性过程对杂环芳纶本身力学性能影响较小,纤维的拉伸强度保持率可以达到100%,基本实现了无损改性。同时,由于PDOPA的保护作用,改性后芳纶的耐紫外辐射性能显著提高;经过168 h紫外线辐照处理后,其拉伸强度保持率可达到92.5%,显著提升了杂环芳纶的耐紫外线辐照特性。     

Multiscale fiber‐reinforced composites prepared by vacuum‐assisted resin transfer molding

Carbon nanotube (CNT)/aramid fiber epoxy composites were produced using a new manufacturing method proposed in this study. The rheological and morphological experiments of the CNT/PEO nanocomposites indicates that the PEO nanocomposites have a good dispersion state of the CNTs. The flexural mechanical properties of the aramid fiber/CNT epoxy composites were measured. The CNTs dispersed in the epoxy resin between the aramid fibers were observed using field emission scanning electron miscroscope (FESEM). It was found that the flexural properties of the multiscale fiber‐reinforced composites were higher than those of aramid fiber/epoxy composites. POLYM. COMPOS., 28:458–461, 2007. © 2007 Society of Plastics Engineers.     

高性能碳纤维表面特性及其对浸润性能的影响

以4种不同型号的高性能碳纤维T700、UTS50、T800和IM7为研究对象,采用扫描电子显微镜和原子力显微镜对碳纤维直径、表面形貌和粗糙度进行表征,通过表面/界面张力仪对纤维表面能和树脂体系的表面张力进行分析,利用旋转流变仪对树脂体系的粘度进行测试。最后对碳纤维与不同温度和不同丙酮质量分数的618环氧树脂浸润性能进行测试,以分析纤维表面性能、温度和溶剂质量分数对碳纤维浸润性能的影响。结果表明,升高温度或提高溶剂质量分数有利于降低树脂体系的表面张力和粘度,从而有效改善碳纤维的浸润性能。纤维直径、表面粗糙度和表面能对碳纤维的浸润性能均有一定影响,其中纤维直径是影响浸润速率的主导因素,表面能和表面粗糙度对浸润质量的影响更加显著。     

Mechanical properties of epoxies reinforced with chloride-treated aramid fibers

Surface treatment of aramid fibers by immersion in a solution of methacryloyl chloride in carbon tetrachloride was carried out, and the resulting material was examined by means of electron microscopy and chemical analysis in an attempt to record any changes in the morphology and nature of the surface. Mechanical testing of tensile, flexural, and interlaminar shear strength, as well as dynamic mechanical analysis (DMA), were performed in an attempt to explore the effect of this treatment on the strength of the fiber. In a subsequent stage, the performance of those fibers as reinforcement in composites of epoxy matrix was assessed. The aim of this study was to provide more information about the interactions between the chloride-treated aramid fibers and the epoxy resin and, more specifically, to compare the behavior of the epoxy matrix composites with those composed of unsaturated polyester, polyethylene, and polyurethane matrix, which were studied in the past. It was found that specimens containing chloride-treated aramids display better flexural properties, whereas their tensile strength is drastically reduced. Improved performance was also identified by the DMA experiments. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:–, 1997     

芳纶纤维等离子体接枝改性处理研究

采用等离子体接枝对芳纶纤维表面进行改性处理,采用XPS、浸润性、界面剪切强度对等离子体接枝处理前后的表面组成、复合材料界面粘接性能等进行了研究,结果表明:等离子体接枝处理可以有效地提高芳纶纤维表面的极性官能团,增加与基体树脂-环氧树脂的浸润性,进而提高芳纶/环氧复合材料的界面粘接强度.     

Wettability Modification of Polyacrylonitrile (PAN)-Based High Modulus Carbon Fibers with Epoxy Resin by Low Temperature Plasma

In this study, low-temperature plasma is used to improve the wettability of polyacrylonitrile (PAN)-based high modulus (HM) carbon fibers with epoxy resin. The effect of plasma treatment time and power is studied. The results indicate that a time of 30 s is long enough for improving wettability of fibers with epoxy resin and there is an optimum power for plasma modification under the given conditions. According to the different effect of plasma treatment at different powers, we take two steps to treat the HM carbon fiber. First, the fibers are treated at moderate power to roughen the surface and then treated at low power to introduce some oxygen-containing functional groups. The results indicate the method is more effective in improving the wettability of HM carbon fibers with resin.