F-12和国产芳纶Ⅲ纤维/环氧单向复合材料力学性能和强度对比分析

采用单向复合材料缠绕型式,对F-12和国产芳纶Ⅲ纤维增强环氧复合材料进行力学性能测试,考核了两种芳纶纤维/环氧复合材料界面黏结性能,并进行拉伸破坏机理与强度分析,获得了强度参数值.结果表明:两种芳纶纤维单向复合材料具有明显的各向异性特征,轴向力学性能远高于径向力学性能;F-12/环氧复合材料力学性能优于国产芳纶Ⅲ/环氧复合材料性能;两种复合材料纤维/树脂界面粘接较差.     

磷酸处理对三维编织芳纶纤维/双马来酰亚胺力学性能的影响

本文采用RTM工艺制备了三维编织芳纶纤维增强双马来酰亚胺复合材料,并考察了磷酸处理芳纶纤维对复合材料界面结合及力学性能的影响.结果表明,磷酸处理能增加纤维表面活性官能团含量,改善纤维与基体间的界面结合,提高复合材料的弯曲、剪切和冲击性能.     

磷酸酯偶联剂改性芳纶纤维增强聚丙烯复合材料的性能研究

采用磷酸酯偶联剂对芳纶纤维表面进行接枝改性,研究了实验条件和纤维含量对芳纶纤维增强聚丙烯(PP)复合材料力学性能的影响,并用电子扫描显微镜观察了PP复合材料的微观形态结构。结果表明:磷酸酯偶联剂成功接枝到芳纶纤维表面上,使芳纶纤维和PP的界面黏结性能得以明显改善。芳纶纤维可以显著地提高PP复合材料的力学性能当,其含量为20%时复,合材料的综合性能最优。     

短芳纶纤维增强聚苯硫醚复合材料的性能

研究了短芳纶纤维增强ＰＰＳ／ＰＥＫ－Ｃ复合材料树脂体系的力学性能。主要讨论了短芳纶纤维的长度、含量及芳纶纤维的表面处理方法和压制温度对复合材料体系力学性能的影响。结果表明：纤维的长度和含量对力学性能有显著影响,在相同纤维含量下,纤维长度增加可使纤维末端数减少,减少了应力集中点,有利于拉伸强度和冲击强度的提高。芳纶纤维不需经过表面化学处理即与ＰＰＳ有良好的界面特性。随加工温度升高,复合材料冲击强度降低,拉伸强度提高     

芳纶纤维表面的络合改性及其天然橡胶复合材料性能的研究

利用合适的溶剂配制成的氯化钙溶液浸渍活化芳纶纤维表面.通过均匀设计实验,研究了氯化钙溶液质量分数及处理时间对芳纶纤维天然橡胶复合材料力学性能的影响.实验结果表明:利用氯化钙甲醇溶液浸渍芳纶纤维,再用甲醇清洗芳纶纤维是降低纤维表面结晶度和提高表面粗糙度的最佳方法,溶液中氯化钙质量分数为2％时,复合材料获得最大300％定伸应力及撕裂强度,处理时间在实验参数范围内对这2种力学性能几乎没有影响.     

典型高性能芳纶及其复合材料性能研究

对Kevlar-49、Armos和国产芳纶Ⅲ高性能芳纶进行力学性能和复合材料界面性能分析,并结合纤维表面形貌分析探讨了这几种芳纶及其复合材料的性能以及影响因素。结果表明,在对位芳纶高分子链上引入杂环结构,可以极大的提高芳纶的力学性能,从而提高其复合材料性能;同时芳纶表面形貌也对其复合材料性能造成影响。     

纤维增强尼龙复合材料研究进展

综述了不同纤维增强尼龙复合材料,研究了添加不同纤维后复合材料的力学性能变化,特别对添加玻璃纤维、芳纶纤维、碳纤维到尼龙材料当中,复合材料的力学性能发生变化做了细致的描述。并对未来纤维增强尼龙复合材料进行展望。     

F-12芳纶纤维合成及其应用研究进展

本文综述了F-12芳纶纤维的结构与性能.着重介绍了纤维表面处理及其复合材料力学性能方面的研究成果.并就提高F-12纤维在复合材料中强度转化率问题提出了一些看法     

芳纶Ⅲ单向纤维增强复合材料测试方法研究

芳纶Ⅲ单向纤维增强复合材料由于其优良的力学性能,在航空航天、军事及个体防护装备等领域中应用广泛,因此采用合理的手段准确测试出芳纶Ⅲ单向纤维增强复合材料的力学性能变得十分重要。本文对芳纶Ⅲ单向纤维增强复合材料的拉伸性能、弯曲性能、压缩性能以及层间剪切性能进行测定,采用正交试验的方法,通过控制不同的测试条件(例如试验速度、试样尺寸、夹具尺寸等),分析不同测试条件对芳纶Ⅲ单向纤维复合材料测试结果的影响,以得到更为准确合理的力学性能试验方法。     

短纤维对NR/BR基胎面胶力学性能的影响

探讨了尼龙短切纤维、芳纶短切纤维和芳纶浆粕纤维对NR／BR基胎面胶复合材料力学性能的影响，采用RPA和DMTA研究了胎面胶的动态力学性能，论证了芳纶短纤维增强NR／BR复合材料具有良好的“模量-滞后平衡效应”。DMTA和RPA测试研究结果表明，采用芳纶短纤维增强的NR／BR复合材料在0℃下的内耗值有所升高，而在60℃下的内耗值略有降低，这对于轮胎胎面胶的抗湿滑性和降低滚动阻力具有重要意义。     

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     

Mechanical properties of glass fiber/organic fiber mixed–mat reinforced thermoplastic composites

The purpose of this study is to investigate the influence of different types of fibers on the mechanical properties of hybrid composite materials. Long and short glass fibers (GF) and different types of organic fibers, viz. aramid fiber, DuPont Kevlar‐49 (KF), liquid crystalline polymer (LCP), and vinylon (VF) in hybrid composites, were used to reinforced the high density polyethylene (HDPE) matrix. The long fiber hybrid composites were prepared in a “fiber separating and flying machine,” while the short fiber hybrid composites were prepared in an “elastic extruder.” The total amount of fibers used in both long and short fiber hybrid composites was fixed at 20 vol%. The influence of fiber content, length, and mixing ratio on mechanical properties, such as tensile, bending, Izod and high rate impact strength, as well as viscoelastic propertics in the solid state, was studied. Fracture surfaces of the materials were also examined using a scanning electron microscopy.     

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。     

Synthesis and characterization of the novel meta‐modified aramid fibers with liquid crystalline properties

To improve the interfacial adhesion between the meta‐aramid fibers and the matrix, the new method of interfacial polymerization was used to complete the aramid's surface modification. Two new kinds of grafted fibers which had liquid crystalline properties were prepared. The structure and properties of the aramid fibers before and after modification were characterized by scanning electron microscope (SEM), Fourier transform infrared, differential scanning calorimetry, and polarizing optical microscope. The surface of grafted aramid fibers was very rough. The range of liquid crystalline phase of the grafted fibers AF‐1 and AF‐2 on the cooling scan, respectively, is from 147 to 209°C and from 163 to 221°C. It was novel that the grafted fibers with rigid‐rod structure had typical nematic texture. The grafted aramid fibers as the ideal substitute material of asbestos were used as reinforcing fibers in nitrile butadiene rubber (NBR) matrix. Combining with NBR, the composites reinforced with the unmodified and grafted aramid fibers were synthesized. The micrographs of the composites' fractured surface were studied by SEM. The mechanical properties of the grafted fibers/NBR composites were superior to the unmodified fibers/NBR composites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

混杂比对交织芳纶碳纤维复合材料力学性能的影响

为了分析混杂比对层内混杂复合材料力学性能的影响,利用交织方式制备芳纶碳纤维混杂增强体织物,并通过交织物纬纱系统中芳纶与碳纤维的纱线配置比例调整碳纤维在增强体结构中的混杂比。采用真空辅助成型技术制备层内混杂结构的芳纶碳纤维混杂（ACFH）复合材料,并对复合材料的拉伸性能、弯曲性能和冲击性能进行测试。结果表明,增强体纬向系统中芳纶与碳纤维的不均质性对ACFC复合材料经方向上的拉伸强度起消极作用;混杂比的增加对ACFC复合材料的纬向拉伸破坏和弯曲损伤具有抑制作用;纬向上,ACFC复合材料的拉伸强度最高提高了近6倍,弯曲强度最小增加了4.04倍;芳纶与碳纤维混杂协同作用有利于ACFC复合材料的抗冲击性能改善,且混杂比存在最佳值。     

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.     

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.     

3种高性能纤维材料的研究进展

重点围绕国内外高性能纤维的发展水平及其在复合材料中的主要用途,介绍了目前广泛应用于树脂基复合材料的3种高性能纤维———碳纤维、芳纶及超高相对分子质量聚乙烯纤维,分析对比了这3种高性能纤维的国内外最新研究进展,并对今后的应用前景提出了展望。     

Fiber–matrix interactions in aramid‐short‐fiber‐reinforced thermoplastic polyurethane composites

The mechanical and dynamic mechanical properties of thermoplastic polyurethane (TPU) elastomers reinforced with two types of aramid short fibers, m‐aramid (Teijin‐Conex) and copoly(p‐aramid) (Technora), were investigated in this study with respect to the fiber loading. In general, both types of composites exhibited very similar stress–strain behaviors, except that Technora–TPU was stronger than Conex–TPU. This was primarily due to the intrinsic strength of the reinforcing fibers. Both types of fibers reinforced TPU effectively without any surface treatment. This could be attributed to good fiber–matrix interactions, which were revealed by the broadening of the tan δ peak in dynamic mechanical analysis. Furthermore, the morphologies of cryogenically fractured surfaces of the composites and extracted fibers, investigated with scanning electron microscopy, revealed possible polar–polar interactions between the aramid fibers and TPU matrices. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1059–1067, 2003