碳纳米管/环氧树脂复合材料研究

将碳纳米管加入到环氧树脂中，经超声分散处理制得复合材料。研究了碳纳米管的加入量与分散程度对材料抗拉强度的影响。研究表明：碳纳米管的加入量小于3％时可有效提高复合材料的抗拉强度，加入量为1．7％，抗拉强度达到最高值52．38MPa，比纯环氧树脂(26．40MPa)提高98．4％。     

高速剪切对碳纳米管/环氧树脂复合材料导电性能的影响

为提高碳纳米管在复合材料中的分散性,利用高速剪切分散工艺将碳纳米管分散于环氧树脂基体中制备碳纳米管/环氧树脂复合材料,研究了剪切时间和碳纳米管加入量对复合材料导电性能的影响.结果表明:剪切速率一定时,复合材料表面电阻率随剪切时间的增加而降低,但当剪切时间超过10min,对导电性能的影响不再明显;随着碳纳米管加入量的增加,复合材料导电性能提高,当碳纳米管的质量分数高于10%时,导电性能的变化趋于平缓.     

碳管分散程度对环氧树脂复合材料的摩擦磨损性能影响

采用浇铸法,制备多壁碳纳米管(MWNTs)/环氧树脂(EP)复合材料,利用M-200摩擦磨损试验机研究了MWNTs含量、分散时间及方式对环氧复合材料摩擦磨损性能影响,通过SEM、TEM分析试样磨损形貌表面、MWNTs分散程度。结果表明:碳纳米管添加量1.5%(质量分数)时,MWNTs/EP复合材料比环氧树脂摩擦因数降低17.8%,磨耗率降低91.7%;加入碳纳米管降低了复合材料粘着磨损与疲劳剥落;延长超声波时间及采用高功率超声波仪器能够有效提高碳纳米管分散程度,提高复合材料摩擦磨损性能。     

离子液体改性环氧树脂复合材料摩擦学性能研究

为探讨离子液体的加入对环氧树脂固化过程及摩擦学性能的影响,制备离子液体(1-丁基-3-甲基咪唑六氟磷酸盐)改性环氧树脂复合材料,并通过红外光谱、核磁共振氢谱、扫描电镜元素分析等考察离子液体在环氧树脂中的存在及分散状态,分析离子液体含量对复合材料动态热力学性能及减摩抗磨性能的影响.结果表明:离子液体与环氧树脂本体及固化剂...     

聚氨酯/碳纳米管复合材料的摩擦性能

采用溶液共混法制备聚氨酯/碳纳米管复合材料,探讨碳纳米管含量和超声分散时间对聚氨酯/碳纳米管复合材料摩擦性能的影响。结果表明:随着碳纳米管含量的增加,聚氨酯/碳纳米管复合材料的摩擦因数逐渐降低,随着载荷的增大,摩擦因数有所减小;超声分散时间对聚氨酯/碳纳米管复合材料摩擦性能影响不大;碳纳米管具有较好的润滑性质,可以降低聚氨酯/碳纳米管复合材料的摩擦因数,改善聚氨酯的摩擦性能。     

碳纳米管增强聚合物复合材料的界面脱黏及应力分布

碳纳米管和复合材料基体间的界面力学行为是影响复合材料宏观力学性能的重要因素,为此本文利用有限单元法对单壁碳纳米管增强聚合物复合材料的界面脱黏、切应力分布及拔出载荷进行了数值模拟。建立了一个轴对称三圆柱壳模型,引入ABAQUS中的Cohesive单元模拟了单壁碳纳米管和聚合物基体之间的界面层,分析了单壁碳纳米管的长细比、界面强度以及热残余应力等因素对碳纳米管与聚合物基体间的界面切应力以及拔出载荷的影响。模拟结果表明：当单壁碳纳米管的长度变化为50~100 nm、与基体之间的界面强度为50~100 MPa、环境温度变化为100℃ 时,碳纳米管的长细比、界面强度以及由于热失配所引起的残余应力对单壁碳纳米管与聚合物基体间的界面切应力以及拔出载荷有着显著的影响。     

液相法制备CNTs/PP复合材料的摩擦性能

采用液相及热压成型法制备碳纳米管/聚丙烯复合材料,对其进行摩擦磨损测试,观察磨损表面形貌研究其摩擦机理。结果表明:超声分散可将2.0 wt%范围内的碳纳米管均匀分散在聚丙烯基体中,碳纳米管的加入可减小复合材料的摩擦系数、降低磨损率,有效地改善聚丙烯基复合材料的摩擦性能。当碳纳米管加入量为2.0wt%时,复合材料具有良好的摩擦性能:摩擦系数0.380、磨损率仅有3.47×10-8mm3/N·m,分别比聚丙烯降低了18.6%和57.7%。这主要归因于均匀分布的碳纳米管具有自润滑效应及良好的导热性,可有效地减小复合材料的摩擦系数,提高热稳定性,从而有效改善耐磨性;碳纳米管的添加使复合材料从粘着磨损转向磨粒磨损与疲劳磨损。     

碳纳米管表面镀覆对碳纳米管-银复合材料性能的影响

研究了碳纳米管的表面镀覆处理对复合材料性能的影响，结果表明，碳纳米管经过化学镀银处理后用于制造复合材料，可以改善碳纳米管在金属基体中的分散性，提高复合材料的界面结合力，提高复合材料的硬度、导电性、抗弯强度。断口分析表明，碳纳米管未进行化学镀时，由于碳纳米管-银的弱界面结合，使碳纳米管拔出长度较长，在碳纳米管经化学镀后，由于改善了碳纳米管-银的界面结合状态，使碳纳米管拔出长度较短。     

碳纳米管/金属复合材料的研究现状与动向

碳纳米管/金属复合材料具有优异的理化和力学性能。综述了碳纳米管金属基复合材料的国内外研究现状,分析了制约碳纳米管金属基复合材料广泛应用的因素,即碳纳米管的分散状态及其与金属基体的界面结合问题。最后,对制备碳纳米管金属基复合材料存在的问题及今后的研究动向进行了分析。     

嵌入HNBR阻尼薄膜的共固化复合材料制作研究

提出一种可以与玻璃纤维/环氧树脂预浸料共固化的HNBR高阻尼黏弹性材料,提出使用四氢呋喃(THF)作为溶剂,将该高阻尼材料制成原胶料溶液,采用双面刷涂工艺,将玻璃纤维/环氧树脂复合材料制成带阻尼薄膜的预浸料,按照设计的铺层根据热压罐固化工艺制成嵌入HNBR阻尼薄膜的共固化高阻尼复合材料试件,模态试验和层间剪切试验验证了该工艺和黏弹性材料组分的有效性,其层间结合力最高可达9.4 MPa,其一阶模态损耗因子可达3.92%。     

聚乙烯亚胺修饰碳纤维对环氧树脂复合材料性能的影响

为提高碳纤维与环氧树脂的界面结合性能,从而提高复合材料的摩擦学性能,用聚多巴胺和聚乙烯亚胺对碳纤维进行表面修饰,利用光谱分析仪和扫描电子显微镜分析修饰前后碳纤维表面的化学组成和微观结构,利用万能材料试验机和摩擦磨损试验机考察碳纤维增强环氧树脂复合材料的力学性能和摩擦学性能。结果表明：碳纤维经表面处理之后的粗糙程度和活性官能团增多,改善了纤维与树脂之间的界面结合,使得复合材料的弯曲强度和拉伸强度得到不同程度的提高;与未修饰碳纤维增强的环氧树脂复合材料相比,表面修饰碳纤维增强环氧树脂复合材料的耐磨性能得到了很大程度的提高,复合材料的磨损机制也由疲劳磨损转变为磨粒磨损。     

Tribological and Mechanical Behaviour of Epoxy/Nanoclay Composites

Due to the nature and availability of nanoclay material, its application as reinforcement of composite materials is well justified. In this work, organo-montmorillonite filler with an epoxy resin matrix was characterised, regarding its mechanical and tribological behaviour. The influence of water ageing was analysed concerning its mechanical properties. Tribological tests were performed in dry and water lubricated environments. The mechanical properties of both the epoxy resin and composite specimens tend to decrease with water ageing. The negative influence of particle agglomeration was verified in the mechanical and tribological properties, especially with high content of filler material.     

Tribological properties of epoxy nanocomposites: III. Characteristics of transfer films

The multiple parts of this study are intended to experimentally and analytically elaborate the tribological properties of epoxy nanocomposites, reinforced by short carbon fibres (SCF), nano-TiO₂ particles, polytetrafluorethylen (PTFE) powders and graphite flakes, in order to understand the role of fillers in modifying the wear behaviour of the materials. In this part, the influences of two solid lubricants, PTFE and graphite, were studied and compared. The transfer films established with two lubricants in sliding wear of epoxy nanocomposites against metallic counterparts were characterised under different sliding conditions. The morphology of transfer films was examined using scanning electronic microscopy (SEM), while their mechanical properties were investigated using micro-hardness tests. A method was proposed to determine the thickness of transfer films based on micro-indentation. The role of transfer films in dissipation of frictional heating was also studied. Epoxy nanocomposites containing both PTFE powders and graphite flakes showed a synergised effect in wear performance, especially under very severe wear conditions.     

环氧树脂材料改性研究及其在天线罩中的应用

文中介绍了环氧树脂材料的组成及改性,主要涉及增韧、提高耐热性及介电性能的改性研究,并列举了环氧树脂材料在天线罩上的实际应用情况,如用作天线罩基体材料、粘接用发泡胶等。通过各种改性,环氧树脂材料展现了较高的机械性能、较低的介电常数及介电损耗角正切值等电学性能,可满足地面、船载、机载等各种场合天线罩的应用需求。     

Moisture and gamma‐ray irradiation effects on the mechanical properties of carbon fibre–reinforced plastics

The effects of γ‐irradiation and moisture absorption on the mechanical properties of carbon fibres–epoxy resin composites were studied. The properties dominated by the matrix and fibre–matrix interface (interlaminar and in‐plane shear strength) were measured at room temperature using standard tests. These tests were carried out before and after exposures to gamma irradiation and before and after immersion in water at 80°C during 21 days. The dosage of gamma irradiation was up to 11.7 MGy. The micrographs of surfaces fractured in performed tests were observed on a scanning electron microscope. They were analyzed with consulting the stated effects on mechanical properties and the measured values of the glass transition temperature of tested coupons before and after irradiation and immersion in water. The obtained results show that moisture and irradiation, if they act one after the other, have a significant influence on the degradation of matrix‐dominated mechanical properties of the tested carbon–epoxy composite.     

An investigation of the fretting behaviour of low friction coatings on steel

Three different low friction coatings on steel (electrolytically deposited cadmium, PTFE solid lubricant in epoxy resin and PTFE solid lubricant in polyimide resin) were studied in order to relate their fretting behaviour with mechanical properties. Particular importance was given to adhesion which was measured using a scratch test. Fretting tests were carried out on the steel substrate and on the coatings under the same conditions. The major parameters of the tribological system were identified and then quantified. The values of the parameters obtained for each coating were compared with the corresponding values for uncoated steel. The mechanical characteristics of the coatings and their fretting parameters were plotted using a polar diagram in order to give an overview of the fretting behaviour of each coating. Differences were noted and the corresponding parameters were identified. The influence of the adherence of the coating and of the fretting test load on the lifetime of the coating was determined.     

Mechanical and Tribological Behavior of Epoxy/Silica Nanocomposites at the Micro/Nano Scale

Micro/nano scale indentation and scratch tests were taken on the epoxy/SiO₂ nanocomposites by using Hysitron TriboIndenter system. The influences of the filling amount of nano-SiO₂ particles on the mechanical and tribological properties of the composites were studied. The indentation results show that the hardness and stiffness of the composites rise from about 0.1878 and 2.5134 GPa for the matrix to 0.2493 and 3.5117 GPa, respectively by the addition of nano-SiO₂. The scratch tests indicate that the proper amount of silica particles can effectively reduce frictional coefficient and scratch depth, consequently improve the tribological properties of the epoxy matrix. Combined with the scratch surface morphologies, the improvements of the tribological behaviors are analyzed and the friction mechanisms of the epoxy/SiO₂ nanocomposites are discussed.     

Tribological studies on rubber-modified epoxies: influence of material properties and operating conditions

An epoxy material has been modified by chemically incorporating siloxane to improve fracture toughness. In this work the friction and wear properties are compared in two test configurations, a steel ball sliding on a cast epoxy surface and an epoxy pin sliding on a glass or a steel disk. The morphologies of the wear surfaces are compared. The friction and wear results indicate that the test configuration has a significant influence on the effect of the siloxane modifier. These effects are a result of different “tribological stresses” acting on the polymers and different wear mechanisms which respond to the different mechanical properties of the polymers. The effect of the siloxane modifier is more pronounced in the steel-ball-on-epoxy-disk configuration in which the wear rate is very sensitive to the size and spacing of the elastomeric domains which segregate during curing.     

碳纤维增强复合材料在空间光学结构中的应用

测试了碳纤维/环氧复合材料的力学性能,设计并测试了热膨胀系数,然后测试了空间辐射后的材料性能,并研究了在空间光学结构中应用碳纤维/环氧复合材料制品的工艺方法。研究表明:碳纤维/环氧复合材料具有高的比强度和比刚度,较铝合金结构可以减重30%以上;碳纤维/环氧复合材料的热膨胀系数可以根据需要进行设计,在需要的方向上可以设计成 "零"或负的热膨胀系数;在空间辐射条件下,碳纤维/环氧复合材料性能良好,其总质量损失为0.15%、可挥发的冷凝物质为7.66×10^-5 g/g、24 h水汽回吸率为0.12%。结果表明,碳纤维/环氧复合材料具有优良的性能指标,在空间光学结构中有广泛的应用。