PE/UPR玻璃钢界面粘接研究

选用SGP10底涂处理剂及改性α-氰基丙烯酸酯胶粘剂,成功地用于水处理容器PE内胆和UPR玻璃钢复合材料层之间粘接,试验结果表明二者之间粘接牢固,这对于复合结构水处理容器质量,使用寿命有很重要意义。     

Influence of fiber wettability on the interfacial adhesion of continuous fiber‐reinforced PPESK composite

Interfacial adhesion between fiber and matrix has a strong influence on composite mechanical performance: better interfacial adhesion can enhance composite transverse properties, flexural properties, and interlaminar shear strength, and so on. To exploit the reinforcement potential of the fibers in advanced composite, it is necessary to reach a deeper understanding on the relation between fiber wettability and interfacial adhesion. In our experiment, we study the influence of fiber wettability on interfacial properties of fiber/PPESK composites by choosing three kinds of fibers with different wettabilities. The relation between fiber wettability and surface free energy was discussed, and the influence of fiber wettability on the interfacial property of fiber/PPESK composites was analyzed. Results indicate that higher surface free energy can enhance the wettability between fiber and matrix, and the humid resistance and interfacial adhesion can be improved at the same time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2544–2551, 2006     

Relation of interfacial adhesion in Kevlar®/epoxy systems to surface characterization and composite performance

A central problem in composite materials is the poorly understood relation between the nature of the surfaces at the fiber/matrix interface, the actual interfacial bond strength, and interface-sensitive composite properties, in this study on the Kevlar®/epoxy composite system, the interface was varied chemically by fiber sizings. The sized and unsized fiber surfaces and the cured matrix surface were characterized by contact angle measurements. The interfacial shear strength was directly measured by single-filament pull-out tests of sized and unsized fibers in epoxy matrix. The shear strengths of the composites made with sized and unsized fibers were measured. The results from surface analysis, interfacial shear tests, and composite shear tests were consitent. This suggests that surface-contact-angle analysis and single-filament pull-out tests may be helpful in screening strength of the composite.     

聚吡咯层对碳纤维/环氧树脂复合材料界面粘结性能的影响

以三氯化铁为氧化剂,采用吡咯液相沉积聚合方法制备聚吡咯-碳纤维(PPy-CF),然后与环氧树脂(EP)复合,制得PPy-CF/EP复合材料,并对其进行拉伸性能测试,研究了聚合温度对PPy-CF/EP复合材料界面剪切强度(IFSS)的影响。结果表明:在CF表面吡咯沉积聚合最佳工艺条件为聚合温度70℃,时间30min,经过吡咯沉积聚合改性后,得到的PPy-CF/EP复合材料的IFSS有所提高;最佳条件下制得的PPy-CF/EP复合材料的IFSS是CF/EP复合材料的1.24倍;在PPy-CF中,PPy与CF之间无化学键作用,PPy-CF/EP复合材料的IFSS与PPy-CF表面含氧基团和粗糙度有关;吡咯化学沉积聚合改性是一种提高纤维与树脂界面粘结性能的有效方法。     

Evaluation of interfacial adhesion in sheath/core composite fibers

Rayon/nylon sheath/core composite fibers were produced using a wire coating-type process. Fumaric acid (FA) was chosen as an adhesion promoter to pretreat the nylon core fiber before rayon coating to improve the adhesion between skin and core. Different FA pretreatment concentrations and times were used and the effects of the pretreatment conditions on the adhesion were evaluated. A fiber pull adhesion test technique was developed to determine the interfacial shear strength of the composite fibers. The results indicated that the interfacial adhesion in the rayon/nylon composite fibers was significantly improved for specific sets of FA application conditions. Adhesion results were confirmed with electron microscopy. © 1993 John Wiley & Sons, Inc.     

Enhanced interfacial adhesion in carbon fiber/poly (acrylonitrile‐butadiene‐styrene) composite through fiber surface treatment by an emulsion sizing

To improve the interfacial adhesion between carbon fiber (CF) and poly(acrylonitrile‐butadiene‐styrene) (ABS) thermoplastic, an emulsion sizing whose film former was a terpolymer N‐phenylmaleimide‐styrene‐maleic anhydride (NSM)/ABS mixture was prepared. NSM, an efficient heat‐resistant modifier for ABS, could make the film former possess a superior heat resistance, which helped the sizing layer maintain integrity during the preparation of CF/ABS composite. Moreover, differential scanning calorimetry (DSC) results demonstrated that the glass transition temperature (T_g) of the NSM modified ABS achieved an improvement of 25.3°C. Particle size and distribution of the sizing agent were investigated to evaluate its stability. The FTIR spectrum obtained demonstrated that the chemical compositions of the sized CF got greatly changed and numerous functional groups appeared on sized CF. Abrasion resistance and fluffs of CF were tested and the results indicated that the sized CF obtained an appreciable enhancement in handleability. Interlaminar shear strength (ILSS) results revealed, after sizing, that the ILSS enhanced by 26.6%, due to the inserted sizing layer between CF and ABS matrix. POLYM. COMPOS., 37:2940–2949, 2016. © 2015 Society of Plastics Engineers     

基于5G打造激光导航移动机器人新模态

激光导航AGV因其能够适应复杂的应用场景和繁琐、智能的指令需求,以及在精益化柔性生产方面展示出来的无与伦比的优势,已成为目前搬运机器人的高水平代表,并在越来越多的智能制造领域得以投入使用。     

Mechanical and optical characterization of a photoviscoplastic material

The mechanical and optical properties of a polyester blend over a wide range of strain rates has been investigated for loading and unloading. The mechanical behavior, while being complex, was modeled adequately with a generalization of the four-parameter viscoelastic model. The optical behavior has at least a three-phenomenological coefficient dependence on the mechanical variables. Further, the stress birefringence is of opposite sign to that of the deformation.     

运用RBF神经网络设计复合材料界面性能

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。利用径向基函数神经网络，建立起工艺参数与复合材料界面性能的关系模型。同时给出实例来验证此方法的有效性。     

Rheological characterization of polymers fiber composite

The use of reinforced polymer composites has continued to show substantial growth due to desirable cost and performance characteristics, especially related to mechanical properties. Wollastonite and glass fibers are materials that can be used to improve polymer performance. Its vast array of applications suggests potential usage in various fields of work (e.g., plastics, friction materials paintings, coating, and construction products), but there is not much data available in the literature related to rheological properties of fiber reinforced polymers. In this work, a study of shear and extensional properties of composite materials containing wollastonite and glass fibers is performed using rotational and extensional rheometry. Suspensions containing different concentrations of wollastonite and glass fibers, in Newtonian and viscoelastic matrices are investigated. Results are obtained for different concentrations and temperatures. It is observed that even the addition of low fiber concentration can affect both shear and elongational properties, leading to different final products characteristics. POLYM. COMPOS. 34:1269–1278, 2013. © 2013 Society of Plastics Engineers     

A composite material made of carbon nanotubes partially embedded in a nanocrystalline diamond film

A composite material, made of carbon nanotubes (CNTs) partially embedded in a nanocrystalline diamond film was produced. The diamond film was first decorated with palladium or nickel nanoparticles. An array of nanopores was drilled in the film in a hot filament CVD (HFCVD) reactor thanks to the anisotropic etching that takes place under the nanoparticles. During this etching process, the metallic particles penetrate the diamond film to a controlled depth, thus remaining at the bottom of the nanopores. The buried nanoparticles remain catalytically active and are used to grow a multiwall carbon nanotube forest using HFCVD in the same reactor without breaking the vacuum. The quality of the CNTs was assessed by scanning electron microscopy and Raman spectroscopy. The interface between the carbon nanotubes and the diamond was characterized by ultrasonication, lateral force microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. As a result of these characterizations, we demonstrate that the buried carbon nanotubes exhibit higher mechanical stability and improved electrical behavior compared to CNTs directly grown on the diamond surface.     

Improved interfacial adhesion in carbon fiber/epoxy composites through a waterborne epoxy resin sizing agent

A series of self‐emulsified waterborne epoxy resin (WEP) emulsions were used as surface sizing for carbon fibers (CFs) to improve the interfacial adhesion between the CF and epoxy matrix. In this work, the hydrogenated bisphenol‐A epoxy resin (HBPAE) was modified by polyethylene glycol (PEG) with molecular weights of 400, 800, 1000, 1500, 2000, 4000, and 6000 g/mol. The properties of the WEP emulsion were examined by Fourier transform infrared spectroscopy, dynamic light scattering, and transmission electron microscopy. The surface characteristics of sized CFs were evaluated using scanning electron microscopy, atomic force microscopy, and X‐ray photoelectron spectroscopy. Afterwards, CF/EP composites were prepared and their fracture surface and interlaminar shear strength (ILSS) were examined. The results indicated that PEG2000 modified HBPAE sizing had the optimum emulsion stability and film‐forming ability. Meanwhile, the results also demonstrated that a continuous and uniform sizing layer was formed on the surface of CFs and the surface sizing was excellent in improving the chemical activity of CFs. Compared with unsized CFs, the O1s/C1s composition ratio was observed to increase from 11.51% to 33.17% and the ILSS of CF/EP composites increased from 81.2 to 89.7 MPa, exhibiting better mechanical property than that of commercial Takemoto S64 sized CFs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44757.     

玄武岩连续纤维及其复合材料

介绍了玄武岩连续纤维及其复合材料在国内外发展的历史和现状,以及该新材料的主要特点、应用领域。     

Enhanced interfacial adhesion via interfacial crystallization between sisal fiber and isotactic polypropylene: direct evidence from single‐fiber fragmentation testing

Bioresource natural sisal fiber (SF) was used to prepare single fiber‐reinforced isotactic polypropylene (iPP) composites. Three kinds of interfacial crystalline morphologies, spherulites, medium nuclei density transcrystallinity (MD‐TC) and high nuclei density transcrystallinity (HD‐TC), were obtained in the single fiber‐reinforced composites by implementing quiescent or dynamic shear‐enhanced crystallization and by modulating the compatibility interaction between SF and iPP. The development of interfacial shear strength (IFSS) during the interfacial crystallization process was demonstrated for the first time using a combination of single‐fiber fragmentation testing and optical microscope observation. A close correlation between IFSS and morphological characteristics of interfacial crystallization was well elucidated. The increases in IFSS were very different for spherulitic, MD‐TC and HD‐TC morphologies. The highest IFSS obtained was 28 MPa, after the formation of HD‐TC, which was about 62% of the tensile strength of neat iPP (45 MPa). These results offer powerful and direct evidence that interfacial crystallization could play an important role in the enhancement of interfacial adhesion of real SF/iPP composites. © 2013 Society of Chemical Industry     

UP/PU嵌段共聚树脂/玻璃纤维界面粘结性的研究

合成了一种异氰酸酯嵌段共聚改性不饱和聚酯树脂(UP/PU),并以玻纤增强制备了复合材料(GFRP)。通过接触角、拉伸性能、弯曲性能测定和扫描电镜观察研究了UP/PU GFRP界面的粘结性能。结果表明:UP/PU树脂与玻璃表面的接触角为20°,对玻璃表面的润湿性较通用邻苯型UP好;GFRP拉伸强度1 050 MPa,弯曲强度1 220 MPa,较通用邻苯型UP的GFRP分别提高了145%和78%,说明UP/PU与玻纤的界面粘结性能较好。     

化工设备材料表面及其对界面黏附强度的影响

设备材料的表面粗糙程度对污垢颗粒界面黏附力的影响较大。本文以设备材料粗糙表面为研究对象,考察了传统指标和分形指标的尺度独立性,发现分形指标随尺度的变化分为不稳定分形区和稳定分形区。通过对二维表面轮廓线的分析,将区域分隔临界点的求取转化为取样长度和夹角α值的定量关系求解,通过实验得出其定量关系,找出稳定分形区。采用原子力显微镜测颗粒在不同粗糙表面的黏附力,结合固体污垢清除机理分析,发现表面的粗糙程度对界面黏附力的影响较大。研究表明Ra<0.4627μm时,随着表面粗糙度增加,黏附力减小;1.3461μm< Ra <2.9755μm时,黏附力逐渐增大;Ra>3μm时,黏附力保持稳定。黏附力随着分形指标的变化而变化,其变化趋势与传统指标正好相反。随着分形维数的增大,黏附力先是保持稳定,后逐渐增大,随着加工工艺的改变,表面粗糙程度有个剧烈的变化,分维值锐减,后逐渐增大。     

Fabrication and characterization of a novel Nafion-PTFE composite hollow fiber membrane

Nafion has been widely used in electrochemistry, but there are only a few reports on its application in other fields, such as, gas separation, even though it exhibits good performance. The primary reason for that is the high cost of Nafion and making a composite membrane with a thin Nafion layer is a potential solution to solve this problem. In this study, a novel Nafion-PTFE composite hollow fiber membrane, which had a thin (~5 μm) and detect-free Nafion layer on PTFE surface, without Nafion filling substrate pores was developed, differing from the reported ones in which Nafion resin was required to impregnate into porous PTFE membrane as thorough as possible to ensure the ion conductivity and operation stability. The surface morphology, crystallite, solubility in ethanol/water mixture, and water uptake of membranes were systemically investigated. The gas permeance tests were also conducted. The permeances of different gasses of prepared composite membranes were significantly enhanced compared with the commercial membranes due to the decrease of Nafion thicknesses, while the selectivity remained the same, verifying the detect-free structure of Nafion layer on PTFE substrate. This study provided a good reference for the preparation and application of low-cost Nafion composite membranes.     

Improvement in interfacial shear strength and fracture toughness for carbon fiber reinforced epoxy composite by fiber sizing

Carbon fiber was sized by a thermoplastic polymer solution mixed with a compatible amine monomer. The effect of sizing agent on tensile strength was studied by single fiber strength testing. Interfacial properties of re‐sized carbon fiber/epoxy composite were investigated, with special emphasis on the improvement in both interfacial shear strength and interfacial fracture toughness. The interfacial fracture toughness of composites was characterized by calculating the effective interphase fracture energy rate through the information obtained from the force–displacement curve in the micro‐bond test. Fracture topography of micro‐bond specimen was observed to discuss the interfacial fracture mechanism. POLYM. COMPOS., 35:482–488, 2014. © 2013 Society of Plastics Engineers     

The role of an interfacial interpenetrating polymer network formation on the adhesion of resin composite layers in immediate dentin sealing

The aim of this study was to evaluate the influence of chemical and physical processes at the resin-composite and composite-cement interface as a function of the resin composite's water exposure on the bond strength (BS) between these two components. The free-radical concentration was studied using electron paramagnetic resonance (EPR), while the chemical changes at the resin composite's surface were studied using attenuated total-reflection FTIR spectroscopy (ATR-FTIR). The free-radical concentration in the studied samples dropped to 10% in 24 h, indicating that prolonged BS values do not correlate with the free-radical concentration. An alternative bonding mechanism between the resin composite and the composite cement was proposed, based on the formation of an interpenetrating polymer network (IPN) layer at the interface. As proven using ATR-FTIR spectroscopy, changes occurred at the resin composite's surface as a consequence of water exposure, comprising the diffusion of water molecules into the resin composite. These changes reduced the diffusion rate of the composite cement's phosphorus-containing monomers into the resin composite, as shown by the linescan SEM-EDS analysis of phosphorus, thus reducing the thickness of the IPN layer at the interface and consequently reducing the BS between both components.This study reveals that the concentration of free radicals at the surface of the resin composite is only relevant immediately after the polymerisation to the bond strength between the resin composite and the composite cement. Therefore, an alternative explanation is given by applying the theory of the formation of a gradient IPN at the interface between the resin composite and the adhesive cement by changes in the rate of diffusion of the adhesive cement's monomers into the resin composite as a function of the resin composite's exposure to water.     

PA6/ODOPB/GNPs阻燃复合材料及纤维的制备与性能表征

将磷系阻燃剂10-(2,5-二羟基苯基)-10-氢-9-氧杂-10-磷杂菲-10-氧化物(ODOPB)与纳米石墨片(GNPs)复配加入到聚酰胺6(PA 6)聚合体系中,通过原位聚合的方式制备了PA 6/ODOPB/GNPs复合材料,再经熔融纺丝得到PA 6/ODOPB/GNPs复合纤维,并对复合材料及纤维的阻燃性能进行了研究。结果表明:ODOPB的加入导致复合材料的相对黏度下降,GNPs的添加对复合材料的相对黏度无明显影响;ODOPB与GNPs的复配协同作用提升了复合材料及纤维的阻燃抗熔滴性能,表现为凝聚相阻燃作用,ODOPB对PA 6具有优异的阻燃效果,GNPs具有优异的抗熔滴和抑烟效果;当添加ODOPB质量分数为5%、GNPs质量分数为2%时,复合材料的极限氧指数(LOI)可达31.8%,垂直燃烧达到V-0等级,复合纤维的LOI达29.8%;加入ODOPB及GNPs均会导致复合纤维的力学性能下降,当ODOPB质量分数为5%、GNPs质量分数为2%时,所得复合纤维的断裂强度从纯PA 6纤维的3.3 cN/dtex下降至1.5 cN/dtex。