Showing papers on "Epoxy published in 2006"
TL;DR: In this paper, the electrical and thermal conductivity of nanoparticulate filled epoxy resins is evaluated with respect to the influence of the type of carbon nanotubes (SWCNT, DWCNT and MWCNT).
1,049 citations
TL;DR: The daily human intake of BPA is <1 microg/kg body weight/day on the basis of several studies, and whether these doses can have an adverse endocrine disruptive effect on humans, especially fetuses, needs to be studied carefully.
776 citations
TL;DR: In this paper, a comprehensive study was carried out on series of nanocomposites containing varying amounts of nanoparticles, either titanium dioxide (TiO 2 ) or aluminium oxide (Al 2 O 3 ).
766 citations
TL;DR: In this paper, the potential of carbon nanotubes as nanofillers in polymers, but also stresses out the limitations and challenges one has to face dealing with nanoparticles in general.
600 citations
TL;DR: The electrical and thermal conductivities of epoxy composites containing 0.005-0.5% of single-walled (SWNTs) or multi-weled (MWNT) carbon nanotubes have been studied.
573 citations
TL;DR: In this article, carbon nanotubes (CNTs) were treated by an acidic solution to remove impurities and modified subsequently by amine treatment or plasma oxidation to improve interfacial bonding and dispersion of CNTs in the epoxy matrix.
490 citations
TL;DR: In this article, a new lightweight fiber/metal laminate (FML) has been developed, which combines metal and polymer composite laminates to create a synergistic effect on many properties.
Abstract: Weight reduction and improved damage tolerance characteristics were the prime drivers to develop new family of materials for the aerospace/aeronautical industry. Aiming this objective, a new lightweight Fiber/Metal Laminate (FML) has been developed. The combination of metal and polymer composite laminates can create a synergistic effect on many properties. The mechanical properties of FML shows improvements over the properties of both aluminum alloys and composite materials individually. Due to their excellent properties, FML are being used as fuselage skin structures of the next generation commercial aircrafts. One of the advantages of FML when compared with conventional carbon fiber/epoxy composites is the low moisture absorption. The moisture absorption in FML composites is slower when compared with polymer composites, even under the relatively harsh conditions, due to the barrier of the aluminum outer layers. Due to this favorable atmosphere, recently big companies such as EMBRAER, Aerospatiale, Boing, Airbus, and so one, starting to work with this kind of materials as an alternative to save money and to guarantee the security of their aircrafts.
461 citations
TL;DR: SiO2/epoxy nanocomposites were formed in situ via a special sol-gel technique supplied by hanse chemie AG, in which silica nanoparticles with an average diameter of 25 nm were almost perfectly dispersed in the epoxy matrix.
436 citations
TL;DR: In this article, the mechanical properties of expanded graphite (EG) reinforced nanocomposites were investigated as a function of particle concentration and processing technique, and it was found that EG reinforced nano-composites showed higher elastic modulus than neat epoxy.
424 citations
TL;DR: An attempt has been made here to evaluate the deleterious effect of temperature on shear strength of carbon/epoxy and glass/ep oxygen composites during hygrothermal conditionings and the effectiveness of the relaxation process in the nullification of environmentally-induced damage in the composites.
424 citations
TL;DR: In this article, a simple but effective fiber treatment (i.e., alkalization) was proposed to enable a better adhesion between flax fibres and epoxy matrix.
Abstract: Present-day industry takes an interest in environment friendly materials, due to economic and ecological reasons. The use of natural materials in composite parts fits well into this picture: plant fibres that reinforce polymer matrices can replace glass fibres in many cases, although applications are often limited to non-structural parts. The poor interface in a non-treated natural fibre reinforced composite prevents the parts to be used to their full capacity. Consequently, this study concentrates on a simple but effective fibre treatment (i.e. alkalisation) that will enable a better adhesion between flax fibres and epoxy matrix. Parameters such as time and concentration are being optimised, in order to develop a continuous process for the treatment and resin impregnation of unidirectional flax fibre epoxy composites. This paper shows a clear improvement of the mechanical properties of the resulting material: e.g. a mild treatment in a 4% NaOH solution for 45 s will increase the transverse composite strength up to 30%.
TL;DR: In this paper, a series of [0/90]3s laminates with varying void contents were fabricated and a characterization of void distribution, size, and shape within the Laminates was obtained using ultrasonic c-scan and optical metallography techniques.
TL;DR: In this paper, a systematic and comparative evaluation of the pyrolysis of halogen-free flame-retarded epoxy resins containing phosphine oxide, phosphinate, phosphonate, and phosphate (phosphorus contents around 2.6 wt%) and the fire behavior of their carbon fiber composites is presented.
TL;DR: In this paper, a new method was developed to construct atomistic molecular models of crosslinked polymers based on commercially important epoxy resin, which employed molecular dynamics/molecular mechanics schemes and assumed close proximity.
TL;DR: In this paper, a new series of microcapsules were prepared by in situ polymerization technology with poly(urea-formaldehyde) (PUF) as a shell material and a mixture of epoxy resins (diglycidyl ether of bisphenol A: DGEBPA) and 1-butyl glycidyl methyl ether (BGE) as core materials.
TL;DR: In this article, the mechanical and viscoelastic behavior of nanocomposites was investigated using a servohydraulic testing machine and a dynamic mechanical analyzer, respectively, and it was found that the addition of clay particles improved both the elastic modulus and storage modulus of pure epoxy significantly.
TL;DR: In this paper, the radar absorbing structures (RAS) having sandwich structures in the X-band (8.2-12.4 GHz) frequencies were designed and fabricated, and the reflection loss characteristics for multi-layer sandwich structures were calculated using the theory of transmission and reflection in a multi-layered medium.
TL;DR: In this article, a comparison between epoxy polymer concrete reinforced with natural fibers, unreinforced and reinforced with synthetic fibers is made, and a brief description of how the natural fibers are obtained and manufacturing process of polymer concrete is also made.
TL;DR: In this paper, a carbon nanotube (CNT) surface was successfully modified using the UV/Ozone treatment and a triethylenetetramine (TETA) solution for use as the reinforcement for polymer matrix composites.
TL;DR: In this paper, the effect of nanoclay additives on the mechanical properties of bisphenol A (DGEBA) epoxy resins was investigated, and it was observed that while the addition of Nanoclay significantly increased the elastic modulus and fracture toughness of DGEBA epoxy resin, it also significantly reduced the failure strength and failure strain.
TL;DR: In this paper, the structural properties of the as-prepared ZnO nanoparticles were studied in detail using thermogravimetry (TGA), differential thermal analysis (DTA), X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FT-IR) and transmission electron microscopy (TEM), respectively.
TL;DR: An effective functionalization method was investigated to take full advantage of the exceptional performance of both carbon nanotubes and epoxy polymer for composite application, and a significant improvement in the elastic modulus of the nanocomposite suggested an effective way to realize an industrial application of nanot tubes reinforcing epoxy composite.
Abstract: An effective functionalization method was investigated to take full advantage of the exceptional performance of both carbon nanotubes and epoxy polymer for composite application. Epoxy polymer curing agent, EPI-W, was grafted to the single-walled carbon nanotubes through diazotization. Fourier transformed infrared spectroscopy, Raman spectroscopy, differential scanning calorimetry, dynamical mechanical analysis and thermo-gravimetric analysis were performed to characterize the functionalization effect. The degree of functionalization was estimated to be 1 in 50 carbons in the nanotube framework. The elastic modulus of the nanocomposite was enhanced 24.6% with only 0.5 wt% loading of functionalized carbon nanotubes, in contrast to the 3.2% increase of un-functionalized carbon nanotube reinforced composite. This significant improvement suggested an effective way to realize an industrial application of nanotubes reinforcing epoxy composite.
TL;DR: In this article, the influence of adding 5 vol % of silica nanoparticles, obtained via a sol-gel process, on an Araldite-F epoxy was investigated.
Abstract: Within this study the influence of adding 5 vol % of silica nanoparticles, obtained via a sol–gel process, on an Araldite-F epoxy was investigated. To characterize toughening effects, compact tension specimens were used to obtain KIC and GIC. Additionally, tensile strength and E-Modulus were measured as well as differential scanning calorimetry and dynamic mechanical thermal analysis were carried out to evaluate the influence on the thermal properties of the epoxy because of addition of the particles. Electronic microscopy was used to check dispersion quality and fracture surfaces, in transmission mode and scanning mode, respectively. The addition of 5 vol %. silica-nanoparticles could improve the stiffness and the toughness of an epoxy resin at the same time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1849–1855, 2006
TL;DR: In this paper, the authors investigated the effect of the self-same epoxy interlayer on the interlaminar fracture properties under modes I and II loadings on the bases of the fractographic observations and mechanism considerations.
TL;DR: In this paper, a novel approach assisted with solvent was developed to disperse clay into epoxy matrix, and the dispersion of clay was examined by means of optical microscopy (OM), wide angle X-ray scattering (WAXS) and transmission electron microscopy(TEM).
Abstract: A novel approach assisted with solvent was developed to disperse clay into epoxy matrix. The dispersion of clay was examined by means of optical microscopy (OM), wide angle X-ray scattering (WAXS) and transmission electron microscopy (TEM). Batches of cured samples containing 1–3 wt.% silane-modified clay (SMC) were prepared and their thermal/mechanical properties were studied by dynamic mechanical analysis (DMA), tensile and fracture tests. Improvements on storage modulus, Young’s modulus and fracture toughness were achieved with incorporation of SMC clay. The fracture surfaces of the nanocomposites were imaged by scanning electron microscopy (SEM) to investigate the toughening mechanisms.
TL;DR: In this paper, the authors investigated the delamination fatigue crack growth behavior in carbon fiber (CF)/epoxy laminates with two kinds of interlayer/interleaf and found that the crack path shifted from the heterogeneous interlayer region (Stage I) to the inter-layer/base lamina interface (Stage II) with the increase of the crack length.
TL;DR: In this paper, the electrical insulation properties of a newly prepared composite material by nano-and micro-filler mixture were investigated by measuring the thermal expansion coefficient and insulation breakdown properties by a needle-plate electrode method.
Abstract: This paper focuses on the electrical insulation properties of a newly prepared composite material by nano- and micro-filler mixture. Nano- and micro-filler mixture composites were made by dispersing nano-scale layered silicate fillers and micro-scale silica fillers in epoxy resin. To investigate the effects of nano- and micro-filler mixture, the thermal expansion coefficient and insulation breakdown properties by a needle-plate electrode method were measured for the filler mixture composite and the conventional filled epoxy. The filler mixture composite had almost the same thermal expansion coefficient as the conventional filled epoxy. In a continuous voltage rising test, the filler mixture composite had 7% higher insulation breakdown strength than the conventional filled epoxy. Moreover, under constant AC voltage (10 kV at 1 kHz), the filler mixture composite had an insulation breakdown time of more than 20,000 minutes whereas the conventional filled epoxy had a breakdown time of 830 minutes. Electron microscope observation showed that the area surrounded by dispersed micro-scale silica fillers were also filled with the nano-scale layered silicate fillers. Furthermore, the estimate of spacing between the fillers and the filler/epoxy interface area showed a more densely-packed structure of the filler mixture composite than the conventional filled epoxy. The morphological feature of the filler mixture composite seems to improve its insulation breakdown strength and time.
TL;DR: In this paper, the authors evaluate the different reinforcement roles of carbon nanotubes in those nanocomposites with different matrix stiffness while the curing process is controlled, and they find that in the soft and ductile composites, carbon Nanotubes show a significant reinforcement without fracture strain decreasing.
TL;DR: In this article, a total of eight reinforced concrete (RC) beams were tested and analyzed: one control beam and seven reinforced with three to six layers of carbon fiber sheets bonded by an inorganic epoxy.
TL;DR: A series of polymer-clay nanocomposite (PCN) materials that consist of siloxane-modified epoxy resin and inorganic nanolayers of montmorillonite (MMT) clay has been prepared through a thermal ring opening polymerization using 1,3-bis(3-aminopropyl)-1,1,3,3tetramethyldisiloxane as a curing agent.
Abstract: A series of polymer–clay nanocomposite (PCN) materials that consist of siloxane-modified epoxy resin and inorganic nanolayers of montmorillonite (MMT) clay has been prepared through a thermal ring opening polymerization using 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane as a curing agent. These PCN materials at low clay concentration in the form of coating on cold-rolled steel (CRS) were found to be much superior in corrosion protection over those of pure epoxy resin when tested for performance in a series of electrochemical measurements of corrosion potential, polarization resistance, corrosion current, and impedance spectroscopy in 5 wt.% aqueous NaCl electrolyte. The as-prepared materials were characterized by infrared spectroscopy, wide-angle X-ray diffraction, and transmission electron microscopy. After measurements, we found advanced protection against corrosion on CRS coupon compared to bulk epoxy resin. Molecular (e.g., O2, N2, and H2O) permeability of epoxy resin–clay nanocomposite membranes was found to be lower than that of bulk epoxy resin along with the loading of nanoclay based on the studies of gas and vapor permeability analysis. Moreover, the epoxy resin–clay nanocomposite materials have significant advantages over standard epoxy resins such as lower water absorption, lower cure shrinkage, moderate glass transition temperature (Tg), and higher tensile strength.