Thermal and mechanical properties of carbon nanotube/epoxy nanocomposites reinforced with pristine and functionalized multiwalled carbon nanotubes (original) (raw)
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Journal of Composite Materials, 2015
In this study, the mechanical, thermal and viscoelastic properties of multi-walled carbon nanotube/epoxy nanocomposite at low-weight percentages of nanotubes are evaluated and discussed. In order to provide better interfacial interactions of constituent materials, the multi-walled carbon nanotubes are functionalized with combination of H2SO4/HNO3. Dynamic-mechanical thermal analysis test and hot plate thermal conductivity are performed to characterize temperature-dependent mechanical and thermal properties. Our results indicate that applying low weight fractions of functionalized multi-walled carbon nanotubes can effectively improve the elastic storage modulus (∼47%) and thermal conductivity (∼36%) as a function of temperature. All steps and characterization are described in detail. For higher concentration of multi-walled carbon nanotubes, SEM characterization of the fracture surfaces of the samples reveals that agglomeration of the nanotubes is the main reason for degradation of t...
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International Journal of Aerospace Engineering
The aim of this research is to study the tensile and shear properties and mechanical behavior of carbon nanotube- (CNT-) reinforced epoxy after the resulting composites have been exposed to different thermal cycling environments. Single-walled carbon nanotubes (SWCNTs) are cylindrical molecules that consist of rolled-up sheet of single-layer carbon atoms (graphene) with a diameter of less than 1 nanometer (nm). Thermal cycling environments can exist in many conditions, such as in-earth orbit for satellites which rotate around the earth and pass through the sun illumination and earth’s shadow, and for airplanes which fly in different altitudes with different temperatures. Carbon nanotube-reinforced epoxy is one of the nanocomposite materials which have been broadly used in many applications such as aerospace, automotive, electronics, and other industries. The goal of this study is to fabricate this nanocomposite with different multiwall and single-wall CNT concentrations and expose i...
— Carbon nanotubes (CNTs) got great attention because of their interesting physical and mechanical properties. Due to these interesting properties observed at the nanoscale have motivated scientific community to utilize CNTs as reinforcement in composite materials. In the present study, different CNTs and epoxy nano-composites with different wt% (1, 2, 3, and 4%) of f-MWCNTs were prepared and their surface morphology and orientation has been investigated in detail. Further, the surface investigation, electrical and mechanical tests were carried out on CNTs-filled and unfilled epoxy at maximum sonication time 30 minute to identify the loading effect on the properties of the materials. Experimental results depicts well dispersion of f-MWCNTs, significant improvement that the resistivity of pure epoxy decreased from 10 8 Ω.m to average value 10 3 Ω.m with 1, 2, 3, and 4wt% f-MWCNTs. The 4.5wt% CNTs/epoxy was attributed to poor dispersion of f-MWCNTs in the nanocomposte. The hardness of nanocomposite loading 1, 2, 3, 4wt% of CNTs, increased 20.7%, 23.02%, 25.62%, 29.09% respectively as compared to pure epoxy. We believe that our strategy for obtaining CNT–reinforced epoxy nanocomposites is a very promising technology and will open a new doors in fields of aviation, aerospace, marine and sporting goods.
Composites Part B: Engineering, 2012
In this work, multi wall carbon nanotubes (MWCNTs) dispersed in a polymer matrix have been used to enhance the thermo-mechanical and toughness properties of the resulting nanocomposites. Dynamic mechanical analysis (DMA), tensile tests and single edge notch 3-point bending tests were performed on unfilled, 0.5 and 1 wt.% carbon nanotube (CNT)-filled epoxy to identify the effect of loading on the aforementioned properties. The effect of the dispersion conditions has been thoroughly investigated with regard to the CNT content, the sonication time and the total sonication energy input. The CNT dispersion conditions were of key importance for both the thermo-mechanical and toughness properties of the modified systems. Sonication duration of 1 h was the most effective for the storage modulus and glass transition temperature (T g ) enhancement for both 0.5 and 1 wt.% CNT loadings. The significant increase of the storage modulus and T g under specific sonication conditions was associated with the improved dispersion and interfacial bonding between the CNTs and the epoxy matrix. Sonication energy was the influencing parameter for the toughness properties. Best results were obtained for 2 h of sonication and 50% sonication amplitude. It was suggested that this level of sonication allowed appropriate dispersion of the CNTs to the epoxy matrices without destroying the CNT's structure.
Effect of carbon nanotubes addition on the mechanical and thermal properties of epoxy matrices
Materials Research-ibero-american Journal of Materials, 2008
Carbon nano-tubes/cement composites (CNTCC) have been prepared by adding different weight ratios of carbon nanotubes (CNT) ranging from (0.01 up to 0.05%). Due to the high potential of CNT to improve the properties of materials, so, this study is aimed to evaluate the effect of the chemical and physical properties of CNT on the mechanical behavior of CNTCC. The effect of CNT addition on compressive, indirect tensile strength, hardness and phase compositions of CNTCC were determined. Rotary mixer was used for dry mixing of CNT with different ratios to the cement matrix to ensure homogeneous distribution. Test samples were prepared following the standard technique as 2×2×2 cm cubes for the compression test and as 1×1×5 cm for hardness test, while test samples as cylinders with 5 cm diameter and 1 cm thickness, was for the indirect tensile strength test. Water of consistency was used for preparing the blended pastes. Indirect tensile and compressive strength tests showed valuable enhancement in mechanical properties of CNTCC with increasing CNT loading ratio. The microstructure of the CNTCC was characterized by means of scanning electron microscope (SEM) analysis, while the mineralogy was analyzed by means of a differential scanning calorimeter (DSC). The addition of CNT by about 0.04% enhanced the indirect tensile strength to about 52%, compression strength to about 48% and hardness to about 232.6%. This is due to uniformly dispersion of CNT and the effect of bridging up the cracks in the composite.
The Influence of CNT Structural Parameters on the Properties of CNT and CNT-Reinforced Epoxy
International Journal of Aerospace Engineering, 2020
The main objective of this research is to review and investigate the influence of carbon nanotube structure on the properties of carbon nanotube and carbon nanotube-reinforced epoxy. Carbon nanotube and carbon nanotube-reinforced epoxy are currently being frequently used in many applications such as aerospace, automotive, and electronics industries due to their excellent properties such as high tensile strength, high Young's modulus, and electrical and thermal conductivity. In this study, the obstacles to apply carbon nanotubes as fibers within the matrix have been introduced and discussed. Additionally, the epoxy properties and application have been cited, and failure mechanisms of carbon nanotube-reinforced epoxy and geometries of carbon nanotubes have been reviewed. Furthermore, with using experimental data and applying an analytical method, the effect of carbon nanotube diameter on interlaminar shear stress within the carbon nanotube-reinforced epoxy interface has been evaluated. Additionally, the effect of temperature variation on the value of interlaminar shear stress within the single-walled carbon nanotube-reinforced epoxy interface has been discussed. Finally, the influence of the number of hexagons in the unit cell on the Young's modulus of zigzag and armchair single-walled carbon nanotubes has been evaluated.
International Journal of Nanotechnology, 2012
Multiwalled carbon nanotubes (MWCNTs) were grown on carbon fi bre (CF) cloth substrates by chemical vapour deposition (CVD) that resulted in strong anchoring of these tubes on the CF surface. These hybrid preforms were used as the reinforcement in epoxy resin matrix to develop hybrid or multiscale CF-MWCNT/ epoxy composites (CF-MWCNT/epoxy). The fl exural strength (FS) as well as the fl exural modulus (FM) of these composites was found to increase with increasing amount of CNTs grown on CF surface. FS of the hybrid composites improved by 80%, i.e., 560 MPa when compared with 310 MPa for the base composite (CF/ epoxy) prepared under identical conditions. FM of these composites also improved by 120%, i.e., 55 GPa for the hybrid composite when compared with 25 GPa for the base composite. The in-plane and the transverse thermal conductivity of these hybrid composites improved from 17.68 W/mK and 1.79 W/mK, respectively, for base composite to 29.05 W/mK to 2.61 W/mK for the hybrid composite.
Polymer Composites, 2013
The processing of carbon nanotube based nanocomposites is one of the fastest growing areas in materials research due to the potential of significantly changing material properties even at low carbon nanotube concentrations. The aim of our work is to study the curing and thermomechanical behavior of carbon nanotubeepoxy nanocomposites that are critical from an application standpoint. Multiwall carbon nanotubes-epoxy composites are prepared by solvent evaporation based on a commercially available epoxy system and functionalized multiwalled carbon nanotubes. Three weight ratio configurations are considered (0.1, 0.5, and 1.0 wt%) and compared to both the neat epoxy to investigate the nano-enrichment effect. We focus here on the modification of the curing behavior of the epoxy polymer in the presence of carbon nanotubes. It has been observed that introducing the multiwall carbon nanotubes delays the polymerization process as revealed by the modification of the activation energy obtained by differential scanning calorimetry. The viscoelastic response of the nanocomposites was studied from the measurements of storage modulus and the loss factor using dynamic mechanical analysis to evaluate the effect of the interface in each matrix=carbon nanotube system with changing matrix mobility. These measurements provide indications about the increase in the storage modulus of the composites, shift in the glass transition temperature due to the restriction of polymer chain movement by carbon nanotubes. POLYM. COM