Surface Activation Of Carbon Nanotubes Generating A Chemical Interaction In Epoxy Nanocomposite (original) (raw)
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Journal of Aerospace Technology and Management, 2015
The focus of this study is to evaluate the effect of carboxyl and amino functionalization of multiwalled carbon nanotubes on the mechanical property of the epoxy resin filled with modified carbon nanotubes. The carbon nanotubes were treated with sulfuric and nitric acids and also with hexamethylenediamine. The presence of acid and amine chemical groups on the carbon nanotube surface was confirmed by X-ray photoelectron spectroscopy. The composites were produced with epoxy resin and modified carbon nanotubes. Vickers hardness tests were carried out on the composites and neat resin. The results showed an increase of hardness in the composite prepared with functionalized carbon nanotubes. This phenomenon is due to the fact that the chemical interaction between modified carbon nanotube and epoxy resin is much stronger than between pristine carbon nanotube and epoxy resin. This stronger interaction is related to the presence of functionalized carbon nanotubes.
Polymers for Advanced Technologies, 2011
Functionalization of multi-walled carbon nanotubes (MWCNTs) influences physico-mechanical properties of MWCNT/epoxy composites. Samples based on epoxy resin (EP) and different weight percentage of MWCNTs (functionalized and non-functionalized) were prepared. Epoxy/carbon nanotubes were prepared by different mixing methods (ultrasounds and a combination of ultrasounds and mechanical mixing) and better dispersion of carbon nanotubes (CNTs) was observed in the case of combination of these processes. CNTs modified with different functional groups were investigated. It was found that modified nanotubes form bigger agglomerates than unmodified ones. Surfactants were used to lower the surface tension of the liquid, which enabled easier spreading and reducing the interfacial tension. Some surfactants facilitate homogeneous dispersion of nanotubes in the resin through the reduction of resin viscosity.
2008
The incorporation of functionalized carbon nanotubes in a polymer matrix is expected to greatly enhance the physical and mechanical properties of the polymer due to inherent superior properties of carbon nanotubes (CNTs): high modulus and strength, high thermal stability and enhanced electrical conductivity. Nanocomposite materials based on epoxy polymer matrix and different types of functionalized carbon nanotubes were synthesized. The effect of CNTs on dynamic mechanical properties by DMA, on curing process by DSC and themostability by TGA and DTG were studied. The system based on diglycidylether of bisphenol A (DGEBA) cured with a polyetheramine (D230) and reinforced with amino-functionalized doublewall carbon nanotubes (DWNT-NH 2 ) showed lower T g values. SEM images reveal an enhance of dispersion if amino-functionalized CNTs are used.
Polymer Composites, 2009
We have studied an effect of three types of modifications of carbon nanotubes (CNTs) on dispersion and mechanical properties of final epoxy-amine based nanocomposites. First approach includes end-walled covalent chemical modification at the ends of nanotubes. The second one is side-walled covalent chemical modification along the whole length of nanotubes. The third procedure is noncovalent, physical modification done by the CNT surface coating with polyaniline. The modification of nanotubes was determined by X-ray photoelectron spectroscopy. The prepared epoxy-amine nanocomposites were characterized by dynamic-mechanical analysis, tensile testing, light microscopy, transmission electron microscopy, and thermogravimetry. We observed an improvement of the mechanical properties and the thermal stability by addition of the carbon nanotubes to the epoxy matrix. The strong interactions between the nanotube and the polymer matrix were discovered in the nanocomposites with physically modified nanotubes.
Functionalised multi-walled carbon nanotubes for epoxy nanocomposites with improved performance
Polymer International, 2009
BACKGROUND: Carbon nanotubes (CNTs) are fast becoming key components in the production of high-strength composite materials. Two methods to prepare nanocomposites by covalent bonding between an epoxy matrix and functionalised CNTs that acted as cross-linkers during polymerisation were investigated. RESULTS: In the standard method, 1 wt% functionalised CNTs was dispersed in epoxy, hardener was added and the composite was cured. In the masterbatch approach, 1 wt% functionalised CNTs was mixed with epoxy in the presence of triethylamine accelerator, then cured. This yielded partially cured epoxy; additional hardener was required to achieve complete curing. Improvements were observed in storage modulus (E ), flexural modulus (E B ), wear resistance and hardness. Thermal stability did not change appreciably for samples prepared by either the standard or masterbatch methods. Variations in the results obtained as a function of preparation method, functionalised CNTs and hardener used are discussed.
Functionalization of carbon nanotubes for fabrication of CNT/epoxy nanocomposites
To improve the dispersion of carbon nanotubes (CNTs) in epoxy matrix composites, polystyrene sulfonate (PSS) and poly(4-aminostyrene) (PAS) were attached on the surface of CNTs by noncovalent functionalization. In the case of PAS, amino groups can also generate chemical bonding with the epoxide groups in the epoxy matrix. CNTs noncovalently functionalized with PSS and PAS were then fabricated to obtain CNT/Epoxy nanocomposites with enhanced mechanical properties. The incorporation of noncovalently functionalized CNTs into the modified bisphenol-A type epoxy matrix yielded Young's modulus of 3.89 GPa and tensile strength of 82.59 MPa with the addition of 1 wt.% PAS-CNTs. The noncovalent functionalization of CNTs was effective in improving the composite's mechanical properties due to their enhanced dispersion and strong affinity with the epoxy matrix.
Multi-Walled Carbon Nanotubes for Improved Performance Epoxy Nanocomposites
2017
BACKGROUND: Carbon nanotubes (CNT) are fast becoming key components in the production of high-strength composite materials. Two methods to prepare nanocomposites by covalent bonding between an epoxy matrix and functionalised CNT which acted as cross-linkers during polymerisation were investigated. RESULTS: In the standard method, 1 wt% functionalised CNT was dispersed in epoxy, hardener added and the composite was cured. In the masterbatch approach, 1 wt% functionalised CNT were mixed with epoxy in the presence of triethylamine accelerator, then cured. This yielded partially-cured epoxy; additional hardener was required to Page 2 of 27 achieve complete curing. Improvements were observed in storage modulus (E′) flexural modulus (EB), wear resistance and hardness were also improved. Thermal stability did not change appreciably for samples prepared by either the standard or masterbatch methods. Variations in the results obtained as a function of preparation method, functionalised CNT a...
IMPROVING MECHANICAL PROPERTIES OF EPOXY BY ADDING MULTI-WALL CARBON NANOTUBE
Warsaw, 2016
In this research, multi-walled carbon nanotubes (MWCNTs) are used as the reinforcement in an epoxy resin with weight percentages (0, 0.2, 0.4, 0.6, 0.8, 1) wt%, respectively, by using both direct (nonhomogeneous) and homogeneous dispersion mixing processes to prepare (epoxy/MWCNTs) nanocomposites. Tensile and drop weight impact tests are used to evalu- ate mechanical properties of the composites. Results show that homogeneous dispersion has a great effect on enhancing mechanical properties of multi-wall carbon nanotube reinforced composites. Adding 0.2wt% of MWCNTs enhances and increases tensile properties, and adding 0.6 wt% of MWCNTs enhances impact properties.
Structure and Mechanical Properties of Polymeric Composites with Carbon Nanotubes
Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference
Experimental investigations of single-wall carbon nanotubes (CNT) effect on the mechanical properties of polymeric composite materials based on epoxy matrix have been carried out. It has been found that addition of CNT at low concentration dramatically increases tensile strength (20 – 30 per cent growth) and Young’s modulus of the samples under study. Structure of polymeric composites with CNT was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). AFM images of the samples under study confirm strong interaction between polymeric matrix and nano-additives, demonstrating intimate contact between CNT and epoxy surroundings which is of great importance for composite material reinforcement. Dependences of tensile strength and those of Young’s modulus on CNT concentration are discussed using micromechanics models for nanocomposites.