Modification of carbon nanotubes and its effect on properties of carbon nanotube/epoxy nanocomposites (original) (raw)
Related papers
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.
Epoxy-based nanocomposites with amine modified single walled carbon nanotubes
e-Polymers, 2010
Carboxylated Single Walled Carbon Nanotubes (SWNT-COOH) were functionalized using different types of amines as modifier agents to improve the compatibility with the epoxy matrix. Covalent attachment was proved by XPS and Raman spectroscopy. TGA showed that only long chain modifier agents improved the thermal stability of modified SWNTs. Epoxy-based composites were synthesized using diglycidyl ether of bisphenol A (DGEBA) as polymer matrix and modified SWNTs as reinforcing agent.
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.
The effect of carbon nanotubes on epoxy matrix nanocomposites
Journal of Thermal Analysis and Calorimetry, 2013
The paper concerns thermal properties of epoxy/nanotubes composites for aircraft application. In this work, influence of carbon nanotubes on thermal stability, thermal conductivity, and crosslinking density of epoxy matrix was determined. Three kinds of nanotubes were used: non-modified with 1-and 1.5-lm length, and 1-lm length modified with amino groups. Scanning electron microscopy observations were done for examining dispersion of nanotubes in the epoxy matrix. Glass transition temperature (T g ) was readout from differential scanning calorimetry. From dynamic mechanical analysis, crosslinking density was calculated for epoxy and its composites. Also, thermogravimetric analysis was done to determine influence of nanotubes addition on thermal stability and decomposition process of composites. Activation energy was calculated from TGA curves by Flynn-Wall-Ozawa method. Thermal diffusivity was also measured. SEM images proved the uniform dispersion of carbon nanotubes without any agglomerates. It was found that nanotubes modified with amino groups lead to the increase of epoxy matrix crosslinking density. The significant increase in T g was also observed. On the other hand, addition of carbon nanotubes leads to the decrease of thermal stability of polymer due to the increase of thermal diffusivity.
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.
Express Polymer Letters, 2012
The continuous demand for new high performance polymer composite for sectors as aerospace or lightweight structures for various structural elements has lead many researchers to investigate the potential application of the CNT as nano-reinforcements for polymer matrix of fiber-reinforced composite. Polymer/CNT composites have attracted considerable attention due to their unique mechanical, surface, multi-functional properties and strong interactions with the matrix, depending on the nano-scale microstructure and large interfacial area [1-5]. Moreover, their impressive mechanical properties with stiffness and strength values falling within the range 100-1800 GPa and 2.5-3.5 GPa respectively, make them ideal candidates to develop novel com-520
Surface Activation Of Carbon Nanotubes Generating A Chemical Interaction In Epoxy Nanocomposite
2015
Carbon nanotubes (CNTs) are known for having high elastic properties with high surface area that promote them as good candidates for reinforcing polymeric matrices. In composite materials, CNTs lack chemical bonding with the surrounding matrix which decreases the possibility of better stress transfer between the components. In this work, a chemical treatment for activating the surface of the multi-wall carbon nanotubes (MWCNT) was applied and the effect of this functionalization on the elastic properties of the epoxy nanocomposites was studied. Functional amino-groups were added to the surface of the CNTs and it was evaluated to be about 34% of the total weight of the CNTs. Elastic modulus was found to increase by about 40% of the neat epoxy resin at CNTs' weight fraction of 0.5%. The elastic modulus was found to decrease after reaching a certain concentration of CNTs which was found to be 1% wt. The scanning electron microscopic pictures showed the effect of the CNTs on the cra...
Effects of Carbon-Nanotubes on the Mechanical and Electrical Properties of Epoxy Nanocomposites
Carbon nanotubes (CNTs) have attracted tremendous interest as a nano-filler for epoxy nanocomposites due to their excellent properties. The efficient reinforcement has been largely limited by the agglomeration of these nano-fillers within epoxy matrix. In this work, shear mixing followed by sonication is used to prepare CNT/epoxy composites. The epoxy reinforced with functionalized Multiwalled Carbon Nanotubes (CNT/epoxy) composite was prepared by mixing (0.1, 0.2, 0.3, 0.4) wt% FMWCNT with epoxy. The tensile properties, electrical conductivity and contact angle were measured. A remarkable improvement in the mechanical properties and electrical conductivity of epoxy composites is demonstrated.
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...
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.