Entity

Time filter

Source Type

Le Touquet – Paris-Plage, France

Montazeri A.,Iran University of Science and Technology | Javadpour J.,Iran University of Science and Technology | Khavandi A.,Iran University of Science and Technology | Tcharkhtchi A.,Laboratoire dingenierie des materiaux | Mohajeri A.,Research Institute of Petroleum Industry RIPI
Materials and Design | Year: 2010

Untreated and acid-treated multi-walled carbon nanotubes (MWNT) were used to fabricate MWNT/epoxy composite samples by sonication technique. The effect of MWNT addition and their surface modification on the mechanical properties were investigated. Modified Halpin-Tasi equation was used to evaluate the Young's modulus and tensile strength of the MWNT/epoxy composite samples by the incorporation of an orientation as well as an exponential shape factor in the equation. There was a good correlation between the experimentally obtained Young's modulus and tensile strength values and the modified Halpin-Tsai theory. The fracture surfaces of MWNT/epoxy composite samples were analyzed by scanning electron microscope. © 2010 Elsevier Ltd. Source


Montazeri A.,Iran University of Science and Technology | Khavandi A.,Iran University of Science and Technology | Javadpour J.,Iran University of Science and Technology | Tcharkhtchi A.,Laboratoire dingenierie des materiaux
Materials and Design | Year: 2010

Along with carbon nanotubes (CNT) morphology, impurity, and functionalization, polymer curing cycle is another important factor in determining the mechanical properties of the CNT/polymer composite samples. This work investigates the effect of two different curing cycles on mechanical and thermo-mechanical properties of the nanotube in the composite in order to optimize the curing condition in term of time and temperature. Nanocomposite samples were prepared by mixing multi-wall carbon nanotubes with epoxy resin using sonication method. The mechanical and viscoelastic properties of the resulting composite samples were evaluated by performing tensile and dynamic mechanical thermal analyses (DMTA) test. The results indicate that the mechanical and viscoelastic properties of pure epoxy and composite samples have been affected by the condition curing process. Concerning viscoelastic modeling, the COLE-COLE diagram has been plotted by the result of DMTA tests. These results show a good agreement between the Perez model and the viscoelastic behavior of the composite. © 2010 Elsevier Ltd. Source


Montazeri A.,Iran University of Science and Technology | Khavandi A.,Iran University of Science and Technology | Javadpour J.,Iran University of Science and Technology | Tcharkhtchi A.,Laboratoire dingenierie des materiaux
Advanced Materials Research | Year: 2011

This work studied the effect of sonication time and dispersing medium on the dispersion state of 0.1%wt multi-wall carbon nanotube (MWCNT) in the MWCNT/epoxy nanocomposite system. Epoxy, hardener, and epoxy/solvent were used as dispersing mediums in this study. Tensile strength, strain at failure, Young's modulus and fracture toughness were measured under different dispersion state of MWCNT. The results indicate that with the increase in sonication time, initially there was an increase in tensile strength and fracture toughness values which was followed by a drop in values at longer sonication times. The highest Young's modulus values were seen in epoxy dispersion and the highest tensile strength and fracture toughness values were observed when the hardener was used as dispersing medium. The results also indicated that the effect of sonication time was more pronounced in the case of epoxy dispersion. The effect of time was least when the epoxy / solvent system was used as CNT dispersing medium. It should also be pointed out that the Young's modulus for the nanocomposite sample obtained after 1h of dispersion in hardener showed good agreement with a modified Halpin-Tsai theory. The scanning electron microscope (SEM) was used to characterize the dispersion state of MWCNT. A good dispersion was obtained when either hardener or solvent were selected as the dispersing medium. © (2011) Trans Tech Publications, Switzerland. Source


Liang G.G.,Monash University | Cook W.D.,Monash University | Tcharkhtchi A.,Laboratoire dingenierie des materiaux | Sautereau H.,INSA Lyon
European Polymer Journal | Year: 2011

An oligomer of a diepoxy (diglycidyl ether of bisphenol-A, DGEBA) and an aromatic diamine (MCDEA) have been used as reactive plasticizers for polycarbonate (PC). A small amount of PC chain scission occurred during this blending process, probably due to transesterification of the PC carbonate group by the hydroxyl group of the DGEBA oligomer. Addition of DGEBA to PC was found to greatly reduce the Tg and processing temperature. Dynamic rheology measurements showed that the added epoxy can very effectively reduce the viscosity, but that the addition of epoxy also accelerated the crystallisation rate of the PC, which was confirmed by XRD, optical transmission microscopy and DMTA. The DMTA results of cured blends also showed that this crystallization of the PC enhanced their heat resistance properties. Sol-gel studies of the cured samples showed that some of the PC was grafted to the crosslinked epoxy network. Studies of the rubbery behaviour, solvent resistance of the cured blend and SEM images suggest that PC is the main continuous phase in the matrix and that the epoxy phase is mainly dispersed as sub-micron particles in the matrix. © 2011 Published by Elsevier Ltd. All rights reserved. Source


Montazeri A.,Iran University of Science and Technology | Khavandi A.,Iran University of Science and Technology | Javadpour J.,Iran University of Science and Technology | Tcharkhtchi A.,Laboratoire dingenierie des materiaux
International Journal of Polymer Analysis and Characterization | Year: 2010

Along with carbon nanotube (CNT) morphology, impurity, and fuctionalization, polymer curing cycle is another important factor in determining the mechanical properties of CNT/polymer composite samples. Nanocomposite samples were prepared by mixing multiwall carbon nanotubes with epoxy resin. The main objective is the investigation of the effects of four curing cycles on the mechanical and thermo-mechanical properties of the conductive filler in the composite and the development of new nanocomposite materials based on epoxy resins with controlled structural and mechanical properties. The mechanical and thermo-mechanical properties of the resulting composite samples were evaluated by performing tensile and dynamic mechanical analyses (DMA) test. The results indicate that the mechanical properties of pure epoxy and composite samples have been affected by the conditions of the curing process. It seems that the effect of the reinforcement is more evident for a less cured resin. © Taylor & Francis Group, LLC. Source

Discover hidden collaborations