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Rheological and morphological properties of nanocomposites based on PA66/PA6/multi-walled carbon nanotube prepared by melt mixing
, Article ICCM International Conferences on Composite Materials, 21 August 2011 through 26 August 2011, Jeju ; August , 2011 ; Shojaei, A ; Bagheri, R ; Sharif University of TechnologyInvestigation of the Effective Parameters on the Morphological and Mechanical Properties of Polyamide 6/Rubber/Carbon Nano Tube Nanocomposites Prepared by Melt Mixing
, Ph.D. Dissertation Sharif University of Technology ; Shojaei, Akbar (Supervisor) ; Bagheri, Reza (Supervisor)
Abstract
Preparation of binary polyamide 6 (PA6) / carbon nano tube (CNT) and ternary PA6 / EPR-g-MA / CNT has been carried out using melt mixing. Four PA6s were selected with different viscosities (and molecular weights) and molecular structures (linear or branched). Effect of CNT content (up to 2 wt%) and mechanical mixing conditions (rotor speed, temperature and time of mixing) have been investigated. Ethylene- propylene rubber grafted maleic anhydride (EPR-g-MA) was selected at 20 wt% as toughening agent for ternary nanocomposites and mixing sequence of PA6 , EPR-g-MA and CNT has been investigated. Morphological observations showed that dispersion of CNT is done by erosion mechanism at low melt...
Fabrication and Electrical Properties Evaluation of PA/CNT Conductive Nanocomposite with Low Percolation Threshold
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor)
Abstract
Polyamide-6 is a thermoplastic polymer that is classified as electrically non-conductive materials. One way of adding conductivity to the polymer matrices is by utilizing them in a nanocomposite form. Superior mechanical and electrical properties of Carbon Nanotubes make them worthy of being chosen as reinforcement in nanocomposites to extend their operation to a broader range of applications, like conductive nanocomposites, mainly polymer-based matrices. The Nanotubes have chemical affinity and tend to entangle and aggregate. Because of this, to achieve a uniform and remarkable electrical conductivity is hard-to-reach. state of entanglement effects correctly melt methods of polymer blend...
Improvement of Physical and Mechanical Properties of Poly (Ethylene Terephthalate) (PET) by Incorporating Metal-organic Framework (MOF) Nanoparticles
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor) ; Molavi, Hossein (Co-Supervisor)
Abstract
Over the past decade, MOFs have been extensively studied due to their very high specific surface area and porous structure. Among a wide range of MOFs, UiO-66 has produced widespread attention for its excellent solvent resistance and high thermal stability. This nanoparticle is formed by 12 coordinates between Zr6O4(OH)4 unit and terephthalic acid ligand, and it seems that the similarity of its organic ligand with one of the PET-forming monomers makes them highly compatible. In this study, for the first time, the role of UiO-66 nanoparticles in improving the amount and rate of crystallization and mechanical and rheological properties of PET was investigated using the melt mixing method. For...
An investigation on the structural characteristics and reinforcement of melt processed polyamide 66/multiwalled carbon nanotube composites
, Article Polymers for Advanced Technologies ; Vol. 25, issue. 4 , 2014 , pp. 406-417 ; ISSN: 10427147 ; Nourbakhsh, P ; Faghihi, M ; Sharif University of Technology
Abstract
Properties of melt processed polyamide 66 (PA66)/multiwalled carbon nanotube composite were first characterized experimentally. The experimental results exhibited the formation of crystalline layer around the nanotubes and a considerable enhancement in mechanical properties by incorporation of multiwalled carbon nanotube up to 1 wt%. Mechanical properties were analyzed in terms of structural parameters using micromechanical models proposed in this study. It was suggested that the mechanical properties were greatly dominated by crystalline layer and nanotube length. It was also deduced that the melt mixing process caused a significant nanotube breakage restricting further enhancement of...
Characterization of PVDF/Nanoclay Nanocomposites Prepared by Melt, Solution, and Co-Precipitation Methods
, Article International Journal of Polymer Analysis and Characterization ; Volume 17, Issue 4 , 2012 , Pages 291-301 ; 1023666X (ISSN) ; Dadbin, S ; Frounchi, M ; Sharif University of Technology
2012
Abstract
Poly (vinylidene fluoride) (PVDF) nanocomposites were prepared via melt, solution, and co-precipitation mixing methods using Cloisite 30B as organoclay. The results from X-ray diffraction patterns display intercalation or exfoliation of nanoclay depending on the nanocomposite preparation method. The solvent cast and co-precipitated samples showed exfoliation, while intercalation was observed in the nanocomposites prepared by melt mixing. Introducing organoclay induced formation of β-crystals in the PVDF nanocomposites as evidenced by XRD and FT-IR. FT-IR analysis indicated that the samples prepared by the co-precipitation method had a higher tendency for β phase formation, while the sample...
Morphological and mechanical properties of polyamide 6/nanodiamond composites prepared by melt mixing: effect of surface functionality of nanodiamond
, Article Polymer International ; Volume 66, Issue 4 , 2017 , Pages 557-565 ; 09598103 (ISSN) ; Shojaei, A ; Sharif University of Technology
John Wiley and Sons Ltd
2017
Abstract
Surface chemistry of as-received nanodiamond (ND) was first tailored by dry thermal oxidation to obtain carboxylated ND (ND-COOH) and by wet chemistry to obtain ethylenediamine-functionalized ND (ND-EDA). Then, the surface-functionalized ND particles were dispersed in polyamide 6 (PA6) using the melt-mixing method. Transmission optical and scanning electron microscopies indicated a fine dispersion at low nanodiamond concentrations, e.g. 0.25 wt%, particularly with ND-EDA. Differential scanning calorimetry revealed that ND-EDA favoured the α-phase crystal and enhanced the degree of crystallinity of PA6. Experimental data indicated that ND-EDA had considerably improved tensile properties at...
Effect of chemical treatment of Teflon powder on the properties of polyamide 66/Teflon composites prepared by melt mixing
, Article Macromolecular Research ; Volume 19, Issue 6 , June , 2011 , Pages 613-621 ; 15985032 (ISSN) ; Gholamalipour, S ; Sharif University of Technology
2011
Abstract
The surface defluorination of Teflon in powdery form was performed using a chemical treatment. The reaction parameters including the reaction time, sodium, naphthalene concentrations were optimized using a Taguchi method to obtain maximum functionality on the particles surface. The surface functionality of the treated particles was analyzed by FTIR, energy dispersive X-ray analysis (EDX) and surface energy. Both treated (g-PTFE) and untreated (PTFE) Teflon were added to polyamide 66 (PA66) at various loadings up to 6 wt%. Mechanical, differential scanning calorimetry (DSC) and tribological analyses for different PA66/Teflon composites were carried out. The chemical treatment enhanced the...
Properties of alumina nanoparticle-filled nitrile-butadiene-rubber/ phenolic-resin blend prepared by melt mixing
, Article Polymer Composites ; Volume 30, Issue 9 , 2009 , Pages 1290-1298 ; 02728397 (ISSN) ; Shojaei, A ; Sharif University of Technology
2009
Abstract
Effect of alumina nanoparticle (ANP) on the properties of rubber compounds based on nitrile-butadiene-rub- ber (NBR) and NBR/phenolic-resin (PH) blend is examined. To investigate the surface characteristics of the nanoparticles on the performance of nanoalumina- filled compounds, trimethoxyvinylsilane (MVS) is attached chemically on the surface of ANP through an appropriate functionalization process. Various NBR and NBR/Ph compounds filled with ANP and functionalized ANP (f-ANP) are prepared via melt mixing using traditional open two-roll mill. Microscopic analysis carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) reveals good dispersion of...