Department of Polymer Engineering (2005 - Present)
Polymer engineering
Polymer Engineering, University of Akron, Akron, U.S.A
Polymer Engineering
Polymer Engineering, University of Akron, Akron, United States of America
Chemical Engineering-Polymer Industries
Chemical Engineering, Amirkabir University of Technology, Tehran, Iran
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AREAS OF EXPERTISE ? Mechanics of Polymeric CompositesNanocomposites ? Tribology (Friction, Wear, and Lubrication) of Polymer Composites ? Science and Engineering of Rubber Parts and Tires ? Fracture and Fatigue of Rubber Composites ? Electroactive Polymers and Dielectric Elastomers EDUCATION ? The University of Akron, Akron, Ohio. -Doctorate of Philosophy in Polymer Engineering, 1997-2000 -Master of Science and Engineering, Polymer Engineering 1994-1997 ? Amir-Kabir University of Technology (Tehran Polytechnic), Tehran, Iran. Bachelor of Science and Engineering, 1984 -1988, Chemical Engineering PROFESSIONAL MEMBERSHIP ? Member of Iranian Society of Science and Technology of Polymers ? Member of SPIE-Smart StructuresNDE scientific committee ? Member of Iranian Association of Chemical Engineers ?Member of Polymer Committee, Supreme Council of Educational Planning, Ministry of Science-Research-and Technology ?Managing Editor of Applied Research in Chemical-Polymer Engineering ?Editorial Board Member of Iranian Polymer Journal ?Editorial Board Member of Basparesh Journal ?Editorial Board Member of Iranian Rubber Journal PROFESSIONAL EXPERIENCE TARBIAT MODARES UNIVERSITY Tehran, Iran
Substitution of petroleum‐based processing oils with eco‐friendly sustainable plasticizers in rubber compounds has gained much global attention due to their toxicity. In this regard, so far, the major attempts have focused on substituting aromatic oils with fatty acid based vegetable oils. In this work, the chemical and physical effects of canola oil as a model of fatty acid based vegetable oils on the process‐ability, vulcanization kinetics, and final properties of carbon‐black filled styrene–butadiene rubbers are systematically investigated. In contrast to the previous studies, it was shown that although these types of vegetable oils have a plasticizing impact, they can indeed threaten the requirements of reinforcing criteria i
In this research, the effects of the surface modification of silica by low-molecular-weight hydroxyl-terminated polybutadiene (HTPB) are compared with those of bis (3-triethoxysilylpropyl) tetrasulfide (TESPT) on the mechanical, viscoelastic, and tribological properties of styrene-butadiene rubber (SBR) vulcanizates. Both modifiers have the ability to make covalent bonds with the rubber matrix, but with different interfacial characteristics controlling the final properties. The results displayed improvements in the tribological behavior of both modified silica-filled vulcanizates over pristine silica-and carbon black-filled vulcanizates. However, the HTPB modification method, despite providing a finer dispersion of the silica in the rubber,
The tear strength (TS) of rubber-silica composites is inevitably lowered by the reduction of viscoelastic dissipation imparted by the use of bifunctional silanes. It is of interest to find out whether promoting crack tip deviation represented by a slip-stick tearing can compensate for such a loss in the tear strength. Here, the phenomenon of crack growth in terms of the TS and also the tearing type is considered for both the untreated and silane-treated silica rubber composites to figure out the microstructure parameters affecting the slip-stick tearing. It was realized that within a certain volume fraction of the reinforcing filler, deviation whether in the form of slip-stick or knotty tearing can be found for both cases. Tearing for silan
The present study investigates the effects of grafting a long-chain organosilane (OS) onto the reduced graphene oxide (rGO) on dielectric and electromechanical performance of polydimethylsiloxane (PDMS). Accordingly, two types of OS-rGO particles were synthesized with different grafting densities and characterized by various tests such as Fourier transform infrared spectroscopy, Raman spectroscopy, and thermo-gravimetric analyses. As-prepared particles were introduced into PDMS using the solution mixing method to manufacture composites with different concentrations of particles. Dielectric results revealed that the composites containing OS-rGO particles offer better dielectric performance in terms of higher “dielectric efficiency” and d
In this study the effects of electron beam irradiated poly (tetrafluoroethylene) (IR‐PTFE) on the mechanical and tribological properties as well as thermal and solvent aging behavior of carbon black filled nitrile‐butadiene rubber vulcanizates were studied. Based on the obtained results, addition of 30phr IR‐PTFE reduced mechanical strength about 10%, whereas coefficient of friction desirably reduced up to 60%. It was shown that IR‐PTFE significantly improved tribological properties by affecting the adhesion contribution of the friction mechanism. Moreover, formation of IR‐PTFE transfer films also contributed to the reduction of coefficient of friction in the long term tests. In addition, it was explained that IR‐PTFE enhances
Particle packing, together with other filler characteristics, can be considered as an important structural parameter of fillers, affecting on the properties of rubber compounds. For this purpose, N220 and N550 carbon blacks with nearly similar structure and surface chemistry but different particle sizes were selected. N220/N550 showed the maximum packed density at the composition 35/65 according to the accepted theory for bimodal packing of spheres. A correlation between the packing behavior of carbon blacks mixtures and physical, electrical and rheological behaviors of filled rubber compounds was investigated. A synergic effect in compounds properties was observed before the vulcanization reaction at the maximum packed composition of carbo
The distinction between abrasion resistance of carbon black and silica reinforced tire tread compounds has drawn attention to the indispensable role of interfacial phenomena on crack growth resistance of rubber composites. Attempts to determine the dependence of interface bonding (from covalent to non-covalent) on crack growth resistance of rubber composites are insufficient without knowledge of the contributions resulting from the interphase (ie the volume of rubber chains with restricted mobility). For highly-filled rubbers, the interphase is mainly formed by strong filler-filler interaction and entrapment of rubbers among filler aggregates. Working on the silane-treated silica reinforced rubber, here the alkyl length and the grafting den
The influence of reduction temperature on the electromechanical properties and actuation behavior of polydimethylsiloxane (PDMS) dielectric elastomer containing the thermally reduced graphene oxide (rGO) with different surface chemistry has been systematically investigated. A set of rGO nanosheets was prepared by thermal reduction of graphene oxide (GO) at four temperatures (150, 200, 300, and 400 ?C). The dielectric permittivity, dielectric loss, and elastic modulus of PDMS composites were increased, while the electrical breakdown strength of composites was decreased with an increase of the reduction temperature of GO. A thermodynamic model applied for studying the electromechanical deformation and stability of PDMS/GO(rGO-x) dielectric el
The important role of interfacial effects, compared to the tortuosity effect, in permeation of nitrogen gas through styrene butadiene rubber-reduced graphene oxide (rGO) composites is presented by varying in-situ reduction of GO particles in SBR latex. Particles were initially synthesized, chemically reduced, and characterized as guidelines for the in-situ reduction in the latex compounding method. The latex mixing method provided a mean to minimize the difference in the state of dispersion and intercalation of particles in the samples, as revealed by field-emission scanning electron microscope and X-ray diffraction. However, in-situ chemical reduction of GO in the latex offered a simple method to manipulate the filler-rubber interfacial be
A novel high performance dielectric elastomer actuator with a high dielectric constant, low dielectric loss, high dielectric breakdown strength and large actuated strain was prepared through introducing hybrid fillers of chemically reduced graphene oxide (rGO) covered by a SiO 2 shell (SiO 2@ rGO). Hybrid particles were synthesized with two different shell coverage using tetraethylorthosilicate (TEOS) and characterized with different methods to identify the surface chemistry, inter-layer spacing, and thickness of the platelets as SiO 2 shells were introduced and reduction process was applied. Composites of polydimethylsiloxane (PDMS) containing different amounts of rGO and SiO 2@ rGO particles were prepared by the solution mixing method. Th
Vol. 32, No. 4, 339-348 October-November 2019 ISSN: 1016-3255 Online ISSN: 2008-0883 DOI: 10.22063/JIPST. 2019.1681 nitrile rubber (NBR), friction, lubrication, irradiated polytetrafluoroethylene (PTFE), carbon blackHypothesis: Poly (tetrafluoroethylene)(PTFE) powder, due to its low surface energy, reduces the friction of nitrile rubber (NBR) composite. Moreover, due to its chemical stability PTFE improves the resistance of the composite to oil solvents. Due to thermal stability, it can improve thermal resistance of rubber compound. However, the dispersion of PTFE particles in the rubbery matrix is limited and the latter may reduce in mechanical properties. Methods: To create better polymer-filler interactions and improve the dispersion of
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