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epoxy-resin
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Investigation of Fracture Toughness of Epoxy Resins by Addition of CNT and Rubber Microparticles
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor)
Abstract
Epoxy resins are relatively brittle and have low resistance to crack propagation. It is common to add rubber particles to improve crack resistance in epoxies, although these particles may deteriorate the strength of the matrix. Different nanomaterials are used to overcome the inherent brittleness of epoxies and to keep the mechanical properties. Among them, carbon nanotubes has been attracted many attentions. Fractue behavior and mechanical properties of two kind of novel nanocomposites, i.e, epoxy/carbon nanotube and epoxy/rubber/carbon nanotube are investigated in current study. Electron microscopy investigations were done to assure the CNTs distribution and fracture mechanisms as well....
Fabrication and Characterization of Hybrid NanoComposites Based on Epoxy/NanoDiamond/CarbonFiber
, M.Sc. Thesis Sharif University of Technology ;
Abstract
Polymer composites, due to its exclusive properties, has a special place in industry. Epoxy resin with high adhesion property, low density, thermal stability and high chemical resistance has a special place as matrix in fabrication of high technology hybrid composites. Hybrid composites, due to its high strength and long fatigue life, used to reinforcing building structures and manufacturing fuselage. Layer and reactive structure near the firm core and wear-resistant of NDs, used to improvement of epoxy reisn and hybrid NanoComposite interphase properties. In this study, for improvement of the properties of hybrid NanoComposites, used the NDs in 0.25, 0.5 and 1 %wt with amine and carboxyl...
Experimental Study of Mass Ratio and Carbon Nono Tube Size on Impact Toughness in Composite Polymers
, M.Sc. Thesis Sharif University of Technology ; Hosseini Kordkheili, Ali (Supervisor)
Abstract
Nowadays, composites have wide applications in different industries especially in aerospace industry because of their high strength to weight ratio. Epoxy 5052 for its relatively good mechanical properties and high thermal resistance has vaidly use for manufacturing of large composite components. However; fracture toghness of epoxy resins is not good in comparison to their other exceptional properties. Therefore, researchers have endeavored to improve this characteristic with different approaches. One of these methods is nanotechnology. Since the components in aerospace industry are often under impact loads and impact strength of these materials has been less studied, effect of carbon...
Study the Toughening Mechanisms in Hybrid Epoxy/Rubber/CNT Nanocomposites
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor) ; Pircheraghi, Gholamreza (Supervisor)
Abstract
Epoxy resins are used for a wide number of application due to good stiffness, chemical resistant and dimensional stability. This is the reason of their use as matrix in composite material. The incorporation of a small amount of carbon nanotubes (CNTs) in epoxy increases mechanical properties if nanocomposite have strong interfacial interaction between epoxy and CNTs, fine dispersion of CNTs and high final aspect ratio CNTs. In Noncovalent functionalization by polymer surfactant, CNTs are dispersed in a solvent/surfactant solution by ultra-sonication and then added to epoxy. In this thesis a novel study of toughening and mechanical properties of epoxy/ rubber/ CNT nanocomposite is presented....
Manufacturing and Mechanical Characterization of Polymeric Composites Reinforced with Natural Fibers
, M.Sc. Thesis Sharif University of Technology ; Rajabzade, Fallah (Supervisor) ; Akbari (Supervisor)
Abstract
With increasing awareness, artificial materials have been replaced by recyclable materials and green materials. In the manufacture of composites, natural and degradable materials are also used. The main object of this research is the fabrication of natural fiber reinforced composites. In this research, fibers are used that are cultivated in the country. Also, the effect of fiber length, fiber mass percentage and fiber correction on composite properties was investigated. The fiber length factor is at two levels of 5 mm and 9 mm, the percentage of fiber mass is in four levels of 5%, 10%, 12.5% and 15%, and the factor for correction of fibers is also in two groups of modified fibers and...
Modeling of Yield Behavior of Rubber Modified Epoxies
, M.Sc. Thesis Sharif University of Technology ; Kuchakzadeh, Mohammad Ali (Supervisor)
Abstract
Because of increasing usage of modified polymers and consequent necessity for investigation and modeling of mechanical behavior of these materials, it is important to get a yield criterion for these materials. For this purpose the Gurson yield criterion presented for porous metals, was modified with regard to mechanical properties of polymers. Indeed pressure sensitivity of polymers and their large elastic strain during deformation, makes using of Gurson yield criterion problematic for modified polymers.
For modification of Gurson criterion, macroscopic hydrostatic yield stress equation was derived for a thick-walled spherical shell of epoxy and then Gurson criterion was modified with...
For modification of Gurson criterion, macroscopic hydrostatic yield stress equation was derived for a thick-walled spherical shell of epoxy and then Gurson criterion was modified with...
Surface Modification of Nanosilica with Glycidoxypropyltrimethoxysilane and Investigating its Effect on the Physical and Mechanical Properties of Epoxy Resin
, M.Sc. Thesis Sharif University of Technology ; Mahmoudi Hashemi, Mohammad (Supervisor) ; Bastani, Saeed (Supervisor)
Abstract
In the first stage of this research, different amounts of glycidoxypropyltrimethoxysilane (GPS) were grafted as a coupling agent on the surface of nanosilica particles (NS). Surface characterization was done by Particle Size Analyzer and Thermal Gravimetric Analyzer (TGA) and that way, samples were distinguished from each other. More comparisons were taken by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Then the different amounts of modified NS were added into the matrix of an epoxy resin and the physical and mechanical properties of samples were tested with Abrasion Resistance test, Tensile Strength test, Thermal Mechanical Analysis (TMA),...
Fabrication of Superhydrophobic Surfaces to Decrease Pressure Drop through the Galvanized Pipe and Study about Feasibility of the Fabricated Surface to Use for Non-newtonian Fluid
, M.Sc. Thesis Sharif University of Technology ; Mousavi, Ali (Supervisor) ; Nouri boroojerdi, Ali (Supervisor)
Abstract
Nowdays, one of the most important concerns for scientists is increasing CO2 emmisions and global warming. To overcome this problem, a large number of studies have been carried out to improve energy system performance and reducing the overall energy consumption. One solution to this problem is using the superhydrophobic surfaces with contact angle larger than 150°.In this study, we try to reduce the pressure drop through the galvanized pipes. So, by reducing the pressure drop, power required for pumps can be reduced. To this end, two different coatings by silica nano-particles which were modified with first hydrophobic agent are used. In first coating which is named as PS coating, stearic...
Synthesis and Application of Carbon Hollow Nanospheres Containing Active Film Forming Agents for Fabrication of Self-Healing Epoxy Resin
, Ph.D. Dissertation Sharif University of Technology ; Ramazani, Ahmad (Supervisor) ; Mahdavian, Mohammad (Supervisor) ; Taheri, Peyman (Co-Supervisor) ; Mol, Arian (Co-Supervisor)
Abstract
Nowadays, self-healing process, repairing minor damages automatically without the need for detection or any type of manual intervention, becomes a hot topic of general interest. In this research, the effect of addition of carbon nanocontainers doped with film forming epoxy and polyamine agents in various contents on the self-healing properties of epoxy resin was investigated. Carbon nanocontainers were synthesized via the silica templating method and carbonization of polysaccharide shells at the high temperature. Loading of the film forming agents into carbon nanocontainers was performed using vacuum jar method in the presence of epoxy/acetone and polyamine/acetone dilute solutions....
Design and Fabrication of Water and Oil Separation Membranes Using Nano Technology and Wettability Properties of Surfaces
, M.Sc. Thesis Sharif University of Technology ; Moosavi, Ali (Supervisor)
Abstract
Due to population growth, the demand for water supply has increased. This need has drawn attention to the use of consumed and treatable water resources. Organic pollutants are a key source of water pollution. On the other hand, petrochemical oil pollution and frequent oil accidents during oil production or maritime transport have become one of the environmental problems.There are different methods for water and oil separation and water purification that in the present project, selective separation can be achieved by using hydrophobic materials and surface roughness and creating surfaces with two properties: superhydrophobic and ultra-oil friendly. This method is also very effective, cheap...
Evaluation the Effect of Oxidized Nano MoS2 on Epoxy Novolac Corrosion Resistance and Rheological Properties
, M.Sc. Thesis Sharif University of Technology ; Ramezani Saadat Abadi, Ahmad (Supervisor) ; Mousavi, Abbas (Supervisor)
Abstract
This study investigated the effect of oxidized molybdenum disulfide (MoS2) nanosheets on the anti-corrosion and rheological properties of epoxy resin. Raw MoS2 sheets were obtained as layered nanosheets with a thickness of 50 to 100 nm using acid washing, oxidation, and heat shock methods. The use of nanoparticle characterization tests such as XRD, FT-IR, FE-SEM, EDS, and TGA supports this claim. Then, in the next step, epoxy coatings containing different percentages (0, 0.3, 0.5, 0.8, and 1.5 wt%) of MoS2 nanosheets were prepared with polyamide hardener to investigate the effect of adding nanosheets and the optimal percentage. The best effect on the corrosion properties of the coating in a...
Fabrication and Evaluation of Mechanical and Anti-corrosion Properties of Epoxy Resin/Carbon Nanofibers Containing Organic Corrosion Inhibitors
, M.Sc. Thesis Sharif University of Technology ; Ramazani Saadat Abadi, Ahmad (Supervisor) ; Mahdavian Ahadi, Mohammad (Supervisor)
Abstract
To protect mild steel against corrosion, an intelligent self-healing epoxy (EP) coating including carbon nanofiber (CNF) modified with polydopamine (PDA)-La (III) complex was successfully fabricated. The high aspect ratio and unique thermal and electrical characteristics of CNF made it an ideal physical barrier against the penetration of corrosive ions. Due to the poor dispersion of CNF, its surface was modified using PDA. PDA, which contains functional groups such as catechol, amine, and imine, can mitigate corrosion reaction by generating the Fe-Catechol complex and also boost the coating's adherence to the metal surface, in addition to anchoring La3+ inorganic corrosion inhibitor....
Kinetic Investigation of the Thermal Treatment of E-Waste with Particular Emphasis on Printed Circuit Boards (PCBs)
, M.Sc. Thesis Sharif University of Technology ; Fotovat, Farzam (Supervisor)
Abstract
In this study, pyrolysis features and corresponding kinetic behavior of non-metallic fractions of the paper-laminated phenol resin printed circuit boards (P-PCB) and fiberglass-reinforced epoxy resin printed circuit boards (E-PCB) were investigated by the use of simultaneous thermogravimetric analysis (TGA/DTG). The kinetic parameters of the P-PCB abs E-PCB during pyrolysis process were estimated from the experimental data by means of three iso-conversional kinetic models, including Friedman, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) methods. The activation energy range obtained for P-PCB and E-PCB utilizing the Friedman method was within 117–594.1 and 88.42-295.3 kJ.mol-1,...
Investigation of Antifouling Coating Paint on Steel
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor)
Abstract
Plants and aquatic creatures growth on the surface of human made structures is a typical phenomena. One of the approaches to prevent algae and moss to grow is using paint coatings including biocides. In this research project, anti-moss paints containing Copper Oxide as the major biocide and Zinc Oxide as the minor biocide have been synthesized. The effects of different parameters like the type of resin, biocide concentration, biocide grain sizes, dip time, and the coating layer thickness on the release rate which is the most important factor to prevent moss growth, have been investigated. Then, the experiment has been conducted on the specimens in algae growth and flustered sea water...
Synthesis and Characterization of Nanodiamond/Epoxy Nanocomposites
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor) ; Bagheri, Reza (Co-Advisor)
Abstract
In recent years, it has been interesting to to use nanodiamond (ND) in oreder to improve mechanical and electrical properties. Producing it in very low dimensions, make it more important to treat ND surface proportional to its application. Hence, with knowledge of influence of ND and its functional groups on curing process, in present research,carboxylic acid and amine were settled on its surface and in addition to untreated ND, they were dispersed in DGEBA epoxy as a reinforcement. Afterward, by adding triethylenetetramine kinetic cure of nanocomposites were investigated. For this purpose, conversion was determined using heat flow of reaction and then activation energy was calculated....
Fracture toughness of a hybrid rubber modified epoxy. II. Effect of loading rate
, Article Journal of Applied Polymer Science ; Volume 125, Issue 3 , January , 2012 , Pages 2476-2483 ; 00218995 (ISSN) ; Kouchakzadeh, M. A ; Bagheri, R ; Sharif University of Technology
Wiley
2012
Abstract
Effect of loading rate on toughness characteristics of hybrid rubber-modified epoxy was investigated. Epoxy was modified by amine-terminated butadiene acrylonitrile (ATBN) and recycled tire. Samples were tested at various loading rates of 1-1000 mm/min. Fracture toughness measurements revealed synergistic toughening in hybrid system at low loading rates (1-10 mm/min); hybrid system exhibited higher fracture toughness value in comparison with the ATBN-modified resin with same modifier content. However, synergistic toughening was eliminated by increasing the loading rate. At higher loading rates (10-1000), the fracture toughness of hybrid system decreased gradually to the level lower than that...
Toughening of epoxy nanocomposites: Nano and hybrid effects
, Article Polymer Reviews ; Volume 56, Issue 1 , 2016 , Pages 70-112 ; 15583724 (ISSN) ; Mai, Y. W ; Bagheri, R ; Pearson, R. A ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
In this paper, we review recent progress made in the field of epoxy-based binary and ternary nanocomposites containing three-, two-, and one-dimensional (i.e., 3D-, 2D-, and 1D) nano-size fillers with a special focus on their fracture behaviors. Despite investigations conducted so far to evaluate the crack-resistance of epoxy nanocomposites and attempts made to clarify the controlling toughening mechanisms of these materials, some questions remain unsolved. It is shown that silica nanoparticles can be as effective as rubber particles in improving the fracture toughness/energy; but incorporation of carbon nanotubes (CNTs) or clay platelets in epoxy matrices delays crack growth only modestly....
Environmental effects on the bond at the interface between FRP and wood
, Article European Journal of Wood and Wood Products ; Volume 76, Issue 1 , 2018 , Pages 163-174 ; 00183768 (ISSN) ; Toufigh, V ; Mofid, M ; Sharif University of Technology
Springer Verlag
2018
Abstract
The advantages of fiber reinforced polymer (FRP), such as high specific strength, resistance against corrosion and formability, have made it a more acceptable alternative to conventional materials regarding repairing and retrofitting of structures. Although investigations in recent years have proved the concern of civil engineers about the environmental effects on the bond between FRP and concrete or masonry (especially moisture and temperature), only few researches have been reported on FRP-wood interfaces. This research investigated the effect of five different environments on the bond at the interface between FRP and wood. A series of pull-out tests were performed on 375 wood specimens...
Synergistic inhibition effect of zinc acetylacetonate and benzothiazole in epoxy coating on the corrosion of mild steel
, Article Journal of Materials Engineering and Performance ; Volume 24, Issue 6 , 2015 , Pages 2464-2472 ; 10599495 (ISSN) ; Mahdavian, M ; Sharif University of Technology
Springer New York LLC
2015
Abstract
The corrosion inhibition effect of zinc acetylacetonate (ZAA) and benzothiazole (BTH) mixture was evaluated for mild steel in 3.5% NaCl solution. To this end, ZAA:BTH mixtures ranged from 6:1 to 1:6 mol ratios were examined by weight loss and open circuit potential to obtain optimal mole ratio. The optimal mixture of ZAA:BTH at 1:5 mol ratio showed a significant corrosion inhibition efficiency proved by electrochemical impedance spectroscopy and polarization studies. The addition of the optimal mixture of ZAA:BTH to epoxy coating showed a considerable increase of corrosion protection evaluated by salt spray exposure
Evaluation of the corrosion protection properties of an epoxy coating containing sol-gel surface modified nano-zirconia on mild steel
, Article RSC Advances ; Volume 5, Issue 36 , Mar , 2015 , Pages 28769-28777 ; 20462069 (ISSN) ; Mahdavian, M ; Karimi, E ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
In this study, the effect of surface modified nano-zirconia (nano-ZrO2) on the corrosion protection of epoxy coating on mild steel was investigated. An organosilane (trimethoxy methyl silane) was used as a surface modifier to improve the dispersability of the inorganic nanoparticles in the organic coating matrix. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to characterize the sol-gel surface modified nanoparticles. The dispersability of the modified and unmodified nano-zirconia in an epoxy coating was examined by field emission-scanning electron microscopy (FE-SEM). Electrochemical impedance spectroscopy (EIS) and salt spray were employed to...