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polyamide
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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 TechnologyNew thermally stable and organosoluble polyamides and copolyamides containing oxazolopyridine pendant moiety
, Article Arabian Journal for Science and Engineering ; Volume 45, Issue 6 , March , 2020 , Pages 4727-4735 ; Koohmareh, G. A ; Mohebbi Zinab, J ; Sharif University of Technology
Springer
2020
Abstract
In this study, a new series of thermally stable polyamides and copolyamides are prepared through reaction of oxazolopyridine functional diamine, 2-(3,5-diaminophenyl) oxazolo [4,5-b] pyridine with four commercial dicarboxylic acids: pyridine 2,6-dicarboxylic acid, pyridine 2,5-dicarboxylic acid, 4,4′-dicarboxylic acid diphenyl sulfone and 4,4′-dicarboxylic acid diphenyl ether. The synthesized polymers were characterized by FT-IR and 1HNMR spectroscopy. The physical properties of the polymers including solubility and viscosity were studied. The results displayed good solubility, viscosity and high thermal stability. Their viscosities and glass transition temperatures are in the range of...
Magnetic and electric field assisted electrospun polyamide nanofibers for on-line μ-solid phase extraction and HPLC
, Article RSC Advances ; Vol. 4, Issue. 94 , 2014 , pp. 52590-52597 ; ISSN: 20462069 ; Piri-Moghadam, H ; Rastegar, S ; Sharif University of Technology
Abstract
The effects of applied magnetic and electric fields on electrospinning were investigated to produce more efficient nanofibers. Considering the previous extensive studies, polyamide nanofibers were prepared by a conventional approach and under auxiliary electric and magnetic fields. The first sorbent was synthesized by electrospinning of a solution of 18% polyamide in formic acid. The second and third types of polyamide were prepared similarly while the electrospinning processes were assisted by an electric and a magnetic field. The third type of polyamide contained a magnetic ionic liquid (MIL) to induce sufficient magnetic susceptibility in the polymeric solution. The SEM images revealed...
Effect of CO2-laser irradiation on properties and performance of thin-film composite polyamide reverse osmosis membrane
, Article Korean Journal of Chemical Engineering ; Volume 33, Issue 3 , 2016 , Pages 1028-1036 ; 02561115 (ISSN) ; Mousavi, S. A ; Farhadi, F ; Vatanpour, V ; Sabzi, B ; Chenari, Z ; Sharif University of Technology
Springer New York LLC
2016
Abstract
CO2-laser irradiation was used to modify the surface properties of thin-film composite (TFC) polyamide reverse osmosis (RO) membranes. These membranes were first synthesized via interfacial polymerization of m-phenylenediamine (MPD) monomers and trimesoyl chloride (TMC) over porous polysulfone ultrafiltration support, followed by a CO2-irradiation. AFM, ATR-FTIR, SEM and contact angle measurements were used to characterize the surface properties of these membranes. The ATR-FTIR results indicated that CO2-laser irradiation did not induce any functional groups on the membrane surface. However, it was found that the laser irradiation enhanced the NaCl salt rejection and slightly reduced the...
Study on dynamic and mechanical characteristics of carbon fiber- and polyamide fiber-reinforced seismic isolators
, Article Materials and Structures/Materiaux et Constructions ; Volume 47, Issue 3 , March , 2014 , Pages 447-457 ; ISSN: 13595997 ; Jafari, M. H ; Valadoust Tabrizi, V ; Sharif University of Technology
Abstract
Seismic isolators are used to decrease the energy and forces of earthquakes. The weight of conventional steel-reinforced elastomeric isolators (SREIs) is high, mostly due to the use of multiple steel shim plates. On the contrary, the damping ratio of SREIs is relatively low. Accordingly, this research utilizes a new approach in which the steel shim plates are replaced by carbon and polyamide fibers. This study attempts to obtain the dynamic and mechanical properties of such carbon fiber- and polyamide fiber-reinforced elastomeric isolators, in comparison with SREIs. In this work, a number of specimens were initially designed and manufactured. Afterwards, compression and cyclic shear tests...
Evaluation of The Effect of Molecular Weight, Mixing Approach and Compatibilizer on Morphologhy and Mechanical Properties of PP/PA/Clay Nanocomposite
,
M.Sc. Thesis
Sharif University of Technology
;
Bagheri, Reza
(Supervisor)
Abstract
Polypropylene/clay nanocomposites are considered as a group of widely used nanocomposites in industrial applications due to their desired properties, yet reasonable cost. However, dissimmilar chemical nature of polypropylene and clay do not allow perfect dispersion of silicate layeres in the matrix and thus restricts full advantages of these composites.An earlier investigation in this group considered solving this shortcoming through incorporation of PA6 as an intermediate phase to enhance clay platelets dispersion. The current project follows this route via studing the influence of molecular weight of the PP matrix, compatibilzer and the mixing procedure of the compound. To investigate the...
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor) ; Bagheri, Reza (Supervisor)
Abstract
Taghizadeh Manzari, M. (MehrdadThe main goals of this project are studding the effect of carbon nanotube on the properties of PA6/PA66 matrix and miscibility of PA6/PA66 blend. So PA6/PA66/CNT nanocomposites were compounded by melt mixing method and samples were prepared by injection molding. Due to study miscibility of PA6 and PA66, we used DMTA test and found that PA6 and PA66 are miscible because of existing one pick on DMTA graph. Also DSC test results confirmed that PA6 and PA66 are miscible. Moreover, according to DMTA results, modulus will be rose by increasing CNT content. Mechanical test showed same results in this case. Adding 1%CNT to matrix caused 10% improvement in modulus and...
Partially aromatic polyamides based on tetraphenylthiophene diamine: Synthesis and characterization [electronic resource]
, Article Journal of Applied Polymer Science ; Volume 77, Issue 5, pages 1144–1153, 1 August 2000 ; Zamanlu, M. R ; Zohuriaan-Mehr, M. J ; Sharif University of Technology
Abstract
Tetraphenylthiophene diamine (TPTDA) was prepared through a modified three-step route to achieve an improved overall yield. TPTDA reacted with succinic, adipic, suberic, sebasic, and fumaric acids via the Yamazaki phosphorylation method to yield novel partially aromatic polyamides (TPT series). A counterpart polyamide series based on p-phenylene diamine (Ph series) was also synthesized under the same conditions. All of the polymers were characterized by means of spectrochemical (Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance (NMR), and 13C-NMR) and thermal (differential scanning calorimetry and thermogravimetric) methods of analysis. Solubility of TPT polyamides was...
Electrospun composite of polypyrrole-polyamide as a micro-solid phase extraction sorbent
, Article Analytical and Bioanalytical Chemistry ; 2011 , Pages 1-7 ; 16182642 (ISSN) ; Aghakhani, A ; Akbari, M ; Ayazi, Z ; Sharif University of Technology
Abstract
A micro-solid phase extraction technique was developed using a novel polypyrrole-polyamide nanofiber sheet, fabricated by electrospinning method. The applicability of the new nanofiber sheet was examined as an extracting medium to isolate malathion as a model pesticide from aqueous samples. Solvent desorption was subsequently performed in a microvial, and an aliquot of extractant was injected into gas chromatography-mass spectrometry. Various parameters affecting the electrospinning process including monomer concentration, polyamide content, applied voltage, and electrospinning time were examined. After fabricating the most suitable preparation conditions, influential parameters on the...
Synthesis and characterization of polyamide membrane for the separation of acetic acid from water using RO process
, Article Membrane Water Treatment ; Volume 8, Issue 4 , 2017 , Pages 323-336 ; 20058624 (ISSN) ; Mousavi, S. A ; Mortazavi, S. S ; Sadeghi, M ; Bastani, D ; Sharif University of Technology
Techno Press
2017
Abstract
The main challenge in many applications of acetic acid is acid dehydration and its recovery from wastewater streams. Therefore, the performance of polyamide thin film composite is evaluated to separate acetic acid from water. To reach this goal, the formation of polyamide layer on polysulfone support membrane was investigated via interfacial polymerization (IP) of meta-phenylenediamine (MPD) in water with trimesoyl chloride (TMC) in hexane. Also, the effect of synthesis conditions, such as concentration of monomers and curing temperature on separation of acetic acid from water were investigated by reverse osmosis process. Moreover, the separation mechanism was discussed. The solute...
Study of the scratch resistance criteria and their relationship with mechanical properties and microstructure in a ternary thermoplastic blend
, Article Wear ; Volume 386-387 , 2017 , Pages 118-128 ; 00431648 (ISSN) ; Bagheri, R ; Sharif University of Technology
Abstract
Polymeric materials generally suffer from a low resistance to various types of surface mechanical damage, among which scratch is a prominent example. While several attempts have been made to assess the scratch resistance and its relationship with the bulk mechanical properties in simple polymeric systems, the available research on the polymeric blends is scarce. This study attempts to fill this gap by studying the link between the scratch resistance and mechanical properties in a ternary polymeric nanocomposite, which has proved to feature superior and tunable mechanical properties. For this aim, blends of polypropylene and polyamide 6 were prepared using melt blending with two different...
Protection of Steel Rebar in Concrete with Zinc Based Coatings in Persian Gulf
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
Reinforced concrete is one of the most important structural materials used in the construction industry worldwide. Nevertheless, certain physical and chemical factors in the service environment can contribute to its deterioration and failure. One of the most significant factors is the reinforcing steel bar (rebar) corrosion. In order to minimize the rebars corrosion, different kinds of coatings were investigated and evaluated by scientists. In this investigation comparative studies were performed on two different kinds of coated rebars (zinc-rich epoxy and polyamide epoxy coated rebars) and uncoated rebar. In order to evaluate these reinforced concretes, the adhesion, durability, thickness...
Investigation 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...
Preparation and Characterization of Morphology and Mechanical Properties of PA6/Nanodiamond Composites
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor)
Abstract
Polyamide or Nylon, due to its remarkable mechanical and tribological properties, has many engineering applications. Hence, improving the properties can develop the polyamide applications. In this study, Polyamide 6 (PA6) has been used as matrix with nanodiamond (ND) reinforcement. Spherical shape, chemically active surface as well as remarkable mechanical properties make nanodiamond an ideal candidate for improving polymers properties. Poor dispersion and agglomeration are present however major problems in achieving improved properties in nanocomposites. To deal with this problem, nanodiamonds were surface modified using Ethylenediamine (EDA) and Hexamethylenediamine (HMD). Nanocomposite...
Enhance the Chlorine Resistance of Reverse Osmosis Membrane
, M.Sc. Thesis Sharif University of Technology ; Mousavi, Abbas (Supervisor) ; Abdekhodaei, Mohammad Jafar (Supervisor)
Abstract
Reverse osmosis membrane one of the common methods used for water desalination, today membrane, thin film composite(TFC) include three layers, top the these layers named selection layer, this poly amid layer contacted with feed water, sensitivity to chlorine in polyamide layer lead to high membrane chlorine sensitive. Difference methods used for enhance the chlorine resistance in polyamide membrane that categorized in three general categories, covering and protection of sensitive areas method has best results in comparison to other methods. In this research protection method choose and used, material that used, sanitized by result from surface analysis of commercial membrane manufactured in...
Improve Performance of Polyamide Reverse Osmosis Membranes by Crosslinking Treatments
, M.Sc. Thesis Sharif University of Technology ; Mousavi, Abbas (Supervisor)
Abstract
Reverse osmosis membranes are one of the most common methods of desalination of water in the world today. In the meantime, aromatic polyamide thin-film composite reverse osmosis membranes have one of the best performances and can be widely used in industry. This project aims to make surface modifications on the made raw membranes and increase the degree of crosslinking to improve the functional properties of the membrane, such as the percentage of salt rejection and the flux of permeate, and the reduction of fouling. For this purpose, polyvinyl alcohol and l-arginine along with maleic anhydride as the crosslinking agent and hexamethylene diisocyanate were used for surface modification of the...
Polyamide membrane surface and bulk modification using humid environment as a new heat curing medium
, Article Journal of Membrane Science ; Volume 523 , 2017 , Pages 129-137 ; 03767388 (ISSN) ; Bazgar Bajestani, M ; Mousavi, S. A ; Mokhtari Garakani, R ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Heat curing was devised in temperature-controlled steam and water environments to synthesize reverse osmosis (RO) polyamide (PA) membrane. The effect of new curing media on the physicochemical properties and RO performance of the synthesized polyamides was fully investigated using X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared (ATR-IR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and water drop contact angle. The results show a reduction in amide linkage content on the surface of the steam-cured polyamide and surface and bulk of the water-cured polyamide. Additionally, it was revealed that heat curing in the humidity-controlled environment...
Carrageenan-g-poly(acrylamide)/poly(vinylsulfonic acid, sodium salt) as a novel semi-IPN hydrogel: Synthesis, characterization, and swelling behavior
, Article Polymer Engineering and Science ; Volume 47, Issue 9 , 2007 , Pages 1388-1395 ; 00323888 (ISSN) ; Ghasemzadeh, H ; Sharif University of Technology
2007
Abstract
A semi-interpenetrating polymer network (semi-IPN) hydrogel based on kappa-carrageenan (κC) and poly (vinylsulfonic acid, sodium salt) (PVSA) was prepared by graft copolymerization of acrylamide (AAm) using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. FTIR spectroscopy was used for confirming the structure of the final product. It was found that the chemical composition of the Semi-IPN hydrogel is equal to the initial homopolymers and monomer feed compositions. The swelling capacity of the hydrogel was shown to be affected by the MBA, APS, and AAm concentration as well as κC/PVSA weight ratio. The swelling behavior of the hydrogel was...
Characterization of Morphology, Rheology and Mechanical Properties of PA-PTFE Composites
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor)
Abstract
polyamides have found great attractions in wide variety of applications due to their desirable mechanical and tribological properties and appropriate processability. Pure polymers are not suitable for this kind of application due to their low mechanical strength. High strength materials are needed for abrasive applications. Polytetrafluoroethylene (PTFE) is one of the most popular materials for abrasive applications. In this study the effect of PTFE and surface modification on PA/PTFE composite properties is investigated. duo to modification of PTFE powder, PTFE is exposed to sodium naphtalenide (Na/naphtha) etchant so as to deflurinate the surface for obtaining carbonyl, carboxyl and...
On-line SPE of Clodinafop Propargyl Traces from Aquatic Media Using Electrospun Polyamide Nanofibers Disks
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
An on-line solid phase extraction (SPE) method coupled with high performance liquid chromatography (HPLC) was developed using electrospun polyamide (PA) nanofibers as the extractin medium for trace determination of clodinafop propargyl herbicide in environmental aqueous samples. The sufficient numbers of disc sheets were cut from the electrospun PA mat and used as packing material in a cartridge. The homogeneity and the porosity of the prepared PA sheet were studied using the scanning electron microscopy (SEM) and the observed nanofiber diameters and lengths proved that the prepared sorbent possess a high aspect ratio. Major parameters affecting the extraction efficiency were optimized. The...