Bābolsar, Iran
Bābolsar, Iran

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Lakouraj M.M.,University of Mazanadaran | Tashakkorian H.,University of Mazanadaran
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry | Year: 2013

Novel polyamides bearing calix[4]arene and triazole units, polytriazolecalixamides (PTCAs), were prepared by direct polycondensation of a new bistriazole substituted dicarboxylic acid derivative of calix[4]arene with commercial diamines. The polytriazolecalixamides were obtained in high yields and possessed inherent viscosities in the range of 0.42-0.59 dl/g. These polytriazolecalixamides were readily soluble in polar aprotic solvents such as NMP, DMSO, DMAc at room temperature and in THF by heating. Nanocrystalline structures were determined by XRD patterns and confirmed by DSC as well as TEM and AFM imaging techniques. The photophysical study was performed by UV-absorption spectroscopy and maximum wavelength for each polymer specified in details. Glass transition temperatures were between 134 and 154°C. Thermogravimetric analysis showed that these polyamides displayed high thermal stability ranged from 273 to 312°C at the point of 10% weight loss, and char yields were about 51.4-67.4% at 600°C in nitrogen. All of these nanocrystalline polycalixamides showed promising sorption properties towards transition metal ions such as Cu2+, Cr2+, Co2+, Cd2+ and especially Pb2+ in solid-liquid extraction which fulfill our needs in synthesizing novel high performance polyamides. © 2013 Copyright Taylor and Francis Group, LLC.


Mohammadi A.,University of Mazanadaran | Lakouraj M.M.,University of Mazanadaran | Barikani M.,Iran Polymer And Petrochemical Institute
Reactive and Functional Polymers | Year: 2014

In this study, a new type of flexible polyurethane foam containing p-tert-butyl thiacalix[4]arene (TC4A) macrocycle was synthesized. TC4A macrocycle was incorporated into polyurethane foam as a part of crosslinking agent as well as glycerol. Structural, morphological, thermal and mechanical properties of this prepared foam were studied and compared with a polyurethane foam based on only glycerol as crosslinking agent, by Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), Thermal gravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA). The effect of introduction of TC4A crosslinker on cream time, rise time, apparent density, and water absorbency of the PU foams was evaluated. Moreover, it was shown that new TC4A-based polyurethane foam (TC-PUF) can be a high performance adsorbent for removal of malachite green from aqueous media using batch adsorption technique. The adsorption results indicated that TC-PUF has a high adsorption capacity of 58.82 mg/g for malachite green due to the presence of TC4A macrocycles in the structure of polyurethane foam. The kinetics of adsorption of malachite green was also investigated using the pseudo-first-order and pseudo-second-order kinetic models. The results of kinetic studies showed that the adsorption of malachite green onto TC-PUF followed pseudo-second-order kinetic model. © 2014 Elsevier Ltd. All rights reserved.


Hamidinezhad H.,University of Mazandaran | Akbar Ashkarran A.,University of Mazanadaran | Abdul-Malek Z.,University of Technology Malaysia
Materials Science in Semiconductor Processing | Year: 2014

Vertically aligned silicon nanowires (SiNWs) have been successfully synthesized using pure silane gas as a precursor by very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) method. The effect of the growth temperature on the morphology, structure and photoluminescence properties of SiNWs has been studied. The SiNWs were needle-liked materials with the length of a few microns having the diameters of tens of nanometers near the bottom and a few nanometers at the top. Thinner nanowires have been obtained at the higher growth temperature process. High resolution transmission electron microscopy confirms that the nanowires are composed of a crystalline silicon core with an oxide shell. The PL spectrum of the Si nanoneedles have shown two emission bands around 450 nm and ∼750, which originate from the defects related to oxygen fault in the oxide shell and interfaces between the crystalline Si core and the oxide shell, respectively. © 2014 Elsevier Ltd.


Mohammadi A.,University of Mazanadaran | Barikani M.,Iran Polymer And Petrochemical Institute
Materials Characterization | Year: 2014

In this study, superparamagnetic thiodiglycol coated Fe3O 4 nanoparticles (TDG-Fe3O4) were synthesized using in situ coprecipitation method in alkali media and were characterized by XRD, FTIR, TGA, VSM, TEM, and SEM. TGA and FTIR results confirmed the binding of thiodiglycol onto the surface of Fe3O4 nanoparticles. XRD pattern showed the presence of peaks corresponding to the inverse spinel structure of Fe3O4 nanoparticles. In addition, the magnetic properties of nanoparticles determined by VSM exhibited TDG-Fe 3O4 nanoparticles that have superparamagnetic property with high enough saturation magnetization of 44.55 emu/g. TEM and SEM results showed that TDG-Fe3O4 nanoparticles have good dispersion and are smaller and less agglomerated than pure Fe3O4 nanoparticles due to reduction in attractive forces between the nanoparticles by thiodiglycol. Additionally, the result of DTG analysis of TDG-Fe 3O4 nanoparticles suggested that thiodiglycol molecules were bonded to the surface of the Fe3O4 nanoparticles with different binding modes. © 2014 Elsevier Inc.


Mohammadi A.,University of Mazanadaran | Barikani M.,Iran Polymer And Petrochemical Institute | Lakouraj M.M.,University of Mazanadaran
Materials Science and Engineering C | Year: 2016

In this study, a series of magnetic polyurethane/Fe3O4 elastomer nanocomposites were prepared by covalently embedding novel thiacalix[4]arenes (TC4As) functionalized Fe3O4 nanoparticles (TC4As-Fe3O4) which contain macrocycles with reactive hydroxyl groups. Surface functionalization of Fe3O4 nanoparticles with TC4As macrocycles as unique reactive surface modifier not only gives specific characteristics to Fe3O4 nanoparticles but also improves the interphase interaction between nanoparticles and the polyurethane matrices through covalent attachment of polymer chains to nanoparticle surfaces. The novel synthesized TC4As-Fe3O4 nanoparticles were characterized by FTIR, XRD, TGA, VSM and SEM analysis. Furthermore, the effect of functionalization of Fe3O4 nanoparticles on the various properties of resulting nanocomposites was studied by XRD, TGA, DMTA, SEM, and a universal tensile tester. It was found that the functionalization of nanoparticles with TC4As affords better mechanical and thermal properties to polyurethane nanocomposites in comparison with unmodified nanoparticles. The SEM analysis showed finer dispersion of TC4As-Fe3O4 nanoparticles than unmodified Fe3O4 nanoparticles within the polyurethane matrices, which arising from formation of covalent bonding between TC4As functionalized Fe3O4 nanoparticles and polyurethane matrices. Moreover, the investigation of in vitro biocompatibility of novel nanocomposites showed that these samples are excellent candidate for biomedical use. © 2016 Elsevier B.V. All rights reserved.


Mohammadi A.,University of Mazanadaran | Lakouraj M.M.,University of Mazanadaran | Barikani M.,Iran Polymer And Petrochemical Institute
RSC Advances | Year: 2016

Thiacalix[4]arenes (TC4As) are macrocyclic compounds with a cavity shape, host-guest properties, and modifiable structure for desired application. In this study, two 1,3-alternate derivatives of TC4As were employed as new macrocyclic emulsifiers bearing sulfonate groups in mixture with dimethylolpropionic acid (DMPA) to synthesize waterborne polyurethanes (WPUs). The effect of type and content of TC4As on the particle size, storage stability and viscosity of the dispersions was studied. Moreover, ATR-FTIR, 1HNMR, XRD, SEM, TGA and DMTA analysis were used to investigate the structure, morphology and thermo-mechanical properties of polyurethane films derived from synthesized WPU dispersions. The morphological inspection of samples exhibited that the microphase separation degree strongly depends on the type and content of TC4As. Furthermore, water contact angle measurements confirmed that the WPUs containing TC4As have higher hydrophobicity in comparison to WPU samples containing only DMPA as emulsifier. This improvement in hydrophobicity of TC4As-based WPUs can be explained in terms of the more hydrophobic structure of the TC4As compared to DMPA. The anti-corrosion performance of the WPUs as environmental friendly coatings for mild steel in 3.5% NaCl solution was also evaluated using PDS and EIS techniques. The results revealed that the sample including macrocyclic SuTC4A as 5 mol% of total emulsifiers has the best corrosion protection ability which was also affirmed by SEM analysis. © The Royal Society of Chemistry 2016.


Lakouraj M.M.,University of Mazanadaran | Tashakkorian H.,University of Mazanadaran
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry | Year: 2012

A series of polyamides having calix[4]arene units in the backbone which are called polycalixamides were prepared by direct polycondensation of dicarboxylic acid derivative of calix[4]arene with commercial diamines. The polycalixamides were obtained in high yields and possessed inherent viscosities of 0.42-0.55 dl/g and glass transition temperatures between 145 and 172C. These polycalixamides were amorphous and therefore readily soluble in polar aprotic solvents such as NMP, DMSO, DMAc and THF. According to thermogravimetric analysis, these polymer series displayed high thermal stability ranged from 330 to 353C at the point of 10% weight loss and char yields between 40.7-58% at 700C in nitrogen. The temperature of maximum decomposition applied in DTG curves of polymers were among 326 to 369C. The photophysical study was performed by UV-absorption spectroscopy and maximum wavelength for each polymer specified in details. It is found that these polyamides were highly efficient for sorption of Cu 2+, Cr 2+, Co 2+ and Cd 2+ in solid-liquid extraction. © 2012 Taylor & Francis Group, LLC.


Mohammadi A.,University of Mazanadaran | Lakouraj M.M.,University of Mazanadaran | Barikani M.,Iran Polymer And Petrochemical Institute
Polymer International | Year: 2015

A series of polyurethane elastomers containing various thiacalix[4]arene derivatives in a mixture with glycerol as chain extenders were synthesized. A series of polyurethane elastomers (PUEs) derived from three thiacalix[4]arene derivatives (TC4As), namely p-tert-butylthiacalix[4]arene, tetrasodium thiacalix[4]arenetetrasulfonate and thiacalix[4]arenetetrasulfonic acid, as a portion of chain extender in a mixture with glycerol were synthesized. The effects of the chemical structure of TC4As used as chain extenders on the various properties of the prepared PUEs were investigated and compared with PUE extended with only glycerol as chain extender using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy and a universal tensile tester. Moreover, the effect of the introduction of TC4As as a portion of chain extender on the hydrophobicity of the PUEs was also evaluated. DSC, FTIR spectroscopy and XRD revealed that the degree of phase separation and crystallinity in TC4A-based PUEs was much higher than that of the glycerol-based ones. Thus, it was concluded that the presence of TC4As in TC4A-based PUEs seems to favour the formation of a more ordered structure due to an increase in the degree of phase separation. The TGA results also showed that, with incorporation of TC4As into the polyurethane backbone, the thermal stability of PUEs was improved. © 2014 Society of Chemical Industry.


PubMed | Iran Polymer And Petrochemical Institute and University of Mazanadaran
Type: | Journal: Materials science & engineering. C, Materials for biological applications | Year: 2016

In this study, a series of magnetic polyurethane/Fe3O4 elastomer nanocomposites were prepared by covalently embedding novel thiacalix[4]arenes (TC4As) functionalized Fe3O4 nanoparticles (TC4As-Fe3O4) which contain macrocycles with reactive hydroxyl groups. Surface functionalization of Fe3O4 nanoparticles with TC4As macrocycles as unique reactive surface modifier not only gives specific characteristics to Fe3O4 nanoparticles but also improves the interphase interaction between nanoparticles and the polyurethane matrices through covalent attachment of polymer chains to nanoparticle surfaces. The novel synthesized TC4As-Fe3O4 nanoparticles were characterized by FTIR, XRD, TGA, VSM and SEM analysis. Furthermore, the effect of functionalization of Fe3O4 nanoparticles on the various properties of resulting nanocomposites was studied by XRD, TGA, DMTA, SEM, and a universal tensile tester. It was found that the functionalization of nanoparticles with TC4As affords better mechanical and thermal properties to polyurethane nanocomposites in comparison with unmodified nanoparticles. The SEM analysis showed finer dispersion of TC4As-Fe3O4 nanoparticles than unmodified Fe3O4 nanoparticles within the polyurethane matrices, which arising from formation of covalent bonding between TC4As functionalized Fe3O4 nanoparticles and polyurethane matrices. Moreover, the investigation of in vitro biocompatibility of novel nanocomposites showed that these samples are excellent candidate for biomedical use.

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