Applied Chemistry
Liu Jiesheng; Li Faping; Xing Shanshan; He Xiang
Volume 6, Issue 2, pp. 109-217, Serial No. 19 , April 2018, , Pages 160-168
Abstract
In this study, the interaction between the silica filler and polydimethylsiloxanes (PDMS) was investigated from the aspects of the bound rubber and morphological characterization. With special attention to the dynamic properties, the dynamic test was conducted by dynamic shear rheometer. The results ...
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In this study, the interaction between the silica filler and polydimethylsiloxanes (PDMS) was investigated from the aspects of the bound rubber and morphological characterization. With special attention to the dynamic properties, the dynamic test was conducted by dynamic shear rheometer. The results show that the modified fillers disperse uniformly within PDMS matrix without aggregation and connect closely with the matrix than that of the unmodified fillers. Surface modification of filler increases the bound rubber content. The increase in silica loading leads to an increase in the silica-silica interaction and a decrease in filler-rubber interaction, which results in the aggregation of fillers and the increase of the bound rubber content. It was apparent that storage modulus, loss modulus and tanδ of unvulcanized PDMS/filler compounds filled with treated silica filler were lower than that of the untreated silica system. Moreover, the tanδ decreases with increasing silica loading.
Applied Chemistry
Milad Kazemnejadi; Aliakbar Dehno Khalaji; Hossein Mighani
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 237-241
Abstract
Schiff base sal-2,5-Clan = 2-(2,5-dichlorobenzylideneamino)phenol used as a new precursor for preparation of poly-2-(2,5-dichlorobenzylideneamino)phenol (PDCBAP). In an aqueous alkaline medium, NaOCl oxidant is capable of oxidative poly-condensation reaction (OP). Both sal-2,5-Clan and PDCBAP were characterized ...
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Schiff base sal-2,5-Clan = 2-(2,5-dichlorobenzylideneamino)phenol used as a new precursor for preparation of poly-2-(2,5-dichlorobenzylideneamino)phenol (PDCBAP). In an aqueous alkaline medium, NaOCl oxidant is capable of oxidative poly-condensation reaction (OP). Both sal-2,5-Clan and PDCBAP were characterized by solubility tests, FT-IR, 1H-NMR spectroscopy and TG-DTA studies. FT-IR and 1H-NMR spectrum of PDCBAP indicates the formation of Ar-O-Ar bond. According to TG/DTA curves, PDCBAP demonstrated higher resistance against temperature than sal-2,5-Clan. At optimum reaction conditions, viz. time = 14h, [NaOCl]0 = 0.12 M, [KOH]0 = 0.1 M and T = 90°C, the yield of PDCBAP is 52.17%. Thermal studies indicated that PDCBAP is more stable than sal-2,5-Clan.
Applied Chemistry
Shahryar Pashaei; Soleyman Hosseinzadeh
Volume 5, Issue 2, pp. 121-236, Serial No. 15 , April 2017, , Pages 138-146
Abstract
Polyvinyl ester green composites were synthesized with walnut shell powder (WSP) by in-situ polymerization technique. The green composites have been evaluated for mechanical properties such as tensile strength, tensile modulus and hardness. Sliding wear loss, specific wear rate and coefficient of friction ...
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Polyvinyl ester green composites were synthesized with walnut shell powder (WSP) by in-situ polymerization technique. The green composites have been evaluated for mechanical properties such as tensile strength, tensile modulus and hardness. Sliding wear loss, specific wear rate and coefficient of friction were investigated by using computerized pin-on–disc machine at normal applied loads of 20, 30 and 40N; at a sliding velocity of 1.5 m/s and at two abrading distances viz., 100 and 200 m. The results indicate that the wear volume loss increases with increasing abrading distance/load. It was found that WSP filled vinyl ester composites exhibit lower wear rate and higher coefficient of friction as compared to vinyl ester green composites. Further, the worn surfaces were examined by scanning electron microscopy (SEM), to give insight in to the wear mechanism, while their mechanical properties were investigated using tensile strength, tensile modulus and hardness test machines.
Applied Chemistry
Soleyman Hosseinzadeh; Shahryar Pashaei; Nazanin Moludpoor
Volume 5, Issue 1, pp. 1-120, Serial No. 14 , January 2017, , Pages 16-27
Abstract
A series of polystyrene hybrid nanocomposites have been fabricated with varying amounts of TiO2 viz., 0, 0.5 and 1 % w/w along with 3% TS by in-situ polymerization method. The influence of surface modified TiO2 nanoparticles on the thermal properties of PS matrix was examined using thermogravimetry and ...
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A series of polystyrene hybrid nanocomposites have been fabricated with varying amounts of TiO2 viz., 0, 0.5 and 1 % w/w along with 3% TS by in-situ polymerization method. The influence of surface modified TiO2 nanoparticles on the thermal properties of PS matrix was examined using thermogravimetry and differential scanning calorimetry. Thermal characteristics of the polystyrene/TS/TiO2 hybrid nanocomposites were evaluated by using differential scanning calorimetric (DSC), thermal analysis (DTA), thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMA). By comparison with the values obtained for the hybrid mixed composites, the thermal properties of 1wt. % TiO2 along with 3wt.% TS are increased. On the other hand, PS/TS/TiO2 nanocomposites have higher glass transition temperature and better thermal and thermo oxidative stability than the bare PS. The morphological behaviors of the prepared polystyrene/TS/TiO2 were analyzed using SEM.
Applied Chemistry
Shahryar Pashaei; Soleyman Hosseinzadeh; Basavarajaiah Siddaramaiah; R. Somashekar; Naser Ghorbani
Volume 4, Issue 4, pp. 359-490, Serial No. 13 , October 2016, , Pages 399-413
Abstract
The aim of this work is to probe the influence of nanoclay and turmeric spends content on microcrystalline of vinyl ester hybrid nanocomposites. A series of vinyl ester hybrid nanocomposites have been fabricated with varying amounts of TS viz., 0, 2.5, 5, 7.5 and 10 % w/w along with 2% nanoclay. The ...
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The aim of this work is to probe the influence of nanoclay and turmeric spends content on microcrystalline of vinyl ester hybrid nanocomposites. A series of vinyl ester hybrid nanocomposites have been fabricated with varying amounts of TS viz., 0, 2.5, 5, 7.5 and 10 % w/w along with 2% nanoclay. The microcrystalline parameters such as crystallite size and lattice strain of vinyl ester hybrid nanocomposites have been measured by using wide-angle X-ray scattering (WAXS). These values were correlated with physico-mechanical properties of the vinyl ester hybrid nanocomposites with and without turmeric spent to understand the holistic behaviour of the nanocomposites. Two prominent Bragg reflections at major peak in the 2θ region 17.35 – 17.79º and a small shoulder in the 2θ region around 40.00 - 42.44º were observed in the wide-angle X-ray diffraction patterns of the vinyl ester hybrid nanocomposites films of various ratios.
Nanochemistry
Fariba Heidarizadeh; Saeed Asadipour
Volume 3, Issue 3, pp. 180-282,Serial No. 8 , July 2015, , Pages 187-198
Abstract
Polypyrrole is one of the most useful conductive polymers, but green synthesis of this polymer has been restricted until now. The objective of the present paper is green synthesis of nano polypyrrole (PPy) by oxidative polymerization using urea-hydrogen peroxide. It was found that conductivity and morphology ...
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Polypyrrole is one of the most useful conductive polymers, but green synthesis of this polymer has been restricted until now. The objective of the present paper is green synthesis of nano polypyrrole (PPy) by oxidative polymerization using urea-hydrogen peroxide. It was found that conductivity and morphology of polypyrrole are highly dependent on the reaction conditions such as the molar ratio of oxidized to monomer, temperature, reaction time, kind of solvents, the presence of a catalyst such as p-toluene sulfonic acid, and specially concentration and addition time of hydrochloric acid. After understanding the relationship between these factors, we turned this enormous variability into improved polypyrrole properties.
Organic chemistry
Abdoulhossien Massoudi; Azam Louie; Omid Louie
Volume 3, Issue 3, pp. 180-282,Serial No. 8 , July 2015, , Pages 276-282
Abstract
Poly methyl methacrylate (PMMA) is the most common material used in Prosthodontics. Several studies indicate a breakdown of the number of very high resin bases after 2 to 3 years to avoid breaking bass and several attempts have been made, such as altering the chemical structure of resin by adding causes ...
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Poly methyl methacrylate (PMMA) is the most common material used in Prosthodontics. Several studies indicate a breakdown of the number of very high resin bases after 2 to 3 years to avoid breaking bass and several attempts have been made, such as altering the chemical structure of resin by adding causes cross linking or copolymerization. The innovative method for improving the physical properties of the prosthesis and increase its strength, a copolymer of styrene - methyl methacrylate was proposed. Tensile strength increased with the increase of styrene with methyl methacrylate in an amount determined to be the most resistant. Polystyrene and poly methyl methacrylate and copolymers characterized by FTIR, CNMR and Tg and tensile strength were measured according to ISO1567 standard.
Applied Chemistry
Omid Louie; Abdoulhossien Massoudi; Samaneh Maghsoodi
Volume 2, Issue 4, pp. 236-325, Serial No. 5 , October 2014, , Pages 269-276
Abstract
Supramolecule self assembly polyamidoamine (PAMAM) dendrimer refers to the chemical systems made up of a discrete number of assembled molecular subunits or components. These strategies involve the covalent assembly of hierarchical components reactive monomers, branch cells or dendrons around atomic or ...
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Supramolecule self assembly polyamidoamine (PAMAM) dendrimer refers to the chemical systems made up of a discrete number of assembled molecular subunits or components. These strategies involve the covalent assembly of hierarchical components reactive monomers, branch cells or dendrons around atomic or molecular cores according to divergent/convergent dendritic branching principles, systematic filling of space around a core with shells (layers) of branch cells. The polydispersity index (PDI) for the Supramolecule megamer are pretty closed to one, are in agreement with the Poisson probability distribution. Polyamidoamine (PAMAM) dendrimer G1-G1 that it was PAMAM Megamer NH2, COOH end group synthesized and characterized by FT-IR, 1H NMR, 13C NMR spectra and Gel Permeation Chromatography (GPC).
Applied Chemistry
Hossein Hosseinzadeh; Mojtaba Abbasian; Shadi Hassanzadeh
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 196-208
Abstract
A novel pH-responsive superabsorbent hydrogel based on gelatin was prepared through crosslinking copolymerization of poly (acrylic acid) and poly (itaconic acid). The copolymerization conditions including monomers, initiator, gelatin and crosslinker concentration, reaction temperature, and neutralization ...
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A novel pH-responsive superabsorbent hydrogel based on gelatin was prepared through crosslinking copolymerization of poly (acrylic acid) and poly (itaconic acid). The copolymerization conditions including monomers, initiator, gelatin and crosslinker concentration, reaction temperature, and neutralization percent were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The hydrogels structure was confirmed using Fourier-transform infrared, thermogravimetric analysis, differential scanning calorimetric and scanning electron microscopy. The swelling of the superabsorbing hydrogel was examined in buffer solutions with pH ranged 3-12. Moreover, the swelling of the hydrogel was conducted in 0.15 M aqueous solutions of NaCl, CaCl2, and AlCl3. Due to the high swelling capacity in salt solutions, the hydrogel may be referred to as "low-salt sensitive" superabsorbent.