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Synthesis and Characterization of Starch Vernolates in Organic Solvents
Tegene Desalegn Zeleke,
Teshome Abdo Segne,
Yonas Chebude
Issue:
Volume 4, Issue 6, December 2016
Pages:
212-220
Received:
13 November 2016
Accepted:
25 November 2016
Published:
17 December 2016
Abstract: In this study the synthesis of epoxy fatty acid esters of starch (starch vernolates) by the reaction of cassava starch with vernonia oil methyl ester (epoxy ester) using basic catalyst K2CO3 and organic solvent, DMSO as a reaction medium is presented. Under current reaction conditions, a high degree of substitution of 1.24 was achieved, at a reaction temperature of 110°C and 12 hours of reaction time. The new starch vernolates were characterized by Scanning electron microscopy (SEM) and X-ray diffraction (XRD) indicated that the new product is an amorphous material with a continuous and shapeless morphology. The melting point measured by differential scanning calorimetry (DSC) was 118°C. The new synthetic method makes the synthesis of starch vernolates less time consuming and more inexpensive. The differences in melting point and degree of substitution with previously synthesized starch vernolates using enzymatic and chemical catalysis suggest a difference in reaction selectivity via this new reaction path.
Abstract: In this study the synthesis of epoxy fatty acid esters of starch (starch vernolates) by the reaction of cassava starch with vernonia oil methyl ester (epoxy ester) using basic catalyst K2CO3 and organic solvent, DMSO as a reaction medium is presented. Under current reaction conditions, a high degree of substitution of 1.24 was achieved, at a reacti...
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Synthesis, Characterization, Swelling Studies and Dye Removal of Chemically Crosslinked Acrylic Acid/Acrylamide/N,N-Dimethyl Acrylamide Hydrogels
Ahmed Galal Ibrahim,
Farag Abdel Hai,
Hamada Abdel Wahab,
Hamza Mahmoud
Issue:
Volume 4, Issue 6, December 2016
Pages:
221-234
Received:
6 November 2016
Accepted:
24 November 2016
Published:
23 December 2016
Abstract: Polymeric hydrogels of acrylic acid (AA), acrylamide (AAm) and N,N-Dimethylacrylamide (DMAm) were prepared by free-radical polymerization at 70°C in methanol, using allylpentaerythritol (APE) as a multifunctional crosslinker and benzoyl peroxide (BPO) as an initiator. The effects of DMAm concentration and variation of pH solutions on the swelling behavior of polymers were investigated. Also AA/AAm/DMAm hydrogel was used in experiments on adsorption of a water soluble monovalent cationic dye such as Basic Blue 9 (BB-9; Methylene blue). FT-IR results confirmed the Structural features of the obtained hydrogels. Results from SEM observation showed a three dimensional porous structure of the hydrogels. Thermogravimetric analysis (TGA) of hydrogels was performed to investigate the thermal properties. The swelling results showed an increase of the swelling of AA/AAm/DMAm hydrogels as the content of DMAm increases in the hydrogel. The swelling percentage and swelling kinetics parameters such as initial swelling rate and swelling rate constant were determined. It was also shown that the swelling of hydrogels increased with the increase of pH and the maximum extent was reached at pH 8 in all compositions. The uptake of BB-9 to AA/AAm/DMAm hydrogel is studied by batch adsorption technique at 25°C. The hydrogel in the dye solution showed coloration. Kinetics and isotherms of dye adsorption were also studied. It was found that the adsorption kinetics of hydrogels followed a pseudo-second-order model. Equilibrium isotherms were analyzed using the Langmuir and Freundlich isotherms. It was seen that the Freundlich model fits the adsorption data better than the Langmuir model.
Abstract: Polymeric hydrogels of acrylic acid (AA), acrylamide (AAm) and N,N-Dimethylacrylamide (DMAm) were prepared by free-radical polymerization at 70°C in methanol, using allylpentaerythritol (APE) as a multifunctional crosslinker and benzoyl peroxide (BPO) as an initiator. The effects of DMAm concentration and variation of pH solutions on the swelling b...
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Design and Application of a Data Analysis System for an Oxygen Bomb Calorimeter
Xiaoli Ma,
Hualing Tian,
Zhi Su
Issue:
Volume 4, Issue 6, December 2016
Pages:
235-241
Received:
28 October 2016
Accepted:
23 November 2016
Published:
4 January 2017
Abstract: Based on the theory of determining heat values using an oxygen bomb combustion method, a data analysis system for oxygen bomb combustion was developed using MATLAB visual programming technology. This system can analyze data for the combustion and enthalpy of the decomposition for organic materials, the enthalpy of formation of volatile liquid materials such as gasoline, aviation kerosene, alcohol, and benzene, as well as for materials having lower heat values such as honey and ethanol, and even complex solid materials such as coal, sludge, waste, architectural materials, and concrete. This new data analysis system can very accurately determine the temperature variation in combustion, and then display the interrelated data on a display screen. Practical mathematical models and methods are listed in the paper. Our research will prove valuable for developing new applications for oxygen bomb technology and solving practical problems involving thermodynamics.
Abstract: Based on the theory of determining heat values using an oxygen bomb combustion method, a data analysis system for oxygen bomb combustion was developed using MATLAB visual programming technology. This system can analyze data for the combustion and enthalpy of the decomposition for organic materials, the enthalpy of formation of volatile liquid mater...
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Phytochemical Analysis and Antimicrobial Activity of Chloroform Extract of Abutilon indicum
Dixa Singh,
Vimal Sheel Singh
Issue:
Volume 4, Issue 6, December 2016
Pages:
242-246
Received:
8 November 2016
Accepted:
24 November 2016
Published:
12 January 2017
Abstract: Powdered Abutilon indicum leaves were extracted from chloroform. Thin layer chromatography technique in combination with column chromatography was used to separate the chemically active constituents. The constituents were subjected to IR, NMR, EIMS analysis to identify the compounds contained in the extract. The antimicrobial activity of the plant extract was examined on Bacillus subtils, Klebsiella pneumonia, Pseudomonas aeruginosa, E.coli and the effect was compared with that of chloramphenicol. The comparative results showed that chloroform extract of Abution indicum can serve well as an antimicrobial agent.
Abstract: Powdered Abutilon indicum leaves were extracted from chloroform. Thin layer chromatography technique in combination with column chromatography was used to separate the chemically active constituents. The constituents were subjected to IR, NMR, EIMS analysis to identify the compounds contained in the extract. The antimicrobial activity of the plant ...
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Synthesis and Properties of New Liquid Crystals as Curing Agents for Epoxy Resins
Anber M. Anber,
Sahar Al-Hariri,
Ayham H. Abazid
Issue:
Volume 4, Issue 6, December 2016
Pages:
247-255
Received:
4 December 2016
Accepted:
5 January 2017
Published:
20 January 2017
Abstract: A novel class liquid crystalline epoxy resins was synthesized by reacting the diglycidyl ether of bisphenol A (DGEBA) with three new liquid crystal diols, 4,4`-di-N-](6-hydroxy hexoxy)-3-pyridyl methylidene [amino phenyl benzamide, 4,4`- di-N-](6-hydroxy butoxy)-3-pyridyl methylidene[amino phenyl benzamide, and 4,4`- di-N-](6-hydroxy etoxy)-3-pyridyl methylidene[amino phenyl benzamide, contain azomethine groups. The new liquid crystals were characterized by Fourier transformed infra-red (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Flexibility and adhesion properties were then investigated for the cured resins based on new azomethine mesogenic diols. The cured polymers were found to exhibit high flexibility and good adhesion properties compared to ordinary amine systems.
Abstract: A novel class liquid crystalline epoxy resins was synthesized by reacting the diglycidyl ether of bisphenol A (DGEBA) with three new liquid crystal diols, 4,4`-di-N-](6-hydroxy hexoxy)-3-pyridyl methylidene [amino phenyl benzamide, 4,4`- di-N-](6-hydroxy butoxy)-3-pyridyl methylidene[amino phenyl benzamide, and 4,4`- di-N-](6-hydroxy etoxy)-3-pyrid...
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Gibbs Free Energy and Activation Free Energy of Complexation of Some Divalent Cations with Ampicillin in Methanol at Different Temperatures
Elsayed T. Helmy,
Esam A. Gomaa,
Elsayed M. Abou Eleef
Issue:
Volume 4, Issue 6, December 2016
Pages:
256-259
Received:
1 September 2016
Accepted:
8 November 2016
Published:
21 January 2017
Abstract: The Complexation reaction between Sodium (2S,5R,6R)-6-{[(2R)-2-amino-2-phenylacetyl]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate (Ampicillin sodium salt) ligand with Ca+2 and Ba+2 ions were studied condctometrically in methanol at four different temperatures (293.15K, 298.15K, 303.15K, 308.15K) On drawing the relation between molar conductance and the ratio of metal to ligand concentrations, different lines are obtained indicating the formation of (1:1 and 2:1 (M:L) stoichiometric complexes. The formation constants, thermodynamic parameters Gibbs free energies and Gibbs free energies of formation of different complexes in methanol were determined.
Abstract: The Complexation reaction between Sodium (2S,5R,6R)-6-{[(2R)-2-amino-2-phenylacetyl]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate (Ampicillin sodium salt) ligand with Ca+2 and Ba+2 ions were studied condctometrically in methanol at four different temperatures (293.15K, 298.15K, 303.15K, 308.15K) On drawing the relation b...
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