samia mokhtar - Academia.edu (original) (raw)
Papers by samia mokhtar
The European Physical Journal Applied Physics, 2015
The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (A... more The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (AN) has been investigated. The rate of polymerization of all the binary systems involved has been measured dilatometrically for the homogeneous polymerization. The reactivity ratios of the three binary systems were calculated and were found to be equal to 0.031 and 0.397 for In/AN copolymers and 0.02 and
Polymer Bulletin, 1992
The solution copolymerization of acrylamide (AAm) with N-vinyl pyrrolidone (NVP) was investigated... more The solution copolymerization of acrylamide (AAm) with N-vinyl pyrrolidone (NVP) was investigated using azobisisobutyronitrile (AIBN) as an initiator at 60°C. The study was performed by measuring the rate of the copolymerization reaction, the molecular weights and by determining the monomer reactivity ratios. In addition, the thermal properties (thermal conductivity, thermal diffusivity and volumetric heat capacity) of the resulted copolymers in aqueous solutions were investigated at various temperatures. The kinetic results and the apparent reactivity ratios indicate that NVP is more reactive than AAm towards the copolymerization process. The values of the thermal properties whowed that the behaviour of such parameters depend on the polymer concentration, the temperatures and the content of vinyl pyrrolidone in the copolymeric chains.
Polymer International, 1997
Gamma radiation-induced graft copolymerization of styrene onto poly(ethylene terephthalate) (PET)... more Gamma radiation-induced graft copolymerization of styrene onto poly(ethylene terephthalate) (PET) films was studied using simultaneous irradiation technique. The effects of grafting conditions on the degree of grafting were investigated. The grafting conditions include monomer concentration, irradiation dose, dose rate, and the type of solvent. Moreover, the effect of the addition of crosslinking agents [i.e., divinylbenzene (DVB) and triallyl cyanurate (TAC)] having various concentrations were also investigated. The degree of grafting was found to be greatly dependent on the grafting conditions. Of the three diluents employed, methylene chloride was found to drastically enhance the degree of grafting. The order of dependence of the initial rate of grafting on the monomer concentration was found to be 2.2. The grafted PET films were identified by FTIR spectroscopy and characterized by X-ray diffraction (XRD).
Polymer Testing, 2002
Itaconic acid was grafted onto cellulose fibers using potassium persulfate as initiator. The effe... more Itaconic acid was grafted onto cellulose fibers using potassium persulfate as initiator. The effect of initiator concentration, monomer concentration and the reaction temperature on the grafting percentage has been investigated. The IR spectroscopy, X-ray diffraction, as well as the surface morphology of the grafted fibers were also studied. Moreover, the dyeing characteristics of the grafted fibers dyed with two basic dyes together with the color fastness of these dyes towards UV radiation was also investigated. The thermal stability of the grafted fibers was also studied using a thermogravimetric technique.
Polymer Testing, 2003
Comonomers of vinylimidazole (VI) and acrylic acid (AA) have been grafted onto Polypropylene (PP)... more Comonomers of vinylimidazole (VI) and acrylic acid (AA) have been grafted onto Polypropylene (PP) films using γ-radiation. The effect of the comonomer composition on the percent graft was investigated. The reactivity ratio of the prepared copolymers was determined by conventional methods. IR spectroscopy, surface morphology, mechanical properties, dyeability, as well as thermal stability of the grafted samples were also studied.
Journal of Molecular Liquids, 1998
The dielectric absorption of some disubstituted ethylenes (dialkyl fumarates) namely dimethyl fum... more The dielectric absorption of some disubstituted ethylenes (dialkyl fumarates) namely dimethyl fumarate (DMF), diethyl fumarate (DEF), diisopropyl fumarate (DIPF), dicyclohexyl fumarate (DCHF), dicyclohexyl maleate (DCHM), dinonyl fumarate (DNF), didodecyl fumarate (DDF) and dicetyl fumarate(DCF) has been measured in the microwave region 0.2–18 GHz. The measurements were carried out at 20°C. The solvent used in all cases was CCl4 and the concentration does not exceed 0.003 mole fraction. The data obtained for the specific absorption Aϵ/x were analyzed using Debye equation into one or even more than one relaxation time. The results were interpreted in terms of dipole reorientation by molecular and intermolecular rotation.Dielectric measurements were also carried for some dialcyl fumarate polymers and copolymers in CCl4 solutions at 30 °C. The dielectric data revealed the existence of three distinct absorption regions related to the main chain and its related motions.
Polymer-plastics Technology and Engineering, 2010
Ethyl 2-amino 4,5,6,7-tetrahydrobenzo thiophene-3-carboxylate maleimide (ETTCM) has been synthesi... more Ethyl 2-amino 4,5,6,7-tetrahydrobenzo thiophene-3-carboxylate maleimide (ETTCM) has been synthesized and investigated as a new thio-maleimide derivative. The structure of the prepared compounds has been elucidated by elemental and spectral analyses. The free radical polymerization of (ETTCM) has been conducted in several solvents using azobisisobutyronitrile (AIBN) as an initiator. The kinetic parameters of polymerization of ETTCM were investigated, and it was found that the polymerization reaction follows the conventional free radical scheme. The initial rate of polymerization, the overall activation energy Ea was determined (Ea = 57.013 kJmol−1) and intrinsic viscosity was measured ([η] = 0.04 dl/g). The prepared polymer is a good chelating agent with some metal ions and a moderate antifungal and antibacterial effect. The monomer reactivity ratios for the copolymerization of ETTCM with methyl methacrylate MMA, vinyl acetate VA, and vinyl ether VE were calculated by two methods, the Kelen-Tüdös and a nonlinear method. Thermal stability of the ETTCM polymers and copolymers were investigated by thermogravimetric analysis.
Journal of Polymer Research, 2000
Polypropylene (PP) films were grafted with N-p-hydroxyphenylmaleinide using γ-radiation. The effe... more Polypropylene (PP) films were grafted with N-p-hydroxyphenylmaleinide using γ-radiation. The effect of both monomer concentration and dose rate on the degree of grafting was measured. Characterization of the grafted PP films included IR spectroscopy, X-ray diffraction, mechanical properties, thermal stability and surface topology and the dyeing characteristics of the grafted films with different dyes were also investigated.
Journal of Applied Polymer Science, 1998
A systematic dielectric study over a frequency range from 100 Hz to 10 MHz was carried out on eth... more A systematic dielectric study over a frequency range from 100 Hz to 10 MHz was carried out on ethylene propylene diene monomer rubber (EPDM) mixed with zinc chloride and ammonium iodide with increasing quantities up to 16 and 8 phr, respectively. The measurements were carried out at a room temperature of Ϸ 25°C. Dielectric data were fitted in the frequency domain by using three Fröhlich terms discussing the different relaxation mechanisms in the system. These terms were interpreted according to the crosslinking that is formed by the addition of such materials to EPDM. The thermal aging for such systems was also studied and the data obtained are compared with those done before aging. The mechanical properties as well as the thermal gravimetric measurements were also studied and the data obtained are discussed.
Journal of Fluorine Chemistry, 2010
Novel 4-(4-trifluoromethyl)phenoxy N-phenyl-maleimide (FPMI) was synthesized. The free radical-in... more Novel 4-(4-trifluoromethyl)phenoxy N-phenyl-maleimide (FPMI) was synthesized. The free radical-initiated polymerization of FPMI was carried out in 1,4-dioxane solution using azobisisobutyronitrile as initiator. The monomer was investigated by FTIR, 1H NMR, 13C NMR and elemental analysis, while the polymer was investigated by FTIR, 1H NMR and 13C NMR. The effect of the monomer concentration, initiator concentration and temperature on the rate of polymerization (Rp) was studied. The activation energy of the polymerization was calculated (ΔE = 48.94 kJ/mol). The molecular weight of PFPMI (M¯w and M¯n) and polydispersity index of the polymer were determined by gel permeation chromatography and were equal to 73,500, 16,700 and 2.27, respectively. The properties of PFPMI, including thermal behavior, thermal stability, the glass transition temperature (Tg = 236 °C), photo-stability, solubility and solution viscosity were studied.Novel 4-(4-trifluoromethyl)phenoxy N-phenyl-maleimide (FPMI) was synthesized. The free radical-initiated polymerization of FPMI was carried out in solution.
Journal of Polymer Research, 2009
The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (A... more The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (AN) has been investigated. The rate of polymerization of all the binary systems involved has been measured dilatometrically for the homogeneous polymerization. The reactivity ratios of the three binary systems were calculated and were found to be equal to 0.031 and 0.397 for In/AN copolymers and 0.02 and 3.82 for In/MMA copolymers and finally 0.152 and 1.20 for AN/MMA copolymers. The rate of terpolymerization in bulk has been measured as well as the relationship between the monomer mixture composition and the obtained terpolymer in order to construct the compositional triangle. Also the effect of initiator concentration on the rate of terpolymerization was investigated. The activation energy of terpolymerization was determined. The terpolymers were characterized by spectral and thermo-gravimetric analyses. The data indicates that polyindene improves the thermal stability of the prepared terpolymers.
Journal of surfactants and …, 2005
... AA Hafiza,*, MY El Awadia, AM Badawia, and SM Mokhtarb aApplied Surfactants Laboratory, Egypt... more ... AA Hafiza,*, MY El Awadia, AM Badawia, and SM Mokhtarb aApplied Surfactants Laboratory, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo, Egypt, and bChemistry Department, College for Women, Ain Shams University, Heleopolis, Cairo ... 204 AA HAFIZ ET AL. ...
Journal of Polymer …, 2003
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Polymer-plastics Technology and Engineering, 2002
The graft copolymerization of N-phenylmaleimide and its p-hydroxy derivative onto cotton fabric u... more The graft copolymerization of N-phenylmaleimide and its p-hydroxy derivative onto cotton fabric using γ-radiation was studied. The effects of monomer concentration, dose rate, and irradiation time have been investigated. The surface topology, the x-ray diffraction, and the thermal stability of the modified fabric also were studied. In addition, the dyeing characteristics of the grafted fabrics when dyed with basic dyes together with the color fastness of these dyes towards UV radiation were investigated.
Polymer Bulletin, 1992
The solution copolymerization of acrylamide (AAm) with N-vinyl pyrrolidone (NVP) was investigated... more The solution copolymerization of acrylamide (AAm) with N-vinyl pyrrolidone (NVP) was investigated using azobisisobutyronitrile (AIBN) as an initiator at 60~ The study was performed by measuring the rate of the copolymerization reaction, the molecular weights and by determining the monomer reactivity ratios. In addition, the thermal properties (thermal conductivity, thermal diffusivity and volumetric heat capacity) of the resulted copolymers in aqueous solutions were investigated at various temperatures. The kinetic results and the apparent reactivity ratios indicate that NVP is more reactive than AAm towards the copolymerization process. The values of the thermal properties showed that the behaviour of such parameters depend on the polymer concentration, the temperatures and the content of vinyl pyrrolidone in the copolymeric chains.
We report measurements of X-ray powder diffraction, vibrational study, the differential scanning ... more We report measurements of X-ray powder diffraction, vibrational study, the differential scanning calorimetry (DSC), and the electric properties of a made-up [C 6 H 9 N 2 ] 2 CuCl 4 sample. The alternative current (ac) conductivity of the compound [C 6 H 9 N 2 ] 2 CuCl 4 has been measured in the temperature range 356-398 K and the frequency range 209 Hz-5 MHz. The Cole-Cole (the imaginer part (Z ) versus real part (Z ) of impedance complex) plots are well fitted to an equivalent circuit model which consists of a parallel combination of a bulk resistance (R) and constant phase elements (CPE). The single semicircle indicates only one primary mechanism for the electrical conduction within [C 6 H 9 N 2 ] 2 CuCl 4 . The variation of the value of these elements with temperatures confirmed the result detected by DSC and dielectric measurements. Thus the conduction in the material is probably due to a hopping or a small polaron tunneling process.
The European Physical Journal Applied Physics, 2015
The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (A... more The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (AN) has been investigated. The rate of polymerization of all the binary systems involved has been measured dilatometrically for the homogeneous polymerization. The reactivity ratios of the three binary systems were calculated and were found to be equal to 0.031 and 0.397 for In/AN copolymers and 0.02 and
Polymer Bulletin, 1992
The solution copolymerization of acrylamide (AAm) with N-vinyl pyrrolidone (NVP) was investigated... more The solution copolymerization of acrylamide (AAm) with N-vinyl pyrrolidone (NVP) was investigated using azobisisobutyronitrile (AIBN) as an initiator at 60°C. The study was performed by measuring the rate of the copolymerization reaction, the molecular weights and by determining the monomer reactivity ratios. In addition, the thermal properties (thermal conductivity, thermal diffusivity and volumetric heat capacity) of the resulted copolymers in aqueous solutions were investigated at various temperatures. The kinetic results and the apparent reactivity ratios indicate that NVP is more reactive than AAm towards the copolymerization process. The values of the thermal properties whowed that the behaviour of such parameters depend on the polymer concentration, the temperatures and the content of vinyl pyrrolidone in the copolymeric chains.
Polymer International, 1997
Gamma radiation-induced graft copolymerization of styrene onto poly(ethylene terephthalate) (PET)... more Gamma radiation-induced graft copolymerization of styrene onto poly(ethylene terephthalate) (PET) films was studied using simultaneous irradiation technique. The effects of grafting conditions on the degree of grafting were investigated. The grafting conditions include monomer concentration, irradiation dose, dose rate, and the type of solvent. Moreover, the effect of the addition of crosslinking agents [i.e., divinylbenzene (DVB) and triallyl cyanurate (TAC)] having various concentrations were also investigated. The degree of grafting was found to be greatly dependent on the grafting conditions. Of the three diluents employed, methylene chloride was found to drastically enhance the degree of grafting. The order of dependence of the initial rate of grafting on the monomer concentration was found to be 2.2. The grafted PET films were identified by FTIR spectroscopy and characterized by X-ray diffraction (XRD).
Polymer Testing, 2002
Itaconic acid was grafted onto cellulose fibers using potassium persulfate as initiator. The effe... more Itaconic acid was grafted onto cellulose fibers using potassium persulfate as initiator. The effect of initiator concentration, monomer concentration and the reaction temperature on the grafting percentage has been investigated. The IR spectroscopy, X-ray diffraction, as well as the surface morphology of the grafted fibers were also studied. Moreover, the dyeing characteristics of the grafted fibers dyed with two basic dyes together with the color fastness of these dyes towards UV radiation was also investigated. The thermal stability of the grafted fibers was also studied using a thermogravimetric technique.
Polymer Testing, 2003
Comonomers of vinylimidazole (VI) and acrylic acid (AA) have been grafted onto Polypropylene (PP)... more Comonomers of vinylimidazole (VI) and acrylic acid (AA) have been grafted onto Polypropylene (PP) films using γ-radiation. The effect of the comonomer composition on the percent graft was investigated. The reactivity ratio of the prepared copolymers was determined by conventional methods. IR spectroscopy, surface morphology, mechanical properties, dyeability, as well as thermal stability of the grafted samples were also studied.
Journal of Molecular Liquids, 1998
The dielectric absorption of some disubstituted ethylenes (dialkyl fumarates) namely dimethyl fum... more The dielectric absorption of some disubstituted ethylenes (dialkyl fumarates) namely dimethyl fumarate (DMF), diethyl fumarate (DEF), diisopropyl fumarate (DIPF), dicyclohexyl fumarate (DCHF), dicyclohexyl maleate (DCHM), dinonyl fumarate (DNF), didodecyl fumarate (DDF) and dicetyl fumarate(DCF) has been measured in the microwave region 0.2–18 GHz. The measurements were carried out at 20°C. The solvent used in all cases was CCl4 and the concentration does not exceed 0.003 mole fraction. The data obtained for the specific absorption Aϵ/x were analyzed using Debye equation into one or even more than one relaxation time. The results were interpreted in terms of dipole reorientation by molecular and intermolecular rotation.Dielectric measurements were also carried for some dialcyl fumarate polymers and copolymers in CCl4 solutions at 30 °C. The dielectric data revealed the existence of three distinct absorption regions related to the main chain and its related motions.
Polymer-plastics Technology and Engineering, 2010
Ethyl 2-amino 4,5,6,7-tetrahydrobenzo thiophene-3-carboxylate maleimide (ETTCM) has been synthesi... more Ethyl 2-amino 4,5,6,7-tetrahydrobenzo thiophene-3-carboxylate maleimide (ETTCM) has been synthesized and investigated as a new thio-maleimide derivative. The structure of the prepared compounds has been elucidated by elemental and spectral analyses. The free radical polymerization of (ETTCM) has been conducted in several solvents using azobisisobutyronitrile (AIBN) as an initiator. The kinetic parameters of polymerization of ETTCM were investigated, and it was found that the polymerization reaction follows the conventional free radical scheme. The initial rate of polymerization, the overall activation energy Ea was determined (Ea = 57.013 kJmol−1) and intrinsic viscosity was measured ([η] = 0.04 dl/g). The prepared polymer is a good chelating agent with some metal ions and a moderate antifungal and antibacterial effect. The monomer reactivity ratios for the copolymerization of ETTCM with methyl methacrylate MMA, vinyl acetate VA, and vinyl ether VE were calculated by two methods, the Kelen-Tüdös and a nonlinear method. Thermal stability of the ETTCM polymers and copolymers were investigated by thermogravimetric analysis.
Journal of Polymer Research, 2000
Polypropylene (PP) films were grafted with N-p-hydroxyphenylmaleinide using γ-radiation. The effe... more Polypropylene (PP) films were grafted with N-p-hydroxyphenylmaleinide using γ-radiation. The effect of both monomer concentration and dose rate on the degree of grafting was measured. Characterization of the grafted PP films included IR spectroscopy, X-ray diffraction, mechanical properties, thermal stability and surface topology and the dyeing characteristics of the grafted films with different dyes were also investigated.
Journal of Applied Polymer Science, 1998
A systematic dielectric study over a frequency range from 100 Hz to 10 MHz was carried out on eth... more A systematic dielectric study over a frequency range from 100 Hz to 10 MHz was carried out on ethylene propylene diene monomer rubber (EPDM) mixed with zinc chloride and ammonium iodide with increasing quantities up to 16 and 8 phr, respectively. The measurements were carried out at a room temperature of Ϸ 25°C. Dielectric data were fitted in the frequency domain by using three Fröhlich terms discussing the different relaxation mechanisms in the system. These terms were interpreted according to the crosslinking that is formed by the addition of such materials to EPDM. The thermal aging for such systems was also studied and the data obtained are compared with those done before aging. The mechanical properties as well as the thermal gravimetric measurements were also studied and the data obtained are discussed.
Journal of Fluorine Chemistry, 2010
Novel 4-(4-trifluoromethyl)phenoxy N-phenyl-maleimide (FPMI) was synthesized. The free radical-in... more Novel 4-(4-trifluoromethyl)phenoxy N-phenyl-maleimide (FPMI) was synthesized. The free radical-initiated polymerization of FPMI was carried out in 1,4-dioxane solution using azobisisobutyronitrile as initiator. The monomer was investigated by FTIR, 1H NMR, 13C NMR and elemental analysis, while the polymer was investigated by FTIR, 1H NMR and 13C NMR. The effect of the monomer concentration, initiator concentration and temperature on the rate of polymerization (Rp) was studied. The activation energy of the polymerization was calculated (ΔE = 48.94 kJ/mol). The molecular weight of PFPMI (M¯w and M¯n) and polydispersity index of the polymer were determined by gel permeation chromatography and were equal to 73,500, 16,700 and 2.27, respectively. The properties of PFPMI, including thermal behavior, thermal stability, the glass transition temperature (Tg = 236 °C), photo-stability, solubility and solution viscosity were studied.Novel 4-(4-trifluoromethyl)phenoxy N-phenyl-maleimide (FPMI) was synthesized. The free radical-initiated polymerization of FPMI was carried out in solution.
Journal of Polymer Research, 2009
The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (A... more The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (AN) has been investigated. The rate of polymerization of all the binary systems involved has been measured dilatometrically for the homogeneous polymerization. The reactivity ratios of the three binary systems were calculated and were found to be equal to 0.031 and 0.397 for In/AN copolymers and 0.02 and 3.82 for In/MMA copolymers and finally 0.152 and 1.20 for AN/MMA copolymers. The rate of terpolymerization in bulk has been measured as well as the relationship between the monomer mixture composition and the obtained terpolymer in order to construct the compositional triangle. Also the effect of initiator concentration on the rate of terpolymerization was investigated. The activation energy of terpolymerization was determined. The terpolymers were characterized by spectral and thermo-gravimetric analyses. The data indicates that polyindene improves the thermal stability of the prepared terpolymers.
Journal of surfactants and …, 2005
... AA Hafiza,*, MY El Awadia, AM Badawia, and SM Mokhtarb aApplied Surfactants Laboratory, Egypt... more ... AA Hafiza,*, MY El Awadia, AM Badawia, and SM Mokhtarb aApplied Surfactants Laboratory, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo, Egypt, and bChemistry Department, College for Women, Ain Shams University, Heleopolis, Cairo ... 204 AA HAFIZ ET AL. ...
Journal of Polymer …, 2003
Skip to Main Content. ...
Polymer-plastics Technology and Engineering, 2002
The graft copolymerization of N-phenylmaleimide and its p-hydroxy derivative onto cotton fabric u... more The graft copolymerization of N-phenylmaleimide and its p-hydroxy derivative onto cotton fabric using γ-radiation was studied. The effects of monomer concentration, dose rate, and irradiation time have been investigated. The surface topology, the x-ray diffraction, and the thermal stability of the modified fabric also were studied. In addition, the dyeing characteristics of the grafted fabrics when dyed with basic dyes together with the color fastness of these dyes towards UV radiation were investigated.
Polymer Bulletin, 1992
The solution copolymerization of acrylamide (AAm) with N-vinyl pyrrolidone (NVP) was investigated... more The solution copolymerization of acrylamide (AAm) with N-vinyl pyrrolidone (NVP) was investigated using azobisisobutyronitrile (AIBN) as an initiator at 60~ The study was performed by measuring the rate of the copolymerization reaction, the molecular weights and by determining the monomer reactivity ratios. In addition, the thermal properties (thermal conductivity, thermal diffusivity and volumetric heat capacity) of the resulted copolymers in aqueous solutions were investigated at various temperatures. The kinetic results and the apparent reactivity ratios indicate that NVP is more reactive than AAm towards the copolymerization process. The values of the thermal properties showed that the behaviour of such parameters depend on the polymer concentration, the temperatures and the content of vinyl pyrrolidone in the copolymeric chains.
We report measurements of X-ray powder diffraction, vibrational study, the differential scanning ... more We report measurements of X-ray powder diffraction, vibrational study, the differential scanning calorimetry (DSC), and the electric properties of a made-up [C 6 H 9 N 2 ] 2 CuCl 4 sample. The alternative current (ac) conductivity of the compound [C 6 H 9 N 2 ] 2 CuCl 4 has been measured in the temperature range 356-398 K and the frequency range 209 Hz-5 MHz. The Cole-Cole (the imaginer part (Z ) versus real part (Z ) of impedance complex) plots are well fitted to an equivalent circuit model which consists of a parallel combination of a bulk resistance (R) and constant phase elements (CPE). The single semicircle indicates only one primary mechanism for the electrical conduction within [C 6 H 9 N 2 ] 2 CuCl 4 . The variation of the value of these elements with temperatures confirmed the result detected by DSC and dielectric measurements. Thus the conduction in the material is probably due to a hopping or a small polaron tunneling process.