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1985 Volume 2 Issue 2
1985, 2(2): 1-6
Abstract:
The adsorption characteristics of the nickel complex with dimethylglyoxime (DMG) Ni (Ⅱ)A2 at the HMDE has been investigated It was found that between-0.20 and -0.90V (vs. SCE) Ni (Ⅱ)A2 can be adsorbed fairly well at the HMDE and the relationship observed by voltammetry with linearly changing tension between the logarithm of the peak current and the logarithm of the sweep velocity is linear and has a slope of 0.98. Experimental peak currents show a Langmuir isotherm with the preconcentration time. The overall reaction of the adsorption voltammetry of nickel-DMG system, which can be divided into three parts, has been discussed. That is 1) Homogeneous reaction between different nickel species in solution, 2) Adsorption preconcentration process of Ni(Ⅱ)A2, 3) Reduction of adsorbed Ni(Ⅱ)A2, by irreversible charge transfer. The sensitivity of the method appears between 10-9M and 10-10M depending on the preconcentration time.
The adsorption characteristics of the nickel complex with dimethylglyoxime (DMG) Ni (Ⅱ)A2 at the HMDE has been investigated It was found that between-0.20 and -0.90V (vs. SCE) Ni (Ⅱ)A2 can be adsorbed fairly well at the HMDE and the relationship observed by voltammetry with linearly changing tension between the logarithm of the peak current and the logarithm of the sweep velocity is linear and has a slope of 0.98. Experimental peak currents show a Langmuir isotherm with the preconcentration time. The overall reaction of the adsorption voltammetry of nickel-DMG system, which can be divided into three parts, has been discussed. That is 1) Homogeneous reaction between different nickel species in solution, 2) Adsorption preconcentration process of Ni(Ⅱ)A2, 3) Reduction of adsorbed Ni(Ⅱ)A2, by irreversible charge transfer. The sensitivity of the method appears between 10-9M and 10-10M depending on the preconcentration time.
1985, 2(2): 7-11
Abstract:
By means of x-ray diffraction analysis and Mossbauer spectroscopy study it has been confirmed that the catalytically active structure of the B104 CO shift catalyst containing about 7-9% Cr consists of non-stoichiometric magn etite and iron-chromium solid solution. It appears that the iron ions in the B site of the magnetite play more important role than those in the A site, and that the electrons being exchanged rapidly between Fe2+ and Fe3+ in the B site may take part in the catalytic process.
By means of x-ray diffraction analysis and Mossbauer spectroscopy study it has been confirmed that the catalytically active structure of the B104 CO shift catalyst containing about 7-9% Cr consists of non-stoichiometric magn etite and iron-chromium solid solution. It appears that the iron ions in the B site of the magnetite play more important role than those in the A site, and that the electrons being exchanged rapidly between Fe2+ and Fe3+ in the B site may take part in the catalytic process.
1985, 2(2): 12-16
Abstract:
The conditions of the formation of multicomponent complexes of Al, Fe, Sc, with CAS in the presence of mixed surfactant have been studied. These color reactions were found to have high sensitivity and selectivity. The method is very simple, no separation is necessary and it may be used for the simultaneous determination of Al, Fe, Scin pure rare earth oxides.
The conditions of the formation of multicomponent complexes of Al, Fe, Sc, with CAS in the presence of mixed surfactant have been studied. These color reactions were found to have high sensitivity and selectivity. The method is very simple, no separation is necessary and it may be used for the simultaneous determination of Al, Fe, Scin pure rare earth oxides.
1985, 2(2): 17-23
Abstract:
The extraction behaviour of rare earth elements(Ⅲ) from nitric acid soltition by HEH[EHP]-hexane has been systematically investigated. The mechanism of extraction carried out in different acidities is discussed in terms of slope, IR and NMR data obtained. It is concluded that at low aqueous acidity, rare earths(Ⅲ) are extracted by a cation-exchange reaction with hydrogen liberation: Ln3++3(HL)2(0)
Ln(HL2)3(0)+3H+ (1) and at high aqueous acidity the extraction is accompanied by a solvation reaction similar to that for TBP; Ln3++3NO3-+2(HL)2(o)
Ln(NO3)3·4HL(o) (2) The influences of temperature and solvent upon the extraction equilibrium under different conditions were discussed in detail. The equilibrium constants (K1 anb K2) andthe thermodynamic functions (ΔH, ΔZn and ΔSz)of extraction reaction were calculated.The dependency of K,ΔZz and ΔSz on the atomic number of rare earth elements werealso discussed.
The extraction behaviour of rare earth elements(Ⅲ) from nitric acid soltition by HEH[EHP]-hexane has been systematically investigated. The mechanism of extraction carried out in different acidities is discussed in terms of slope, IR and NMR data obtained. It is concluded that at low aqueous acidity, rare earths(Ⅲ) are extracted by a cation-exchange reaction with hydrogen liberation: Ln3++3(HL)2(0)
Ln(HL2)3(0)+3H+ (1) and at high aqueous acidity the extraction is accompanied by a solvation reaction similar to that for TBP; Ln3++3NO3-+2(HL)2(o)Ln(NO3)3·4HL(o) (2) The influences of temperature and solvent upon the extraction equilibrium under different conditions were discussed in detail. The equilibrium constants (K1 anb K2) andthe thermodynamic functions (ΔH, ΔZn and ΔSz)of extraction reaction were calculated.The dependency of K,ΔZz and ΔSz on the atomic number of rare earth elements werealso discussed.
1985, 2(2): 24-28
Abstract:
IPNs from PU(HTBN) and Polymethacrylates were synthesized by simultaneous crosslinking polymerization. The relationship between the dynamical properties of IPNs and the ratio of two components,the side groups and their contents in polymethacrylate networks were studied by means of torsional pendulum analysis.The results showed that the IPNs are semicompatible or compatible.Some more widened peaks were found in Δ-T plots of IPNs containing poly(n-BMA) and poly (iso-BMA) than of those containing poly (MMA). Acrylonitrile component was shown more affecting on the dynamic mechanical properties of IPNs obtained.
IPNs from PU(HTBN) and Polymethacrylates were synthesized by simultaneous crosslinking polymerization. The relationship between the dynamical properties of IPNs and the ratio of two components,the side groups and their contents in polymethacrylate networks were studied by means of torsional pendulum analysis.The results showed that the IPNs are semicompatible or compatible.Some more widened peaks were found in Δ-T plots of IPNs containing poly(n-BMA) and poly (iso-BMA) than of those containing poly (MMA). Acrylonitrile component was shown more affecting on the dynamic mechanical properties of IPNs obtained.
1985, 2(2): 29-32
Abstract:
Kinetic study on the reaction of waste aluminum powder with hydrochloric acid has been carried out by measuring the volume of released hydrogen gas. The reaction rate is found to be in direct proportion to the 1.5th power of the concentration of HCl solutions in the range of 0.5~3N HCl. The apparent activation energy is 48 kJ/mol-H2. The rate equation for the waste aluminum powder as follows: dH2/dt=6.2×102·exp(-5.8×103/t)·W·CHCl1.5(mol/s)
Kinetic study on the reaction of waste aluminum powder with hydrochloric acid has been carried out by measuring the volume of released hydrogen gas. The reaction rate is found to be in direct proportion to the 1.5th power of the concentration of HCl solutions in the range of 0.5~3N HCl. The apparent activation energy is 48 kJ/mol-H2. The rate equation for the waste aluminum powder as follows: dH2/dt=6.2×102·exp(-5.8×103/t)·W·CHCl1.5(mol/s)
1985, 2(2): 33-38
Abstract:
The infrared spectra of polybutadiene in the region from 3100 to 2800 cm-1 have been investigated.The spectra give reliable information related to the microstructure of poly-butadiene, i.e cis-1, 4 trans-1,4 and1,2. The microstructure of polybutadiene samples has been determined by factor analysis of IR spectra in the region from 3100 to 2800 cm-1 as well as from 1000 to 650 cm-1. The scectra from the first region were proved more reasonable for the microstructure determination in comparison with those used in the traditional IR analysis.
The infrared spectra of polybutadiene in the region from 3100 to 2800 cm-1 have been investigated.The spectra give reliable information related to the microstructure of poly-butadiene, i.e cis-1, 4 trans-1,4 and1,2. The microstructure of polybutadiene samples has been determined by factor analysis of IR spectra in the region from 3100 to 2800 cm-1 as well as from 1000 to 650 cm-1. The scectra from the first region were proved more reasonable for the microstructure determination in comparison with those used in the traditional IR analysis.
1985, 2(2): 39-42
Abstract:
The study on thermo-oxidation behavior of polybutadienes with different contents of 1,2-units shows that the thermo-oxidation reaction takes place more easily at the doble bond in the main chain than in the side vinyl group of polybutadiene,as being attributed to having more α-H's in the former case. Based on the thermo-oxidation temperature and apparent activation energy E, it has been concluded that the syndiotactic 1,2-poly-butadiene with high vinyl content synthesized on the cobolt catalyst system is more stable than that obtained with molybdenum catalyst system. The E of the former is more than 150kJ/mol, but -100kJ/mol for the latter. The variation is considered due to the difference in macromolecular aggregatoin.
The study on thermo-oxidation behavior of polybutadienes with different contents of 1,2-units shows that the thermo-oxidation reaction takes place more easily at the doble bond in the main chain than in the side vinyl group of polybutadiene,as being attributed to having more α-H's in the former case. Based on the thermo-oxidation temperature and apparent activation energy E, it has been concluded that the syndiotactic 1,2-poly-butadiene with high vinyl content synthesized on the cobolt catalyst system is more stable than that obtained with molybdenum catalyst system. The E of the former is more than 150kJ/mol, but -100kJ/mol for the latter. The variation is considered due to the difference in macromolecular aggregatoin.
1985, 2(2): 43-46
Abstract:
Nine cobalt 5, 15-di(p-substituted phenyl) cctaalkyl porphyrins were synthesized and the effect of para-phenyl substituents on coordination reaction of porphyrins with cobalt salt was studied. It has been shown that the reaction follows the rate expression: -dH2P/dt=Kobh[H2P] and the reaction rate is influenced by substituents: H >CH3 >OCH3 >N <CH3CH3, corresponding to the Hammett relationship. The experimental results shown that the presence of electron-donating substituent improvs the catalytic activity of title compound in hydroquinone oxidation reaction.
Nine cobalt 5, 15-di(p-substituted phenyl) cctaalkyl porphyrins were synthesized and the effect of para-phenyl substituents on coordination reaction of porphyrins with cobalt salt was studied. It has been shown that the reaction follows the rate expression: -dH2P/dt=Kobh[H2P] and the reaction rate is influenced by substituents: H >CH3 >OCH3 >N <CH3CH3, corresponding to the Hammett relationship. The experimental results shown that the presence of electron-donating substituent improvs the catalytic activity of title compound in hydroquinone oxidation reaction.
1985, 2(2): 47-51
Abstract:
The kinetics of butadiene polymerization with a soluble rare earth catalyst(Nd(OCt)3-HAl(i-Bu)2-CH2=CHCH2Cl) has been studied. The experimental results showed that the rate of polymerization is first order in both the concentrations of monomer and neodymium compound, but is 1/3 order in the concentration of diisobutyl aluminum hydride. The number of active center and the apparent activation energy and the propagation activation energy of butadiene polymerization were determined.
The kinetics of butadiene polymerization with a soluble rare earth catalyst(Nd(OCt)3-HAl(i-Bu)2-CH2=CHCH2Cl) has been studied. The experimental results showed that the rate of polymerization is first order in both the concentrations of monomer and neodymium compound, but is 1/3 order in the concentration of diisobutyl aluminum hydride. The number of active center and the apparent activation energy and the propagation activation energy of butadiene polymerization were determined.
1985, 2(2): 52-56
Abstract:
Radiation-induced crosslinking mechanism of poly (vinylidene fluoride) and characterization of the crosslinking density by XPS have been first studied. The calculated β value of poly (vinylidene fluoride). is 0.7. It is found that the radiation-induced crosslinking of poly (vinylidene fluoride) is in agreement with the general expression,in which the sol fraction is telated to radiation dose[1]. The dose of gelation of poly-(vinylidene fluoride) obtained by XPS is 1.59 mrad.
Radiation-induced crosslinking mechanism of poly (vinylidene fluoride) and characterization of the crosslinking density by XPS have been first studied. The calculated β value of poly (vinylidene fluoride). is 0.7. It is found that the radiation-induced crosslinking of poly (vinylidene fluoride) is in agreement with the general expression,in which the sol fraction is telated to radiation dose[1]. The dose of gelation of poly-(vinylidene fluoride) obtained by XPS is 1.59 mrad.
1985, 2(2): 57-61
Abstract:
By using in-situ and on-line Fourier transform infrared spectroscopic methods (FTIR),the dynamic change of solid and gaseous products of acrylonitrile (AN) /diacetone acr-ylamide (DAA)/methylacrylate(MA) copolymers was monitored durin g its pyrolysis in nitrogen atmosphere. It was found that at lower temperature of pyrolysis (below 300℃) the cyclization,occurred mainly, then the dehydrogenation reactions. The samples wereeventually pyrolyzed at the temperature between 300℃ and 950℃. The gaseous products evolved were HCN, NH3, CH4, CO2, CO etc. and the solid residues were of amor-phous carbonaceous structure.
By using in-situ and on-line Fourier transform infrared spectroscopic methods (FTIR),the dynamic change of solid and gaseous products of acrylonitrile (AN) /diacetone acr-ylamide (DAA)/methylacrylate(MA) copolymers was monitored durin g its pyrolysis in nitrogen atmosphere. It was found that at lower temperature of pyrolysis (below 300℃) the cyclization,occurred mainly, then the dehydrogenation reactions. The samples wereeventually pyrolyzed at the temperature between 300℃ and 950℃. The gaseous products evolved were HCN, NH3, CH4, CO2, CO etc. and the solid residues were of amor-phous carbonaceous structure.
1985, 2(2): 62-64
Abstract:
The polarographic behaviour of Eriochrome Biue Black B and its complex with magnesium ion was investigated. The experimental data showed that the complex of magnsium ion with the dye exists in ratio 1: 1.The apparent stability constants under different experimental conditions were calculated from the heights of polarographie waves.
The polarographic behaviour of Eriochrome Biue Black B and its complex with magnesium ion was investigated. The experimental data showed that the complex of magnsium ion with the dye exists in ratio 1: 1.The apparent stability constants under different experimental conditions were calculated from the heights of polarographie waves.
1985, 2(2): 65-68
Abstract:
The oxidation activity of polybutadiene(PB) with different chain structures and the effect of molybdenum catalyst have been investigated. It has been found that the oxidation activity of PB decreases with the increase of the vinyl contents independent of the conditions under which the reaction was carried out (photo-or-thermal oxidation,under oxygen or nitrogen atmospheres).
The oxidation activity of polybutadiene(PB) with different chain structures and the effect of molybdenum catalyst have been investigated. It has been found that the oxidation activity of PB decreases with the increase of the vinyl contents independent of the conditions under which the reaction was carried out (photo-or-thermal oxidation,under oxygen or nitrogen atmospheres).
1985, 2(2): 69-71
Abstract:
The optically active p-vinyl-α-methylbenzyl alcohol obtained from p-vinyl acetophenone via asymmetric reduction using (S)-2-anilinomethylpyrrolidine-LiAlH4 as a chiral reagent was polymerised to the poly(p-vinyl-α-methylbenzyl alcohol). The optical purity of the chiral polymer was found to be 61.5%.
The optically active p-vinyl-α-methylbenzyl alcohol obtained from p-vinyl acetophenone via asymmetric reduction using (S)-2-anilinomethylpyrrolidine-LiAlH4 as a chiral reagent was polymerised to the poly(p-vinyl-α-methylbenzyl alcohol). The optical purity of the chiral polymer was found to be 61.5%.
1985, 2(2): 72-73
Abstract:
A new approach to the electrochemical synthesis of adiponitrile is introduced. A considerably inexpensive diaphragm oell for industrial use has been designed. The cathodic polarization curves were determined. The electrclytic process was shown to have a number of advantages: easier separation,higher yield and higher purity of the product.
A new approach to the electrochemical synthesis of adiponitrile is introduced. A considerably inexpensive diaphragm oell for industrial use has been designed. The cathodic polarization curves were determined. The electrclytic process was shown to have a number of advantages: easier separation,higher yield and higher purity of the product.
1985, 2(2): 74-75
Abstract:
A modified method for Nd(O-i-C3H7)2Cl synthesis directly from NdCl3·3HO-i-C3H7 and NaO-i-C3H7 is presented. The advantage of the method lies in the making use of halogen from NdCl3 instead of [that] from CH3COCl as in the conventional method.
A modified method for Nd(O-i-C3H7)2Cl synthesis directly from NdCl3·3HO-i-C3H7 and NaO-i-C3H7 is presented. The advantage of the method lies in the making use of halogen from NdCl3 instead of [that] from CH3COCl as in the conventional method.
1985, 2(2): 76-79
Abstract:
Density and surface tension of molten salt systems KCl·NaCl-MgCl2, KCl·NaCl-YCl3 and KCl·NaCl-MgCl2-YCl3 were measured by maximum bubble pressure method atdifferent temperatures and compositions.
Density and surface tension of molten salt systems KCl·NaCl-MgCl2, KCl·NaCl-YCl3 and KCl·NaCl-MgCl2-YCl3 were measured by maximum bubble pressure method atdifferent temperatures and compositions.
