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1986 Volume 3 Issue 3
1986, 3(3): 1-7
Abstract:
In this review the emphasis will be placed on the electrochemical reactivity of synthetic metalloporphyrin complex in nonaqueous media. This review will summarize mechanistic data associated with the oxidation and reduction of metalloporphyrin and attempt to show the correlation of halfwave potentials (E1/2) and electron transfer path ways with some factors such as substituent effect, axial-ligand coordination with nitrogeneous bases, with halide anions and with diatomic molecules; specific structure of the porphyrin ring system; basicity of the porphyrin ring; hydrogen ionbonding with the solvent etc.
In this review the emphasis will be placed on the electrochemical reactivity of synthetic metalloporphyrin complex in nonaqueous media. This review will summarize mechanistic data associated with the oxidation and reduction of metalloporphyrin and attempt to show the correlation of halfwave potentials (E1/2) and electron transfer path ways with some factors such as substituent effect, axial-ligand coordination with nitrogeneous bases, with halide anions and with diatomic molecules; specific structure of the porphyrin ring system; basicity of the porphyrin ring; hydrogen ionbonding with the solvent etc.
1986, 3(3): 8-12
Abstract:
Five ferric compounds, α-Fe2O3, γ-Fe2O4, ZnFe2O4, ZnFe2O4·20% α-Fe2O3 and ZnFe2O4·20%γ-Fe2O3,used as catalysts for oxidative dehydrogenation of butene to butadiene were prepared and identified by X-ray diffraction. The catalytic sites on the ferrite surface were studied by chemisorption and TPD of oxygen and n-butene. It was found that ZnFe2O4 adsorbed more butene than α- and γ-Fe2O3, the later two oxides adsorbed more oxygen than the former compound,and the mixtures of the Fe2O3 isomers have the greater ability for chemisorption of both butene and oxygen. The reaction mechanism was discussed based on the different behaviours of these five ferric compounds acting as sorbent and oxygen-carrier in oxydative dehydrogenation of nbutene to butadiene or carbon dioxide.
Five ferric compounds, α-Fe2O3, γ-Fe2O4, ZnFe2O4, ZnFe2O4·20% α-Fe2O3 and ZnFe2O4·20%γ-Fe2O3,used as catalysts for oxidative dehydrogenation of butene to butadiene were prepared and identified by X-ray diffraction. The catalytic sites on the ferrite surface were studied by chemisorption and TPD of oxygen and n-butene. It was found that ZnFe2O4 adsorbed more butene than α- and γ-Fe2O3, the later two oxides adsorbed more oxygen than the former compound,and the mixtures of the Fe2O3 isomers have the greater ability for chemisorption of both butene and oxygen. The reaction mechanism was discussed based on the different behaviours of these five ferric compounds acting as sorbent and oxygen-carrier in oxydative dehydrogenation of nbutene to butadiene or carbon dioxide.
1986, 3(3): 13-18
Abstract:
The samples having almost the same molecular weight but different MWD were prepared by precipitation fractionating and then mixing in solution. The influence of MWD on the viscoelastic properties of raw rubber was studied using the methods of GPC and stress relaxation. The effect of low molecular weight fractions on the density of chain entanglement networks and the contribution of high molecular weight fractions to the viscoelastic properties of raw rubber were also examined.
The samples having almost the same molecular weight but different MWD were prepared by precipitation fractionating and then mixing in solution. The influence of MWD on the viscoelastic properties of raw rubber was studied using the methods of GPC and stress relaxation. The effect of low molecular weight fractions on the density of chain entanglement networks and the contribution of high molecular weight fractions to the viscoelastic properties of raw rubber were also examined.
1986, 3(3): 19-24
Abstract:
A series of polydimethylsiloxane-polyphenolphlein tererpthalate multi-blook copolymer have been synthesized by using low temperature solution condensation tcchnique.Structure characterization of the block copolymers by IR, 1H-NMR,viscosimetry,TEM etc. indicates that copolymers with controlled siloxane content can be obtained in high molecular weight.The copolymers can be either elastomeric or rigid depending on the siloxane block length and its content.The copolymers show two-phase morphology, good mechanical properties, thermostability and film formability.
A series of polydimethylsiloxane-polyphenolphlein tererpthalate multi-blook copolymer have been synthesized by using low temperature solution condensation tcchnique.Structure characterization of the block copolymers by IR, 1H-NMR,viscosimetry,TEM etc. indicates that copolymers with controlled siloxane content can be obtained in high molecular weight.The copolymers can be either elastomeric or rigid depending on the siloxane block length and its content.The copolymers show two-phase morphology, good mechanical properties, thermostability and film formability.
1986, 3(3): 25-29
Abstract:
Seven complexes[Pt(1, 3-DACH)X2] (1, 3-DACH=1, 3-diaminocyclohexane, X=Cl-,Br-,(1/2)Ox2-, (1/2)mal2-,AC-Cl-, (1/2)SO42-,NO3-) have been synthesized and characterized. It is found that[Pt(1, 3-DACH)(AC-CL)2] has the strongest inhibition effect on L-1210 and S-180 in mice. The relationship between the antitumour activity and structure of the complexes is discussed.
Seven complexes[Pt(1, 3-DACH)X2] (1, 3-DACH=1, 3-diaminocyclohexane, X=Cl-,Br-,(1/2)Ox2-, (1/2)mal2-,AC-Cl-, (1/2)SO42-,NO3-) have been synthesized and characterized. It is found that[Pt(1, 3-DACH)(AC-CL)2] has the strongest inhibition effect on L-1210 and S-180 in mice. The relationship between the antitumour activity and structure of the complexes is discussed.
1986, 3(3): 30-34
Abstract:
Dispersion of γ-Fe2O3 powder in polymer solution plays an important role in governing the recording density of magnetic recording materials. The wetting of the powders,disintegration of agglomerates and agglutination of particles are closely related to the surface characteristics of γ-Fe2O3 powder. In this paper, the wetting characteristics and the apparent contact angles of γ-Fe2O3 powder in polar and non-polar liquids were estimated by determining the penetration rates of these liquids through powders, as well as the sedimentative volume of powders in liquids. Based on Fowkes' theoretical assumption,the values of the surface tension of γ-Fe2O3 powder were calculated:γsd=24 dyn/cm,γsp=17dyn/cmand γs=41dyn/cm.
Dispersion of γ-Fe2O3 powder in polymer solution plays an important role in governing the recording density of magnetic recording materials. The wetting of the powders,disintegration of agglomerates and agglutination of particles are closely related to the surface characteristics of γ-Fe2O3 powder. In this paper, the wetting characteristics and the apparent contact angles of γ-Fe2O3 powder in polar and non-polar liquids were estimated by determining the penetration rates of these liquids through powders, as well as the sedimentative volume of powders in liquids. Based on Fowkes' theoretical assumption,the values of the surface tension of γ-Fe2O3 powder were calculated:γsd=24 dyn/cm,γsp=17dyn/cmand γs=41dyn/cm.
1986, 3(3): 35-39
Abstract:
The mechanism of the reaction between acetate and polybutadienyl-lithium was inquired by using naphthalenelithium as initiator in extracted naphtha solution. It was found that a coupling reaction occurs after vinyl acetate and polybutadinyl lithium have been brought together in an evacuated vessel acompanyied by a simultaneous introduce of hydroxyl groups into the polymer chain.
The mechanism of the reaction between acetate and polybutadienyl-lithium was inquired by using naphthalenelithium as initiator in extracted naphtha solution. It was found that a coupling reaction occurs after vinyl acetate and polybutadinyl lithium have been brought together in an evacuated vessel acompanyied by a simultaneous introduce of hydroxyl groups into the polymer chain.
1986, 3(3): 40-44
Abstract:
The influence of temperature, current density, foil purity and the additive on A.C. etching of aluminum electrolytic capacitor foil in hydrochloric acid were studied. It was shown that in order to obtain a high developed surface, it is necessary to have a high quality etch film, in its formation SO42- ion plays an important role. The results were interpreted in terms of the potential response patterns and the film weight on per unit area of real surface, calculated from the weight loss before and after stripping off the film and the coefficient of surface area gain K. The formation of the black powders and smutting of the surface after etching with a certain quantity of electricity may be attributed to the higher pH value developed during the cathodic period, causing the precipitation of voluminous hydrated aluminum oxide and blocking of the etch pits. Sufficient supply of H+ ion is another important condition for high developed surface of foil.
The influence of temperature, current density, foil purity and the additive on A.C. etching of aluminum electrolytic capacitor foil in hydrochloric acid were studied. It was shown that in order to obtain a high developed surface, it is necessary to have a high quality etch film, in its formation SO42- ion plays an important role. The results were interpreted in terms of the potential response patterns and the film weight on per unit area of real surface, calculated from the weight loss before and after stripping off the film and the coefficient of surface area gain K. The formation of the black powders and smutting of the surface after etching with a certain quantity of electricity may be attributed to the higher pH value developed during the cathodic period, causing the precipitation of voluminous hydrated aluminum oxide and blocking of the etch pits. Sufficient supply of H+ ion is another important condition for high developed surface of foil.
1986, 3(3): 45-49
Abstract:
Copolymerization of acrylamide and sodium acrylate initiated by K2S2O8-NH2CONH2 was studied. The molecular weight and composition of copolymers can be effectively con-trolled by addition of various amounts of chaintransfer agent and by changing the pH and temperature of reaction system up to 98-100% conversion. Water-soluble copolymers with intrinsic viscosity of 2-28dl/g and sodium acrylate content of 0-100 mol.% were obtained.The copolymers were found to be in agreement with that of second order Markov process by 13C-NMR determination.
Copolymerization of acrylamide and sodium acrylate initiated by K2S2O8-NH2CONH2 was studied. The molecular weight and composition of copolymers can be effectively con-trolled by addition of various amounts of chaintransfer agent and by changing the pH and temperature of reaction system up to 98-100% conversion. Water-soluble copolymers with intrinsic viscosity of 2-28dl/g and sodium acrylate content of 0-100 mol.% were obtained.The copolymers were found to be in agreement with that of second order Markov process by 13C-NMR determination.
1986, 3(3): 50-55
Abstract:
The tacticity of 1,2-polybutadienes Was determined by using 13C-NMR technique.The results obtained show that the tacticity of the molecules did not change much with the change of molecular weight. Therefore the long chain branching of 1,2-polybutadiene may be characterized by GPC-AUV technique. The long chain branching of 1,2-polybutadienes was measured by a GPC coupled with an automatic recording capillary viscometer. In this work the experimental relation [η](v) was translated to the calibration curve [η](VR) for the mono disperse samples.The curve[η}(VR) combined with the principle of universal calibration will provide the molecular weight distribution and the average brandhing effect in the samples.
The tacticity of 1,2-polybutadienes Was determined by using 13C-NMR technique.The results obtained show that the tacticity of the molecules did not change much with the change of molecular weight. Therefore the long chain branching of 1,2-polybutadiene may be characterized by GPC-AUV technique. The long chain branching of 1,2-polybutadienes was measured by a GPC coupled with an automatic recording capillary viscometer. In this work the experimental relation [η](v) was translated to the calibration curve [η](VR) for the mono disperse samples.The curve[η}(VR) combined with the principle of universal calibration will provide the molecular weight distribution and the average brandhing effect in the samples.
1986, 3(3): 56-60
Abstract:
An epitaxial p-Si(p+/p-Si)containing semiconductive high-low junction was used as photocathode in both photoelectrochemical voltaic and photoassisted hydrogen evolution cells. The conversion efficiencies were 7.4%(V2+/3+) redox couple) and 7.8% (Co-W alloydecorated) respectively. The role of high-low junction in improving conversion efficiencywas disscussed.
An epitaxial p-Si(p+/p-Si)containing semiconductive high-low junction was used as photocathode in both photoelectrochemical voltaic and photoassisted hydrogen evolution cells. The conversion efficiencies were 7.4%(V2+/3+) redox couple) and 7.8% (Co-W alloydecorated) respectively. The role of high-low junction in improving conversion efficiencywas disscussed.
1986, 3(3): 61-66
Abstract:
The kinetics and mechanism of the extraction of Co(Ⅱ) from sulphate solution with HDEHPin kerosene were studied by means of single drop method at 25℃, The experimental results indicate that the extraction process is controlled by the following interface reactions:Co+++2HA(i)=CoA2(i)+2H+, CoA2(i)+2H2A2(o)=CoA2·2HA(o)+2HA(i)where (O) and (i) represent organic phase and interface respectively. The influences of sulphate, chloride and nitrate concentration on the extraction rate were also discussed.
The kinetics and mechanism of the extraction of Co(Ⅱ) from sulphate solution with HDEHPin kerosene were studied by means of single drop method at 25℃, The experimental results indicate that the extraction process is controlled by the following interface reactions:Co+++2HA(i)=CoA2(i)+2H+, CoA2(i)+2H2A2(o)=CoA2·2HA(o)+2HA(i)where (O) and (i) represent organic phase and interface respectively. The influences of sulphate, chloride and nitrate concentration on the extraction rate were also discussed.
1986, 3(3): 67-69
Abstract:
ADR-06010 and ADR-06011 damping materials, the unfilled and filled butyl rubber, have inherently high damping capacity. The metal structures with these dampingmaterials show an excellent efficiency on vibration control. The result shows that the bushings of ADR-06010 and ADR-06011 damping rubber have good isolation behaviour.
ADR-06010 and ADR-06011 damping materials, the unfilled and filled butyl rubber, have inherently high damping capacity. The metal structures with these dampingmaterials show an excellent efficiency on vibration control. The result shows that the bushings of ADR-06010 and ADR-06011 damping rubber have good isolation behaviour.
1986, 3(3): 70-72
Abstract:
The ammoxidation of propylene using antimony-iron oxide catalyst was investigated by means of a fluidized bed reactor. The reactivity, amount of carbon deposited, and ESR spectrum data were determined, The results indicate that vanadium dopped system resists the carbon deposition, stabilizing the structure of the catalysts, and accelerates the reoxidation ratt of the reduced catalysts.
The ammoxidation of propylene using antimony-iron oxide catalyst was investigated by means of a fluidized bed reactor. The reactivity, amount of carbon deposited, and ESR spectrum data were determined, The results indicate that vanadium dopped system resists the carbon deposition, stabilizing the structure of the catalysts, and accelerates the reoxidation ratt of the reduced catalysts.
1986, 3(3): 73-75
Abstract:
In this paper the reaction of Nd metal vapor produced at high temperture under Vacuum below 10-4 mmHg with chlorobezene at -196℃ to give phenyl neodymium chloride has been preliminary investigated.The composition of the product was identified as C6H5NdCl by chemical analysis. The compound is a black crystalline, insoluble in organic solvents,stable at room temperatue, extremely air-moisture sensitive, and pyrophoric in air. The complex combined with Al(i-Bu)2H is able to polymerize diene to polybutadiene with cis-1, 4 contents of 94.4%, trans-1, 4 4.7%, 1.2-0.9% and polyisoprene with cis-1, 4 contents of 94.4% and 3,4-of 5.6%.
In this paper the reaction of Nd metal vapor produced at high temperture under Vacuum below 10-4 mmHg with chlorobezene at -196℃ to give phenyl neodymium chloride has been preliminary investigated.The composition of the product was identified as C6H5NdCl by chemical analysis. The compound is a black crystalline, insoluble in organic solvents,stable at room temperatue, extremely air-moisture sensitive, and pyrophoric in air. The complex combined with Al(i-Bu)2H is able to polymerize diene to polybutadiene with cis-1, 4 contents of 94.4%, trans-1, 4 4.7%, 1.2-0.9% and polyisoprene with cis-1, 4 contents of 94.4% and 3,4-of 5.6%.
1986, 3(3): 76-78
Abstract:
The following emperical expression was derived from the measurement of electrocon-ductivity x of HCl+H2O+CH3OH at 25℃ in the range of 0.002 <mHC1 <0.05 and 0.2H2O <1 (WH2O, grams H2O/grams solvent), x=[A0+A1(WH2O1.5expWH2O-0.7WH2O2)]mHC1+10-5 This expression is capable of representing the conductance of a strong 1-1 electrolyte in various alchoholic aqueous solutions. By measuring the conductivity of the solution,analyzing the molarlity of the electrolyte through conductometric titration the composition of the solution can be conveniently determined with certain accuracy.
The following emperical expression was derived from the measurement of electrocon-ductivity x of HCl+H2O+CH3OH at 25℃ in the range of 0.002 <mHC1 <0.05 and 0.2
1986, 3(3): 79-80
Abstract:
Spherulite growth rates and morphological structure changes during the crystallization of PET were investigated using depolarimetry, polarized microscopy(PLM) and small angle light scattering(SALS). The unusual behavior of spherulite growth rate curves under various conditions in the crystallization of PET was observed by depolarimetry. A plot of depolarised light versus crystallization time indicates that there is a slight reduction in the crystallinity at higher temperature. It is suggested for this phenmenon that partial melting and recrystallization of the crystallite occur at higher temperature. In other words, imperfect crystallites are melted and changed into more perfect forms (better crystal lattice, larger crystal size). Observations with PLM have confirmed the explanation suggested. Three types of spherulites patterns (usual, unusual and complex) in PET under different crystallization temperatures have been observed with PLM. The usual spherulites formed at lower temperatures, while unusual spherulites formed at higher temperatures.The results agreed with Hv patterns of the SALS.
Spherulite growth rates and morphological structure changes during the crystallization of PET were investigated using depolarimetry, polarized microscopy(PLM) and small angle light scattering(SALS). The unusual behavior of spherulite growth rate curves under various conditions in the crystallization of PET was observed by depolarimetry. A plot of depolarised light versus crystallization time indicates that there is a slight reduction in the crystallinity at higher temperature. It is suggested for this phenmenon that partial melting and recrystallization of the crystallite occur at higher temperature. In other words, imperfect crystallites are melted and changed into more perfect forms (better crystal lattice, larger crystal size). Observations with PLM have confirmed the explanation suggested. Three types of spherulites patterns (usual, unusual and complex) in PET under different crystallization temperatures have been observed with PLM. The usual spherulites formed at lower temperatures, while unusual spherulites formed at higher temperatures.The results agreed with Hv patterns of the SALS.
1986, 3(3): 81-83
Abstract:
An anodic-stripping voltammetry method is modified for trace tin determination.Hydrochloric acid-methyl alcohol systsm was used as a supporting electrolyte in which Sn gives a well-defined stripping peak. Pb doesn't interfere with the determination of Sn and can be simultanenusly determined under the experimental condition deseribed without separation. The precision, sensitivity, recovery and interference of various coexisted ions were discussed. 10-6%Sn in wine and 10-5%Sn in asparagus were determined by this method with average errors of recovery less than 10%.
An anodic-stripping voltammetry method is modified for trace tin determination.Hydrochloric acid-methyl alcohol systsm was used as a supporting electrolyte in which Sn gives a well-defined stripping peak. Pb doesn't interfere with the determination of Sn and can be simultanenusly determined under the experimental condition deseribed without separation. The precision, sensitivity, recovery and interference of various coexisted ions were discussed. 10-6%Sn in wine and 10-5%Sn in asparagus were determined by this method with average errors of recovery less than 10%.
