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1996 Volume 13 Issue 1
1996, 13(1): 1-5
Abstract:
The solubility and colloidal properties of 2-acrylamidoalkanesulfonic acids were found to vary markedly with the alkyl length.Due to the existence of a chiral carbon,the peaks of methylene protons adjacent to it clearly split on the 1H NMR spectra.The polymerization kinetics and colloidal properties of 2-acrylamidohexadecane sulfonic acid in water/dioxane mixed solvents were investigated.It is found that both the polymerization rate and the relative molecular mass of the resultant polymer have a minimum value when water/dioxane volume ratio is in the range of 1~1/2.The critical micelle concentration increases with the content of dioxane in the mixed solvent, and no apparent micelle formation is observed when water/dioxane volume ratio is 1/2~1/4.
The solubility and colloidal properties of 2-acrylamidoalkanesulfonic acids were found to vary markedly with the alkyl length.Due to the existence of a chiral carbon,the peaks of methylene protons adjacent to it clearly split on the 1H NMR spectra.The polymerization kinetics and colloidal properties of 2-acrylamidohexadecane sulfonic acid in water/dioxane mixed solvents were investigated.It is found that both the polymerization rate and the relative molecular mass of the resultant polymer have a minimum value when water/dioxane volume ratio is in the range of 1~1/2.The critical micelle concentration increases with the content of dioxane in the mixed solvent, and no apparent micelle formation is observed when water/dioxane volume ratio is 1/2~1/4.
1996, 13(1): 6-9
Abstract:
Fe3O4/P(St-AA) core-shell composite microspheres,having 1~23μm diameter,0~0.1 mmol/g surface carboxyl groups and 0.5~9.0 mg/g magnetite,were prepared by dispersion polymerization of styrene-acrylic acid,with magnetic colloidal particles dispersing in ethanol/water or tetrahydrofuran/water.The size and magnetic response of composite microspheres are highly dependent on the amount of magnetic colloidal particles,solubility parameters of solvents,amount of monomer and initiator.
Fe3O4/P(St-AA) core-shell composite microspheres,having 1~23μm diameter,0~0.1 mmol/g surface carboxyl groups and 0.5~9.0 mg/g magnetite,were prepared by dispersion polymerization of styrene-acrylic acid,with magnetic colloidal particles dispersing in ethanol/water or tetrahydrofuran/water.The size and magnetic response of composite microspheres are highly dependent on the amount of magnetic colloidal particles,solubility parameters of solvents,amount of monomer and initiator.
1996, 13(1): 10-13
Abstract:
The cationic copolymerization of α-pinene and styrene initiated by AlCl3 alone and AlCl3/SbCl3 compound catalyst respectively was investigated.The results showed that, with AlCl3 alone,the polymerization of α-pinene was rather slow,but the polymerization of styrene was fast.Thus, it was difficult for them to copolymerize because of the significant difference in activity between the two monomers.On the other hand,the activity difference of the two monomers was reduced obviously with AlCl3/SbCl3 compound catalyst.This made the copolymerization easier.
The cationic copolymerization of α-pinene and styrene initiated by AlCl3 alone and AlCl3/SbCl3 compound catalyst respectively was investigated.The results showed that, with AlCl3 alone,the polymerization of α-pinene was rather slow,but the polymerization of styrene was fast.Thus, it was difficult for them to copolymerize because of the significant difference in activity between the two monomers.On the other hand,the activity difference of the two monomers was reduced obviously with AlCl3/SbCl3 compound catalyst.This made the copolymerization easier.
1996, 13(1): 14-17
Abstract:
3-N,N-Dimethyl-1,3-propanediamine(DPA) is a useful catalyst for Knoevenagel reaction.2-(4-Nitrophenyl sulfonyl)-cinnamonitriles(3a~k) were obtained by condensation of 4-nitrophenylsulfonylacetonitrile(1) with aromatic aldehydes(2a~k) in the presence of DPA.The yields ranged from 83%~98%.However,the condensation between 2-hydroxybenzaldehyde and 4-nitrophenylsulfonyl-acetonitril gave a six-memberod lactone(31).The structure of compounds 3a~1 was confirmed by elemental analysis,IR,1H NMR and MS.
3-N,N-Dimethyl-1,3-propanediamine(DPA) is a useful catalyst for Knoevenagel reaction.2-(4-Nitrophenyl sulfonyl)-cinnamonitriles(3a~k) were obtained by condensation of 4-nitrophenylsulfonylacetonitrile(1) with aromatic aldehydes(2a~k) in the presence of DPA.The yields ranged from 83%~98%.However,the condensation between 2-hydroxybenzaldehyde and 4-nitrophenylsulfonyl-acetonitril gave a six-memberod lactone(31).The structure of compounds 3a~1 was confirmed by elemental analysis,IR,1H NMR and MS.
1996, 13(1): 18-21
Abstract:
The adsorption mechanism for extraction of palladium with primary amine N1923levextrel resin in the medium of low and high concentration of hydrochloric acid was studied.The adsorptive compounds have been determined and different mechanisms have been derived based on the results obtained using constant mole method,slope method,IR and NMR measurements.
The adsorption mechanism for extraction of palladium with primary amine N1923levextrel resin in the medium of low and high concentration of hydrochloric acid was studied.The adsorptive compounds have been determined and different mechanisms have been derived based on the results obtained using constant mole method,slope method,IR and NMR measurements.
1996, 13(1): 22-25
Abstract:
The isolongifolanone was synthesized from the longifolene using a one-step method with a yield close to that of two-step method.Also,the two isomers of isolongifolanone and their derivatives were prepared and the types of fragrance of the products were defined.
The isolongifolanone was synthesized from the longifolene using a one-step method with a yield close to that of two-step method.Also,the two isomers of isolongifolanone and their derivatives were prepared and the types of fragrance of the products were defined.
1996, 13(1): 26-29
Abstract:
This work dealt with a new method for preparing graft copolymer composed of polysiloxane main chain and uniform polyoxyethylene grafts which were synthesized preliminarily through anionic polymerization using potassium naphthalene as initiator and dimethyl sulfoxide as solvent.The copolymer was characterized with IR and NMR and its expected molecular structure was verified.
This work dealt with a new method for preparing graft copolymer composed of polysiloxane main chain and uniform polyoxyethylene grafts which were synthesized preliminarily through anionic polymerization using potassium naphthalene as initiator and dimethyl sulfoxide as solvent.The copolymer was characterized with IR and NMR and its expected molecular structure was verified.
1996, 13(1): 30-33
Abstract:
Chromium(Ⅲ) phenanthroline and 8-hydroxyqinoline complexes/y-zeolite were prepared respectively.The formation of the metal complexes within the cages of Y-zeolite and their crystal structure were determined by elemental analysis,diffuse reflectance UV-Vis,SEM,BET,and XRD methods.The influence of experimental parameters upon phenol conversion and product selectivity were investigated as well.
Chromium(Ⅲ) phenanthroline and 8-hydroxyqinoline complexes/y-zeolite were prepared respectively.The formation of the metal complexes within the cages of Y-zeolite and their crystal structure were determined by elemental analysis,diffuse reflectance UV-Vis,SEM,BET,and XRD methods.The influence of experimental parameters upon phenol conversion and product selectivity were investigated as well.
1996, 13(1): 34-37
Abstract:
The solubility,octanol/water partition coefficients and toxicity to photobacterium phosphoreum of 12 triazines were determined.Based on molecular connectivity indices.quantitative structure-activity relationship equations were established to estimate the solubility,octanol/water partition coefficients and toxicity of triazines.
The solubility,octanol/water partition coefficients and toxicity to photobacterium phosphoreum of 12 triazines were determined.Based on molecular connectivity indices.quantitative structure-activity relationship equations were established to estimate the solubility,octanol/water partition coefficients and toxicity of triazines.
1996, 13(1): 38-42
Abstract:
Quantum chemistry parameters of ethylenedicarboxylic acids and their esters were calculated with complete neglect of differential overlap method,and the regression and correlation analyses between the antibacterial activity and molecular structure characteristics of these compounds were given.Results show that the antibacterial activity increases with the increase of hydrophobicity of molecules and decreases with the increase of intramolecular interaction force.The antibacterial bioactivity and antimetabolism are negatively correlated to the energy of lowest unoccupied molecular orbitals.The α,β-unsaturated carbonyl group structure is the antibacterial function domain of these compounds, and the active centers are located at β-carbon and oxygen in carbonyl groups.
Quantum chemistry parameters of ethylenedicarboxylic acids and their esters were calculated with complete neglect of differential overlap method,and the regression and correlation analyses between the antibacterial activity and molecular structure characteristics of these compounds were given.Results show that the antibacterial activity increases with the increase of hydrophobicity of molecules and decreases with the increase of intramolecular interaction force.The antibacterial bioactivity and antimetabolism are negatively correlated to the energy of lowest unoccupied molecular orbitals.The α,β-unsaturated carbonyl group structure is the antibacterial function domain of these compounds, and the active centers are located at β-carbon and oxygen in carbonyl groups.
1996, 13(1): 43-46
Abstract:
Four novel cobalt(Ⅱ) complexes have been synthesized and characterized,namely[Co2(4Br-PHTH)(L)4](ClO4)2(L denotes 1,10-phenanthroline(phen)(1),5-nitro-1,10-phenanthroline(NO2-phen) (2),2,2'-bipyridyl(bpy)(3) and 4,4'-dimethyl-2,2'-bipyridyl(Me2bpy)(4),respectively),where 4Br-PHTH is the tetrabromophthalate anion. Based on IR,elemental analysis and conductivity measurements,these complexes are proposed to have extended tetrabromophthalato-bridged structure consisting of two cobalt ions in which each cobalt(Ⅱ) ion has a distorted octahedral environment.The temperature dependence of the magnetic susceptibility for all the complexes were measured over the range 75~300 K and the observed data were successfully simulated by an equation based on the spin Hamiltonian operator(Ĥ=-2JŜ1·Ŝ2),giving the exchange integral J=-0.87 cm-1,J=-0.84cm-1(2),J=-0.82 cm-1(3) and J=-0.85 cm-1(4).These results indicate the existence of weak antiferromagnetic spin exchange interaction between the metal ions.
Four novel cobalt(Ⅱ) complexes have been synthesized and characterized,namely[Co2(4Br-PHTH)(L)4](ClO4)2(L denotes 1,10-phenanthroline(phen)(1),5-nitro-1,10-phenanthroline(NO2-phen) (2),2,2'-bipyridyl(bpy)(3) and 4,4'-dimethyl-2,2'-bipyridyl(Me2bpy)(4),respectively),where 4Br-PHTH is the tetrabromophthalate anion. Based on IR,elemental analysis and conductivity measurements,these complexes are proposed to have extended tetrabromophthalato-bridged structure consisting of two cobalt ions in which each cobalt(Ⅱ) ion has a distorted octahedral environment.The temperature dependence of the magnetic susceptibility for all the complexes were measured over the range 75~300 K and the observed data were successfully simulated by an equation based on the spin Hamiltonian operator(Ĥ=-2JŜ1·Ŝ2),giving the exchange integral J=-0.87 cm-1,J=-0.84cm-1(2),J=-0.82 cm-1(3) and J=-0.85 cm-1(4).These results indicate the existence of weak antiferromagnetic spin exchange interaction between the metal ions.
1996, 13(1): 47-49
Abstract:
The stability constants of the binary complexes Pd(CA)+ and the ternary complexes Pd(Phen)(CA)+ have been determined by potentiometric pH titration.The stability difference among the ternary mixed-ligand complexes has been discussed.The experimental results indicate the existence of intramolecular aromatic ring stacking interactions in the ternary mixed-ligand complexes Pd (Phen)(PheCA)+.The extent of stacking depends on the number of methylene groups between the phenyl moiety and the coordinated carboxylate groups.The best fit stacking is reached with 2-phenylacetate and 3-phenylpropionate.
The stability constants of the binary complexes Pd(CA)+ and the ternary complexes Pd(Phen)(CA)+ have been determined by potentiometric pH titration.The stability difference among the ternary mixed-ligand complexes has been discussed.The experimental results indicate the existence of intramolecular aromatic ring stacking interactions in the ternary mixed-ligand complexes Pd (Phen)(PheCA)+.The extent of stacking depends on the number of methylene groups between the phenyl moiety and the coordinated carboxylate groups.The best fit stacking is reached with 2-phenylacetate and 3-phenylpropionate.
1996, 13(1): 50-53
Abstract:
The ternary complexes RE(Gly)2.5(Ala)1.5(ClO4)3·H2O(RE=La~Lu except Pm;Gly=glycine;Ala=L-alanine) have been synthesized in aqueous solution and characterized by elemental analysis,amino acid analysis,IR,1H NMR,13C NMR, X-ray diffraction,thermal analysis and fluorescence spectrometry.The fluorescence intensities of the complexes of Eu(Ⅲ) and Tb(Ⅲ) (Eu:5D0→7F2;Tb:5D0→7F5,7F6) have increased by 10-fold as compared with those of the corresponding perchlorate hydrates of Eu(Ⅲ) and Tb(Ⅲ).
The ternary complexes RE(Gly)2.5(Ala)1.5(ClO4)3·H2O(RE=La~Lu except Pm;Gly=glycine;Ala=L-alanine) have been synthesized in aqueous solution and characterized by elemental analysis,amino acid analysis,IR,1H NMR,13C NMR, X-ray diffraction,thermal analysis and fluorescence spectrometry.The fluorescence intensities of the complexes of Eu(Ⅲ) and Tb(Ⅲ) (Eu:5D0→7F2;Tb:5D0→7F5,7F6) have increased by 10-fold as compared with those of the corresponding perchlorate hydrates of Eu(Ⅲ) and Tb(Ⅲ).
1996, 13(1): 54-57
Abstract:
The interfacial tension(IFT) between crude oil and mixed solution which is composed of partially neutralized vegetable oil acid,Tween-60 and salts was studied.The result indicated that IFT is affected not noly by concentration and neutralization ratio of vegetable oil acid but also by Tween-60 concentration.Introduction of Tween-60 into the system can improve the solubility of vegetable oil acid in aqueous solution but gives rise to increase of IFT.The effects of NaCl and CaCl2 on IFT are relatively small.Thus,the system containing 0.90% vegetable oil acid with a neutralization ratio of 0.85,0.10% Tween-60,0.4% NaCl and 0.02% CaCl2 is stable with low IFT.
The interfacial tension(IFT) between crude oil and mixed solution which is composed of partially neutralized vegetable oil acid,Tween-60 and salts was studied.The result indicated that IFT is affected not noly by concentration and neutralization ratio of vegetable oil acid but also by Tween-60 concentration.Introduction of Tween-60 into the system can improve the solubility of vegetable oil acid in aqueous solution but gives rise to increase of IFT.The effects of NaCl and CaCl2 on IFT are relatively small.Thus,the system containing 0.90% vegetable oil acid with a neutralization ratio of 0.85,0.10% Tween-60,0.4% NaCl and 0.02% CaCl2 is stable with low IFT.
1996, 13(1): 58-61
Abstract:
Structural studies of poly(ether ether ketone ketone) and poly(ether biphenyl ether ketone ketone) copolymers by means of SAXS and one dimensional electron density correlation function methods revealed that the structure of the aggregated state of copolymers depended closely on the biphenyl content(nb) in the copolymers. When nb=0.35,the invariant Q,long period L,average crystal lamellae d and electron density difference ηc-ηa(obtained by SAXS analysis) and the degree of crystallinity Wc,x gave minimum values, but the specific inner surfaces Os possessed maximum values.
Structural studies of poly(ether ether ketone ketone) and poly(ether biphenyl ether ketone ketone) copolymers by means of SAXS and one dimensional electron density correlation function methods revealed that the structure of the aggregated state of copolymers depended closely on the biphenyl content(nb) in the copolymers. When nb=0.35,the invariant Q,long period L,average crystal lamellae d and electron density difference ηc-ηa(obtained by SAXS analysis) and the degree of crystallinity Wc,x gave minimum values, but the specific inner surfaces Os possessed maximum values.
1996, 13(1): 62-64
Abstract:
The characteristics of Rayleigh scattering of high density polyethylene in the presence of dibenzylidenesorbital as nucleation reagent was investigated and the existence of rodlike crystals was confirmed. The effect of nucleation reagent on the crystallization was discussed and the length and radius of rod crystal were calculated.
The characteristics of Rayleigh scattering of high density polyethylene in the presence of dibenzylidenesorbital as nucleation reagent was investigated and the existence of rodlike crystals was confirmed. The effect of nucleation reagent on the crystallization was discussed and the length and radius of rod crystal were calculated.
1996, 13(1): 65-67
Abstract:
Ultra-fine SnO2 powder with mean size of 2~3 nm was prepared by a sol-gel process.The structure and properties of the powder were studied.It is found that the tetragonal tin dioxide formed essentially during the gel drying at 70℃,and further crystallized on heating at 240~330℃,which was much lower than the temperature reported for the powder prepared with other method.The temperature dependent curue of conductivity for the thick film gas sensors made of this ultrafine powders showed a peak at 130℃,which was obviously lower than that reported in literature.The gas sensing layer of the element exhibited good strength and good resistivity stability as well as high sensitivity to H2 and C2H2 gases.
Ultra-fine SnO2 powder with mean size of 2~3 nm was prepared by a sol-gel process.The structure and properties of the powder were studied.It is found that the tetragonal tin dioxide formed essentially during the gel drying at 70℃,and further crystallized on heating at 240~330℃,which was much lower than the temperature reported for the powder prepared with other method.The temperature dependent curue of conductivity for the thick film gas sensors made of this ultrafine powders showed a peak at 130℃,which was obviously lower than that reported in literature.The gas sensing layer of the element exhibited good strength and good resistivity stability as well as high sensitivity to H2 and C2H2 gases.
1996, 13(1): 68-70
Abstract:
A new synthetic method for dodecyl diethylenetriamine from lauric acid and diethylenetriamine via imidazoline is reported.The reduction of imidazoline and the effects of reaction condition on reduction are discussed.
A new synthetic method for dodecyl diethylenetriamine from lauric acid and diethylenetriamine via imidazoline is reported.The reduction of imidazoline and the effects of reaction condition on reduction are discussed.
1996, 13(1): 71-73
Abstract:
The temperature dependence of ionic conductivity in polytriethylene glycol dimethacrylate(PTREGD)-LiClO4-propylene carbonate(PC) three component gel electrolytes was investigated.It is found that the dependence of ionic conductivity on temperature in the electrolytes can be expressed by Arrhenius equation. If the content of PC in the gel electrolyte is high enough,the influence of polymer matrix on ion migration can be neglected.Generally,the Arrhenius-type temperature dependence does not hold in the gel elctrolytes with high lithium salt content.The extent to which Arrhenius equation is applied depends upon the nature of lithium salt.However,LiBF4 is an exception with which the nonArrhenius behaviour is observed.The activation energy for ion migration depends upon both the nature and the concentration of Li salt, and actually it is also a measure of conductance in the gel electrolyte.
The temperature dependence of ionic conductivity in polytriethylene glycol dimethacrylate(PTREGD)-LiClO4-propylene carbonate(PC) three component gel electrolytes was investigated.It is found that the dependence of ionic conductivity on temperature in the electrolytes can be expressed by Arrhenius equation. If the content of PC in the gel electrolyte is high enough,the influence of polymer matrix on ion migration can be neglected.Generally,the Arrhenius-type temperature dependence does not hold in the gel elctrolytes with high lithium salt content.The extent to which Arrhenius equation is applied depends upon the nature of lithium salt.However,LiBF4 is an exception with which the nonArrhenius behaviour is observed.The activation energy for ion migration depends upon both the nature and the concentration of Li salt, and actually it is also a measure of conductance in the gel electrolyte.
1996, 13(1): 74-76
Abstract:
Poly(n-butyl acrylate)/styrene/acrylonitrile copolymer(ASA) was synthesized,and its structure-property relationship was studied.It was found that the rubber particle size can be controlled by using the seed emulsion polymerization technique.The impact strength of the ASA depends on its composition and rubber particle size.The optimum particle size is 0.135μm,and the optimum composition of the matrix is 28/72(AN/St).
Poly(n-butyl acrylate)/styrene/acrylonitrile copolymer(ASA) was synthesized,and its structure-property relationship was studied.It was found that the rubber particle size can be controlled by using the seed emulsion polymerization technique.The impact strength of the ASA depends on its composition and rubber particle size.The optimum particle size is 0.135μm,and the optimum composition of the matrix is 28/72(AN/St).
1996, 13(1): 77-79
Abstract:
Naphthyloxy-5,12-naphthacenequinone(1) was synthesized by reacting 6-chloro-5,12-naphthacenequinone with 1-naphthol in dry DMF in the presence of potassium carbonate.Its characterization results of 1H NMR and IR were presented.Like phenoxynaphthacenequinones,1 showed normal photochromism in a DMSO solution,exhibiting a characteristic double peak at 454 and 483 nm with isosbestic points at 405,362,342 and 278nm during irradiation with 365 nm UV light.
Naphthyloxy-5,12-naphthacenequinone(1) was synthesized by reacting 6-chloro-5,12-naphthacenequinone with 1-naphthol in dry DMF in the presence of potassium carbonate.Its characterization results of 1H NMR and IR were presented.Like phenoxynaphthacenequinones,1 showed normal photochromism in a DMSO solution,exhibiting a characteristic double peak at 454 and 483 nm with isosbestic points at 405,362,342 and 278nm during irradiation with 365 nm UV light.
1996, 13(1): 80-82
Abstract:
A flow injection-turbidimetric method for determination of sulphate in water with on-line preconcentration by cation exchange fiber was established.Under the conditions of the acidity of sample being PH=5.0 and the concentration of eluent(NaCl) being 1.0 mol/L,the results of the determination of sulphate are satisfactory.The linear range,the recovery,the detection limit and the RSD of the present method are 8~320 mg/L,98%~102%,0.11mg/L and 0.26% respectively.The sampling rate is 40/h.
A flow injection-turbidimetric method for determination of sulphate in water with on-line preconcentration by cation exchange fiber was established.Under the conditions of the acidity of sample being PH=5.0 and the concentration of eluent(NaCl) being 1.0 mol/L,the results of the determination of sulphate are satisfactory.The linear range,the recovery,the detection limit and the RSD of the present method are 8~320 mg/L,98%~102%,0.11mg/L and 0.26% respectively.The sampling rate is 40/h.
1996, 13(1): 83-85
Abstract:
Inhibition properties of organophosphonic acids and copolymers on calcium carbonate and phosphate scale were studied.Experimental results indicated that scale inhibition percentages of 1-hydroxyethylidene diphosphonic acid(HEDP) on calcium carbonate did not increase with the increasing concentrations of HEDP;for copolymers AA/AMPS and AA/AMPS/MMA,there existed critical concentrations for inhibiting calcium phosphate scale;AA/HPA(or AA/AMPS) and orthophosphate had synergistic effects for inhibiting calcium carbonate scale within certain concentration ranges.These conclusions may have directive value on the practical use of organophosphonic acids and copolymers.
Inhibition properties of organophosphonic acids and copolymers on calcium carbonate and phosphate scale were studied.Experimental results indicated that scale inhibition percentages of 1-hydroxyethylidene diphosphonic acid(HEDP) on calcium carbonate did not increase with the increasing concentrations of HEDP;for copolymers AA/AMPS and AA/AMPS/MMA,there existed critical concentrations for inhibiting calcium phosphate scale;AA/HPA(or AA/AMPS) and orthophosphate had synergistic effects for inhibiting calcium carbonate scale within certain concentration ranges.These conclusions may have directive value on the practical use of organophosphonic acids and copolymers.
1996, 13(1): 86-88
Abstract:
Uniform acicular hematite used as starting material for magnetic recording were prepared by hydrothermal reaction from condensed ferric hydroxide gel.The simplified procedure under general experimental conditions was used.In the presence of organic chelating agent(HEDP) acicular particles were observed.However,with concentration of HEDP increasing from 1×10-3 mol/L to 1×10-2 mol/L,uniform cubic α-Fe2O3 was obtained.The experimental results show that the volume of the particles is dependent on the number of nuclei produced in the precipitation stage of Fe(OH)3.
Uniform acicular hematite used as starting material for magnetic recording were prepared by hydrothermal reaction from condensed ferric hydroxide gel.The simplified procedure under general experimental conditions was used.In the presence of organic chelating agent(HEDP) acicular particles were observed.However,with concentration of HEDP increasing from 1×10-3 mol/L to 1×10-2 mol/L,uniform cubic α-Fe2O3 was obtained.The experimental results show that the volume of the particles is dependent on the number of nuclei produced in the precipitation stage of Fe(OH)3.
1996, 13(1): 89-91
Abstract:
A highly effective floating agent for graphite was synthesized with mixed hydrocarbons(by-products of petroleum) and some addendum agents.This floating agent increases the quality grade of floatation from 85% to 93% and recovery from 65% to 85%.Meanwhile,the relationship between the synthesized product and floatation efficiency was investigated.The structure of the product was determined by FTIR spectra.
A highly effective floating agent for graphite was synthesized with mixed hydrocarbons(by-products of petroleum) and some addendum agents.This floating agent increases the quality grade of floatation from 85% to 93% and recovery from 65% to 85%.Meanwhile,the relationship between the synthesized product and floatation efficiency was investigated.The structure of the product was determined by FTIR spectra.
1996, 13(1): 92-94
Abstract:
Coupling agent promotes the compatibility of poly(vinyl chloride)(PVC) with poly(propylene carbonate)(PPC),greatly improves mechanical properties of PVC/PPC system,causes light cross-linking which is about 10 weight percent of these blends.Mechanical properties of PVC/PPC blends are generally best when the ratio of NBR/PPC is 70/30,nitrile content of NBR 34% and BPO dosage 2.5 parts in coupling agent.And a short pre-vulcanization time for coupling agent is adequate.
Coupling agent promotes the compatibility of poly(vinyl chloride)(PVC) with poly(propylene carbonate)(PPC),greatly improves mechanical properties of PVC/PPC system,causes light cross-linking which is about 10 weight percent of these blends.Mechanical properties of PVC/PPC blends are generally best when the ratio of NBR/PPC is 70/30,nitrile content of NBR 34% and BPO dosage 2.5 parts in coupling agent.And a short pre-vulcanization time for coupling agent is adequate.
1996, 13(1): 95-97
Abstract:
The performance of the solid polymer electrolyte(SPE) membrane electrode composite ozone generator has been examined in deionized water for more than 10000 hours with the current density 1.5 Acm-2.The average current efficiency of O3 evolution is about 20%.The optimal specific power consumption is 58.3 Whg-1(O3).The stability of the anode catalysts on SPE membrane composite ozone generator has been studied by X-ray diffraction and atomic absorption spectrometry techniques.The results show that both the current efficiency of O3 production and the stability of the composite with β-PbO2 anode catalyst are better than those with the mixed α-PbO2 and β-PbO2 catalyst.
The performance of the solid polymer electrolyte(SPE) membrane electrode composite ozone generator has been examined in deionized water for more than 10000 hours with the current density 1.5 Acm-2.The average current efficiency of O3 evolution is about 20%.The optimal specific power consumption is 58.3 Whg-1(O3).The stability of the anode catalysts on SPE membrane composite ozone generator has been studied by X-ray diffraction and atomic absorption spectrometry techniques.The results show that both the current efficiency of O3 production and the stability of the composite with β-PbO2 anode catalyst are better than those with the mixed α-PbO2 and β-PbO2 catalyst.
1996, 13(1): 98-100
Abstract:
An acidic heteropolysaccharide,which is composed of xylose,mannose,galactose and glucose/glucuronic acid(mass ratio such as 0.1:1.1:1.0:1.2) and has molecular weight of 51.0×104,was isolated from the fruiting body of Auricularia Auricula-judae.The results determined by calorimetric method with carbazole, viscometry and GPC showed that the molecular weights and polydispersity indexes of the samples treated by ultrasonic irradiation decreased with the increase of irradiation time,and the glucuronic acid content did not show significant change.
An acidic heteropolysaccharide,which is composed of xylose,mannose,galactose and glucose/glucuronic acid(mass ratio such as 0.1:1.1:1.0:1.2) and has molecular weight of 51.0×104,was isolated from the fruiting body of Auricularia Auricula-judae.The results determined by calorimetric method with carbazole, viscometry and GPC showed that the molecular weights and polydispersity indexes of the samples treated by ultrasonic irradiation decreased with the increase of irradiation time,and the glucuronic acid content did not show significant change.
1996, 13(1): 101-103
Abstract:
The extraction mechanism of Ga3+ from hydrochloric acid solution with momo(2-ethylhexyl)2-ethylhexyl phosphonate has been investigated. Results show that the extraction reaction is Ga3++2H2A2(o)=GaA3HA(o)+3H+ ΔH0=-11.009 kJ/mol,ΔG0=9.384~11.136 kJ/mol,-ΔS0=68.43~68.74 J/mol.
The extraction mechanism of Ga3+ from hydrochloric acid solution with momo(2-ethylhexyl)2-ethylhexyl phosphonate has been investigated. Results show that the extraction reaction is Ga3++2H2A2(o)=GaA3HA(o)+3H+ ΔH0=-11.009 kJ/mol,ΔG0=9.384~11.136 kJ/mol,-ΔS0=68.43~68.74 J/mol.
1996, 13(1): 104-106
Abstract:
Trace Fe(Ⅲ) catalyzes the discoloring oxidation reaction of arsenazo Ⅲ by potassium periodate(KIO4) in sulfuric acid medium.The kinetic conditions have been studied in detail.A new method of kinetic spectrophotometry for the determination of trace Fe(Ⅲ) is established.The sensitivity of method is 8 ng/L.The range of measurement is 0~0.06mg/L Fe(Ⅲ).The coexisting metal ions can be separated by mercapto-containing dextran gel.This method has been applied to the determination of trace iron(Ⅲ) in water and human hair samples with satisfactory results.
Trace Fe(Ⅲ) catalyzes the discoloring oxidation reaction of arsenazo Ⅲ by potassium periodate(KIO4) in sulfuric acid medium.The kinetic conditions have been studied in detail.A new method of kinetic spectrophotometry for the determination of trace Fe(Ⅲ) is established.The sensitivity of method is 8 ng/L.The range of measurement is 0~0.06mg/L Fe(Ⅲ).The coexisting metal ions can be separated by mercapto-containing dextran gel.This method has been applied to the determination of trace iron(Ⅲ) in water and human hair samples with satisfactory results.
1996, 13(1): 107-108
Abstract:
The stacking interactions of aromatic rings in the Cu2+-bpy-PCA- system(bpy=2,2'-bipyridyl,PCA=phenylcarboxylic acid) have been studied by extraction method in perchloric acid medium.The content of the stacked isomers of the extracted species[Cu(bPy)(PCA)(H2O)]+ increases in the order:Bz-- - -.The composition of complexes has been determined by slope method and elemental analysis.
The stacking interactions of aromatic rings in the Cu2+-bpy-PCA- system(bpy=2,2'-bipyridyl,PCA=phenylcarboxylic acid) have been studied by extraction method in perchloric acid medium.The content of the stacked isomers of the extracted species[Cu(bPy)(PCA)(H2O)]+ increases in the order:Bz-
1996, 13(1): 109-111
Abstract:
We have studied the kinetics of interaction between ferric nucleotide coordination compounds and transferrin with spectrophotometry. Results showed that the exchange rate of ferric ion is Fe(Ⅲ)PYR >Fe(Ⅲ)ATP >Fe(Ⅲ)ADP >Fe(Ⅲ)AMP.The exchange reactions between Fe(Ⅲ)ATP,Fe(Ⅲ)ADP or Fe(Ⅲ)PYR and deferrization transferrin are second order reactions, but the reaction mechanism of Fe(Ⅲ) ATP and Fe(Ⅲ) PYR is different from that of Fe(Ⅲ)ADP.The exchange reaction of Fe(Ⅲ) AMP is a first order reaction.
We have studied the kinetics of interaction between ferric nucleotide coordination compounds and transferrin with spectrophotometry. Results showed that the exchange rate of ferric ion is Fe(Ⅲ)PYR >Fe(Ⅲ)ATP >Fe(Ⅲ)ADP >Fe(Ⅲ)AMP.The exchange reactions between Fe(Ⅲ)ATP,Fe(Ⅲ)ADP or Fe(Ⅲ)PYR and deferrization transferrin are second order reactions, but the reaction mechanism of Fe(Ⅲ) ATP and Fe(Ⅲ) PYR is different from that of Fe(Ⅲ)ADP.The exchange reaction of Fe(Ⅲ) AMP is a first order reaction.
1996, 13(1): 112-113
Abstract:
Toughening of epoxy resin by incorporation of PnBA/PMMA core/shell structure impact modifier was studied.It is found that the impact strength of epoxy resin is substantially enhanced by the addition of impact modifier.For the phthalic anhydride cured system.adding 30 parts of impact modifier to 100 parts of epoxy resin has changed the mode of fracture from brittle to ductile in Izod impact test,and the impact strength has increased by a factor of 30.
Toughening of epoxy resin by incorporation of PnBA/PMMA core/shell structure impact modifier was studied.It is found that the impact strength of epoxy resin is substantially enhanced by the addition of impact modifier.For the phthalic anhydride cured system.adding 30 parts of impact modifier to 100 parts of epoxy resin has changed the mode of fracture from brittle to ductile in Izod impact test,and the impact strength has increased by a factor of 30.
1996, 13(1): 114-115
Abstract:
The catalytic esterification activity of some bentonite samples treated with different methods were characterized.It was found that the catalytic activity of activited bentonite could be increased greatly by loading with rare earth. However,no evident increase of catalytic activity with the amount of loaded rare earth in bentonite was observed in high rare earth content range.These results showed that the surface acidity and rare earth accounted for the catalytic activity and the former factor played a more important role than the other in the catalytic esterification.
The catalytic esterification activity of some bentonite samples treated with different methods were characterized.It was found that the catalytic activity of activited bentonite could be increased greatly by loading with rare earth. However,no evident increase of catalytic activity with the amount of loaded rare earth in bentonite was observed in high rare earth content range.These results showed that the surface acidity and rare earth accounted for the catalytic activity and the former factor played a more important role than the other in the catalytic esterification.
1996, 13(1): 116-118
Abstract:
The thermograms of Aerobacter aerogenes in solutions with different concentrations of Schiff base metal complexes have been determined by use of the LKB-2277 Bioactivity Monitor.The experimental results show that the sequence of antiaerobacter aerogenes activity of Schiff base metal complexes is:Co(Ⅲ)-2,4-L >Zn-2,4-L >2,4-L >Fe(Ⅲ)-2,4-L >Cu(Ⅰ)-2,4-L(2,4-L:2,4-dihydroxybenzaldehyde glucosamine Schiff bases).Their half inhibitory concentrations also increase with this sequence.
The thermograms of Aerobacter aerogenes in solutions with different concentrations of Schiff base metal complexes have been determined by use of the LKB-2277 Bioactivity Monitor.The experimental results show that the sequence of antiaerobacter aerogenes activity of Schiff base metal complexes is:Co(Ⅲ)-2,4-L >Zn-2,4-L >2,4-L >Fe(Ⅲ)-2,4-L >Cu(Ⅰ)-2,4-L(2,4-L:2,4-dihydroxybenzaldehyde glucosamine Schiff bases).Their half inhibitory concentrations also increase with this sequence.
