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1995 Volume 12 Issue 5
1995, 12(5): 1-4
Abstract:
Supported Zr/MAO/SiO2 catalysts with different Zr content have been synthe-sized. The influence of the amount of methylaluminoxane in reactants on the Zr content in the catalysts and the catalytic activity has been examined. Copolymerization of ethylene with linear 1-alkenes by the catalysts was investigated. It was found that hexene-1 and octene-1 were highly incorporated,while for decene-1,the copolymers contained low comonomer component. The effect of chain length of α-olfin on the catalytic activity has been explained. It is observed from SEM that α-olefin in the copolymers can improve polymer particle mor-phology.
Supported Zr/MAO/SiO2 catalysts with different Zr content have been synthe-sized. The influence of the amount of methylaluminoxane in reactants on the Zr content in the catalysts and the catalytic activity has been examined. Copolymerization of ethylene with linear 1-alkenes by the catalysts was investigated. It was found that hexene-1 and octene-1 were highly incorporated,while for decene-1,the copolymers contained low comonomer component. The effect of chain length of α-olfin on the catalytic activity has been explained. It is observed from SEM that α-olefin in the copolymers can improve polymer particle mor-phology.
1995, 12(5): 5-9
Abstract:
The reaction conditions for preparing the organic soluble precursor polymer of poly(2,5-dimethoxy phenylene vinylene) have been examined. The results indicated that NaOH was an effective initiator for this polymerization. The optimum reaction conditions were as follows: molar ratio of monomer to NaOH 1:1;concentration of monomer 0.05 to 0.2mol/L;polymerization time 2 hours and temperature below 5℃. Hexane and petroleum ether can effectively increase the monome,conversion and precursor polymer yield. The structure of the polymer precursor were characterized by IR, UV-Vis,1H NMR,TGA and DSC.
The reaction conditions for preparing the organic soluble precursor polymer of poly(2,5-dimethoxy phenylene vinylene) have been examined. The results indicated that NaOH was an effective initiator for this polymerization. The optimum reaction conditions were as follows: molar ratio of monomer to NaOH 1:1;concentration of monomer 0.05 to 0.2mol/L;polymerization time 2 hours and temperature below 5℃. Hexane and petroleum ether can effectively increase the monome,conversion and precursor polymer yield. The structure of the polymer precursor were characterized by IR, UV-Vis,1H NMR,TGA and DSC.
1995, 12(5): 10-14
Abstract:
The sodium di-alkyl phosphates(phosphonates) NaDEHP,NaEHEHP and NaDTMPP (NaA) used in preserit paper are anionic surfactants. The water solubilization in the W/O microemulsion systems of NaA-ROH-oil-H2O has been measured;the microemul-sion regions have been determined by means of pseudo-ternary phase diagrams;the third phase formation and the transition of Winsor type Ⅰ,Ⅱ,Ⅲ have been investigated under different conditions. The effect of oil,alcohol, salinity and temperature on the phase behavior has been dis-cussed.
The sodium di-alkyl phosphates(phosphonates) NaDEHP,NaEHEHP and NaDTMPP (NaA) used in preserit paper are anionic surfactants. The water solubilization in the W/O microemulsion systems of NaA-ROH-oil-H2O has been measured;the microemul-sion regions have been determined by means of pseudo-ternary phase diagrams;the third phase formation and the transition of Winsor type Ⅰ,Ⅱ,Ⅲ have been investigated under different conditions. The effect of oil,alcohol, salinity and temperature on the phase behavior has been dis-cussed.
1995, 12(5): 15-19
Abstract:
Cyclohexene has been oxidized to cyclohexanone catalytically by catalyst systems of Pd(OAc)2/HQ with macrocyclic compounds: metallophthalocyanine(MPc,M=Fe,Cr,Co) and chlorometalloporphyrin(MTPPCI,M=Fe,Cr,Mn) in an acidic aqueous solution of acetonitrile. The best results were obtained by using Pd(OAc)2/HQ/FePc system. The yield of cyclohexanone was 84% with selectivity of 98% on 30min reaction. Some factors influenc-ing the activity of the catalyst have been examined.
Cyclohexene has been oxidized to cyclohexanone catalytically by catalyst systems of Pd(OAc)2/HQ with macrocyclic compounds: metallophthalocyanine(MPc,M=Fe,Cr,Co) and chlorometalloporphyrin(MTPPCI,M=Fe,Cr,Mn) in an acidic aqueous solution of acetonitrile. The best results were obtained by using Pd(OAc)2/HQ/FePc system. The yield of cyclohexanone was 84% with selectivity of 98% on 30min reaction. Some factors influenc-ing the activity of the catalyst have been examined.
1995, 12(5): 20-24
Abstract:
The oxidation of cyclohexene to cyclohexanone catalyzed by Pd(OAc)2/HQ/FePc was investigated in an acidic aqueous solution of acetonitrile. The role of each component in catalyst system during the oxidation of cyclohexene was examined by UV-Vis,IR,XPS spectroscopy and cyclic voltammetry, respectively. Based on the experimental results,the mechanism of oxidation of cyclohexene catalyzed by Pd(OAc)2/HQ/FePc was discussed.
The oxidation of cyclohexene to cyclohexanone catalyzed by Pd(OAc)2/HQ/FePc was investigated in an acidic aqueous solution of acetonitrile. The role of each component in catalyst system during the oxidation of cyclohexene was examined by UV-Vis,IR,XPS spectroscopy and cyclic voltammetry, respectively. Based on the experimental results,the mechanism of oxidation of cyclohexene catalyzed by Pd(OAc)2/HQ/FePc was discussed.
1995, 12(5): 25-28
Abstract:
Ten coordination polymers of rare earth with 1,4-dihydroxyanthraquinone were prepared. The thermal stabilities, electrical conductivities, magnetic moments and infrared spectra of the complexes have been determined.
Ten coordination polymers of rare earth with 1,4-dihydroxyanthraquinone were prepared. The thermal stabilities, electrical conductivities, magnetic moments and infrared spectra of the complexes have been determined.
1995, 12(5): 29-32
Abstract:
Through interfacial polycondensation of bis(β-alkoxycarbonylalkyl)tin dichlorides with various diacids,diphenols,diols and dithiols,a series of new orgallo-tin polyesters,polyethers and polythioethers were prepared. The synthesized polymers are potential ther-mostabilizers for PVC products.
Through interfacial polycondensation of bis(β-alkoxycarbonylalkyl)tin dichlorides with various diacids,diphenols,diols and dithiols,a series of new orgallo-tin polyesters,polyethers and polythioethers were prepared. The synthesized polymers are potential ther-mostabilizers for PVC products.
1995, 12(5): 33-36
Abstract:
Detailed investigation on the preparation and properties of telluratocuprate(Ⅱ,Ⅲ) complexes has been performed. In the solution of H6TeO6/KOH,Cu(Ⅲ) complex was obtained by adopting ozone as oxidant and a new copper(Ⅲ) compound Ba4K[Cu (H2TeO6)2](OH)4·6H2O was isolated. The cyclic voltammogram of "Cu(Ⅲ)/Cu(Ⅱ)"couple in alka-line solution was described. According to the electronic spectra and Cu2p XPS of the new Cu(Ⅲ) compound, Na4H[Cu(H2TeO6)2]·17H2O and related Cu(Ⅱ) complexes, the ligand field parameters and the binding energies of Cu2p3/2 for these Cu(Ⅲ) and Cu(Ⅱ) complexes were determined.
Detailed investigation on the preparation and properties of telluratocuprate(Ⅱ,Ⅲ) complexes has been performed. In the solution of H6TeO6/KOH,Cu(Ⅲ) complex was obtained by adopting ozone as oxidant and a new copper(Ⅲ) compound Ba4K[Cu (H2TeO6)2](OH)4·6H2O was isolated. The cyclic voltammogram of "Cu(Ⅲ)/Cu(Ⅱ)"couple in alka-line solution was described. According to the electronic spectra and Cu2p XPS of the new Cu(Ⅲ) compound, Na4H[Cu(H2TeO6)2]·17H2O and related Cu(Ⅱ) complexes, the ligand field parameters and the binding energies of Cu2p3/2 for these Cu(Ⅲ) and Cu(Ⅱ) complexes were determined.
1995, 12(5): 37-41
Abstract:
Six μ-oxamido heterobinuclear complexes,namely Cu(oxen)Ln(phen)2(ClO4)3, (oxen:N,N'-bis(2-aminoethyl) oxamido dianion;phen:1,10-phenanthroline and Ln:Y,La,Ce,Nd,Gd,Yb) have been synthesized and characterized. The variable-temperature mag-netic susceptibility of Cu(oxen)Gd(phen)2(ClO4)3·H2O was measured over 4~300K and the susceptibility data were least-squares fit to the susceptibility equation derived from the spin Hamiltonian operator Ĥ=-2JŜ1·Ŝ2. The exchange integral J was found to be 2.3cm-1,indicating that a very weak ferromagnetic spin-exchange interaction operates be-tween Cu(Ⅱ) and Gd(Ⅲ) ions. The antibacterial activity of the complexes were also exam-ined.
Six μ-oxamido heterobinuclear complexes,namely Cu(oxen)Ln(phen)2(ClO4)3, (oxen:N,N'-bis(2-aminoethyl) oxamido dianion;phen:1,10-phenanthroline and Ln:Y,La,Ce,Nd,Gd,Yb) have been synthesized and characterized. The variable-temperature mag-netic susceptibility of Cu(oxen)Gd(phen)2(ClO4)3·H2O was measured over 4~300K and the susceptibility data were least-squares fit to the susceptibility equation derived from the spin Hamiltonian operator Ĥ=-2JŜ1·Ŝ2. The exchange integral J was found to be 2.3cm-1,indicating that a very weak ferromagnetic spin-exchange interaction operates be-tween Cu(Ⅱ) and Gd(Ⅲ) ions. The antibacterial activity of the complexes were also exam-ined.
1995, 12(5): 42-45
Abstract:
The synthesis and photochromic mechanism of 4-aza-15-crown-5-4'-methoxya-zobenzene and 4-aza-15-crown-5-4'-nitroazobenzene were described. It was found that the photochromic mechanism of these two compounds was the photo-inducing twisted in-tramolecular charge transfer and was not cis-trans isomerization.
The synthesis and photochromic mechanism of 4-aza-15-crown-5-4'-methoxya-zobenzene and 4-aza-15-crown-5-4'-nitroazobenzene were described. It was found that the photochromic mechanism of these two compounds was the photo-inducing twisted in-tramolecular charge transfer and was not cis-trans isomerization.
1995, 12(5): 46-49
Abstract:
PbO2-WC composite electrode formed by dispersion of WC particles in PbO2 was prepared by using composite electrodeposition technique. The crystallographic structure and performance of anodic oxygen evolution reaction in sulfuric acid medium of the composite electrode were studied. The results show that,as compared with the PbO2 electrode contain-ing no WC particles,the PbO2-WC composite electrode is smaller in crystal grain and more compact in structure,its α-PbO2 content is higher and crystallites are preferentially orientat-ed. Electrocatalytic activity for oxygen evolution reaction in 0.5mol/L H2SO4 solution of the composite electrode is increased nearly by one-fold. Chemical stability and electrochemical stability of the composite coating are excellent.
PbO2-WC composite electrode formed by dispersion of WC particles in PbO2 was prepared by using composite electrodeposition technique. The crystallographic structure and performance of anodic oxygen evolution reaction in sulfuric acid medium of the composite electrode were studied. The results show that,as compared with the PbO2 electrode contain-ing no WC particles,the PbO2-WC composite electrode is smaller in crystal grain and more compact in structure,its α-PbO2 content is higher and crystallites are preferentially orientat-ed. Electrocatalytic activity for oxygen evolution reaction in 0.5mol/L H2SO4 solution of the composite electrode is increased nearly by one-fold. Chemical stability and electrochemical stability of the composite coating are excellent.
1995, 12(5): 50-53
Abstract:
A method of third derivative spectrophotometric simultaneous determination of micro amount of copper,cobalt and cadmium with meso-tetrakis[4-(trimethylammonium)phenyl]porphine has been established. The absorption maxima of the third derivative spectra for copper,cobalt and cadmium complexes were localed at 412nm,434nm,438nm,respec-tively. They could be used for simultaneous determinatlon of copper,cobalt and cadmium. The molar absorptivities of third derivative spectra were 1.11 × 106(Cu),3.95 × 105(Co) and 6.47 × 105(Cd)L·mol-1·cm-1,respectively. The method has been used to determine syn-thetic mixtures of copper,cobalt and cadmium,and satisfactory results were obtained with relative errors < 4%.
A method of third derivative spectrophotometric simultaneous determination of micro amount of copper,cobalt and cadmium with meso-tetrakis[4-(trimethylammonium)phenyl]porphine has been established. The absorption maxima of the third derivative spectra for copper,cobalt and cadmium complexes were localed at 412nm,434nm,438nm,respec-tively. They could be used for simultaneous determinatlon of copper,cobalt and cadmium. The molar absorptivities of third derivative spectra were 1.11 × 106(Cu),3.95 × 105(Co) and 6.47 × 105(Cd)L·mol-1·cm-1,respectively. The method has been used to determine syn-thetic mixtures of copper,cobalt and cadmium,and satisfactory results were obtained with relative errors < 4%.
1995, 12(5): 54-57
Abstract:
The composition and structure of La-Th-O mixed oxides as well as their catalytic activity for methane oxidative coupling have been studied by means of XRD,XPS and IR. The results indicated that the solid solution of LaxTh1-xO2-δ with the fluorite structure was formed in the range O≤x≤0.6,and it was the main active phase for oxidative coupling of methane.
The composition and structure of La-Th-O mixed oxides as well as their catalytic activity for methane oxidative coupling have been studied by means of XRD,XPS and IR. The results indicated that the solid solution of LaxTh1-xO2-δ with the fluorite structure was formed in the range O≤x≤0.6,and it was the main active phase for oxidative coupling of methane.
1995, 12(5): 58-61
Abstract:
The synergistic extraction of uranitim(Ⅵ) by a ternary system composed of 4,4'-decanedioyl-bis-(1-phenyl-3-methyl-5-pyrazolone), trioctylphosphine oxide (TOPO) and pyridine was studied. The composition of the extracted compound in solution was determined using the slope method. The extracted solid termary complex was characterized by means of elemental analysis,IR and 1H NMR preliminarily.
The synergistic extraction of uranitim(Ⅵ) by a ternary system composed of 4,4'-decanedioyl-bis-(1-phenyl-3-methyl-5-pyrazolone), trioctylphosphine oxide (TOPO) and pyridine was studied. The composition of the extracted compound in solution was determined using the slope method. The extracted solid termary complex was characterized by means of elemental analysis,IR and 1H NMR preliminarily.
1995, 12(5): 62-66
Abstract:
In the present paper the adsorption of anionic dve carmine(CM) on the activated carbon under various pH has been studied, and revealed that the zeta potential of the activat-ed carbon has a large effect on the adsorption capacity of CM. The results show that the zeta potential of the carbon surface is positive when the pH of the suspension is lower than pHzpc. Therefore, with decreasing zeta potential the electrostatic attraction between anionic dye and the carbon surface greatly reduces the adsorption capacity. On the other hand the color change of CM from orange to rose in the pH range 3.5~6.8 results to the solubility increase of CM with increasing pH. Therefore,the adsorption capacity is gradually reduced and down to vanish. The adsorption kinetics and thermodynamic parameters as a function of pH have been evaluated. The mechanism for adsorption of anionic dve CM on the activated carbon has also been studied.
In the present paper the adsorption of anionic dve carmine(CM) on the activated carbon under various pH has been studied, and revealed that the zeta potential of the activat-ed carbon has a large effect on the adsorption capacity of CM. The results show that the zeta potential of the carbon surface is positive when the pH of the suspension is lower than pHzpc. Therefore, with decreasing zeta potential the electrostatic attraction between anionic dye and the carbon surface greatly reduces the adsorption capacity. On the other hand the color change of CM from orange to rose in the pH range 3.5~6.8 results to the solubility increase of CM with increasing pH. Therefore,the adsorption capacity is gradually reduced and down to vanish. The adsorption kinetics and thermodynamic parameters as a function of pH have been evaluated. The mechanism for adsorption of anionic dve CM on the activated carbon has also been studied.
1995, 12(5): 67-72
Abstract:
This paper concerns with lowering the internal stress of epoxy molding com-pounds by incorporation of epoxy-terminated polydimethylsiloxanes. When the modifier was blended with epoxy resin and novolac resin curing agent directly,surface bleeding of the polysiloxane occurred. When the polysiloxane was first prereacted with the novolac resin to form a block copolymer and then blended with the epoxy resin,the polysiloxane bleeding was prevented,the polysiloxane phase was smaller in size and the domain distribution in the resin matrix was more even. The main factors influencing the internal stress were investigat-ed. It was found that the domain size of the polysiloxane phase depended on the synthetic conditions of the copolymers,the length of polysiloxane chain and the content of polysilox-ane in the cured resin. The flexural modulus of the epoxy molding compounds depended mainly on the interface area between the polysiloxane phase and the resin matrix, while the thermal expansion coefficient below Tg was dependent not only on the interface area between the two phases,but also on the interaction between the resin/filler matrix and polysiloxane phase to a great extent.
This paper concerns with lowering the internal stress of epoxy molding com-pounds by incorporation of epoxy-terminated polydimethylsiloxanes. When the modifier was blended with epoxy resin and novolac resin curing agent directly,surface bleeding of the polysiloxane occurred. When the polysiloxane was first prereacted with the novolac resin to form a block copolymer and then blended with the epoxy resin,the polysiloxane bleeding was prevented,the polysiloxane phase was smaller in size and the domain distribution in the resin matrix was more even. The main factors influencing the internal stress were investigat-ed. It was found that the domain size of the polysiloxane phase depended on the synthetic conditions of the copolymers,the length of polysiloxane chain and the content of polysilox-ane in the cured resin. The flexural modulus of the epoxy molding compounds depended mainly on the interface area between the polysiloxane phase and the resin matrix, while the thermal expansion coefficient below Tg was dependent not only on the interface area between the two phases,but also on the interaction between the resin/filler matrix and polysiloxane phase to a great extent.
1995, 12(5): 73-75
Abstract:
With bis(trichloromethyl)carbonate as the substitute of phosgene, benzophenones have been prepared from benzene,chlorobenzene,toluene and N,N-dimethyl aniline. The relation between the activities of catalysts and reactants has been studied. The preparation is safe and convenient and gives good yields.
With bis(trichloromethyl)carbonate as the substitute of phosgene, benzophenones have been prepared from benzene,chlorobenzene,toluene and N,N-dimethyl aniline. The relation between the activities of catalysts and reactants has been studied. The preparation is safe and convenient and gives good yields.
1995, 12(5): 76-78
Abstract:
Organoantimony compounds of the formula ph3SbX2,where X=Cl,Br and pen-tachlorophenoxy,have been prepared from the reaction of triphenylantimony with CuCl2,bromine and pentachlorophenol respectively. The compounds were characterized by elemen-tal analysis,melting point determination, infrared spectra and thermal behavior. The ther-mal decomposition mechanism was studied in air by differential scanning calorimetry. The flame retardancy of the compounds in polyvinyl chloride(PVC) was determined,which indi-cated that these compounds had high flame resisting activities for PVC at low additive levels.
Organoantimony compounds of the formula ph3SbX2,where X=Cl,Br and pen-tachlorophenoxy,have been prepared from the reaction of triphenylantimony with CuCl2,bromine and pentachlorophenol respectively. The compounds were characterized by elemen-tal analysis,melting point determination, infrared spectra and thermal behavior. The ther-mal decomposition mechanism was studied in air by differential scanning calorimetry. The flame retardancy of the compounds in polyvinyl chloride(PVC) was determined,which indi-cated that these compounds had high flame resisting activities for PVC at low additive levels.
1995, 12(5): 79-81
Abstract:
The complex sequential oscillation phenomenon in a mixed sugar-KBrO3-H2SO4-MnSO4-acetone-KBr system has been investigated. The kinetic behavior,oscillating orbit and suitability of FKN mechanism have also been studied.
The complex sequential oscillation phenomenon in a mixed sugar-KBrO3-H2SO4-MnSO4-acetone-KBr system has been investigated. The kinetic behavior,oscillating orbit and suitability of FKN mechanism have also been studied.
1995, 12(5): 82-84
Abstract:
The swelling of castor oil polyurethane/polymethyl methacrylate crosslinked copolymers in a number of solvents has been studied. It is found that the swelling behavior is in relation with the presence of the continuous phase in the crosslinked copolymers and the binary diffusion coefficients are able to reflect the phase inversion of the copolymers.
The swelling of castor oil polyurethane/polymethyl methacrylate crosslinked copolymers in a number of solvents has been studied. It is found that the swelling behavior is in relation with the presence of the continuous phase in the crosslinked copolymers and the binary diffusion coefficients are able to reflect the phase inversion of the copolymers.
1995, 12(5): 85-87
Abstract:
The temperature dependence of resistance to crack extension and tearing modulus of phenolphthalein polyether ketone(PEK-C) has been investigated. The relationship be-tween tearing instability of PEK-C and temperature has been discussed.
The temperature dependence of resistance to crack extension and tearing modulus of phenolphthalein polyether ketone(PEK-C) has been investigated. The relationship be-tween tearing instability of PEK-C and temperature has been discussed.
1995, 12(5): 88-90
Abstract:
We have synthesized four resins of polyvinyl chloride supported schiff-base, mea-sured their adsorbabilities for Cu2+, Hg2+, Ag+, Co2+, Ni2+ ions, and found that these resins have good adsorbabilities for Hg2+.
We have synthesized four resins of polyvinyl chloride supported schiff-base, mea-sured their adsorbabilities for Cu2+, Hg2+, Ag+, Co2+, Ni2+ ions, and found that these resins have good adsorbabilities for Hg2+.
1995, 12(5): 91-93
Abstract:
The dynamic mechanical behavior of poly(ether ether ketone) (PEEK) mixed with carbon fibre(CF) has been investigated from room temperature to 250℃. Two internal friction peaks (α peak and α' peak) have been found in this temperature range. The experi-ments show that α peak relates to a relaxation course in which glasslike state transforms to rubberlike state and peak α' relates to a pre-melting course. PEEK specimens containing dif-ferent CF content show different behavior for both α and α'peaks. DSC tests give out the same results as the dvnamic mechanical measurements.
The dynamic mechanical behavior of poly(ether ether ketone) (PEEK) mixed with carbon fibre(CF) has been investigated from room temperature to 250℃. Two internal friction peaks (α peak and α' peak) have been found in this temperature range. The experi-ments show that α peak relates to a relaxation course in which glasslike state transforms to rubberlike state and peak α' relates to a pre-melting course. PEEK specimens containing dif-ferent CF content show different behavior for both α and α'peaks. DSC tests give out the same results as the dvnamic mechanical measurements.
1995, 12(5): 94-96
Abstract:
The title complex was used as catalyst for the polymerization of methyl methacry-late. The results indicated that the catalytic activity markedly depends on the amount of the catalyst,temperature of polymerization,the monomer concentration and nature of the monomer. The tacticity of PMMA is syndiotactic in majority.
The title complex was used as catalyst for the polymerization of methyl methacry-late. The results indicated that the catalytic activity markedly depends on the amount of the catalyst,temperature of polymerization,the monomer concentration and nature of the monomer. The tacticity of PMMA is syndiotactic in majority.
1995, 12(5): 97-99
Abstract:
In this paper, we have investigated Sm3+→Sm2+ valence transform in process of preparing KMgF3: Sm by high temperature decomposition of SmF3. We have also investi-gated the effect of host structure on the stability of Sm2+ in some complex fluorides and alka-line earth metal fluorohalogenides.
In this paper, we have investigated Sm3+→Sm2+ valence transform in process of preparing KMgF3: Sm by high temperature decomposition of SmF3. We have also investi-gated the effect of host structure on the stability of Sm2+ in some complex fluorides and alka-line earth metal fluorohalogenides.
1995, 12(5): 100-102
Abstract:
Biological potential of tooth surface and dental pulp has been measured and stud-ied by electrochemical method. For the first time potential difference between these two parts of tooth has been obtained experimentally,the statistical average being 11.1mV. An experimental method of simulating biological potential of living tooth has been established for leaving body tooth. Ion transferred to tooth hard organism was studied by simulating the biological potential of tooth. Change of biological potential of tooth in the real environment of oral cavity has been discussed. Also the feasibility of two commonly used compounds of SrCl2 and NaF for dental disease was discussed from the viewpoint of the effect of bioelectric field. Scientific basis for the oral local administration has been provided.
Biological potential of tooth surface and dental pulp has been measured and stud-ied by electrochemical method. For the first time potential difference between these two parts of tooth has been obtained experimentally,the statistical average being 11.1mV. An experimental method of simulating biological potential of living tooth has been established for leaving body tooth. Ion transferred to tooth hard organism was studied by simulating the biological potential of tooth. Change of biological potential of tooth in the real environment of oral cavity has been discussed. Also the feasibility of two commonly used compounds of SrCl2 and NaF for dental disease was discussed from the viewpoint of the effect of bioelectric field. Scientific basis for the oral local administration has been provided.
1995, 12(5): 103-104
Abstract:
A Cheap and fast synthetic method for tetraethylmethylenediphosphonate has been proposed. In nonpolar solvent, soft needle-like crystals of sodium diethylphosphonate is prepared. By adding dichloromethane to the salt,methylenediphosphonate is produced af-ter stirring for two days at room temperature.
A Cheap and fast synthetic method for tetraethylmethylenediphosphonate has been proposed. In nonpolar solvent, soft needle-like crystals of sodium diethylphosphonate is prepared. By adding dichloromethane to the salt,methylenediphosphonate is produced af-ter stirring for two days at room temperature.
1995, 12(5): 105-106
Abstract:
The methyl-,ethyl-,n-propyl-,i-propyl and n-butyl esters of R-thiazolidine-2-thione-4-carboxyic acid were prepared in 72%~98.6% yields by reaction of R-thiazolidine-2-thione-4-carboxylic acid with corresponding alcohols in the presence of SOCl2.
The methyl-,ethyl-,n-propyl-,i-propyl and n-butyl esters of R-thiazolidine-2-thione-4-carboxyic acid were prepared in 72%~98.6% yields by reaction of R-thiazolidine-2-thione-4-carboxylic acid with corresponding alcohols in the presence of SOCl2.
1995, 12(5): 107-108
Abstract:
The ring-opening polymerization of cyclopentene,cyclohexene,α-pinene and ter-pene catalyzed by Mo(CO)6 with CHnX4-n(n=0,1;X=Cl,Br) under UV irradiation has been studied. It was found that addition of small amount of anhydrous AlCl3 promoted the polymerization. The optimum conditions of polymerization were reported.
The ring-opening polymerization of cyclopentene,cyclohexene,α-pinene and ter-pene catalyzed by Mo(CO)6 with CHnX4-n(n=0,1;X=Cl,Br) under UV irradiation has been studied. It was found that addition of small amount of anhydrous AlCl3 promoted the polymerization. The optimum conditions of polymerization were reported.
1995, 12(5): 109-110
Abstract:
Some α-acetylthioformanilides have been svnthesized under ultrasonic irradiation, and the compounds have been confirmed by elemental analysis,IR and MS. The method is superior in reaction velocity and yield.
Some α-acetylthioformanilides have been svnthesized under ultrasonic irradiation, and the compounds have been confirmed by elemental analysis,IR and MS. The method is superior in reaction velocity and yield.
1995, 12(5): 111-112
Abstract:
Two N-alkyl pyrrolidone,N-octyl pyrrolidone and N-lauryl pyrrolidone,were prepared by means of solid-liquid phase transfer catalysis in 83.8% and 87.2% yield respec-tively. The new art in which tetra-butyl-ammonium bromide is used as phase-transfer cata-lyst and KOH-K2CO3 as mixed base,is characteristic of short reaction time,mild reaction conditions and easy operation.
Two N-alkyl pyrrolidone,N-octyl pyrrolidone and N-lauryl pyrrolidone,were prepared by means of solid-liquid phase transfer catalysis in 83.8% and 87.2% yield respec-tively. The new art in which tetra-butyl-ammonium bromide is used as phase-transfer cata-lyst and KOH-K2CO3 as mixed base,is characteristic of short reaction time,mild reaction conditions and easy operation.
Graft Copolymerization of Glycidyl Methacrylate onto Ethylene-Propylene Copolymer via Melt Extruding
1995, 12(5): 113-114
Abstract:
Grafting of glycidyl methacrylate (GMA) onto ethylene-propylene copolymer (EPM) has been carried out successfully by means of melt reaction extruding in the presence of dicumyl peroxide as initiator. The grafted EPMl-g-GMA samples were characterized by FTIR and ESCA. Grafting of GMA changed the crystallization temperature,melting tem-perature,and crystal form of EPM.
Grafting of glycidyl methacrylate (GMA) onto ethylene-propylene copolymer (EPM) has been carried out successfully by means of melt reaction extruding in the presence of dicumyl peroxide as initiator. The grafted EPMl-g-GMA samples were characterized by FTIR and ESCA. Grafting of GMA changed the crystallization temperature,melting tem-perature,and crystal form of EPM.
1995, 12(5): 115-116
Abstract:
Ni-La alloy coating containing 22.58 wt% rare earth La was prepared by elec-trodeposition technique from aqueous solution. The results of XRD tests and calculation based on the XRD spectra show that the Ni-La alloy coating obtained is a displacement solid solution. Activation energy of cathodic hydrogen evolution reaction in alkaline solution and real surface area of the Ni-La alloy and Ni electrodes were determined through electrochemi-cal tests. It is found from the results that the real surface area of the Ni-La allov electrode is substantially larger than that of Ni electrode. Activation energy of cathodic hydrogen evolu-tion reaction in 25wt% NaOH solution of the Ni-La alloy electrode is enormously lower than that of Ni electrode. It can be concluded that the coating of electrodeposited rare earth alloy Ni-La possesses excellent electrocatalytic activity for hydrogen evolution reaction.
Ni-La alloy coating containing 22.58 wt% rare earth La was prepared by elec-trodeposition technique from aqueous solution. The results of XRD tests and calculation based on the XRD spectra show that the Ni-La alloy coating obtained is a displacement solid solution. Activation energy of cathodic hydrogen evolution reaction in alkaline solution and real surface area of the Ni-La alloy and Ni electrodes were determined through electrochemi-cal tests. It is found from the results that the real surface area of the Ni-La allov electrode is substantially larger than that of Ni electrode. Activation energy of cathodic hydrogen evolu-tion reaction in 25wt% NaOH solution of the Ni-La alloy electrode is enormously lower than that of Ni electrode. It can be concluded that the coating of electrodeposited rare earth alloy Ni-La possesses excellent electrocatalytic activity for hydrogen evolution reaction.
1995, 12(5): 117-118
Abstract:
New solid compound of TiOHC5H6O4·H2O was synthesized by the reaction of ti-tanium trichloride with glutaric acid. The molecular structure was characterized by elemental analysis,magnetic susceptibility,IR and TG methods. TiN was prepared by decomposition of the complex in NH3 at 700℃.
New solid compound of TiOHC5H6O4·H2O was synthesized by the reaction of ti-tanium trichloride with glutaric acid. The molecular structure was characterized by elemental analysis,magnetic susceptibility,IR and TG methods. TiN was prepared by decomposition of the complex in NH3 at 700℃.
