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1999 Volume 16 Issue 2
1999, 16(2): 5-8
Abstract:
Irradiation of ethylacrylate (EA) in air by 60Co at dose rate>1.5 Gy/s gave three peroxide compenents in different contents depending on the dose rate used. At 1.0 Gy/s the second component was formed uniquely. The structures of the peroxides have been determined by IR, NMR and MS measurements. The results showed that the second component had alternative peroxide structure and greater initiation activity than others. It could initiate polymerization of some vinyl monomers, requiring lower initiation temperature and shorter initiation time than K2S2O8, and the polymerization carried out more smooth with high molecular weight polymer product.
Irradiation of ethylacrylate (EA) in air by 60Co at dose rate>1.5 Gy/s gave three peroxide compenents in different contents depending on the dose rate used. At 1.0 Gy/s the second component was formed uniquely. The structures of the peroxides have been determined by IR, NMR and MS measurements. The results showed that the second component had alternative peroxide structure and greater initiation activity than others. It could initiate polymerization of some vinyl monomers, requiring lower initiation temperature and shorter initiation time than K2S2O8, and the polymerization carried out more smooth with high molecular weight polymer product.
1999, 16(2): 9-12
Abstract:
The compatibility, specific interaction and ringed spherulite morphology of PCL/EC blends have been studied by DSC, FTIR and optical microscopy. It is shown that the blend is characteristic of low compatibility and weak specific interaction. Distinct ringed spherulites in such a system suggest that high compatibility and strong interaction between components may not be an essential factor for their formation. Addition of PCL into the ethyl cellulose/dichloroacetic acid solution was favorable for the formation of cholesteric liquid crystalline mesophases. The results are explained in terms of Flory's theory about staff-like molecule-random chain molecule-solvent ternary system.
The compatibility, specific interaction and ringed spherulite morphology of PCL/EC blends have been studied by DSC, FTIR and optical microscopy. It is shown that the blend is characteristic of low compatibility and weak specific interaction. Distinct ringed spherulites in such a system suggest that high compatibility and strong interaction between components may not be an essential factor for their formation. Addition of PCL into the ethyl cellulose/dichloroacetic acid solution was favorable for the formation of cholesteric liquid crystalline mesophases. The results are explained in terms of Flory's theory about staff-like molecule-random chain molecule-solvent ternary system.
1999, 16(2): 13-17
Abstract:
Fourteen 1-(Z-[2-(triarylstannyl) vinyl] cyclopentanols were prepared by the reaction of triaryltin hydrids with 1-ethynylcyclopentanol. The reaction of compounds 1 and 2 with ICI, Br2, and I2 gave six organotin halides, respectively. The compounds were characterized by elemental analysis, IR, 1H NMR and some of them showed antitumor and immune activities.
Fourteen 1-(Z-[2-(triarylstannyl) vinyl] cyclopentanols were prepared by the reaction of triaryltin hydrids with 1-ethynylcyclopentanol. The reaction of compounds 1 and 2 with ICI, Br2, and I2 gave six organotin halides, respectively. The compounds were characterized by elemental analysis, IR, 1H NMR and some of them showed antitumor and immune activities.
1999, 16(2): 18-21
Abstract:
Polystyrene-g-polymethylmethacrylate(PSt-g-PMMA) with controlled molecular weight and lower polydispersity was obtained through anionic polymerization, group transfer polymerization(GTP) and polymer reaction. First, polystyrene with narrow Mn distribution prepared by anionic polymerization was chloromethylated by methylal and sulfurylchloride to form chloromethylated poly-styrene (CMPS), which was then dissolved in THF for purification by addition of naphthalene sodium and reacted with living PMMA prepared by GTP. Results showed that the grafting rate increased with increase of the chlorinity of CMPS and decreased with increase of the molecular weight of CMPS. The graft copolymer(PSt-g-PMMA) was characterized and investigated by GPC, 1H NMR, FTIR and SEM.
Polystyrene-g-polymethylmethacrylate(PSt-g-PMMA) with controlled molecular weight and lower polydispersity was obtained through anionic polymerization, group transfer polymerization(GTP) and polymer reaction. First, polystyrene with narrow Mn distribution prepared by anionic polymerization was chloromethylated by methylal and sulfurylchloride to form chloromethylated poly-styrene (CMPS), which was then dissolved in THF for purification by addition of naphthalene sodium and reacted with living PMMA prepared by GTP. Results showed that the grafting rate increased with increase of the chlorinity of CMPS and decreased with increase of the molecular weight of CMPS. The graft copolymer(PSt-g-PMMA) was characterized and investigated by GPC, 1H NMR, FTIR and SEM.
1999, 16(2): 22-26
Abstract:
Fourteen complexes of rare earth with 3-pyridine carboxylic acid(HL) and 1,10-phenanthroline (Phen) have been synthesized. The complexes have the constitution of REL3·Phen (RE=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y) as characterized by elemental analysis, molar conductance measurement, IR, UV, 1H NMR, X-ray powder analysis, TG and DTA techniques. The fluorescence intensities of EuL3·Phen and TbL3·Phen were found to be enhanced by introduction of the neutral ligand Phen.
Fourteen complexes of rare earth with 3-pyridine carboxylic acid(HL) and 1,10-phenanthroline (Phen) have been synthesized. The complexes have the constitution of REL3·Phen (RE=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y) as characterized by elemental analysis, molar conductance measurement, IR, UV, 1H NMR, X-ray powder analysis, TG and DTA techniques. The fluorescence intensities of EuL3·Phen and TbL3·Phen were found to be enhanced by introduction of the neutral ligand Phen.
1999, 16(2): 27-30
Abstract:
A series of O-(4-quinazolinyl)hydroximic thioesters(amides) were synthesized by a phase transfer catalysis method. The compounds were found to have good stabilities and antiphy-toviral activities. Some compounds had higher activities against tobacco mosaic virus than 2,4-dioxohexahydro-1,3,5-triazine.
A series of O-(4-quinazolinyl)hydroximic thioesters(amides) were synthesized by a phase transfer catalysis method. The compounds were found to have good stabilities and antiphy-toviral activities. Some compounds had higher activities against tobacco mosaic virus than 2,4-dioxohexahydro-1,3,5-triazine.
1999, 16(2): 31-34
Abstract:
The non-isothermal crystallization and its kinetics of syndiotactic polystyrene (sPS) have been studied by DSC technique. The methods of Ozawa and Jeziorny for non-isothermal crystallization are applied to analyse the DSC data. It is found that the half-time of sPS crystallization decreases as an exponential function of the cooling rate ranged from 2.5 to 40℃/min. The non-isothermal crystallization of sPS follows the Ozawa equation, but fails to agree with the Avrami equation in the Jeziorny method. The values of the Avrami exponent determined by the Ozawa equation are between 3.6~4.1, higher than those reported values obtained by means of isothermal methods.
The non-isothermal crystallization and its kinetics of syndiotactic polystyrene (sPS) have been studied by DSC technique. The methods of Ozawa and Jeziorny for non-isothermal crystallization are applied to analyse the DSC data. It is found that the half-time of sPS crystallization decreases as an exponential function of the cooling rate ranged from 2.5 to 40℃/min. The non-isothermal crystallization of sPS follows the Ozawa equation, but fails to agree with the Avrami equation in the Jeziorny method. The values of the Avrami exponent determined by the Ozawa equation are between 3.6~4.1, higher than those reported values obtained by means of isothermal methods.
1999, 16(2): 35-38
Abstract:
The Sj-SEA has been immobilized onto the title copolymer latex particles by physical adsorption and covalent coupling. The effects of the latex particles on the activity and amount of the immobilized Sj-SEA have been investigated. The results show that the more hydrophobic the latex particle, or the higher the latex's surface tension, the larger the amount of Sj-SEA adsorbed, but its activity does not necessarily high. The higher the density of the carboxyl groups on the surface of the latex, the larger the amount of coupled Sj-SEA; the activity increases with increase of the density of coupled Sj-SEA, when it immobilized not too much.
The Sj-SEA has been immobilized onto the title copolymer latex particles by physical adsorption and covalent coupling. The effects of the latex particles on the activity and amount of the immobilized Sj-SEA have been investigated. The results show that the more hydrophobic the latex particle, or the higher the latex's surface tension, the larger the amount of Sj-SEA adsorbed, but its activity does not necessarily high. The higher the density of the carboxyl groups on the surface of the latex, the larger the amount of coupled Sj-SEA; the activity increases with increase of the density of coupled Sj-SEA, when it immobilized not too much.
1999, 16(2): 39-41
Abstract:
A novel adsorbent for the adsorption of triglyceride (TG) was prepared by immobilizing sulfanilic acid onto the cross-linked polyvinyl alcohol based bead. The adsorption results indicated that this type of adsorbent could cut down the concentration of TG in vitro effectively, but has little effect on total protein. It's adsorption efficiency increases with increase of amount of sulfanilic acid immobilized, and decreases with increase of the cross-linking degree of polyvinyl alcohol. Serum taken from different patients also influenced the adsorption efficiency.
A novel adsorbent for the adsorption of triglyceride (TG) was prepared by immobilizing sulfanilic acid onto the cross-linked polyvinyl alcohol based bead. The adsorption results indicated that this type of adsorbent could cut down the concentration of TG in vitro effectively, but has little effect on total protein. It's adsorption efficiency increases with increase of amount of sulfanilic acid immobilized, and decreases with increase of the cross-linking degree of polyvinyl alcohol. Serum taken from different patients also influenced the adsorption efficiency.
1999, 16(2): 42-45
Abstract:
Nanocrystalline Ni-Mo alloy deposit was obtained on red copper from a mixture solution containing NiSO4, Na2MoO4, K4P2O7, (NH4)2HPO4 and sodium benzene sulfinate at pH=8.5 and 25℃ with current density of 6 A/cm2. XRD results indicated that the alloy had size of 1.7 nm and its crystal lattice appeared a greater distortion. XPS results revealed that the binding energy of Mo 3d in alloy deposit increased 09 eV and that of Ni 2p1/2 increased 1.0 eV. The nanocrystalline Ni-Mo alloy electrode offered better electrocatalytic performance than polycrystalline Ni electrode. The overpotential of hydrogen evolution reaction on the nanocrystalline Ni-Mo alloy electrode in 30% KOH was 255 mV lower than that on the polycrystalline Ni electrode. The exchange current density of hydrogen evolution reaction on the nanocrystalline electrode was 6.9 times as great as that on the polycrystalline Ni electrode. The hydrogen evolution reaction is found to be followed by Volmer-Heyrovsky's mechanism.
Nanocrystalline Ni-Mo alloy deposit was obtained on red copper from a mixture solution containing NiSO4, Na2MoO4, K4P2O7, (NH4)2HPO4 and sodium benzene sulfinate at pH=8.5 and 25℃ with current density of 6 A/cm2. XRD results indicated that the alloy had size of 1.7 nm and its crystal lattice appeared a greater distortion. XPS results revealed that the binding energy of Mo 3d in alloy deposit increased 09 eV and that of Ni 2p1/2 increased 1.0 eV. The nanocrystalline Ni-Mo alloy electrode offered better electrocatalytic performance than polycrystalline Ni electrode. The overpotential of hydrogen evolution reaction on the nanocrystalline Ni-Mo alloy electrode in 30% KOH was 255 mV lower than that on the polycrystalline Ni electrode. The exchange current density of hydrogen evolution reaction on the nanocrystalline electrode was 6.9 times as great as that on the polycrystalline Ni electrode. The hydrogen evolution reaction is found to be followed by Volmer-Heyrovsky's mechanism.
1999, 16(2): 46-50
Abstract:
The monolayer dispersion of Cr2O3, MoO3, SO42- and CuSO4 on the surface of SnO2 and their effects on the thermal stability of SnO2 ultrafine powder have been studied. The results show that all of these compounds can disperse onto the surface of SnO2 in a monolayer form, and their dispersion thresholds close with their ultimate dispersion capacities estimated according to a close-packed monolayer model. The monolayer coverage on the surface of SnO2 can effectively suppress the sintering of SnO2 grains at high temperature. The radius and specific surface area of SnO2 grain in the samples sintered at 500℃ depend on the surface coverage of these compounds on SnO2, which displays an obvious "threshold effect". The sintering of SnO2 grains can be retarded when the monolayer coverage of the compounds is high enough.
The monolayer dispersion of Cr2O3, MoO3, SO42- and CuSO4 on the surface of SnO2 and their effects on the thermal stability of SnO2 ultrafine powder have been studied. The results show that all of these compounds can disperse onto the surface of SnO2 in a monolayer form, and their dispersion thresholds close with their ultimate dispersion capacities estimated according to a close-packed monolayer model. The monolayer coverage on the surface of SnO2 can effectively suppress the sintering of SnO2 grains at high temperature. The radius and specific surface area of SnO2 grain in the samples sintered at 500℃ depend on the surface coverage of these compounds on SnO2, which displays an obvious "threshold effect". The sintering of SnO2 grains can be retarded when the monolayer coverage of the compounds is high enough.
1999, 16(2): 51-55
Abstract:
Uniform copolymer latex of styrene/butylacrylate/acrylic acid with 70.69 nm number-average diameter was obtained by semicontinuous emulsion polymerization process. The ordered two-dimensional arrays had been fabricated by the liquid capillary meniscus attraction force method. The formation process appeared to be in nucleation and growth stages. The interaction forces among particles could be controlled by adding a certain amount of NaCl electrolyte. The morphologies of the two-dimensional arrays were observed by TEM images.
Uniform copolymer latex of styrene/butylacrylate/acrylic acid with 70.69 nm number-average diameter was obtained by semicontinuous emulsion polymerization process. The ordered two-dimensional arrays had been fabricated by the liquid capillary meniscus attraction force method. The formation process appeared to be in nucleation and growth stages. The interaction forces among particles could be controlled by adding a certain amount of NaCl electrolyte. The morphologies of the two-dimensional arrays were observed by TEM images.
1999, 16(2): 56-59
Abstract:
The gas-sensing semiconductor Cd2V2O7 was prepared by a solid state reaction. The effects of the preparation conditions on the phases of the products have been investigated and discussed in relation to the reaction mechanism. The conductance measurement manifests that the material exhibits a typical surface resistance controlling behavior. The dependence of the gas sensing property on the preparation conditions also have been studied. Results indicated pretty good sensitivity, selectivity, stability and quick response-recovery of the compound to ethanol gas.
The gas-sensing semiconductor Cd2V2O7 was prepared by a solid state reaction. The effects of the preparation conditions on the phases of the products have been investigated and discussed in relation to the reaction mechanism. The conductance measurement manifests that the material exhibits a typical surface resistance controlling behavior. The dependence of the gas sensing property on the preparation conditions also have been studied. Results indicated pretty good sensitivity, selectivity, stability and quick response-recovery of the compound to ethanol gas.
1999, 16(2): 60-63
Abstract:
Ultrafine γ-Mn2O3 powder was prepared by an oxidation method under hydrothermal conditions. After sintering at 100~550℃ in air the products exhibit good stability and have been characterized by XRD, TEM, XPS, IR and UV spectra measurements to be fine crystals of single phase, majority in ball form. Their average sizes increase with increase of the sintering temperatures. The manganese in γ-Mn2O3 is in Mn(Ⅲ) form.
Ultrafine γ-Mn2O3 powder was prepared by an oxidation method under hydrothermal conditions. After sintering at 100~550℃ in air the products exhibit good stability and have been characterized by XRD, TEM, XPS, IR and UV spectra measurements to be fine crystals of single phase, majority in ball form. Their average sizes increase with increase of the sintering temperatures. The manganese in γ-Mn2O3 is in Mn(Ⅲ) form.
1999, 16(2): 64-68
Abstract:
The electrocatalytic oxidation of formic acid on poly(2,5-dimethoxyaniline) (PDMA) film modified with Pt microparticles has been studied by cyclic voltammetry. The morphology and structure of the electrode were examined by SEM and XPS. The Pt microparticles with av. size of 300 nm produced by cyclic voltammetry were highly dispersed in and on the PDMA. The modified electrode exhibits a very high electrocatalytic activity for the oxidation of formic acid in 0.5 mol/L HClO4 and the catalytic activity was found in dependence on the Pt loading, kind of anions, reaction temperature and concentration of the formic acid.
The electrocatalytic oxidation of formic acid on poly(2,5-dimethoxyaniline) (PDMA) film modified with Pt microparticles has been studied by cyclic voltammetry. The morphology and structure of the electrode were examined by SEM and XPS. The Pt microparticles with av. size of 300 nm produced by cyclic voltammetry were highly dispersed in and on the PDMA. The modified electrode exhibits a very high electrocatalytic activity for the oxidation of formic acid in 0.5 mol/L HClO4 and the catalytic activity was found in dependence on the Pt loading, kind of anions, reaction temperature and concentration of the formic acid.
1999, 16(2): 69-72
Abstract:
The separation factor (αwater/ethanol) of chitosan(CS) membrane was increased from 10.2 to 499 by addition of sulfuric acid to the water/ethanol mixture. The mechanism of the improvement has been investigated. It appeared that protonization of NH2 groups in CS decreases the ability of the more or less neutral ethanol molecules to pass through the CS membrane, increasing its adsorption selectivity to water molecules. In addition, partially crosslinking between CS chains may occur as a result of the reaction of SO42- with -NH3+, that greatly increases the water permeability of the CS membrane.
The separation factor (αwater/ethanol) of chitosan(CS) membrane was increased from 10.2 to 499 by addition of sulfuric acid to the water/ethanol mixture. The mechanism of the improvement has been investigated. It appeared that protonization of NH2 groups in CS decreases the ability of the more or less neutral ethanol molecules to pass through the CS membrane, increasing its adsorption selectivity to water molecules. In addition, partially crosslinking between CS chains may occur as a result of the reaction of SO42- with -NH3+, that greatly increases the water permeability of the CS membrane.
1999, 16(2): 73-75
Abstract:
A series of SnO2 and SnO2-Ta2O5 electrodes coated with IrO2 have been prepared and their microstructures, electrocatalytic activities and anodic stabilities have been investigated. It is found that the oxidation temperature in the course of catalyst preparation has a great influence on the miscibility of SnO2 and IrO2. The method requires lower temperature and the partly substitution of Ta2O5 with SnO2 reduces the cost of the electrodes.
A series of SnO2 and SnO2-Ta2O5 electrodes coated with IrO2 have been prepared and their microstructures, electrocatalytic activities and anodic stabilities have been investigated. It is found that the oxidation temperature in the course of catalyst preparation has a great influence on the miscibility of SnO2 and IrO2. The method requires lower temperature and the partly substitution of Ta2O5 with SnO2 reduces the cost of the electrodes.
1999, 16(2): 76-78
Abstract:
(3R,4R)-4-Methyl-3-heptanol, the enatiomer of aggregation pheromone of the smaller European elm bark beetle (Scolytus Multistrialus), was stereoselectively synthesized using N-bornane-2,10-sultam as a chiral auxiliary. The two asymmetric carbon atoms of the target product were achieved by employing asymmetric syn-aldolization of N-propionylbornane-2,10-sultam (3) with propylaldehyde. The enantiomeric excess of (3R,4R)-4-methyl-3-heptanol prepared by this route is about 94.3%.
(3R,4R)-4-Methyl-3-heptanol, the enatiomer of aggregation pheromone of the smaller European elm bark beetle (Scolytus Multistrialus), was stereoselectively synthesized using N-bornane-2,10-sultam as a chiral auxiliary. The two asymmetric carbon atoms of the target product were achieved by employing asymmetric syn-aldolization of N-propionylbornane-2,10-sultam (3) with propylaldehyde. The enantiomeric excess of (3R,4R)-4-methyl-3-heptanol prepared by this route is about 94.3%.
1999, 16(2): 79-81
Abstract:
Four Schiff base complexes: NaCuL·1/2H2O, NaZnL·3H2O, Na2CoL(Ac)·2H2O, Na2NiLCl·3H2O(H3L=L-aspartic acid-o-vanillylidene Schiff base) have been synthesized and characterized by elemental analysis, molar conductance, thermal analysis, electronic spectrum and infrared spectrum measurements. The possible structures of the complexes have been discussed.
Four Schiff base complexes: NaCuL·1/2H2O, NaZnL·3H2O, Na2CoL(Ac)·2H2O, Na2NiLCl·3H2O(H3L=L-aspartic acid-o-vanillylidene Schiff base) have been synthesized and characterized by elemental analysis, molar conductance, thermal analysis, electronic spectrum and infrared spectrum measurements. The possible structures of the complexes have been discussed.
1999, 16(2): 82-84
Abstract:
Hybrid bilayer membranes supported on gold and consisting of octadecanethiol and phospho-lipid were fabricated through self-assembling method.Their electrical parameters are determined by electrochemical impedance spectroscopy and cyclic voltammetry.Their electrochemical behavior in Fe(CN)6-3/-4 revealed that they have good insulating properties to the redox species in solution.
Hybrid bilayer membranes supported on gold and consisting of octadecanethiol and phospho-lipid were fabricated through self-assembling method.Their electrical parameters are determined by electrochemical impedance spectroscopy and cyclic voltammetry.Their electrochemical behavior in Fe(CN)6-3/-4 revealed that they have good insulating properties to the redox species in solution.
1999, 16(2): 85-87
Abstract:
Selective reduction of the phenyl ring beared carboxyl group was realized successfully with sodium and amyl alcohol at 140~145℃.Through cis-trans isomerization trans-4-(4'-pentylphenyl) cyclohexyl carboxylic acid and trans-4'[2'-(4"-pentylphenyl) ethylene]cyclohexyl carboxylic acid were obtained in good yield and their structures were characterized by elemental analysis,IR,13C NMR and MS measurements.
Selective reduction of the phenyl ring beared carboxyl group was realized successfully with sodium and amyl alcohol at 140~145℃.Through cis-trans isomerization trans-4-(4'-pentylphenyl) cyclohexyl carboxylic acid and trans-4'[2'-(4"-pentylphenyl) ethylene]cyclohexyl carboxylic acid were obtained in good yield and their structures were characterized by elemental analysis,IR,13C NMR and MS measurements.
1999, 16(2): 88-90
Abstract:
The polyvinylidene fluoride membranes have been used to study the transfer and extraction performances of Er(Ⅲ) and Yb(Ⅲ) with the extraction system of HBTMPP-n-heptane. The results show that the membrane material offers a good transfer performance. The extraction reaction in the membrane module is the same as that in liquid-liquid process. Use of the ammoniated extractant offers the same increasing effect on the mass transfer coefficient as increase of the extractant concentration. The extraction reaction can be thought as first order reaction whether the extractant is ammoniated or not. The controlling mechanism of the membrane extraction process is a diffusion model accompanied by an interfacial reaction. When extraction and strip-extraction are carried out simuetaneously, the transfer coefficient of the membrane increases greatly.
The polyvinylidene fluoride membranes have been used to study the transfer and extraction performances of Er(Ⅲ) and Yb(Ⅲ) with the extraction system of HBTMPP-n-heptane. The results show that the membrane material offers a good transfer performance. The extraction reaction in the membrane module is the same as that in liquid-liquid process. Use of the ammoniated extractant offers the same increasing effect on the mass transfer coefficient as increase of the extractant concentration. The extraction reaction can be thought as first order reaction whether the extractant is ammoniated or not. The controlling mechanism of the membrane extraction process is a diffusion model accompanied by an interfacial reaction. When extraction and strip-extraction are carried out simuetaneously, the transfer coefficient of the membrane increases greatly.
1999, 16(2): 91-93
Abstract:
A novel reaction device is reported, in which photocatalytic and photochemical actions on aniline take place simutaneously. It is made up of supported TiO2 film electrode, Ru-Ti ele-ctrode and air electrode. The reaction substance of the air electrode is oxygen and the main product is H2O2. The results show that aniline is degraded in higher rate in the system than in single photocatalytic or photochemical system.
A novel reaction device is reported, in which photocatalytic and photochemical actions on aniline take place simutaneously. It is made up of supported TiO2 film electrode, Ru-Ti ele-ctrode and air electrode. The reaction substance of the air electrode is oxygen and the main product is H2O2. The results show that aniline is degraded in higher rate in the system than in single photocatalytic or photochemical system.
1999, 16(2): 94-96
Abstract:
A series of α-(2-benzothiazolyl)-aminoalkyl-phosphonic acid diphenyl esters were synthesized from 2-aminobenzothiazole with aldehyde and triphenyl phosphite.The experiments indicated that the reaction proceeded through the addition of imine with diphenyl phosphite.The bioassy results showed that the compounds have good anti-TMV (tobacco mosaic virus) activities.
A series of α-(2-benzothiazolyl)-aminoalkyl-phosphonic acid diphenyl esters were synthesized from 2-aminobenzothiazole with aldehyde and triphenyl phosphite.The experiments indicated that the reaction proceeded through the addition of imine with diphenyl phosphite.The bioassy results showed that the compounds have good anti-TMV (tobacco mosaic virus) activities.
1999, 16(2): 97-99
Abstract:
Copolymers of styrene(St) and butyl methacrylate(BMA) were prepared by atom transfer radical polymerization using a bifunctional initiator bis(chloroethyl)benzene. The molecular weights of the polymers were determined by gel permeation chromatography. The block copolymers of BMA and St with predicted molecular weight (1×104~7×104) and narrow molecular weight distribution (1.2~1.8) were obtained. The random copolymer compositions were determined by 1H NMR spectroscopy and the reactivity ratios were evaluated by the extended Kelen-Tudos method to be rSt=0.81, rBMA=0.16. St was found to be more reactive than BMA in atom transfer radical copolymerization.
Copolymers of styrene(St) and butyl methacrylate(BMA) were prepared by atom transfer radical polymerization using a bifunctional initiator bis(chloroethyl)benzene. The molecular weights of the polymers were determined by gel permeation chromatography. The block copolymers of BMA and St with predicted molecular weight (1×104~7×104) and narrow molecular weight distribution (1.2~1.8) were obtained. The random copolymer compositions were determined by 1H NMR spectroscopy and the reactivity ratios were evaluated by the extended Kelen-Tudos method to be rSt=0.81, rBMA=0.16. St was found to be more reactive than BMA in atom transfer radical copolymerization.
1999, 16(2): 100-102
Abstract:
Copper phthalocyanine (CuPc) was microencapsulated in polystyrene(PS) by a phase separation method. The results show that the flowability and dispersing extent of CuPc were greatly improved after microencapsulation and the molecular weight of PS showed an effect on the property of the final products.
Copper phthalocyanine (CuPc) was microencapsulated in polystyrene(PS) by a phase separation method. The results show that the flowability and dispersing extent of CuPc were greatly improved after microencapsulation and the molecular weight of PS showed an effect on the property of the final products.
1999, 16(2): 103-105
Abstract:
Cu/Al2O3 powder has been prepared by chemical deposition under ultrasonic irradiation. The effects of deposition parameters on the phase structure and morphology of the deposited Cu layer have been studied by XRD and metallographic analysis. Under suitable conditions, Cu/Al2O3 powder with uniform thickness and high Cu% can be obtained.
Cu/Al2O3 powder has been prepared by chemical deposition under ultrasonic irradiation. The effects of deposition parameters on the phase structure and morphology of the deposited Cu layer have been studied by XRD and metallographic analysis. Under suitable conditions, Cu/Al2O3 powder with uniform thickness and high Cu% can be obtained.
1999, 16(2): 106-108
Abstract:
The catalytic activities of lanthanocene amides in ring-opening polymerization of ε-caprolactone have been investigated. Both the central metals and the ligands in amides showed effects on the catalytic activity. For the central metal, the activity increased with increase of ionic radii of the metal elements; for the amido groups, NC5H10 showed greater effect than N(i-Pr)2; for substituted cyclopentadienyl ligands, effect of t-BuC5H4 was greater than that of MeC5H4. The mechanism of the ring-opening polymerization has been briefly discussed.
The catalytic activities of lanthanocene amides in ring-opening polymerization of ε-caprolactone have been investigated. Both the central metals and the ligands in amides showed effects on the catalytic activity. For the central metal, the activity increased with increase of ionic radii of the metal elements; for the amido groups, NC5H10 showed greater effect than N(i-Pr)2; for substituted cyclopentadienyl ligands, effect of t-BuC5H4 was greater than that of MeC5H4. The mechanism of the ring-opening polymerization has been briefly discussed.
1999, 16(2): 109-111
Abstract:
Four methyl-substituted poly (aryl ether ketone ketone) (MePEKK) were synthesized from methyl substituted diphenyl ether and terephthaloyl chloride. Their structures and properties have been studied by IR, DSC and WAXD measurements. The polymers obtained showed an excellent heat-resistance and good solvent-resistance.
Four methyl-substituted poly (aryl ether ketone ketone) (MePEKK) were synthesized from methyl substituted diphenyl ether and terephthaloyl chloride. Their structures and properties have been studied by IR, DSC and WAXD measurements. The polymers obtained showed an excellent heat-resistance and good solvent-resistance.
1999, 16(2): 112-114
Abstract:
α-Methylstyrene is reacted with phenol, in the presence of paratoluene sulfonic acid as a catalyst, to prepare paracumyl phenol. The effects of the reaction conditions, such as the molar ratio of phenol to α-Methylstyrene, feeding rate of the α-Methylstyrene, reaction temperature, and reaction time, are examined. Steam-distillation and re-crystallization are combined to achieve the optimum purification of the reaction product.
α-Methylstyrene is reacted with phenol, in the presence of paratoluene sulfonic acid as a catalyst, to prepare paracumyl phenol. The effects of the reaction conditions, such as the molar ratio of phenol to α-Methylstyrene, feeding rate of the α-Methylstyrene, reaction temperature, and reaction time, are examined. Steam-distillation and re-crystallization are combined to achieve the optimum purification of the reaction product.
1999, 16(2): 115-116
Abstract:
The thermal oxidative and thermal aging behaviour of epoxidized natural rubber(ENR) have been studied by FTIR. The results showed that the thermal oxidative aging reaction of ENR in air is an autocatalytic oxidation, the aging destruction occurrs in the epoxy and carbon-carbon double bonds of the ENR molecule and the products of aging are alcohols, aldehydes, ketones, carboxylic acids and esters. The destruction of double bonds is more serious than that of epoxy bonds in the earlier stage, but in the later stage the destruction occurs mainly in epoxy bonds. The thermal aging of ENR in vacuum is also an autocatalytic reaction, the products of aging are similar to that after thermal oxidative aging, but the destruction of epoxy bonds always takes place at first.
The thermal oxidative and thermal aging behaviour of epoxidized natural rubber(ENR) have been studied by FTIR. The results showed that the thermal oxidative aging reaction of ENR in air is an autocatalytic oxidation, the aging destruction occurrs in the epoxy and carbon-carbon double bonds of the ENR molecule and the products of aging are alcohols, aldehydes, ketones, carboxylic acids and esters. The destruction of double bonds is more serious than that of epoxy bonds in the earlier stage, but in the later stage the destruction occurs mainly in epoxy bonds. The thermal aging of ENR in vacuum is also an autocatalytic reaction, the products of aging are similar to that after thermal oxidative aging, but the destruction of epoxy bonds always takes place at first.
1999, 16(2): 117-118
Abstract:
A novel cationic dye-borate complex has been synthesized and used for infrared laser-induced photopolymerization. The result showed that the photoinitiator could initiate the polymerization of trihy-droxymethylpropane triacrylate in 23.4% conversion under IR laser irradiation.
A novel cationic dye-borate complex has been synthesized and used for infrared laser-induced photopolymerization. The result showed that the photoinitiator could initiate the polymerization of trihy-droxymethylpropane triacrylate in 23.4% conversion under IR laser irradiation.
1999, 16(2): 119-120
Abstract:
Hydrazones containing isothiazole heterocycle were synthesized and their structures were confirmed by elemental analysis, 1H NMR and IR techniques. The preliminary bioassay showed that some compounds possessed plant regulator activity.
Hydrazones containing isothiazole heterocycle were synthesized and their structures were confirmed by elemental analysis, 1H NMR and IR techniques. The preliminary bioassay showed that some compounds possessed plant regulator activity.
