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1997 Volume 14 Issue 5
1997, 14(5): 1-4
Abstract:
Twelve open chain and cyclic T-oxo-T-imidazolylketene N,S;N,N;N,O-acetals were obtained and their biological activities were examined. N,N-Acetals were found to have relatively good activity of plant growth regulator.
Twelve open chain and cyclic T-oxo-T-imidazolylketene N,S;N,N;N,O-acetals were obtained and their biological activities were examined. N,N-Acetals were found to have relatively good activity of plant growth regulator.
1997, 14(5): 5-9
Abstract:
A series of heterospirop[4.5] compounds were synthsized by 1,3-dipolar cycloaddition of nitrile oxides to 4,4-methylene-1-methylpiperidine. NMR study showed that only one stereoioisomer was formed selectively. In the consecutive step these were cleaved by hydrogenolysis to V-amino-alcohols, which in a final step were recyclized by insertion of a C-1 unit, giving the target structure.
A series of heterospirop[4.5] compounds were synthsized by 1,3-dipolar cycloaddition of nitrile oxides to 4,4-methylene-1-methylpiperidine. NMR study showed that only one stereoioisomer was formed selectively. In the consecutive step these were cleaved by hydrogenolysis to V-amino-alcohols, which in a final step were recyclized by insertion of a C-1 unit, giving the target structure.
1997, 14(5): 10-14
Abstract:
Copper-containing mesoporous molecular sieve(Cu-HMS) was prepared at room temperature; XRD, IR and ESR spectra studies revealed the incorporation of copper in the framework. Compared with other catalysts V-HMS, Ti-HMS, TS-1, Cu-ZSM-5 and Cu-Y, Cu-HMS showed an excellent catalytic activity for phenol hydroxylation with hydrogen peroxide as oxygen donor. The mechanism of the reaction has been discussed.
Copper-containing mesoporous molecular sieve(Cu-HMS) was prepared at room temperature; XRD, IR and ESR spectra studies revealed the incorporation of copper in the framework. Compared with other catalysts V-HMS, Ti-HMS, TS-1, Cu-ZSM-5 and Cu-Y, Cu-HMS showed an excellent catalytic activity for phenol hydroxylation with hydrogen peroxide as oxygen donor. The mechanism of the reaction has been discussed.
1997, 14(5): 15-18
Abstract:
Poly(acrylic salt-acrylamide) as superabsorbents were synthesized by means of inverse suspension polymerization, in which the suspension stabilizer was an amphiphilic copolymer of acrylic acid with its octadecyl ester. Polymerization conditions such as amount of crosslinking monomer, stabilizer, initator, comonomer, neutralization degree of acrylic acid and chain transfer agent on the water-absorbency of the absorbent were studied. The optimum absorbency of the superabsorbent obtained is 1050 mL/g and 86 mL/g in distilled water and 0.9% NaCl solution, respectively. The effect of different counter ions of PAA on the absorbency was also studied.
Poly(acrylic salt-acrylamide) as superabsorbents were synthesized by means of inverse suspension polymerization, in which the suspension stabilizer was an amphiphilic copolymer of acrylic acid with its octadecyl ester. Polymerization conditions such as amount of crosslinking monomer, stabilizer, initator, comonomer, neutralization degree of acrylic acid and chain transfer agent on the water-absorbency of the absorbent were studied. The optimum absorbency of the superabsorbent obtained is 1050 mL/g and 86 mL/g in distilled water and 0.9% NaCl solution, respectively. The effect of different counter ions of PAA on the absorbency was also studied.
1997, 14(5): 19-22
Abstract:
Interaction of RuCl2(DMSO)4 with one equivalent of N,N'-bis[o-(diphenylpho-sphino) benzylidene]-1,2-propanediamine[P2N2Me] or N,N'-bis[o-(diphenylphosphino) benzyl]-1,2-propanediamine[P2N2H4Me] in refluxing toluene gave trans-RuCl2(P2N2Me) and trans-RuCl2(P2N2H4Me) in moderate yield, respectively. The complexes have been fully cha-racterized by analytical and spectroscopic methods. The structure of trans-RuCl2(P2N2Me) has been established by an X-ray diffraction study and the result indicates a distorted-octahedral configuration. The complexes were found to be an effective catalyst for hydrogen transfer hydrogenation of acetophenone. The catalytical cycle mechanism is also discussed.
Interaction of RuCl2(DMSO)4 with one equivalent of N,N'-bis[o-(diphenylpho-sphino) benzylidene]-1,2-propanediamine[P2N2Me] or N,N'-bis[o-(diphenylphosphino) benzyl]-1,2-propanediamine[P2N2H4Me] in refluxing toluene gave trans-RuCl2(P2N2Me) and trans-RuCl2(P2N2H4Me) in moderate yield, respectively. The complexes have been fully cha-racterized by analytical and spectroscopic methods. The structure of trans-RuCl2(P2N2Me) has been established by an X-ray diffraction study and the result indicates a distorted-octahedral configuration. The complexes were found to be an effective catalyst for hydrogen transfer hydrogenation of acetophenone. The catalytical cycle mechanism is also discussed.
1997, 14(5): 23-27
Abstract:
The group transfer block copolymerization of methyl-methacrylate(MMA) and C7~9 methacrylate(C7~9 MA) has been studied by using a bifunctional initiator and an anionic catalyst. The influences of temperature、monomer sequence、concentration ratio of initiator to catalyst and concentration of monomers have been investigated. When T1=85℃, T2=25℃,[I]=1.35×10-2 mol/L,[Cat]/[I]=0.126, C7~9 MA as first monomer, the block copolymerization of C7~9 MA and MMA appeared to be predominate. The thermal deformation temperatures of the copolymers obtained are reported. The triblock copolymer (PMMA-PC7~9 MA-PMMA) has been characteriaced by FT-IR, 1H NMR, and GPC as a homogeneous phase system.
The group transfer block copolymerization of methyl-methacrylate(MMA) and C7~9 methacrylate(C7~9 MA) has been studied by using a bifunctional initiator and an anionic catalyst. The influences of temperature、monomer sequence、concentration ratio of initiator to catalyst and concentration of monomers have been investigated. When T1=85℃, T2=25℃,[I]=1.35×10-2 mol/L,[Cat]/[I]=0.126, C7~9 MA as first monomer, the block copolymerization of C7~9 MA and MMA appeared to be predominate. The thermal deformation temperatures of the copolymers obtained are reported. The triblock copolymer (PMMA-PC7~9 MA-PMMA) has been characteriaced by FT-IR, 1H NMR, and GPC as a homogeneous phase system.
1997, 14(5): 28-31
Abstract:
Twelve bulkier substituted titanocene and zirconocene dichlorides have been synthesized by reactions of 6,6-dialkyfulvenes with 1-lithiocycloheptene followed by treatment with MCl4(M=Ti, Zr), Their 1H NMR, EIMS and IR spectra have been discussed.
Twelve bulkier substituted titanocene and zirconocene dichlorides have been synthesized by reactions of 6,6-dialkyfulvenes with 1-lithiocycloheptene followed by treatment with MCl4(M=Ti, Zr), Their 1H NMR, EIMS and IR spectra have been discussed.
1997, 14(5): 32-35
Abstract:
The method for calculating kinetic crystallizability from the nonisothermal crystallization curves determined by using differential scanning calorimetry (DSC) has been investigated. A new equation was derived in terms of the differential equation for the nonisothermal crystallization. The kinetic crystallizability of polyethylene terephthalate containing different catalysts was calculated. The results indicate that the key to calculating the kinetic crystallizability lies in correctly selecting the temperature of maximum crystallization rate. The kinetic crystallizability obtained by this method gives the overall information of the polymer crystallization.
The method for calculating kinetic crystallizability from the nonisothermal crystallization curves determined by using differential scanning calorimetry (DSC) has been investigated. A new equation was derived in terms of the differential equation for the nonisothermal crystallization. The kinetic crystallizability of polyethylene terephthalate containing different catalysts was calculated. The results indicate that the key to calculating the kinetic crystallizability lies in correctly selecting the temperature of maximum crystallization rate. The kinetic crystallizability obtained by this method gives the overall information of the polymer crystallization.
1997, 14(5): 36-38
Abstract:
The scavening action to hydroxyl free radical of benzisoselenazolones and diselenides has been studied by fluorometry. The hydroxyl free radicals were produced via Fenton reaction. The method used provides a sensitive, simple and accurate measurement of the scavening action to hydroxyl free radical for synthetic drugs of highly biological activity.
The scavening action to hydroxyl free radical of benzisoselenazolones and diselenides has been studied by fluorometry. The hydroxyl free radicals were produced via Fenton reaction. The method used provides a sensitive, simple and accurate measurement of the scavening action to hydroxyl free radical for synthetic drugs of highly biological activity.
1997, 14(5): 39-42
Abstract:
Ternary excitation energy transfer from biphenyl donor embeded in the interior of bilayer membranes cascading through membrane-bound titan yellow to membrane-bound rhodamine B was investigated in the mixture system of DBBTAB(4-(4'-decyloxybiphenyl-4-oxytrimethyl) ammonium bromide) vesicles. The energy transfer efficiency of the ternary system was good. The specific function of the DBBTAB vesicles in energy transfer was explored and the mechanism of energy transfer was discussed. Furthermore, the cascading energy transfer among biphenyl, titan yellow, fluorescein, rhodamine B and tetraphenyl porphin, which anchored on the surface of the DBBTAB membrane except biphenyl, was also observed in the same mixture system. It improved the light efficiency and extended the spectral region. The experiment results imply that DBBTAB vesicle is a promising efficient medium for energy transfer in dye lasers and a better membrane mimetic agent.
Ternary excitation energy transfer from biphenyl donor embeded in the interior of bilayer membranes cascading through membrane-bound titan yellow to membrane-bound rhodamine B was investigated in the mixture system of DBBTAB(4-(4'-decyloxybiphenyl-4-oxytrimethyl) ammonium bromide) vesicles. The energy transfer efficiency of the ternary system was good. The specific function of the DBBTAB vesicles in energy transfer was explored and the mechanism of energy transfer was discussed. Furthermore, the cascading energy transfer among biphenyl, titan yellow, fluorescein, rhodamine B and tetraphenyl porphin, which anchored on the surface of the DBBTAB membrane except biphenyl, was also observed in the same mixture system. It improved the light efficiency and extended the spectral region. The experiment results imply that DBBTAB vesicle is a promising efficient medium for energy transfer in dye lasers and a better membrane mimetic agent.
1997, 14(5): 43-46
Abstract:
Six derivatives of alkoxy metal phthalocyanine were synthesized and identified by elemental analysis. They have solubility of 10~30 g/L in chloroform. Their spectroscopic properties in solution and thin film were investigated. In solution the red shift was observed in the Q-band absorption for compounds Ⅴ and Ⅵ. The absorption spectra of the thin film was found to be broadened and shifted to long wave length, dependent on the chain length of the substituents.
Six derivatives of alkoxy metal phthalocyanine were synthesized and identified by elemental analysis. They have solubility of 10~30 g/L in chloroform. Their spectroscopic properties in solution and thin film were investigated. In solution the red shift was observed in the Q-band absorption for compounds Ⅴ and Ⅵ. The absorption spectra of the thin film was found to be broadened and shifted to long wave length, dependent on the chain length of the substituents.
1997, 14(5): 47-50
Abstract:
Grafting of T-methylacrylic acid onto the surface of PP powder was performed in water-toluene medium. The effect of monomer and initiator (benzoyl peroxide) concentrations, reaction time on graft degree and graft efficiency were investigated by using the orthogonal design method. The grafted PP was characterized by means of PGC and SEM. The result showed that the monomer concentration effected the graft degree and graft efficiency greatly. The highest graft degree was 35.2% and the graft efficiency was 86.4%. The grafted PP was laminated with polar materials, such as aluminium foil and nylon, and showed much stronger adhesion than unmodified PP. The grafted PP also enhanced the interfacial surface affinity between PP and CaCO3 in PP filled composite, and the tensile strength and impact strength of the composite was improved greatly.
Grafting of T-methylacrylic acid onto the surface of PP powder was performed in water-toluene medium. The effect of monomer and initiator (benzoyl peroxide) concentrations, reaction time on graft degree and graft efficiency were investigated by using the orthogonal design method. The grafted PP was characterized by means of PGC and SEM. The result showed that the monomer concentration effected the graft degree and graft efficiency greatly. The highest graft degree was 35.2% and the graft efficiency was 86.4%. The grafted PP was laminated with polar materials, such as aluminium foil and nylon, and showed much stronger adhesion than unmodified PP. The grafted PP also enhanced the interfacial surface affinity between PP and CaCO3 in PP filled composite, and the tensile strength and impact strength of the composite was improved greatly.
1997, 14(5): 51-54
Abstract:
Remarkable improvement of some properties(e.g. oil resistant, friction coefficient) of nitrile-butadiene rubber(NBR) was observed after surface fluorination by XeF2. The surface structure of the fluorinated NBR has been studied by XPS and the carbon 1S peaks have been measured mathematically by curve fitting technique. The results showed that with the increase of fluorinating time the H atoms on the surface of NBR are substituted by F atoms, resulting gradually-CH2-CHF-CH2-、-CHF-CH2-CHF- and -CHF-CHF-CHF-groups. The SEM photographs showed about 8~9 μm thickness of the fluorinated surface of NBR.
Remarkable improvement of some properties(e.g. oil resistant, friction coefficient) of nitrile-butadiene rubber(NBR) was observed after surface fluorination by XeF2. The surface structure of the fluorinated NBR has been studied by XPS and the carbon 1S peaks have been measured mathematically by curve fitting technique. The results showed that with the increase of fluorinating time the H atoms on the surface of NBR are substituted by F atoms, resulting gradually-CH2-CHF-CH2-、-CHF-CH2-CHF- and -CHF-CHF-CHF-groups. The SEM photographs showed about 8~9 μm thickness of the fluorinated surface of NBR.
1997, 14(5): 55-58
Abstract:
The catalysis of metal ions has been studied in bacterial leaching with Thiobacillus ferrooxidans in extraction of copper and nickel from complex low grade Cu and Ni sulphide minerals. Some metal ions (Ag+, Hg2+, Co2+, Bi3+) promote the leaching rate significantly. The order of the catalytical ability of metal ions studied in leaching copper was:Ag+ >> Co2+ > Bi3+ > Hg2+ and in leaching nikel was:Bi3+ > Ag+ > Co2+ > Hg2+. The property and concentration of metal ions, and the size of the minerals showed influences on the catalytical ability of metal ions.
The catalysis of metal ions has been studied in bacterial leaching with Thiobacillus ferrooxidans in extraction of copper and nickel from complex low grade Cu and Ni sulphide minerals. Some metal ions (Ag+, Hg2+, Co2+, Bi3+) promote the leaching rate significantly. The order of the catalytical ability of metal ions studied in leaching copper was:Ag+ >> Co2+ > Bi3+ > Hg2+ and in leaching nikel was:Bi3+ > Ag+ > Co2+ > Hg2+. The property and concentration of metal ions, and the size of the minerals showed influences on the catalytical ability of metal ions.
1997, 14(5): 59-62
Abstract:
The ionic conductivity, conduction mechanism and application to electrochromic Smart windows of polymeric gel electrolyte LiClO4-propylene carbonate-polymethyl methacrylate(LiClO4-PC-PMMA) have been investigated. The ionic conductivity as a function of temperature followed the empirical Vogel-Tammann-Fulcher equation and depended on the weight content and Tg of PMMA, and concentration of LiClO4. The electrolyte had a good adhesivity, good transparency and high ionic conductivity at room temperature (e=8.75×10-4 S/cm), when concentration of LiClO4 was 0.5 mol/L and weight percentage of PMMA was 35%. The assembled electrochromic Smart window had good spectral behavour, at 633.3 nm its optical modulation was 40%~60%. Its optical switching time only 5 s.
The ionic conductivity, conduction mechanism and application to electrochromic Smart windows of polymeric gel electrolyte LiClO4-propylene carbonate-polymethyl methacrylate(LiClO4-PC-PMMA) have been investigated. The ionic conductivity as a function of temperature followed the empirical Vogel-Tammann-Fulcher equation and depended on the weight content and Tg of PMMA, and concentration of LiClO4. The electrolyte had a good adhesivity, good transparency and high ionic conductivity at room temperature (e=8.75×10-4 S/cm), when concentration of LiClO4 was 0.5 mol/L and weight percentage of PMMA was 35%. The assembled electrochromic Smart window had good spectral behavour, at 633.3 nm its optical modulation was 40%~60%. Its optical switching time only 5 s.
1997, 14(5): 63-66
Abstract:
The selective catalytic synthesis of dimethylamine from ammonia and methylalcohol over cerium modified mordenite under ambient pressure in a fixed bed reactor has been studied. The effects of the reaction conditions (temperature, ratio of ammonia to methylalcohol and methylalcohol space velocity) and the catalyst preparation conditions on the selectivity to dimethylamine have been investigated.
The selective catalytic synthesis of dimethylamine from ammonia and methylalcohol over cerium modified mordenite under ambient pressure in a fixed bed reactor has been studied. The effects of the reaction conditions (temperature, ratio of ammonia to methylalcohol and methylalcohol space velocity) and the catalyst preparation conditions on the selectivity to dimethylamine have been investigated.
1997, 14(5): 67-70
Abstract:
A novel composite membrane based on chitosan/starch/polyvinyl alcohol was prepared by solvent-casting technique and its mechanical properties were measured. The drug release and its mechanism in static state from the composite membranes containing ciprofloxacin and protocatechuic acid have been investigated. The release rate was found to be controlled by the starch content in membrane matrices as well as by crosslinking state.
A novel composite membrane based on chitosan/starch/polyvinyl alcohol was prepared by solvent-casting technique and its mechanical properties were measured. The drug release and its mechanism in static state from the composite membranes containing ciprofloxacin and protocatechuic acid have been investigated. The release rate was found to be controlled by the starch content in membrane matrices as well as by crosslinking state.
1997, 14(5): 71-73
Abstract:
The ceric and cerous solid complexes with phytic acid were synthesized and chara-cterized by means of elemental analysis, IR and TG-DTA. The results show that under the experimental conditions for Ce(Ⅲ) only one form complex is formed:[(C6H6)H4(PO4)6]3Ce8·13H2O(Ⅰ), but two complexes were formed for Ce(Ⅳ):[(C6H6)H4(PO4)6]3·[Ce(OH)]8·9H2O(Ⅱ) and [(C6H6)(PO4)6]3[Ce(OH)]12·9H2O(Ⅲ); the thermal stability of (Ⅲ) was less than that of (Ⅰ). On thermal decomposition the ceric was reduced to cerous and the final product was CePO4.
The ceric and cerous solid complexes with phytic acid were synthesized and chara-cterized by means of elemental analysis, IR and TG-DTA. The results show that under the experimental conditions for Ce(Ⅲ) only one form complex is formed:[(C6H6)H4(PO4)6]3Ce8·13H2O(Ⅰ), but two complexes were formed for Ce(Ⅳ):[(C6H6)H4(PO4)6]3·[Ce(OH)]8·9H2O(Ⅱ) and [(C6H6)(PO4)6]3[Ce(OH)]12·9H2O(Ⅲ); the thermal stability of (Ⅲ) was less than that of (Ⅰ). On thermal decomposition the ceric was reduced to cerous and the final product was CePO4.
1997, 14(5): 74-76
Abstract:
Copolymerization of styrene and acrylic acid in ethanol-water medium dispersed with magnetite particles of 30 nm diameter was carried out using potassium persulfate as initiator. The affinity among the magnetite particles, monomers and initiators was improved by coating the magnetite particles with polyethylene glycol. The effects of polyethylene glycol, dispersion medium, initiator and polymerization time on the formation of magnetic polymer microspheres have been investigated. Magnetic polymer microspheres of 30~1000 μm diameter were prepared.
Copolymerization of styrene and acrylic acid in ethanol-water medium dispersed with magnetite particles of 30 nm diameter was carried out using potassium persulfate as initiator. The affinity among the magnetite particles, monomers and initiators was improved by coating the magnetite particles with polyethylene glycol. The effects of polyethylene glycol, dispersion medium, initiator and polymerization time on the formation of magnetic polymer microspheres have been investigated. Magnetic polymer microspheres of 30~1000 μm diameter were prepared.
1997, 14(5): 77-79
Abstract:
A method to acquire high quality acrylamide by active carbon refining is offered. Optimum refining conditions have been established by selecting active carbon material, amount, size, refining time and solution pH value. The effect of active carbon refining on the molecular weight of polyacrylamide has been investigated as well.
A method to acquire high quality acrylamide by active carbon refining is offered. Optimum refining conditions have been established by selecting active carbon material, amount, size, refining time and solution pH value. The effect of active carbon refining on the molecular weight of polyacrylamide has been investigated as well.
1997, 14(5): 80-82
Abstract:
Six organic compounds have been firstly isolated from the South China Sea Gorgonian Menella spinifera Kukenthal. Their chemical structures have been determined on the basis of spectral data of UV, IR, MS, 1H NMR and 31C NMR as:n-hexadecanol(Ⅰ),3U-OH-5T-Pregnane-20-one(Ⅱ), Batyl alcohol(Ⅲ), 9H-Purin-6-amino-N.9-dimethyl(Ⅳ), Thymidine(Ⅴ) and Picolinic acid N-methyl betaine(Ⅵ). Spectral data of compound Ⅵ were first reported.
Six organic compounds have been firstly isolated from the South China Sea Gorgonian Menella spinifera Kukenthal. Their chemical structures have been determined on the basis of spectral data of UV, IR, MS, 1H NMR and 31C NMR as:n-hexadecanol(Ⅰ),3U-OH-5T-Pregnane-20-one(Ⅱ), Batyl alcohol(Ⅲ), 9H-Purin-6-amino-N.9-dimethyl(Ⅳ), Thymidine(Ⅴ) and Picolinic acid N-methyl betaine(Ⅵ). Spectral data of compound Ⅵ were first reported.
1997, 14(5): 83-85
Abstract:
Factors affecting plasma oxidative desulfurization of organic sulfides in mixture with n-heptane were investigated. As organic sulfide isobutyl mercaptan (1.20%), ethyl-thioether (1.44%), and thiophene(1.32%) with n-heptane were examined separately. The results show that the plasma load of power, i.e. ratio of oxygen flow rate to plasma power, and reaction time are primary factors affecting the desulfurization, when the temperature of reactant was about -85℃. Under reasonable conditions, the degree of desulfurization of isobutyl mercaptan, ethyl-thioether and thiophene can be achieved up to 99%, 80% and 79% respectively.
Factors affecting plasma oxidative desulfurization of organic sulfides in mixture with n-heptane were investigated. As organic sulfide isobutyl mercaptan (1.20%), ethyl-thioether (1.44%), and thiophene(1.32%) with n-heptane were examined separately. The results show that the plasma load of power, i.e. ratio of oxygen flow rate to plasma power, and reaction time are primary factors affecting the desulfurization, when the temperature of reactant was about -85℃. Under reasonable conditions, the degree of desulfurization of isobutyl mercaptan, ethyl-thioether and thiophene can be achieved up to 99%, 80% and 79% respectively.
1997, 14(5): 86-88
Abstract:
Chitosan film exhibited a high ability of absorbing iodine in aqueous solution and the ability was increased with increase of the deacetylation degree of chitin. The iodine adsorption ability of chitosan film was independent of the thickness of the film. In organic solvents the absorbition ability was larger in polar solvents than in nonpolar solvents.
Chitosan film exhibited a high ability of absorbing iodine in aqueous solution and the ability was increased with increase of the deacetylation degree of chitin. The iodine adsorption ability of chitosan film was independent of the thickness of the film. In organic solvents the absorbition ability was larger in polar solvents than in nonpolar solvents.
1997, 14(5): 89-91
Abstract:
The relationship between the composition of water soluble acrylic copolymer (WSAC) resin, staining technology and character of the final coloured film have been investigated. It is found that an aqueous solution containing 8%~10% WSAC (Tg 34~39℃) and pigment in 1.1 times its effective concentration was rather reasonable. From this mixture a good corrosion resistant coloured phosphate film was prepared when it was macerated for 15~30 s and dried for 20~40 min at 60~80℃.
The relationship between the composition of water soluble acrylic copolymer (WSAC) resin, staining technology and character of the final coloured film have been investigated. It is found that an aqueous solution containing 8%~10% WSAC (Tg 34~39℃) and pigment in 1.1 times its effective concentration was rather reasonable. From this mixture a good corrosion resistant coloured phosphate film was prepared when it was macerated for 15~30 s and dried for 20~40 min at 60~80℃.
1997, 14(5): 92-94
Abstract:
Poly(propylene oxide) containing two acrylate end groups was prepared firstly by reaction of poly(propylene oxide) with tolylene diisocyanate and 2-hydroxyethylene acrylate. Then it was used as a reactive modifier for epoxy resins of diglycidyl ether of bisphenol A type in the presence of curing agent containing amine groups. Due to the linkage between acrylate end groups and curing agents, the compatibility of epoxy resin with modifiers was improved.
Poly(propylene oxide) containing two acrylate end groups was prepared firstly by reaction of poly(propylene oxide) with tolylene diisocyanate and 2-hydroxyethylene acrylate. Then it was used as a reactive modifier for epoxy resins of diglycidyl ether of bisphenol A type in the presence of curing agent containing amine groups. Due to the linkage between acrylate end groups and curing agents, the compatibility of epoxy resin with modifiers was improved.
1997, 14(5): 95-97
Abstract:
Surface modification of polyacrylonitrile membranes by direct amination has been studied. The membrane was firstly hydrolyzed with NaOH solution, then treated with 1,6-hexamethyldiamine(HMDA). Amino amount on the membrane has been measured by titration method. It showed that-NH2 amount varied with hydrolyzation conditions and HMDA concentration. Results of water absorption and contact angle showed that the hydrophilicity of aminated membrane was better than that of original PAN membrane.
Surface modification of polyacrylonitrile membranes by direct amination has been studied. The membrane was firstly hydrolyzed with NaOH solution, then treated with 1,6-hexamethyldiamine(HMDA). Amino amount on the membrane has been measured by titration method. It showed that-NH2 amount varied with hydrolyzation conditions and HMDA concentration. Results of water absorption and contact angle showed that the hydrophilicity of aminated membrane was better than that of original PAN membrane.
1997, 14(5): 98-100
Abstract:
The ZnPht[Pht=o-C6H4(CO2)22-] and double salt Zn9K3.9(OH)5.5Pht8.2·0.35H2Pht·4H2O were synthesized by semi solid reaction and solution reaction methods, respectively. Their infrared spectra and TG and DTA curves were measured. The crystal structures were characterized by powder X-ray diffractometry. Both are monoclinic:for ZnPht a=1.1044, b=0.9687, c=2.5949 nm, U=92.19°, for double salt a=1.7138, b=0.8343, c=1.6879 nm, U=113.35°.
The ZnPht[Pht=o-C6H4(CO2)22-] and double salt Zn9K3.9(OH)5.5Pht8.2·0.35H2Pht·4H2O were synthesized by semi solid reaction and solution reaction methods, respectively. Their infrared spectra and TG and DTA curves were measured. The crystal structures were characterized by powder X-ray diffractometry. Both are monoclinic:for ZnPht a=1.1044, b=0.9687, c=2.5949 nm, U=92.19°, for double salt a=1.7138, b=0.8343, c=1.6879 nm, U=113.35°.
1997, 14(5): 101-103
Abstract:
BPSDMA of high purity was easily synthesized from bisphenol-S by phase transfer catalysis at low temperature and its structure was characterized by FTIR, NMR and elemental analysis. Transparent resins of BPSDMA with styrene and styrene-thiodiglycol dimethacrylate (TDGDMA) copolymers were prepared and their properties were measured and studied.
BPSDMA of high purity was easily synthesized from bisphenol-S by phase transfer catalysis at low temperature and its structure was characterized by FTIR, NMR and elemental analysis. Transparent resins of BPSDMA with styrene and styrene-thiodiglycol dimethacrylate (TDGDMA) copolymers were prepared and their properties were measured and studied.
1997, 14(5): 104-106
Abstract:
The inhibition of dezincification of brass by benzyltriphenyl phosphonium bromide(BPB), benzotriazole(BTA) and traces of arsenic in the alloy was investigated by chronoamperometry and measurements of positron lifetime spectra in chloride solution. The results show that BPB and BTA in the solution and arsenic in the alloy can obviously decrease the transient diffusion current densities of zinc dissolution and reduce the diffusion coefficient of zinc in brass by the order of one to two. The results are interpreted in terms of the (di)vacancy diffusion mechanism.
The inhibition of dezincification of brass by benzyltriphenyl phosphonium bromide(BPB), benzotriazole(BTA) and traces of arsenic in the alloy was investigated by chronoamperometry and measurements of positron lifetime spectra in chloride solution. The results show that BPB and BTA in the solution and arsenic in the alloy can obviously decrease the transient diffusion current densities of zinc dissolution and reduce the diffusion coefficient of zinc in brass by the order of one to two. The results are interpreted in terms of the (di)vacancy diffusion mechanism.
1997, 14(5): 107-109
Abstract:
Epoxycyclohexane was prepared in yield of 86.2% by electrochemical epoxidation of cyclohexene at Ti/SnO2+Sb2O3/PbO2 anode, at current density 0.4 A/dm2 in H2O-NaBr-MeCN medium (VH2O:VMeCN=4:1, CNaBr=0.04 mol/dm3). Ti/SnO2+Sb2O3/PbO2 anode showed a more excellent catalytic activity than Ti/RuO2 anode.
Epoxycyclohexane was prepared in yield of 86.2% by electrochemical epoxidation of cyclohexene at Ti/SnO2+Sb2O3/PbO2 anode, at current density 0.4 A/dm2 in H2O-NaBr-MeCN medium (VH2O:VMeCN=4:1, CNaBr=0.04 mol/dm3). Ti/SnO2+Sb2O3/PbO2 anode showed a more excellent catalytic activity than Ti/RuO2 anode.
1997, 14(5): 110-111
Abstract:
The flow injection spectrophotometry was used for determination of nitrite in meat products satisfactorily. The method is convenient and rapid. The relative standard deviation was less than 1.0%.
The flow injection spectrophotometry was used for determination of nitrite in meat products satisfactorily. The method is convenient and rapid. The relative standard deviation was less than 1.0%.
1997, 14(5): 112-114
Abstract:
The compatibility of polyvinylidene fluoride(PVDF) and polyacrylonitrile(PAN) has been investigated. The influence of the compatibility of the blend solution and casting technology on the membrane properties has been examined. The results showed that the PVDF/PAN ultrafiltration membrane made from homogeneous and clear casting solution of blend possessed fairly great flux and high retention ratio and the membrane morphologically consisted of uniform finger-like holes.
The compatibility of polyvinylidene fluoride(PVDF) and polyacrylonitrile(PAN) has been investigated. The influence of the compatibility of the blend solution and casting technology on the membrane properties has been examined. The results showed that the PVDF/PAN ultrafiltration membrane made from homogeneous and clear casting solution of blend possessed fairly great flux and high retention ratio and the membrane morphologically consisted of uniform finger-like holes.
1997, 14(5): 115-116
Abstract:
A rare earth coordination catalyst system:Nd(P507)3-H2O-Al(i-Bu)3 was used for isospecific polymerization of styrene. The polymers were extracted with boiling 2-butanone. 13C NMR and DSC data indicate that the extracted polystyrene is highly isotactic. The isospecificity is sensitive to the water added in the system. The conversion and isospecificity reach maximums at H2O/Al(i-Bu)3 molar ratio of 0.05~0.08.
A rare earth coordination catalyst system:Nd(P507)3-H2O-Al(i-Bu)3 was used for isospecific polymerization of styrene. The polymers were extracted with boiling 2-butanone. 13C NMR and DSC data indicate that the extracted polystyrene is highly isotactic. The isospecificity is sensitive to the water added in the system. The conversion and isospecificity reach maximums at H2O/Al(i-Bu)3 molar ratio of 0.05~0.08.
