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1997 Volume 14 Issue 3
1997, 14(3): 1-4
Abstract:
Microencapsulation of lead chrome yellow and its mechanism have been researched and the quantitative method characterization of particle surface shape by surface fractal dimensionality(D) has been investigated. The results showed that inorganic microencapsulation of the lead chrome yellow particles in W/O emulsion is an effective method, raising the acid/baseresistance of the particles.
Microencapsulation of lead chrome yellow and its mechanism have been researched and the quantitative method characterization of particle surface shape by surface fractal dimensionality(D) has been investigated. The results showed that inorganic microencapsulation of the lead chrome yellow particles in W/O emulsion is an effective method, raising the acid/baseresistance of the particles.
1997, 14(3): 5-8
Abstract:
Some Schiff base complexes: KZnLAc, K2CoL(Ac)2·H2O, KCuLAc·H2O, KFeLCl2·3H2O, KNi2LCl3·2H2O, KCd2L(NO3)3·H2O, where H2L=L-alanine-o-vaniline Schiff base, have been synthesized and characterized by elemental analysis, molar conductance, infrared spectrum, electronic spectrum, thermal analysis and ESR spectrum measurements. Properties of KHL and the complexes in scavenging O2.- have been investigated.
Some Schiff base complexes: KZnLAc, K2CoL(Ac)2·H2O, KCuLAc·H2O, KFeLCl2·3H2O, KNi2LCl3·2H2O, KCd2L(NO3)3·H2O, where H2L=L-alanine-o-vaniline Schiff base, have been synthesized and characterized by elemental analysis, molar conductance, infrared spectrum, electronic spectrum, thermal analysis and ESR spectrum measurements. Properties of KHL and the complexes in scavenging O2.- have been investigated.
1997, 14(3): 9-11
Abstract:
Dealuminated mordenites with Si/Al ratio of 15~112 have been prepared. The amount of dealumination defects in the zeolites was measured by IR method. Experimental results on the thermal stability and hydrophobicity of the zeolites showed that the majority of the terminal silanol groups formed during dealumination still remains as hydrophilic center. Additional treatment with steam or (NH4)2SiF6 solution,which transforms the hydrophilic surface silanol groups into hydrophobic-Si-O-Si-bonds, markedly increases the hydrophobicity of the dealuminated zeolite.
Dealuminated mordenites with Si/Al ratio of 15~112 have been prepared. The amount of dealumination defects in the zeolites was measured by IR method. Experimental results on the thermal stability and hydrophobicity of the zeolites showed that the majority of the terminal silanol groups formed during dealumination still remains as hydrophilic center. Additional treatment with steam or (NH4)2SiF6 solution,which transforms the hydrophilic surface silanol groups into hydrophobic-Si-O-Si-bonds, markedly increases the hydrophobicity of the dealuminated zeolite.
1997, 14(3): 12-15
Abstract:
Using the high temperature and shearing stress of the extruder, we synthesized the graft copolymer of starch with ethyl acrylate by a simple dry method. The effects of reaction conditions on graft copolymerization were discussed. Grafted starch used as a compatibilizer for the blend system of starch and polyethylene was further investigated. The results indicated that grafted starch as a compatibilizer can improve the mechanical properties of the blend of starch and polyethylene.
Using the high temperature and shearing stress of the extruder, we synthesized the graft copolymer of starch with ethyl acrylate by a simple dry method. The effects of reaction conditions on graft copolymerization were discussed. Grafted starch used as a compatibilizer for the blend system of starch and polyethylene was further investigated. The results indicated that grafted starch as a compatibilizer can improve the mechanical properties of the blend of starch and polyethylene.
1997, 14(3): 16-18
Abstract:
Polyvinyl chloride(PVC) were toughened with polybutyl acrylate/polymethyl methacrylate core/shell impact modifier. The relationship between impact modifier's structure and its toughening efficiency to PVC was studied. Experimental results indicate that the toughening efficiency increases with particle size of the modifier. The optimum structure for the modifier is core/shell ratio 72/28~82/18, particle size 0.22 μm, fraction of crosslinking and grafting agent 0.5%~1.0%, respectively. SEM and TEM study on the morphology of the modified PVC shows that the impact modifier is uniformly dispersed in the PVC matrix.
Polyvinyl chloride(PVC) were toughened with polybutyl acrylate/polymethyl methacrylate core/shell impact modifier. The relationship between impact modifier's structure and its toughening efficiency to PVC was studied. Experimental results indicate that the toughening efficiency increases with particle size of the modifier. The optimum structure for the modifier is core/shell ratio 72/28~82/18, particle size 0.22 μm, fraction of crosslinking and grafting agent 0.5%~1.0%, respectively. SEM and TEM study on the morphology of the modified PVC shows that the impact modifier is uniformly dispersed in the PVC matrix.
1997, 14(3): 19-23
Abstract:
The catalytic activity of Ni/T-Al2O3 for partial oxidation of methane to synthesis gas has been studied. It is found that the catalyst of 10% Ni content was the best one for partial oxidation of methane under the conditions of 600~900℃ reaction temperature, 0.05 MPa pressure, a high space velocity of methane, and CH4/O2=2.0. Under the conditions used the methane conversion and the selectivity of CO and H2 were increased with increase of temperature (600~900℃) and decreased with increase of pressure(0.05 MPa~0.4 MPa) the space velocity influenced the catalyst activity. During the reaction, Ni component was found to be sintered and diminished, as confirmed by SEM observations and chemical analysis.
The catalytic activity of Ni/T-Al2O3 for partial oxidation of methane to synthesis gas has been studied. It is found that the catalyst of 10% Ni content was the best one for partial oxidation of methane under the conditions of 600~900℃ reaction temperature, 0.05 MPa pressure, a high space velocity of methane, and CH4/O2=2.0. Under the conditions used the methane conversion and the selectivity of CO and H2 were increased with increase of temperature (600~900℃) and decreased with increase of pressure(0.05 MPa~0.4 MPa) the space velocity influenced the catalyst activity. During the reaction, Ni component was found to be sintered and diminished, as confirmed by SEM observations and chemical analysis.
1997, 14(3): 24-28
Abstract:
Structure changes in polyethylene single crystals caused by annealing at 75, 90 and 105℃ were examined by the mixed-crystal infrared spectroscopy, SAXS, DSC and Raman spectroscopy. It was found that different annealing mechanisms were obeyed below 90℃ and above 105℃.
Structure changes in polyethylene single crystals caused by annealing at 75, 90 and 105℃ were examined by the mixed-crystal infrared spectroscopy, SAXS, DSC and Raman spectroscopy. It was found that different annealing mechanisms were obeyed below 90℃ and above 105℃.
1997, 14(3): 29-32
Abstract:
Four copper(Ⅱ) complexes of Schiff bases of symmetical triazole and salicylaldehyde were synthesized, namely[Cu(L1)Cl2](Ⅰ) and trinuclear complexes[Cu3(L2~L4)2Cl4]·nH2O(Ⅱ~Ⅳ) where L1, L2, L3 L4 are Schiff bases of 4-amino-1,2,4-triazole, 4-amino-3,5-dimethyl-1,2,4-triazole, 4-animo-3,5-diethyl-1,2,4-triazole and 4-amino-3,5-dihydroxymethyl-1,2,4-triazole, respectively. The complexes were characterized by elemental analysis, conductivity, IR spectrum, thermoanalysis, electronic spectrum, ESR and susceptibility measurements. The complexes have been proposed to have distorted square configuration. The results of variable temperature magnetic susceptibility of complex(Ⅱ) indicated the weak antiferromagnetic spin exchange interaction between the copper(Ⅱ) ions.J=-18.9 cm-1,g=2.08, F=2.7×10-3. The biological activity tests of the complexes showed that they are capable of inhibiting B cell.
Four copper(Ⅱ) complexes of Schiff bases of symmetical triazole and salicylaldehyde were synthesized, namely[Cu(L1)Cl2](Ⅰ) and trinuclear complexes[Cu3(L2~L4)2Cl4]·nH2O(Ⅱ~Ⅳ) where L1, L2, L3 L4 are Schiff bases of 4-amino-1,2,4-triazole, 4-amino-3,5-dimethyl-1,2,4-triazole, 4-animo-3,5-diethyl-1,2,4-triazole and 4-amino-3,5-dihydroxymethyl-1,2,4-triazole, respectively. The complexes were characterized by elemental analysis, conductivity, IR spectrum, thermoanalysis, electronic spectrum, ESR and susceptibility measurements. The complexes have been proposed to have distorted square configuration. The results of variable temperature magnetic susceptibility of complex(Ⅱ) indicated the weak antiferromagnetic spin exchange interaction between the copper(Ⅱ) ions.J=-18.9 cm-1,g=2.08, F=2.7×10-3. The biological activity tests of the complexes showed that they are capable of inhibiting B cell.
1997, 14(3): 33-36
Abstract:
The enhanced effect of U-cyclodextrin(U-CD) or surfactants on the oxidation reaction of H2O2 with 4-aminoantipyrine and phenol, using iron-(4-sulphophenyl) porphine (Fe-TPPS4) as catalyst has been studied. It is indicated that the initial rate and sensitivity of this color reaction are increased with the added amount of U-CD or sodium dodecylbenzene sulfate(SDBS). A sensitive method for the determination of H2O2 in the presence of U-CD has been developed. Trace amount of SDBS can be determined based on the linear relationship between the increment of the reaction rate and the concentration of the surfactant.
The enhanced effect of U-cyclodextrin(U-CD) or surfactants on the oxidation reaction of H2O2 with 4-aminoantipyrine and phenol, using iron-(4-sulphophenyl) porphine (Fe-TPPS4) as catalyst has been studied. It is indicated that the initial rate and sensitivity of this color reaction are increased with the added amount of U-CD or sodium dodecylbenzene sulfate(SDBS). A sensitive method for the determination of H2O2 in the presence of U-CD has been developed. Trace amount of SDBS can be determined based on the linear relationship between the increment of the reaction rate and the concentration of the surfactant.
1997, 14(3): 37-40
Abstract:
Ten trans-2-{4-[2-(4-R-phenyl) ethenyl] phenyl}-5-(4-biphenyl) oxazoles (R=H, Me, Et, i-Pr, t-Bu, Ph, OMe, F, Cl, Br) were synthesized. They were identified by elemental analysis、IR、UV and MS. Their FL spectra, fluorescence quantum yields and laser conversion efficiencies are reported and discussed.
Ten trans-2-{4-[2-(4-R-phenyl) ethenyl] phenyl}-5-(4-biphenyl) oxazoles (R=H, Me, Et, i-Pr, t-Bu, Ph, OMe, F, Cl, Br) were synthesized. They were identified by elemental analysis、IR、UV and MS. Their FL spectra, fluorescence quantum yields and laser conversion efficiencies are reported and discussed.
1997, 14(3): 41-44
Abstract:
The synergistic extraction of La(Ⅲ) and Dy(Ⅲ) from nitrate medium with 1,9-bis(1'-phenyl-3'-methyl-5'-oxopyrazol-4'-yl) nonanedione-[1,9] (BPMPND or H2A) and trioctylphosphine oxide (TOPO or B) in chloroform has been studied at 25℃. Method of constant molarity was used to study the synergistic effect. The acidic synergistic extraction coefficient and the synergistic extraction coefficient of La(Ⅲ) and Dy(Ⅲ) were calculated. By using slope analysis method, the compositions of the synergistic extracted species have been shown to be LaA·HA·B and DyA·HA·B and their synergistic extraction equilibrium constants were determined. The influence of temperature on the synergistic extraction distribution ratio was studied in extraction of dysprosium(Ⅲ). The solid synergistic species were obtained and their compositions have been analyzed and explored through elemental analysis, IR, TG and DTA.
The synergistic extraction of La(Ⅲ) and Dy(Ⅲ) from nitrate medium with 1,9-bis(1'-phenyl-3'-methyl-5'-oxopyrazol-4'-yl) nonanedione-[1,9] (BPMPND or H2A) and trioctylphosphine oxide (TOPO or B) in chloroform has been studied at 25℃. Method of constant molarity was used to study the synergistic effect. The acidic synergistic extraction coefficient and the synergistic extraction coefficient of La(Ⅲ) and Dy(Ⅲ) were calculated. By using slope analysis method, the compositions of the synergistic extracted species have been shown to be LaA·HA·B and DyA·HA·B and their synergistic extraction equilibrium constants were determined. The influence of temperature on the synergistic extraction distribution ratio was studied in extraction of dysprosium(Ⅲ). The solid synergistic species were obtained and their compositions have been analyzed and explored through elemental analysis, IR, TG and DTA.
1997, 14(3): 45-48
Abstract:
The relationship between the compatibility in bulk and surface enrichment of PDMS has been studied with a series of[PSF-PDMS-PHS]n/PSF blends, where PSF polysulfone, PDMS polydimethylsiloxane, PHS poly-p-hydroxystyrene. DSC, DMA and TEM were used to characterize the bulk morphology, and XPS was used to obtain the information of the surface composition. It is shown that the level of surface enrichment of PDMS was affected by the compatibility between the homopolymer PSF and the hard phase of [PSF-PDMS-PHS]n. PDMS surface enrichment in the blends was similar to that in the corresponding ternary segmented copolymer [PSF-PDMS-PHS]n, when the homopolymer PSF and the hard phase of [PSF-PDMS-PHS]n were miscible. XPS results on the immiscible blends of [PSF-PDMS-PHS]n /PSF indicated a higher surface enrichment of PDMS, and the latter increased rapidly when the bulk siloxane concentrztion increased from 1% to 5%.
The relationship between the compatibility in bulk and surface enrichment of PDMS has been studied with a series of[PSF-PDMS-PHS]n/PSF blends, where PSF polysulfone, PDMS polydimethylsiloxane, PHS poly-p-hydroxystyrene. DSC, DMA and TEM were used to characterize the bulk morphology, and XPS was used to obtain the information of the surface composition. It is shown that the level of surface enrichment of PDMS was affected by the compatibility between the homopolymer PSF and the hard phase of [PSF-PDMS-PHS]n. PDMS surface enrichment in the blends was similar to that in the corresponding ternary segmented copolymer [PSF-PDMS-PHS]n, when the homopolymer PSF and the hard phase of [PSF-PDMS-PHS]n were miscible. XPS results on the immiscible blends of [PSF-PDMS-PHS]n /PSF indicated a higher surface enrichment of PDMS, and the latter increased rapidly when the bulk siloxane concentrztion increased from 1% to 5%.
1997, 14(3): 49-52
Abstract:
Active carbon adsorbents suitable for wastewater treatments were prepared from natural elutrilithe by chemical activation with K2CO3. The effect of the activation conditions on the specific area, porosity and ash content of the adsorbent was investigated. The qualities of the adsorbent are further improved via additional simple prior and post treatments. An ideal active carbon adsorbent with a BET specific area of 1236 m2/g and a total pore volume of 0.679 cm3/g was obtained. The adsorbents are hydrophobic in nature and exhibit large adsorption capacities for various phenolic compounds from aqueous solutions.
Active carbon adsorbents suitable for wastewater treatments were prepared from natural elutrilithe by chemical activation with K2CO3. The effect of the activation conditions on the specific area, porosity and ash content of the adsorbent was investigated. The qualities of the adsorbent are further improved via additional simple prior and post treatments. An ideal active carbon adsorbent with a BET specific area of 1236 m2/g and a total pore volume of 0.679 cm3/g was obtained. The adsorbents are hydrophobic in nature and exhibit large adsorption capacities for various phenolic compounds from aqueous solutions.
1997, 14(3): 53-57
Abstract:
In a supporting electrolyte containing 0.1 mol/L NH4Ac(pH 7.8), a reduction peak of clozapine(CLP) was found by linear-sweep voltammetry at Hg electrode. The peak shows a potential of -1.34 V(vs. Ag/AgCl) and adsorptive characteristics. When the concentration of CLP is sufficiently low, the sweep rate is sufficiently rapid and the accumulation time is sufficiently long, the peak current is totally contributed by the reduction of the adsorbed CLP. The adsorbed species is most probably neutral molecules of CLP. The saturated adsorption amount of CLP at Hg electrode is 2.7×10-10 mol/cm2 and every CLP molecule occupies 0.62 nm2. On the surface of HMDE, the adsorption of CLP obeys Frumkin adsorption isotherm. The adsorption coefficient is 6.28×105, the attractive factor is 0.75. The number of electrons transferred per CLP molecule, n, is 2 and the transfer coefficient of the irreversible adsorptive system of CLP is 0.53. The mechanism of electrochemical reduction of CLP at Hg electrode has been explored. The detection limit of the adsorptive stripping voltammetry of CLP is 8.0×10-9 mol/L under optimum condition.
In a supporting electrolyte containing 0.1 mol/L NH4Ac(pH 7.8), a reduction peak of clozapine(CLP) was found by linear-sweep voltammetry at Hg electrode. The peak shows a potential of -1.34 V(vs. Ag/AgCl) and adsorptive characteristics. When the concentration of CLP is sufficiently low, the sweep rate is sufficiently rapid and the accumulation time is sufficiently long, the peak current is totally contributed by the reduction of the adsorbed CLP. The adsorbed species is most probably neutral molecules of CLP. The saturated adsorption amount of CLP at Hg electrode is 2.7×10-10 mol/cm2 and every CLP molecule occupies 0.62 nm2. On the surface of HMDE, the adsorption of CLP obeys Frumkin adsorption isotherm. The adsorption coefficient is 6.28×105, the attractive factor is 0.75. The number of electrons transferred per CLP molecule, n, is 2 and the transfer coefficient of the irreversible adsorptive system of CLP is 0.53. The mechanism of electrochemical reduction of CLP at Hg electrode has been explored. The detection limit of the adsorptive stripping voltammetry of CLP is 8.0×10-9 mol/L under optimum condition.
1997, 14(3): 58-61
Abstract:
The trans form of the title complex was synthesized in high yield by interaction of equimole RuCl2(Ph3P)4 or RuCl2(DMSO)4 (DMSO=dimethylsulfoxide) with P2N2 (i.e.=N,N'-bis[o-(diphenylphosphine-benzylidene)] ethylene diamine) in refluxing toluene. The complex has been investigated as catalyst for selective hydrogenation of T,U-unsaturated acids and some functionalized olefins. The hydrogenation catalytic activity was observed as follows:styrene > acrylic acid > benzaldehyde > salicyl aldehyde > cyclohexanone > furfural > methylacrylic acid》acetophenone. The effect of addition of NH4PF6 or AgNO3 as promotor has also been studied.
The trans form of the title complex was synthesized in high yield by interaction of equimole RuCl2(Ph3P)4 or RuCl2(DMSO)4 (DMSO=dimethylsulfoxide) with P2N2 (i.e.=N,N'-bis[o-(diphenylphosphine-benzylidene)] ethylene diamine) in refluxing toluene. The complex has been investigated as catalyst for selective hydrogenation of T,U-unsaturated acids and some functionalized olefins. The hydrogenation catalytic activity was observed as follows:styrene > acrylic acid > benzaldehyde > salicyl aldehyde > cyclohexanone > furfural > methylacrylic acid》acetophenone. The effect of addition of NH4PF6 or AgNO3 as promotor has also been studied.
1997, 14(3): 62-65
Abstract:
By means of TPD、XRD、BET and H2S-resistence test a comparative study of the copper-based catalyst C207 and its modified one (with addition of some metal oxide) NC208 for methanol sunthesis from syngas has been carried out. The results showed that NC208 had an obviously better thermostability and H2S-resistance, its optimum working temperature was 240℃, about 10℃ lower than C207s. NC208 had higher Cu+/Cu0 ratio and valency stability. Under the reaction conditions of 5.0 MPa and 210~230℃ the catalytic activity of NC208 was 30% higher than that of C207. Under 10.0 MPa and 2.5%~4.5% CO content in syngas, after heat treatment at 450℃ for 5 h, the conversion of CO was about 7% higher than that on using NC208.
By means of TPD、XRD、BET and H2S-resistence test a comparative study of the copper-based catalyst C207 and its modified one (with addition of some metal oxide) NC208 for methanol sunthesis from syngas has been carried out. The results showed that NC208 had an obviously better thermostability and H2S-resistance, its optimum working temperature was 240℃, about 10℃ lower than C207s. NC208 had higher Cu+/Cu0 ratio and valency stability. Under the reaction conditions of 5.0 MPa and 210~230℃ the catalytic activity of NC208 was 30% higher than that of C207. Under 10.0 MPa and 2.5%~4.5% CO content in syngas, after heat treatment at 450℃ for 5 h, the conversion of CO was about 7% higher than that on using NC208.
1997, 14(3): 66-69
Abstract:
Seven novel amino acid derivatives of benzisoselenazolone were found to have significant glutathione peroxidase(GSH-Px) like activity as determined by coupling test using NADPH/GSSG reductase as an indicator. They catalysed the reduction reaction of hydroperoxides in the presence of GSH with good structure-activity relationships. The activities of the compounds 1, 6 and 7 were almost equal to that of Ebselen, which is known as the best mimic of GSH-Px. It was also found that the concentration of the mimics and GSH, the temperature and the pH value of the reaction system had great effects on the catalytic activity of the mimics. The apparent activation energy of compounds 4 and 7 had been determined as 101 and 87.3 kJ/mol respectively.
Seven novel amino acid derivatives of benzisoselenazolone were found to have significant glutathione peroxidase(GSH-Px) like activity as determined by coupling test using NADPH/GSSG reductase as an indicator. They catalysed the reduction reaction of hydroperoxides in the presence of GSH with good structure-activity relationships. The activities of the compounds 1, 6 and 7 were almost equal to that of Ebselen, which is known as the best mimic of GSH-Px. It was also found that the concentration of the mimics and GSH, the temperature and the pH value of the reaction system had great effects on the catalytic activity of the mimics. The apparent activation energy of compounds 4 and 7 had been determined as 101 and 87.3 kJ/mol respectively.
1997, 14(3): 70-73
Abstract:
The mechanism of extraction of acetic acid with primary amine N1923 has been studied at 298±1 K. The composition of the extracted complexes was determined by methods of the corresponding solution, saturation extraction and infrared spectrometry. The influence of temperature upon the extraction equilibrium has been discussed. The back-extraction of the acetic acid from loading organic phase with NaOH solution has been explored.
The mechanism of extraction of acetic acid with primary amine N1923 has been studied at 298±1 K. The composition of the extracted complexes was determined by methods of the corresponding solution, saturation extraction and infrared spectrometry. The influence of temperature upon the extraction equilibrium has been discussed. The back-extraction of the acetic acid from loading organic phase with NaOH solution has been explored.
1997, 14(3): 74-77
Abstract:
The B stage codensed polynuclear aromatic resin (B-COPNA) was synthesized from pyrene and benzaldehyde in the presence of p-toluenesulfonic acid. Its structure was characterized by IR, 1H NMR and 13 C NMR measurements. Results showed that the polymer possesses triarylmethane structure. On heating under inert gas at 500℃, 600℃ and 800℃ COPNA resin dehydrogenated and converted to an insoluble and infusible one, which, as ESR results shows, exhibits an obvious paramagnetic property and very high concentration of stable free radicals:2.28×1022 spins/g.
The B stage codensed polynuclear aromatic resin (B-COPNA) was synthesized from pyrene and benzaldehyde in the presence of p-toluenesulfonic acid. Its structure was characterized by IR, 1H NMR and 13 C NMR measurements. Results showed that the polymer possesses triarylmethane structure. On heating under inert gas at 500℃, 600℃ and 800℃ COPNA resin dehydrogenated and converted to an insoluble and infusible one, which, as ESR results shows, exhibits an obvious paramagnetic property and very high concentration of stable free radicals:2.28×1022 spins/g.
1997, 14(3): 78-80
Abstract:
Six dialkyltin mercaptides have been prepared by reaction of bis(U-alkoxycarbonylethyl) tin dichlorides with i-octyl thioacetate, i-octyl thiopropionate and dodecanethiol. Their properties as heat stabilizer for polyvinyl chloride during processing have been investigated.
Six dialkyltin mercaptides have been prepared by reaction of bis(U-alkoxycarbonylethyl) tin dichlorides with i-octyl thioacetate, i-octyl thiopropionate and dodecanethiol. Their properties as heat stabilizer for polyvinyl chloride during processing have been investigated.
1997, 14(3): 81-83
Abstract:
The solid-solid state reaction of 2,2'-(p-phenylenedimethylenethio) diacetic acid with cobalt acetate tetrahydrate has been studied. XRD, IR, ESR, TG-DTA and elemental analysis were used to characterize the solid product. The kinetics of the isothermal solid state reaction was investigated by using the electrical conductivity measurement. The kinetics of this system conforms to a A3 mechanism, the activation energy is calculated to be Ea=104.7 kJ/mol.
The solid-solid state reaction of 2,2'-(p-phenylenedimethylenethio) diacetic acid with cobalt acetate tetrahydrate has been studied. XRD, IR, ESR, TG-DTA and elemental analysis were used to characterize the solid product. The kinetics of the isothermal solid state reaction was investigated by using the electrical conductivity measurement. The kinetics of this system conforms to a A3 mechanism, the activation energy is calculated to be Ea=104.7 kJ/mol.
1997, 14(3): 84-86
Abstract:
An UV-spectrophotometric method for direct determination of furfural in liquor is reported. The method has a linear range 0~10 mg/L, correlation coefficient V=0.9984 and recovery 98.4%~104.6%.
An UV-spectrophotometric method for direct determination of furfural in liquor is reported. The method has a linear range 0~10 mg/L, correlation coefficient V=0.9984 and recovery 98.4%~104.6%.
1997, 14(3): 87-89
Abstract:
Nine alkyldimethylsilylmethyl T-naphthylacetates were synthesized. Their structures were characterized by elemental analysis, IR and 1H NMR measurements. The biological activity experiments showed that the compounds obtained gave a higher yield of orange than the unsilyl substituted ones.
Nine alkyldimethylsilylmethyl T-naphthylacetates were synthesized. Their structures were characterized by elemental analysis, IR and 1H NMR measurements. The biological activity experiments showed that the compounds obtained gave a higher yield of orange than the unsilyl substituted ones.
1997, 14(3): 90-92
Abstract:
The synthetic method of aryloxy(arylthio) acetic acids has been improved. Seventeen aryloxyacetic acids and three arylthioacetic acids have been easily synthesized by refluxing sodium chloroacetate with sodium salts of phenols(thoils) in ethanol-water mixture.
The synthetic method of aryloxy(arylthio) acetic acids has been improved. Seventeen aryloxyacetic acids and three arylthioacetic acids have been easily synthesized by refluxing sodium chloroacetate with sodium salts of phenols(thoils) in ethanol-water mixture.
1997, 14(3): 93-95
Abstract:
Poly(butyl acrylate)/poly(methyl methacrylate) core/shell impact modifiers were prepared by seeded emulsion polymerization. The structures of the modifiers have been designed and the factors affecting the structure formation have been discussed. In order to inhibite the formation of new particles during seeded polymerization, an oil-soluble redox initiator was used and the concentration of the emulsifier and feed speed of the monomer were controlled. The results showed that the particle size of the impact modifier can be adjusted by varing the amount of seed emulsion used in the seeded emulsion polymerization. TEM micrographs showed that the impact modifiers are monodisperse particles of spherical structure.
Poly(butyl acrylate)/poly(methyl methacrylate) core/shell impact modifiers were prepared by seeded emulsion polymerization. The structures of the modifiers have been designed and the factors affecting the structure formation have been discussed. In order to inhibite the formation of new particles during seeded polymerization, an oil-soluble redox initiator was used and the concentration of the emulsifier and feed speed of the monomer were controlled. The results showed that the particle size of the impact modifier can be adjusted by varing the amount of seed emulsion used in the seeded emulsion polymerization. TEM micrographs showed that the impact modifiers are monodisperse particles of spherical structure.
1997, 14(3): 96-98
Abstract:
Eight alkyl phosphoric dialkyl esters were synthesized by reacting potassium dialkyl phosphite with different halohydrocarbons in the presence of quaternary ammonium salt and KOH. Their structures were identified by IR and NMR. The mixtures of epoxy resin with phosphonates showed a better flame retardancy and plasticization than that with phosphates.
Eight alkyl phosphoric dialkyl esters were synthesized by reacting potassium dialkyl phosphite with different halohydrocarbons in the presence of quaternary ammonium salt and KOH. Their structures were identified by IR and NMR. The mixtures of epoxy resin with phosphonates showed a better flame retardancy and plasticization than that with phosphates.
1997, 14(3): 99-101
Abstract:
The oligomerization of ethylene catalyzed by P-O ligands, diphenylphosphi nobenzoic acid(DPP) and diphenylphosphinoacetic sodium(DPE), has been investigated. In catalytic system DPP/NiCl2·6H2O/NaBH4 the content of lower olefins (C4=~C8=) increases with increase of DPP/Ni molar ratio and the content of higher olefins decreases markedly. Phosphines P(CH3)2Ph, P(OPh)3, P(C4H9)3, PClPh2 and PPh3 added in the catalytic system DPE/NiCl2·6H2O/NaBH4 increase the content of C4= up ot 77.96%~95.29% from 49.45%(without their addition). Among these phosphines only P(C4H9)3 could increase the selectivity to linear T-olefin. The reaction conditions have been investigated.
The oligomerization of ethylene catalyzed by P-O ligands, diphenylphosphi nobenzoic acid(DPP) and diphenylphosphinoacetic sodium(DPE), has been investigated. In catalytic system DPP/NiCl2·6H2O/NaBH4 the content of lower olefins (C4=~C8=) increases with increase of DPP/Ni molar ratio and the content of higher olefins decreases markedly. Phosphines P(CH3)2Ph, P(OPh)3, P(C4H9)3, PClPh2 and PPh3 added in the catalytic system DPE/NiCl2·6H2O/NaBH4 increase the content of C4= up ot 77.96%~95.29% from 49.45%(without their addition). Among these phosphines only P(C4H9)3 could increase the selectivity to linear T-olefin. The reaction conditions have been investigated.
1997, 14(3): 102-104
Abstract:
The chemical adsorption behavior of three adsorbates (methanol, n-butylamine and hydrogen gas) on Ni-W/F-Al2O3-SiO2 catalyst and supported Ni catalyst have been investigated. The roughness fractal dimension (Dr) and the chemisorption fractal dimension (Dc) of two catalysts were estimated based on the fractal geometry consideration. The difference between Dc and Dr was used to characterize the chemical heteorgeneity of the active sites on the catalyst surface. The results showed that the chemical heterogeneity of the acid sites of Ni-W/F-Al2O3-SiO2 was very great and that of the supported Ni catalyst was decreased with increase of the impregnation time during catalyst preparation. For the supported Ni catalyst it is found that the chemical heterogeneity of its active surface was eliminated after four times impregnation.
The chemical adsorption behavior of three adsorbates (methanol, n-butylamine and hydrogen gas) on Ni-W/F-Al2O3-SiO2 catalyst and supported Ni catalyst have been investigated. The roughness fractal dimension (Dr) and the chemisorption fractal dimension (Dc) of two catalysts were estimated based on the fractal geometry consideration. The difference between Dc and Dr was used to characterize the chemical heteorgeneity of the active sites on the catalyst surface. The results showed that the chemical heterogeneity of the acid sites of Ni-W/F-Al2O3-SiO2 was very great and that of the supported Ni catalyst was decreased with increase of the impregnation time during catalyst preparation. For the supported Ni catalyst it is found that the chemical heterogeneity of its active surface was eliminated after four times impregnation.
1997, 14(3): 105-106
Abstract:
The cane drosses or corncobs were hydrolytically decomposed to xylose liquid of concentration 50%, which was then electrolytically reduced on the film with current density 5 A/m2 and 25~30 V(dc) in Na2SO4 solution of pH=7. Over 95% xylose were reduced to xylitol. Yield over 8.6%, purity 98.5%.
The cane drosses or corncobs were hydrolytically decomposed to xylose liquid of concentration 50%, which was then electrolytically reduced on the film with current density 5 A/m2 and 25~30 V(dc) in Na2SO4 solution of pH=7. Over 95% xylose were reduced to xylitol. Yield over 8.6%, purity 98.5%.
1997, 14(3): 107-108
Abstract:
Some N-alkyl-T-aminobenzylenephosphonic acids were prepared directly from benzaldehyde or p-nitrobenzaldehyde with amines and phosphorous acid using tetramethylenesulfone as solvent. The method offers the advantages of giving good yields, easy purification of the products, simplicity and rapidity.
Some N-alkyl-T-aminobenzylenephosphonic acids were prepared directly from benzaldehyde or p-nitrobenzaldehyde with amines and phosphorous acid using tetramethylenesulfone as solvent. The method offers the advantages of giving good yields, easy purification of the products, simplicity and rapidity.
1997, 14(3): 109-110
Abstract:
Polytrimethylsilylpropyne(PTMSP) ultrathin composite membrane has been prepared. The effects of the morphology and structure of the support membrane on gas permeation of the composite membrane has been studied. The relationship between the relative molecular mass of PTMSP and permeability of the membrane are discussed, and the effects of the membrane forming process on its gas permeation property has been examined.
Polytrimethylsilylpropyne(PTMSP) ultrathin composite membrane has been prepared. The effects of the morphology and structure of the support membrane on gas permeation of the composite membrane has been studied. The relationship between the relative molecular mass of PTMSP and permeability of the membrane are discussed, and the effects of the membrane forming process on its gas permeation property has been examined.
1997, 14(3): 111-112
Abstract:
Milk powder was emulsified by emulsifier OP. The iron in it was then determined by FAAS using air-acetylene flame. The results are consistent with those obtained by ashing method.
Milk powder was emulsified by emulsifier OP. The iron in it was then determined by FAAS using air-acetylene flame. The results are consistent with those obtained by ashing method.
1997, 14(3): 113-114
Abstract:
A series of 2-(4-R-phenylsulfonyl)-1-(2-thienyl) ethanone( R=H, CH3, F, Cl, Br) were prepared in 75%~96% yields by reaction of sodium arylsulfinate with 2-chloro-1-(2-thienyl) ethanone in the presence of triethyl benzylam monium ohldride at 80~85℃.Their structures were confirm ed by elemental analysis, IR and 1H NMR.
A series of 2-(4-R-phenylsulfonyl)-1-(2-thienyl) ethanone( R=H, CH3, F, Cl, Br) were prepared in 75%~96% yields by reaction of sodium arylsulfinate with 2-chloro-1-(2-thienyl) ethanone in the presence of triethyl benzylam monium ohldride at 80~85℃.Their structures were confirm ed by elemental analysis, IR and 1H NMR.
1997, 14(3): 115-116
Abstract:
Reacting guanosine with benzoyl chloride gave a mixture containing 2',3',5'-tribenzoyl guanosine. After distillation in vacuum the residual solid was acetylated directly and 1-O-acetyl-2,3,5-tri-O-benzoyl-U-D-ribofuranose (2) was obtained. Being reacted with Me3SiCN, (2) led to the title compound(1). The method reported here is more convenient and cheaper with a considerably higher yield.
Reacting guanosine with benzoyl chloride gave a mixture containing 2',3',5'-tribenzoyl guanosine. After distillation in vacuum the residual solid was acetylated directly and 1-O-acetyl-2,3,5-tri-O-benzoyl-U-D-ribofuranose (2) was obtained. Being reacted with Me3SiCN, (2) led to the title compound(1). The method reported here is more convenient and cheaper with a considerably higher yield.
