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1994 Volume 11 Issue 2
1994, 11(2): 1-6
Abstract:
The phase diagrams showed that for Triton X-100/C10H21OH/H2O system thelamellar liquid crystals were formed more easily and were more stable than Triton X-100/C6H6/H2O system lamellar liquid crystals.SAXD showed that C10H21OH and Triton X-100are arranged in turn in the amphipathic-layer of Triton X-100/C10H21OH/H2O lamellar liquidcrystal and that the thickness of the layer d0 was independent of the weight ratio of C10H21OHto Triton X-100.When C6H6 was used instead of C10H21OH as in Triton X-100/C6H6/H2Olamellar liquid crystals,the d0 values increased with increase of weight ratio of C6H6/Triton X-100.
The phase diagrams showed that for Triton X-100/C10H21OH/H2O system thelamellar liquid crystals were formed more easily and were more stable than Triton X-100/C6H6/H2O system lamellar liquid crystals.SAXD showed that C10H21OH and Triton X-100are arranged in turn in the amphipathic-layer of Triton X-100/C10H21OH/H2O lamellar liquidcrystal and that the thickness of the layer d0 was independent of the weight ratio of C10H21OHto Triton X-100.When C6H6 was used instead of C10H21OH as in Triton X-100/C6H6/H2Olamellar liquid crystals,the d0 values increased with increase of weight ratio of C6H6/Triton X-100.
1994, 11(2): 7-12
Abstract:
The characteristics of molecular motion of the vinylidene fluoride (73)/trifluoro ethylene (27) copolymer ferroelectric have been investigated by dielectric relaxation measure-ments at low temperatures and low frequencies.With increase of the crystallinity of the copolymer,the Curie-point temperature Tc decreased and the dielectric constant increased in the region of ferroelectric-paraelectric phase transition.The frequency spectra of the copoly-mers below room temperature consisted of a low-frequency part ascribed to the micro-Brownian motion of molecular segments in the noncrystalline regions and a high-frequency part designated as the local motions of small-scale segments.The Tg (=-37℃) and △H (=48.8kJ/mol) of copolymers were obtained from the fitted results using two Cole-Cole functions andcalculation with WLF equation and Arrhenius formula respectively.
The characteristics of molecular motion of the vinylidene fluoride (73)/trifluoro ethylene (27) copolymer ferroelectric have been investigated by dielectric relaxation measure-ments at low temperatures and low frequencies.With increase of the crystallinity of the copolymer,the Curie-point temperature Tc decreased and the dielectric constant increased in the region of ferroelectric-paraelectric phase transition.The frequency spectra of the copoly-mers below room temperature consisted of a low-frequency part ascribed to the micro-Brownian motion of molecular segments in the noncrystalline regions and a high-frequency part designated as the local motions of small-scale segments.The Tg (=-37℃) and △H (=48.8kJ/mol) of copolymers were obtained from the fitted results using two Cole-Cole functions andcalculation with WLF equation and Arrhenius formula respectively.
1994, 11(2): 13-17
Abstract:
Nine phenolic polycondensates with crown ethers were prepared by the condensation of 2,6-dihydroxymehtyl-4-methyl phenol (or 2,6-dihydroxymethyl-4-sulfo phenol) withd1benzo-18-crown-6(2B18C6),dibenzo-24-crown-8(2B24C8),benzo-15-crown-5(B15C5),benzo-18-crown-6(B18C6) respectively,and characterized by IR,1H NMR and DSC.The polymeric crown ethers can be used as complexing resins to enrich cations and as stationary phase in gas chromatography for separation of mixed organic compounds.
Nine phenolic polycondensates with crown ethers were prepared by the condensation of 2,6-dihydroxymehtyl-4-methyl phenol (or 2,6-dihydroxymethyl-4-sulfo phenol) withd1benzo-18-crown-6(2B18C6),dibenzo-24-crown-8(2B24C8),benzo-15-crown-5(B15C5),benzo-18-crown-6(B18C6) respectively,and characterized by IR,1H NMR and DSC.The polymeric crown ethers can be used as complexing resins to enrich cations and as stationary phase in gas chromatography for separation of mixed organic compounds.
1994, 11(2): 18-22
Abstract:
Cyclovoltametric results showed that there exist charge transfer complexes (CTC) consisted of cationic dyes,amino acids and molecular oxygen which possess more positive re-duction potentials or higher peak currents than dyes.Irradiating the CTCS at their λmaxCTC reveals that it is the amino acids of the silk that accelerate the light fading of the dyes.
Cyclovoltametric results showed that there exist charge transfer complexes (CTC) consisted of cationic dyes,amino acids and molecular oxygen which possess more positive re-duction potentials or higher peak currents than dyes.Irradiating the CTCS at their λmaxCTC reveals that it is the amino acids of the silk that accelerate the light fading of the dyes.
1994, 11(2): 23-26
Abstract:
Three new chelating agents of phenylenediacyl bis 1-phenyl-3-methylpyrazol-5-one (PMP) end groups have been synthesized.Their structures have been characterized by elemental analysis,UV,IR,1H NMR and MS spectra.The extraction of U (Ⅵ) with these compounds have been studied.The values of the pH1/2,logKex and chemical composition of the complexes have been obtained by the slope analysis method.
Three new chelating agents of phenylenediacyl bis 1-phenyl-3-methylpyrazol-5-one (PMP) end groups have been synthesized.Their structures have been characterized by elemental analysis,UV,IR,1H NMR and MS spectra.The extraction of U (Ⅵ) with these compounds have been studied.The values of the pH1/2,logKex and chemical composition of the complexes have been obtained by the slope analysis method.
1994, 11(2): 27-30
Abstract:
The photopolymerization of phenylglycidylether (PGE) and an epoxy resin (E-51) initiated by bis-[4-(diphenylsulfonio) phenyl]sulfide-bis-hexafluorophosphate[BDS(PF6)2] has been studied using a modified home-made CDR-1 model differential scanning calorimeter.For PGE,the polymerization rate was proportional to the 0.90 power of the initiator concentration and to the 0.87 power of the light intensity.For E-51,the polymerization rate was proportional to the 0.78 power of the initiator concentration,whereas the influence of light intensity was rather complicated.The polymerization rate increased with temperature markedly at≤70℃(for PGE) or≤80℃(for E-51).PGE as a reactive diluent greatly in-creased the polymerization rate of E-51.
The photopolymerization of phenylglycidylether (PGE) and an epoxy resin (E-51) initiated by bis-[4-(diphenylsulfonio) phenyl]sulfide-bis-hexafluorophosphate[BDS(PF6)2] has been studied using a modified home-made CDR-1 model differential scanning calorimeter.For PGE,the polymerization rate was proportional to the 0.90 power of the initiator concentration and to the 0.87 power of the light intensity.For E-51,the polymerization rate was proportional to the 0.78 power of the initiator concentration,whereas the influence of light intensity was rather complicated.The polymerization rate increased with temperature markedly at≤70℃(for PGE) or≤80℃(for E-51).PGE as a reactive diluent greatly in-creased the polymerization rate of E-51.
1994, 11(2): 31-34
Abstract:
The adsorption of oxygen on ZnSnO3 has been studied by X-ray photoelectron spectroscopy.At temperatures ranging from 25℃ to 300℃ the charge states of the chemisorbed oxygen were found to be O2- and O-,and the former may convert into O-(or O2-) with increasing temperature.ZnSnO3 is a typical surface-controlled sensor.The activation energy of oxygen adsorbed on ZnSnO3 was 0.52eV.The ZnSnO3-based sensor showed the greatest sensitivity to C2H5OH gas than to other reducing gases:petrol,C2H2,LPG,and H2.
The adsorption of oxygen on ZnSnO3 has been studied by X-ray photoelectron spectroscopy.At temperatures ranging from 25℃ to 300℃ the charge states of the chemisorbed oxygen were found to be O2- and O-,and the former may convert into O-(or O2-) with increasing temperature.ZnSnO3 is a typical surface-controlled sensor.The activation energy of oxygen adsorbed on ZnSnO3 was 0.52eV.The ZnSnO3-based sensor showed the greatest sensitivity to C2H5OH gas than to other reducing gases:petrol,C2H2,LPG,and H2.
1994, 11(2): 35-39
Abstract:
Ninefeen solid complexes of 4',5'-diiodobenzo-15-crown-5,4',5'-dibromobenzo-15-crown-5,4'-bromo-5'-nitrobenzo-15-crown-5,and tetrabromodibenzo-18-crown-6 with nitrates,perchlorates,chlorides of Mn (Ⅱ),Co (Ⅱ),Cu (Ⅱ),Zn (Ⅱ),Ag (Ⅰ),and Cd (Ⅱ) have been synthesized Their compositions and properties have been characterized by elemental analysis,thermal analysis,IR spectra,X-ray diffraction analysis and molar conductance measurements.
Ninefeen solid complexes of 4',5'-diiodobenzo-15-crown-5,4',5'-dibromobenzo-15-crown-5,4'-bromo-5'-nitrobenzo-15-crown-5,and tetrabromodibenzo-18-crown-6 with nitrates,perchlorates,chlorides of Mn (Ⅱ),Co (Ⅱ),Cu (Ⅱ),Zn (Ⅱ),Ag (Ⅰ),and Cd (Ⅱ) have been synthesized Their compositions and properties have been characterized by elemental analysis,thermal analysis,IR spectra,X-ray diffraction analysis and molar conductance measurements.
1994, 11(2): 40-43
Abstract:
The polyaniline film electrodes with platinum microparticles were prepared by electrochemical method.The morphology of the electrode was examined by scanning electron microscopy.Oxidation of methanol in 0.5mol/L H2SO4 indicated that the platinum microparticles were dispersed in a three-dimensional array in polyaniline film,mainly loaded on the surface of polyaniline film.A very high electrocatalytic activity in oxidation of methanol in 0.5mol/L H2SO4 was found.The catalytic current was much higher than that obtained on the bare platinum and polyaniline film electrode.
The polyaniline film electrodes with platinum microparticles were prepared by electrochemical method.The morphology of the electrode was examined by scanning electron microscopy.Oxidation of methanol in 0.5mol/L H2SO4 indicated that the platinum microparticles were dispersed in a three-dimensional array in polyaniline film,mainly loaded on the surface of polyaniline film.A very high electrocatalytic activity in oxidation of methanol in 0.5mol/L H2SO4 was found.The catalytic current was much higher than that obtained on the bare platinum and polyaniline film electrode.
1994, 11(2): 44-47
Abstract:
The stability of polydimethylsiloxane cationic emulsions towards electrolytes was studied.The results indicate that inorganic salts such as NaCl or Na2SO4 from the emulsfierand catalyst during the emulsion polymerization may cause a slow coagulation of emulsionparticles to form large emulsion particles which would result in creaming of the cationicemulsions.Addition of a non-ionic surfactant of polyethylene glycol oxide type greatly in-creases the stability of the cationic emulsions towards electrolytes,preventing the coagulation of emulsions particles and formation of large emulsion particles caused by electrolytes.
The stability of polydimethylsiloxane cationic emulsions towards electrolytes was studied.The results indicate that inorganic salts such as NaCl or Na2SO4 from the emulsfierand catalyst during the emulsion polymerization may cause a slow coagulation of emulsionparticles to form large emulsion particles which would result in creaming of the cationicemulsions.Addition of a non-ionic surfactant of polyethylene glycol oxide type greatly in-creases the stability of the cationic emulsions towards electrolytes,preventing the coagulation of emulsions particles and formation of large emulsion particles caused by electrolytes.
1994, 11(2): 48-52
Abstract:
A new optical sensor for the determination of picric acid based on reversible fluorescence quenching of anthracene dissolved in plasticized poly (vinyl chloride) membrane has been developed.The optimum membrane of the sensor consists of 6~8mg anthracene,50mg PVC,100mg bis (2-ethylhexyl) phalate.With the optimum membrane described,picric acid in sample solutions from 3.04×10-6 mol/L to 6.16×10-3 mol/L can be determined.Besides a high reproducibility of the optical signals,the very short response times of less than 40s are realized.The sensor has a good selectivity,common hydrophobic anions do not interfere the determination.The sensor has been applied to indirect determination of some drugs,such as quinine,cinchonine,with satisfactory results.
A new optical sensor for the determination of picric acid based on reversible fluorescence quenching of anthracene dissolved in plasticized poly (vinyl chloride) membrane has been developed.The optimum membrane of the sensor consists of 6~8mg anthracene,50mg PVC,100mg bis (2-ethylhexyl) phalate.With the optimum membrane described,picric acid in sample solutions from 3.04×10-6 mol/L to 6.16×10-3 mol/L can be determined.Besides a high reproducibility of the optical signals,the very short response times of less than 40s are realized.The sensor has a good selectivity,common hydrophobic anions do not interfere the determination.The sensor has been applied to indirect determination of some drugs,such as quinine,cinchonine,with satisfactory results.
1994, 11(2): 53-56
Abstract:
Needlelike α-FeOOH microparticles have been prepared by the acid method.Theeffects of the Fe2+ concentration,pH value of solution,temperature and reaction time on themean lengths of α-FeOOH microparticles have been investigated.
Needlelike α-FeOOH microparticles have been prepared by the acid method.Theeffects of the Fe2+ concentration,pH value of solution,temperature and reaction time on themean lengths of α-FeOOH microparticles have been investigated.
1994, 11(2): 57-61
Abstract:
ε-Caprolactone was rapidly polymerizaed at 225℃ in the presence of succinic acid under nitrogen atmosphere.The results of polymer characterization through IR,1H NMR and 13C NMR suggested that the acid has been incorporated into poly (ε-caprolactone) chain,giving two terminal carboxylic acid groups.The VPO,1H NMR and the end group titration methods have been used to determine the molecular weight of the polymers.It is found that the molecular weights of the polymers increased with the increase of the ratio of ε-caprolactam to succinic acid and after 3 hours of reaction it reached a maximum value,Mn=3×103.
ε-Caprolactone was rapidly polymerizaed at 225℃ in the presence of succinic acid under nitrogen atmosphere.The results of polymer characterization through IR,1H NMR and 13C NMR suggested that the acid has been incorporated into poly (ε-caprolactone) chain,giving two terminal carboxylic acid groups.The VPO,1H NMR and the end group titration methods have been used to determine the molecular weight of the polymers.It is found that the molecular weights of the polymers increased with the increase of the ratio of ε-caprolactam to succinic acid and after 3 hours of reaction it reached a maximum value,Mn=3×103.
1994, 11(2): 62-66
Abstract:
The sulfurization and desulfurization of water gas shift catalyst CoMoK/Al2O3 have been investigated by TPS and TPDS techniques,using H2S and CS2 as sulfurizing agents.Only H2S consumption and H2O formation were found when the catalyst was sulfurized with H2S/H2.When CS2/H2 was used as sulfurizing agent,CO2 was formed at first,then CH4,H2O and H2S as shown by TPS curves.Carbon deposition on the catalyst during the sulfurization with CS2/H2 caused lowering of the catalytic activity,but the deposifed carbon could be reduced in the run of WGS reaction.The results of TPDS indicated that N2 does not act in desulfurization and H2 or CO also does not give an obvious effect on the desulfurization.However,H2O shows a strong desulfurizing effect.Oxygen caused a permanent loss of the activity in some part of the catalyst.XPS results showed that Mo4+ has been changed to Mo5+ and Mo6+ in desulfurized catalyst,decreasing its activity.
The sulfurization and desulfurization of water gas shift catalyst CoMoK/Al2O3 have been investigated by TPS and TPDS techniques,using H2S and CS2 as sulfurizing agents.Only H2S consumption and H2O formation were found when the catalyst was sulfurized with H2S/H2.When CS2/H2 was used as sulfurizing agent,CO2 was formed at first,then CH4,H2O and H2S as shown by TPS curves.Carbon deposition on the catalyst during the sulfurization with CS2/H2 caused lowering of the catalytic activity,but the deposifed carbon could be reduced in the run of WGS reaction.The results of TPDS indicated that N2 does not act in desulfurization and H2 or CO also does not give an obvious effect on the desulfurization.However,H2O shows a strong desulfurizing effect.Oxygen caused a permanent loss of the activity in some part of the catalyst.XPS results showed that Mo4+ has been changed to Mo5+ and Mo6+ in desulfurized catalyst,decreasing its activity.
1994, 11(2): 67-69
Abstract:
The dispersion copolymerization of styrene and p-t-butoxycarbonyloxystyrene in alcohols has been studied.The monodispersion particles prepared sized 1.3~6.6 μm.The effects of solubility parameters of solvents,reaction temperature,monomer ratio and dispersant on the formation of copolymer particles have been examined.
The dispersion copolymerization of styrene and p-t-butoxycarbonyloxystyrene in alcohols has been studied.The monodispersion particles prepared sized 1.3~6.6 μm.The effects of solubility parameters of solvents,reaction temperature,monomer ratio and dispersant on the formation of copolymer particles have been examined.
1994, 11(2): 70-72
Abstract:
Three kinds of optically active ligands were combined with copper (Ⅱ)-acetate to give 8 chiral copper complexes:d-camphor-10-sulfonic acid and its derivatives of Schiff base,hydroxypinocamphone and its derivatives of Schiff base,and bis-oxazoline.The optical yields of 2,2-diphenylcyclopropanecarboxylic ethyl ester were 5%~50e.e..The reaction of diphenylethylene or isobutylene with menthyl diazoaceteta by chiral copper (Ⅱ) bis-oxazo-line gave an enantioselectivity of 81.5% e.e.and 95% e.e.,respectively.
Three kinds of optically active ligands were combined with copper (Ⅱ)-acetate to give 8 chiral copper complexes:d-camphor-10-sulfonic acid and its derivatives of Schiff base,hydroxypinocamphone and its derivatives of Schiff base,and bis-oxazoline.The optical yields of 2,2-diphenylcyclopropanecarboxylic ethyl ester were 5%~50e.e..The reaction of diphenylethylene or isobutylene with menthyl diazoaceteta by chiral copper (Ⅱ) bis-oxazo-line gave an enantioselectivity of 81.5% e.e.and 95% e.e.,respectively.
1994, 11(2): 73-76
Abstract:
The electrode coated with PVP (polyvinyl-pyridine) film electrostatically bound has been studied by means of cyclic voltammetry.The results showed that the electrode has a good electrocatalytic activity in the oxidation of Fe2+ to Fe3+ in aqueous acidic solution.The rate-controlling step and the kinetic parameters of catalytic reaction were determined by rotating disk electrode coated with PVP electrostatically bound PtCl62-.The rateconstant of the catalvtic reaction was calculated to be 5.67×106cm3·mol-1·s-1.The number of electron transfered and the anodic transfer coeffcient were determined.The electrode coated with promoted PVP electrostatically bound PtCl62- give very stable response for the oxidation of Fe2+ to Fe3+.
The electrode coated with PVP (polyvinyl-pyridine) film electrostatically bound has been studied by means of cyclic voltammetry.The results showed that the electrode has a good electrocatalytic activity in the oxidation of Fe2+ to Fe3+ in aqueous acidic solution.The rate-controlling step and the kinetic parameters of catalytic reaction were determined by rotating disk electrode coated with PVP electrostatically bound PtCl62-.The rateconstant of the catalvtic reaction was calculated to be 5.67×106cm3·mol-1·s-1.The number of electron transfered and the anodic transfer coeffcient were determined.The electrode coated with promoted PVP electrostatically bound PtCl62- give very stable response for the oxidation of Fe2+ to Fe3+.
1994, 11(2): 77-80
Abstract:
Scandium (Ⅲ) was extracted by the emulsion liquid membrane (ELM) method using 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-on as a carrier.The extraction rate of Sc (Ⅲ) was more than 95.5% and the separation factor for Sc (Ⅲ) and mixed rare earths βSC/RE was 32.0.The optimum conditions for the extraction as follows:pH=1.7~3.8 for feed liquid,PMBP 0.4%,surfactant Span 80.3%,mixed solution of liquid paraffin and kerosene 5%,concentration of HCl in the internal phase 3mol/L,Roi=1:1,Rwe=20:1.
Scandium (Ⅲ) was extracted by the emulsion liquid membrane (ELM) method using 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-on as a carrier.The extraction rate of Sc (Ⅲ) was more than 95.5% and the separation factor for Sc (Ⅲ) and mixed rare earths βSC/RE was 32.0.The optimum conditions for the extraction as follows:pH=1.7~3.8 for feed liquid,PMBP 0.4%,surfactant Span 80.3%,mixed solution of liquid paraffin and kerosene 5%,concentration of HCl in the internal phase 3mol/L,Roi=1:1,Rwe=20:1.
1994, 11(2): 81-84
Abstract:
The separation of ethanol/water mixture by pervaporation by crosslinked PVA-MA membrane containing LiCl,NaCl and KCl has been investigated.The flux increased markedly when salt content was less than 6 wt% in the dry membrane,and the separation factor increased when ethanol concentration in feed solution was high.The DSC results showed that the membranes adsorbed 5%~8wt% of free water from ethanol/water mixture (50/50wt/wt),which is hardly observed by weighing method.
The separation of ethanol/water mixture by pervaporation by crosslinked PVA-MA membrane containing LiCl,NaCl and KCl has been investigated.The flux increased markedly when salt content was less than 6 wt% in the dry membrane,and the separation factor increased when ethanol concentration in feed solution was high.The DSC results showed that the membranes adsorbed 5%~8wt% of free water from ethanol/water mixture (50/50wt/wt),which is hardly observed by weighing method.
1994, 11(2): 85-88
Abstract:
Trace amount of iron in atmospheric particulate matter has been directly deter-mined by graphite probe furnace atomic absorption spectrometry after collection with agraphite probe filter.The method was accurate,sensitive,and rapid.It has a recovery of 98% and a precision of 3.0% RSD,being checked against the certified values of NBS SRM-1648 urban particulate matter.The concentration of iron and absorbance (Peak-area mode) showed an excellent linear relation in the range of 0~100 ng/ml and no memory effect.Thecharacteristic mass and detection limit of iron were 14.6pg and 24.0pg,respectively.
Trace amount of iron in atmospheric particulate matter has been directly deter-mined by graphite probe furnace atomic absorption spectrometry after collection with agraphite probe filter.The method was accurate,sensitive,and rapid.It has a recovery of 98% and a precision of 3.0% RSD,being checked against the certified values of NBS SRM-1648 urban particulate matter.The concentration of iron and absorbance (Peak-area mode) showed an excellent linear relation in the range of 0~100 ng/ml and no memory effect.Thecharacteristic mass and detection limit of iron were 14.6pg and 24.0pg,respectively.
1994, 11(2): 89-92
Abstract:
The thermotropic phase transition of a series of long-chain n-alkylammonium halides (CnH2n+1NH3X,n=8~18,X=Cl,Br) has been studied by differential scanning calorimetry.2 The results show that the main transition temperature of solid-solid structural phase transitions is proportional to the length of hydrocarbon chain.The reverse transitions of the structural transitions exhibit variously hysteresis effect.The melting temperatures decrease linearly with the increase of hydrocarbon chain length.The results suggest that the process of phase transition is relative to the aging and crystallization course of the crystalline samples.
The thermotropic phase transition of a series of long-chain n-alkylammonium halides (CnH2n+1NH3X,n=8~18,X=Cl,Br) has been studied by differential scanning calorimetry.2 The results show that the main transition temperature of solid-solid structural phase transitions is proportional to the length of hydrocarbon chain.The reverse transitions of the structural transitions exhibit variously hysteresis effect.The melting temperatures decrease linearly with the increase of hydrocarbon chain length.The results suggest that the process of phase transition is relative to the aging and crystallization course of the crystalline samples.
1994, 11(2): 93-95
Abstract:
The title bisspirooxazine was synthesized by reacting 1-nitroso-2-naphthol with N,N'-1,4-butylene bis (2-methylene-3,3-dimethyl-indoline) in anhydrous ethanol.Thestructure of the compound was identified by IR,UV,1H NMR and elemental analysis.Thephotochromic behavior of the bisspiro compound also has been examined.
The title bisspirooxazine was synthesized by reacting 1-nitroso-2-naphthol with N,N'-1,4-butylene bis (2-methylene-3,3-dimethyl-indoline) in anhydrous ethanol.Thestructure of the compound was identified by IR,UV,1H NMR and elemental analysis.Thephotochromic behavior of the bisspiro compound also has been examined.
1994, 11(2): 96-98
Abstract:
Poly[1-(trimethylsilyl)-1-propyne]membranes were modified with fluorine gas.The fluorinated membranes exhibited good gas permeation properties and a significant increase in gas selectivity over the unfluorinated PTMSP membranes.The oxygen-nitrogen separation coefficient αO2/N2 increased from 1.5 to 4.75,the oxygen permeation PO2 coefficients decreased from 8600 to 370 barrier,and the constancy of gas permeabitily of the membranes was improved.
Poly[1-(trimethylsilyl)-1-propyne]membranes were modified with fluorine gas.The fluorinated membranes exhibited good gas permeation properties and a significant increase in gas selectivity over the unfluorinated PTMSP membranes.The oxygen-nitrogen separation coefficient αO2/N2 increased from 1.5 to 4.75,the oxygen permeation PO2 coefficients decreased from 8600 to 370 barrier,and the constancy of gas permeabitily of the membranes was improved.
1994, 11(2): 99-101
Abstract:
The apparent phase diagram of nylon1010/nylon6 copolymers has been determined by melting point analysis and DSC technique.There are four kinds of repeat chain structure units:1010,106,610 and 6.The theoretical value of the composition at the minimum melting point is 1010/6=60/40 in weight and 1/2 in motor ratio of nylon1010 to polycaprolactam very close to the results from phase diagram.
The apparent phase diagram of nylon1010/nylon6 copolymers has been determined by melting point analysis and DSC technique.There are four kinds of repeat chain structure units:1010,106,610 and 6.The theoretical value of the composition at the minimum melting point is 1010/6=60/40 in weight and 1/2 in motor ratio of nylon1010 to polycaprolactam very close to the results from phase diagram.
1994, 11(2): 102-104
Abstract:
An improved method for the preparation of title compounds was reported.Refluxing lchloro-2-(3,4-dichlorophenoxy) ethane 3a with sodium iodide in 1-butanol gave 1-iodo-2-(3,4-dichlorophenoxy) ethane 4a in yield of 87%.Reacting 4a with diethylamine in acetoneafforded 2-(3,4-dichlorophenoxy) ethyldiethylamine 1a in good yield (88%).The analogues 1b,2a and 2b were prepared similarly.
An improved method for the preparation of title compounds was reported.Refluxing lchloro-2-(3,4-dichlorophenoxy) ethane 3a with sodium iodide in 1-butanol gave 1-iodo-2-(3,4-dichlorophenoxy) ethane 4a in yield of 87%.Reacting 4a with diethylamine in acetoneafforded 2-(3,4-dichlorophenoxy) ethyldiethylamine 1a in good yield (88%).The analogues 1b,2a and 2b were prepared similarly.
1994, 11(2): 105-107
Abstract:
HIPS has been grafted by maleic anhydride in the presence of dicumyl peroxide.The influences of the reaction time and the feed ratio of the reactants on the graft rate have been examined.The IR spectra revealed the grafting.As to the dynamic mechanical propertyof the HIPS-g-MA,two new damping peaks at 29℃ and 52℃ were observed on its tanδ-T Curve.
HIPS has been grafted by maleic anhydride in the presence of dicumyl peroxide.The influences of the reaction time and the feed ratio of the reactants on the graft rate have been examined.The IR spectra revealed the grafting.As to the dynamic mechanical propertyof the HIPS-g-MA,two new damping peaks at 29℃ and 52℃ were observed on its tanδ-T Curve.
1994, 11(2): 108-109
Abstract:
A UV spectrophotometric method for the determination of the deacetylation degree of chitin is described based on the stability of chitosan in 0.001mol/L hydrochloric acid.The method is rapid,simple and the pretreatment of the samples is not necessary.
A UV spectrophotometric method for the determination of the deacetylation degree of chitin is described based on the stability of chitosan in 0.001mol/L hydrochloric acid.The method is rapid,simple and the pretreatment of the samples is not necessary.
1994, 11(2): 110-112
Abstract:
A linear copolymer of methyl acrylate and N-vinylcarbazole was prepared in ben-zene using AIBN as an initiator and then hydrolyzed in NaOH aqueous solution.The fluores-cence intensities of the aqueous solution of the hydrolyzed water soluble copolymer increasewith the increase of the pH value and the concentration of the cationic surfactant.Mercuryions (Hg2+) showed a certain quenching effect on the fluorescene of the copolymer aqueoussolution.The concentration of Hg2+ is in a linear relationship with the fluorescence intensity (logI0/I) of the polymer solution,that may be used to determine the trace amount of mer-cury by fluorescence quenching method.
A linear copolymer of methyl acrylate and N-vinylcarbazole was prepared in ben-zene using AIBN as an initiator and then hydrolyzed in NaOH aqueous solution.The fluores-cence intensities of the aqueous solution of the hydrolyzed water soluble copolymer increasewith the increase of the pH value and the concentration of the cationic surfactant.Mercuryions (Hg2+) showed a certain quenching effect on the fluorescene of the copolymer aqueoussolution.The concentration of Hg2+ is in a linear relationship with the fluorescence intensity (logI0/I) of the polymer solution,that may be used to determine the trace amount of mer-cury by fluorescence quenching method.
1994, 11(2): 113-115
Abstract:
Three crystal forms of chloroaluminum chlorophthalocyanine were obtained on a larger scale and identified by X-ray diffraction and Fourier transform infrared spectroscopy.Their absorption spectra in RTV silicone rubbers were recorded.
Three crystal forms of chloroaluminum chlorophthalocyanine were obtained on a larger scale and identified by X-ray diffraction and Fourier transform infrared spectroscopy.Their absorption spectra in RTV silicone rubbers were recorded.
1994, 11(2): 116-118
Abstract:
The relationship between the thermal property and conlposition of ethylene oxide/propylene oxide copolymer and its complexes with LiClO4 has been studied by DSC.It is found that the conductivity of the copolymer,as well as its salt-complexes was mainly affected by the amorphous portion of the copolymer.
The relationship between the thermal property and conlposition of ethylene oxide/propylene oxide copolymer and its complexes with LiClO4 has been studied by DSC.It is found that the conductivity of the copolymer,as well as its salt-complexes was mainly affected by the amorphous portion of the copolymer.
