Login In
1996 Volume 13 Issue 6
1996, 13(6): 1-6
Abstract:
This paper briefly describes the detection methods and factors influencing the solid state reaction at low-heating and room temperatures.Applications of the reaction in synthetic chemistry including cluster compounds, polymetallates,simple coordination compounds and metastable substances,material chemisty,and industry are summarized.
This paper briefly describes the detection methods and factors influencing the solid state reaction at low-heating and room temperatures.Applications of the reaction in synthetic chemistry including cluster compounds, polymetallates,simple coordination compounds and metastable substances,material chemisty,and industry are summarized.
1996, 13(6): 7-10
Abstract:
Poly(2,5-dimethylaniline)(PDMeAn) powder has been synthesized by chemical method. The electric conductivity of polymer was measured by the method of four standard probes.The polymer was characterized by FTIR,UV-Vis spectroscopy and cyclic voltammetry.The structure of PDMeAn is close to that of polyaniline and poly(2,5-dimethoxyaniline),with monomer units linked through the nitrogen atom at para positions.Intrinsic PDMeAn can be dissolved in a variety of organic solvents(DMF,DMSO,CHCl3,CH2Cl2,etc.).It exhibits excellent environmental stability and electrochemical activity.
Poly(2,5-dimethylaniline)(PDMeAn) powder has been synthesized by chemical method. The electric conductivity of polymer was measured by the method of four standard probes.The polymer was characterized by FTIR,UV-Vis spectroscopy and cyclic voltammetry.The structure of PDMeAn is close to that of polyaniline and poly(2,5-dimethoxyaniline),with monomer units linked through the nitrogen atom at para positions.Intrinsic PDMeAn can be dissolved in a variety of organic solvents(DMF,DMSO,CHCl3,CH2Cl2,etc.).It exhibits excellent environmental stability and electrochemical activity.
1996, 13(6): 11-14
Abstract:
In this paper the preparation of nano-grade TiO2 particles by photochemical reaction of Ti3+ in aqueous medium and the reaction kinetics are studied.Quantum size effect of absorption spectrum is discussed.The nano-size of TiO2 particles is determined by TEM to be 15~25 nm.The hydrogen evolved in the reaction process is analysed by gas chromatography.
In this paper the preparation of nano-grade TiO2 particles by photochemical reaction of Ti3+ in aqueous medium and the reaction kinetics are studied.Quantum size effect of absorption spectrum is discussed.The nano-size of TiO2 particles is determined by TEM to be 15~25 nm.The hydrogen evolved in the reaction process is analysed by gas chromatography.
1996, 13(6): 15-18
Abstract:
The copolymerization reactivity ratios of vinyl-containing polysiloxane(SV) with styrene(ST),methyl methacrylate(MMA) or n-butyl methacrylate(BMA) were measured using Fineman-Ross method,and the results were:rST=1.45 and rSV=1.08 for ST-SV,rMMA=0.78 and rSV=2.01 for MMA-SV,rn-BMA=0.46 and rSV=3.49 for BMA-SV,respectively.The reactivity ratios between vinyl-containing polysiloxane and vinyl monomers had a strong effect on the morphology of the particles prepared by the seeded emulsion polymerization.
The copolymerization reactivity ratios of vinyl-containing polysiloxane(SV) with styrene(ST),methyl methacrylate(MMA) or n-butyl methacrylate(BMA) were measured using Fineman-Ross method,and the results were:rST=1.45 and rSV=1.08 for ST-SV,rMMA=0.78 and rSV=2.01 for MMA-SV,rn-BMA=0.46 and rSV=3.49 for BMA-SV,respectively.The reactivity ratios between vinyl-containing polysiloxane and vinyl monomers had a strong effect on the morphology of the particles prepared by the seeded emulsion polymerization.
1996, 13(6): 19-23
Abstract:
Twelve title compounds were synthesized by acylation of α-aminocyclododecanone(Ⅱ) and characterized by IR,MS,1H NMR and elemental analysis.Preliminary bioassay shows that some of them have good herbicidal activity against barnyard and rape.During the synthysis of Ⅱ a crystalline compound was separated.Its structure was determined to be bis(o-1,10-decylene) pyrazine by IR,MS,1H NMR,13C NMR and elemental analysis and confirmed by its synthesis from Ⅱ.
Twelve title compounds were synthesized by acylation of α-aminocyclododecanone(Ⅱ) and characterized by IR,MS,1H NMR and elemental analysis.Preliminary bioassay shows that some of them have good herbicidal activity against barnyard and rape.During the synthysis of Ⅱ a crystalline compound was separated.Its structure was determined to be bis(o-1,10-decylene) pyrazine by IR,MS,1H NMR,13C NMR and elemental analysis and confirmed by its synthesis from Ⅱ.
1996, 13(6): 24-27
Abstract:
Anion cellulosic beads were used as support for immobilization of glycosyltransferase GT-1.The immobilized enzyme was used to catalyze the synthesis of α-glycosylstevia sugar.Various influencing factors were discussed.The result showed that when the reaction reached to a certain extent,transglycosylated amount changed very little with increase of amounts of enzyme and starch.The activity of immobilized GT-1 lost very little after repeated uses for 8 times.
Anion cellulosic beads were used as support for immobilization of glycosyltransferase GT-1.The immobilized enzyme was used to catalyze the synthesis of α-glycosylstevia sugar.Various influencing factors were discussed.The result showed that when the reaction reached to a certain extent,transglycosylated amount changed very little with increase of amounts of enzyme and starch.The activity of immobilized GT-1 lost very little after repeated uses for 8 times.
1996, 13(6): 28-30
Abstract:
The immobilized cyclodextrin glycosyltransferase(CGTase) was used for preparation of cyclodextrin(CD).The influence of reaction time,concentration of alcohol and liquification degree of starch on yield of CD was discussed.The highest yield of CD could reach 54% and the main product was β-CD.The activity of immobilized CGTase lost very little after repeated use.
The immobilized cyclodextrin glycosyltransferase(CGTase) was used for preparation of cyclodextrin(CD).The influence of reaction time,concentration of alcohol and liquification degree of starch on yield of CD was discussed.The highest yield of CD could reach 54% and the main product was β-CD.The activity of immobilized CGTase lost very little after repeated use.
1996, 13(6): 31-34
Abstract:
The forward initial extraction rate of gallium(Ⅲ) with HDEHP has been measured by means of growing drop method at 298±1K.The experimental results indicate that the rate-determining step of the extraction process is controlled by interfacial reactions Ga3++Ai-=GaAi2+,GaAi2++Ai-=GaA2i+ The addition of anionic surfactant(SDS,ABS) has no effect on the distribution ratio,but decreases the forward initial rate of extraction.Firstly,it is caused by the competitive adsorption of HDEHP,SDS and ABS on the interface.Secondly,surfactants bring about close molecular arrangement in the interfacial membrane and the thickening of membrane,producing greater mass transport resistance than in the absence of surfactants.
The forward initial extraction rate of gallium(Ⅲ) with HDEHP has been measured by means of growing drop method at 298±1K.The experimental results indicate that the rate-determining step of the extraction process is controlled by interfacial reactions Ga3++Ai-=GaAi2+,GaAi2++Ai-=GaA2i+ The addition of anionic surfactant(SDS,ABS) has no effect on the distribution ratio,but decreases the forward initial rate of extraction.Firstly,it is caused by the competitive adsorption of HDEHP,SDS and ABS on the interface.Secondly,surfactants bring about close molecular arrangement in the interfacial membrane and the thickening of membrane,producing greater mass transport resistance than in the absence of surfactants.
1996, 13(6): 35-38
Abstract:
The hydroxy-terminated phenoxy resin was prepared by the reaction of bisphenol-A and epichlorohydrin using BF3·OEt2 as a catalyst,and then mixed with castor oil and reacted with toluene diisocyanate,hexamethylene diisocyanate and isophorone diisocyanate,respectively,to give a series of polyurethanes.The mechanical properties of the polyurethanes with various compositions were investigated.Under optimum content of castor oil and NCO/OH mole ratio,a series of polyurethanes with good mechanical properties have been obtained.
The hydroxy-terminated phenoxy resin was prepared by the reaction of bisphenol-A and epichlorohydrin using BF3·OEt2 as a catalyst,and then mixed with castor oil and reacted with toluene diisocyanate,hexamethylene diisocyanate and isophorone diisocyanate,respectively,to give a series of polyurethanes.The mechanical properties of the polyurethanes with various compositions were investigated.Under optimum content of castor oil and NCO/OH mole ratio,a series of polyurethanes with good mechanical properties have been obtained.
1996, 13(6): 39-41
Abstract:
A novel ausolid-state electrochromic window was prepared by using WO3 as electrochromic layer,NiOx as counter-electrode layer and oxymethylene-linked polyoxyethylene/LiClO4 complex with good transparency as electrolyte.The modulation depth from 700 nm to 900 nm can exceed 50% The electrochromic ability of the window increases with increasing temperature and increasing LiClO4 concentration,and the window exhibits good storage life of information without energy supply.
A novel ausolid-state electrochromic window was prepared by using WO3 as electrochromic layer,NiOx as counter-electrode layer and oxymethylene-linked polyoxyethylene/LiClO4 complex with good transparency as electrolyte.The modulation depth from 700 nm to 900 nm can exceed 50% The electrochromic ability of the window increases with increasing temperature and increasing LiClO4 concentration,and the window exhibits good storage life of information without energy supply.
1996, 13(6): 42-45
Abstract:
The miscibility and crystallization behaviour of poly(β-hydroxybutyrate)(PHB)/poly(vinyl acetate)(PVAc) blends,obtained by solution blend with cholroform as solvent,have been investigated using differential scanning calorimetry, polarizing microscopy and small-angle X-ray scattering.It is found that PHB is immiscible with PVAc in such cast film form.The addition of PVAc has no effect on the crystallinity of PHB phase in this case.However,when quenched from the melt,the system is miscible.The addition of PVAc not only affects the crystallinity,but also the cold crystallization peak temperature,isothermal crystallization rate and the structure of its spherulites.
The miscibility and crystallization behaviour of poly(β-hydroxybutyrate)(PHB)/poly(vinyl acetate)(PVAc) blends,obtained by solution blend with cholroform as solvent,have been investigated using differential scanning calorimetry, polarizing microscopy and small-angle X-ray scattering.It is found that PHB is immiscible with PVAc in such cast film form.The addition of PVAc has no effect on the crystallinity of PHB phase in this case.However,when quenched from the melt,the system is miscible.The addition of PVAc not only affects the crystallinity,but also the cold crystallization peak temperature,isothermal crystallization rate and the structure of its spherulites.
1996, 13(6): 46-48
Abstract:
LaGa1-xCrxO3(x=0,0.2,0.4,0.6,0.8,1.0) were synthesized by solid state reaction for the first time. The effects of chromium ion substitution on the structure,IR spectra,electric properties and magnetic properties of LaGa1-xCrxO3 were investigated.Some regularities of changes were obtained.The results show that Cr3+ enters into lattice and induces the lattice distortion of compounds.The Ga-O stretching vibrations and O-Ga-O deformation vibrations are shifted to high frequencies after substitution of Cr3+ for Ga3+.The resistivity decreases and susceptibility increases as the concentration of Cr3+ increases.
LaGa1-xCrxO3(x=0,0.2,0.4,0.6,0.8,1.0) were synthesized by solid state reaction for the first time. The effects of chromium ion substitution on the structure,IR spectra,electric properties and magnetic properties of LaGa1-xCrxO3 were investigated.Some regularities of changes were obtained.The results show that Cr3+ enters into lattice and induces the lattice distortion of compounds.The Ga-O stretching vibrations and O-Ga-O deformation vibrations are shifted to high frequencies after substitution of Cr3+ for Ga3+.The resistivity decreases and susceptibility increases as the concentration of Cr3+ increases.
1996, 13(6): 49-51
Abstract:
The chemical reactivity of Ba-K-Bi-O(BKBO) superconductor with various solutions including water,acid,alkali and organic solvents has been investigated systematically.Results show that BKBO has a strong reaction with HCl acid,a mild reaction with alkali and a very weak reaction with pure water.BKBO almost does not react with organic solvents.Protective layers of polypyrrole(PPy) and polythiophene(PTh) have been prepared electrochemically on BKBO films respectively.Magnetic measurements for PPy/BKBO and PTh/BKBO composites show that the electrochemical process does not degrade the superconductivity of BKBO. Results of wet experiments and magnetic susceptibility measurements show that the PPy layer is able to protect BKBO against acid.
The chemical reactivity of Ba-K-Bi-O(BKBO) superconductor with various solutions including water,acid,alkali and organic solvents has been investigated systematically.Results show that BKBO has a strong reaction with HCl acid,a mild reaction with alkali and a very weak reaction with pure water.BKBO almost does not react with organic solvents.Protective layers of polypyrrole(PPy) and polythiophene(PTh) have been prepared electrochemically on BKBO films respectively.Magnetic measurements for PPy/BKBO and PTh/BKBO composites show that the electrochemical process does not degrade the superconductivity of BKBO. Results of wet experiments and magnetic susceptibility measurements show that the PPy layer is able to protect BKBO against acid.
1996, 13(6): 52-54
Abstract:
Based on metal organic chemical deposition technique,a thin film of titanium dioxide was grown on the surface of p/p+-Si substrate from tetrabutyl titanate.The structure and transmission spectrum of the film were analyzed by X-ray diffraction and ultraviolet-visible spectroscopy.The photoresponse of p/p+-Si/TiO2 and photoelectrochemical reduction of carbon dioxide on it were studied.In this electrode reaction,formic acid and formaldehyde were obtained and light energy was partially converted into electrochemical energy.
Based on metal organic chemical deposition technique,a thin film of titanium dioxide was grown on the surface of p/p+-Si substrate from tetrabutyl titanate.The structure and transmission spectrum of the film were analyzed by X-ray diffraction and ultraviolet-visible spectroscopy.The photoresponse of p/p+-Si/TiO2 and photoelectrochemical reduction of carbon dioxide on it were studied.In this electrode reaction,formic acid and formaldehyde were obtained and light energy was partially converted into electrochemical energy.
1996, 13(6): 55-57
Abstract:
The oxidation reactions of(TPP)Ni(Ⅱ) were reinvestigated by cyclic voltammetry and spectroelectrochemistry in the presence of F- anions in methylene chloride solution.It was found that the addition of F-led to the appearance of Ni(Ⅱ)/Ni(Ⅲ) redox step at E1/2=0.60 V(vs.SCE),which were followed by two one-electron oxidation reactions of the porphyrin ring at E1/2=0.95V and 1.25 V,respectively.In-situ thin-layer spectra were obtained and assigned to these ring oxidized Ni(Ⅲ) species.An intermediate spectrum of (TPP)Ni(Ⅲ) was observed in a time-resolved thin-layer electrolysis.A box mechanism of F- coordination-redox reactions was proposed for this system.
The oxidation reactions of(TPP)Ni(Ⅱ) were reinvestigated by cyclic voltammetry and spectroelectrochemistry in the presence of F- anions in methylene chloride solution.It was found that the addition of F-led to the appearance of Ni(Ⅱ)/Ni(Ⅲ) redox step at E1/2=0.60 V(vs.SCE),which were followed by two one-electron oxidation reactions of the porphyrin ring at E1/2=0.95V and 1.25 V,respectively.In-situ thin-layer spectra were obtained and assigned to these ring oxidized Ni(Ⅲ) species.An intermediate spectrum of (TPP)Ni(Ⅲ) was observed in a time-resolved thin-layer electrolysis.A box mechanism of F- coordination-redox reactions was proposed for this system.
1996, 13(6): 58-60
Abstract:
Lanthanum,niobium and magnesium doped lead titanates have been prepared by the mixed oxide method.The crystal type of PbTiO3 does not change after doping with these atoms,but its photocatalytic activity is enhanced.Experiments show that organic dyes are photodegraded into small inorganic molecule in La-PbTiO3,syetem under the illumination of a high pressure mercury lamp.
Lanthanum,niobium and magnesium doped lead titanates have been prepared by the mixed oxide method.The crystal type of PbTiO3 does not change after doping with these atoms,but its photocatalytic activity is enhanced.Experiments show that organic dyes are photodegraded into small inorganic molecule in La-PbTiO3,syetem under the illumination of a high pressure mercury lamp.
1996, 13(6): 61-63
Abstract:
The starch/xylitol blends were extruded in a single extruder.Their properties such as mechanical properties,rheological properties,as well as the effect of components and processing parameters,including the processing time and temperature,on these properties were studied.The activation energy for viscous flow was about 225.1 kJ/mol.The micromophology and crystallinity of the blends have been investigated by scanning electronic microscope and X-ray diffraction method.The result of tests showed that the starch granules were broken and the crystallinity decreased in the blends of starch and xylitol.
The starch/xylitol blends were extruded in a single extruder.Their properties such as mechanical properties,rheological properties,as well as the effect of components and processing parameters,including the processing time and temperature,on these properties were studied.The activation energy for viscous flow was about 225.1 kJ/mol.The micromophology and crystallinity of the blends have been investigated by scanning electronic microscope and X-ray diffraction method.The result of tests showed that the starch granules were broken and the crystallinity decreased in the blends of starch and xylitol.
1996, 13(6): 64-66
Abstract:
The borage seed,containing 32% of fatty acids(FA) was extracted for getting from its oil 22.55% γ-linolenic acid (GLA),After separations through methods of urea occlusion and AgNO3SiO2 column chromatograghy, GLA contents can reach 80.4% and 93.7% respectively.The GLA content in products was determined by gas chromatograghy after esterification with iodomethane.The effects of urea,Ag+ and temperature during the separation process were discussed.When urea/FA=3:1,t=2℃ in the urea occlusion and AgNO3/(SiO2+AgNO3)=6%,the best separation of GLA from borage seed oil may be obtained.
The borage seed,containing 32% of fatty acids(FA) was extracted for getting from its oil 22.55% γ-linolenic acid (GLA),After separations through methods of urea occlusion and AgNO3SiO2 column chromatograghy, GLA contents can reach 80.4% and 93.7% respectively.The GLA content in products was determined by gas chromatograghy after esterification with iodomethane.The effects of urea,Ag+ and temperature during the separation process were discussed.When urea/FA=3:1,t=2℃ in the urea occlusion and AgNO3/(SiO2+AgNO3)=6%,the best separation of GLA from borage seed oil may be obtained.
1996, 13(6): 67-68
Abstract:
Title compounds have been prepared by treating pyrrol with Ar-CHO and copper(Ⅱ) acetate or vanadyl acetylacetonate in one-step route.Three phenols are used as solvents.The experimental results show that 2,4-dichlorophenol is the best one for preparation.
Title compounds have been prepared by treating pyrrol with Ar-CHO and copper(Ⅱ) acetate or vanadyl acetylacetonate in one-step route.Three phenols are used as solvents.The experimental results show that 2,4-dichlorophenol is the best one for preparation.
1996, 13(6): 69-71
Abstract:
A series of new Mannich base ligands,4-R-2-N-(benzo-aza-15-crown-5)methyl phenols,have been synthesized.The extraction of alkali metal (Li+、Na+ and K+) picrates with the title compounds in CHCl3-H2O system at room temperature has been investigated.
A series of new Mannich base ligands,4-R-2-N-(benzo-aza-15-crown-5)methyl phenols,have been synthesized.The extraction of alkali metal (Li+、Na+ and K+) picrates with the title compounds in CHCl3-H2O system at room temperature has been investigated.
1996, 13(6): 72-74
Abstract:
Cobalt chromium mixed oxide ultrafine particle catalysts were prepared by coprecipitation and sol-gel methods. The catalytic properties of catalysts for catalytic oxidation of 2,3,6-trimethylphenol to trimethyl-p-benzoquinone were investigated.It is shown that the catalyst with Co/Cr=1 prepared by sol-gel method is the best.The structures of catalysts were characterized by TEM,XRD and DTA-TG.The mixed oxide is amorphous under 350℃.The thermal stability of this amorphous catalyst is higher than that of Co3O4 and Cr2O3.
Cobalt chromium mixed oxide ultrafine particle catalysts were prepared by coprecipitation and sol-gel methods. The catalytic properties of catalysts for catalytic oxidation of 2,3,6-trimethylphenol to trimethyl-p-benzoquinone were investigated.It is shown that the catalyst with Co/Cr=1 prepared by sol-gel method is the best.The structures of catalysts were characterized by TEM,XRD and DTA-TG.The mixed oxide is amorphous under 350℃.The thermal stability of this amorphous catalyst is higher than that of Co3O4 and Cr2O3.
1996, 13(6): 75-77
Abstract:
A new type of tetraethylammonium-bis(1,3-dithiole-2-thione-4,s-dithiolate) metal complexes(Et4N)m·M(dmit)2) was synthesized,three of which(M=Mn,Co,Sn) were reported for the first time.The complexes were characterized by elemental analysis,ICP and 1H NMR spectra.The infrared and ultraviolet spectra of the complexes were also measured and discussed.
A new type of tetraethylammonium-bis(1,3-dithiole-2-thione-4,s-dithiolate) metal complexes(Et4N)m·M(dmit)2) was synthesized,three of which(M=Mn,Co,Sn) were reported for the first time.The complexes were characterized by elemental analysis,ICP and 1H NMR spectra.The infrared and ultraviolet spectra of the complexes were also measured and discussed.
1996, 13(6): 78-80
Abstract:
Poly-L-valine was modified on graphite to produce polymer modified graphite electrode(Ce/PLV) on which phenylglyoxylic acid(PGA) was reduced to S(+)-mandelic acid(SMA).By using Ce/PLV,the optical yield(o.y.) of SMA and conversion percent of PGA were measured as functions of various factors.The highest o.y. obtained under optimized conditions was 63.8%.A possible stereochemical model of asymmetric reduction of PGA was proposed.
Poly-L-valine was modified on graphite to produce polymer modified graphite electrode(Ce/PLV) on which phenylglyoxylic acid(PGA) was reduced to S(+)-mandelic acid(SMA).By using Ce/PLV,the optical yield(o.y.) of SMA and conversion percent of PGA were measured as functions of various factors.The highest o.y. obtained under optimized conditions was 63.8%.A possible stereochemical model of asymmetric reduction of PGA was proposed.
1996, 13(6): 81-83
Abstract:
The chain transfer to AlEt3 in the polymerization of isoprene with Nd(i-PrO)2Cl-AlEt3 has been carried out.The chain transfer activation energy of isoprene polymerization has been found to be 176 kJ/mol in heptane.The results showed that the chain transfer to AlEt3 is very low in this system.
The chain transfer to AlEt3 in the polymerization of isoprene with Nd(i-PrO)2Cl-AlEt3 has been carried out.The chain transfer activation energy of isoprene polymerization has been found to be 176 kJ/mol in heptane.The results showed that the chain transfer to AlEt3 is very low in this system.
1996, 13(6): 84-86
Abstract:
The synthesis and poling of polyurethane and polyacrylate functionalized with benzothiazole azo group are reported.The doubling coefficient d33 of poled polymer film is determined through order parameter measurement by visible spectrometry.A long term stability of the dipole alignment at room temperature is demonstrated.
The synthesis and poling of polyurethane and polyacrylate functionalized with benzothiazole azo group are reported.The doubling coefficient d33 of poled polymer film is determined through order parameter measurement by visible spectrometry.A long term stability of the dipole alignment at room temperature is demonstrated.
1996, 13(6): 87-89
Abstract:
An ethylene-propylene copolymer(EPM) has been functionalized with acrylic acid(AA) by means of a radical-initiated melt process.Different degrees of grafting have been obtained by varying the overall composition of the reaction mixture.The influence of the grafting degree on the structure has been investigated by differential scanning calorimetry(DSC),fourier transform infrared analysis(FTIR) and wide angle X-ray scattering(WAXS) techniques.The results of structural investigations suggest that the grafting preferentially occurs onto the ethylene sequences of EPM.After acrylic acid was grafted onto EPM,the grafted PAA acted as a nucleation agent,and it caused the increase of crystallization temperature of propylene sequences of EPM-g-PAA.
An ethylene-propylene copolymer(EPM) has been functionalized with acrylic acid(AA) by means of a radical-initiated melt process.Different degrees of grafting have been obtained by varying the overall composition of the reaction mixture.The influence of the grafting degree on the structure has been investigated by differential scanning calorimetry(DSC),fourier transform infrared analysis(FTIR) and wide angle X-ray scattering(WAXS) techniques.The results of structural investigations suggest that the grafting preferentially occurs onto the ethylene sequences of EPM.After acrylic acid was grafted onto EPM,the grafted PAA acted as a nucleation agent,and it caused the increase of crystallization temperature of propylene sequences of EPM-g-PAA.
1996, 13(6): 90-92
Abstract:
Several novel polyarylether sulfones containing different alkyl substituents were synthesized by "one-step" solution polycondensation reaction of 2',2"-dimethylphenolphthalein,2',5',2",5"-tetramethylphenolphthalein,and 2',2"-diisopropyl-5',5"-dimethylphenolphthalein with bis(4-fluorophenyl) sulfone in the presence of anhydrous K2CO3.Their structure and properties were characterized by FTIR,differential scanning calorimetry,thermogravimetry,etc.While maintaining high glass transition temperature,excellent heat-resistant and mechanical properties of phenolphthalein based polyarylethersulfone,the solubility of the polymers prepared were improved greatly.The results indicate that the polymers may have potential applications for gas separation membrane.
Several novel polyarylether sulfones containing different alkyl substituents were synthesized by "one-step" solution polycondensation reaction of 2',2"-dimethylphenolphthalein,2',5',2",5"-tetramethylphenolphthalein,and 2',2"-diisopropyl-5',5"-dimethylphenolphthalein with bis(4-fluorophenyl) sulfone in the presence of anhydrous K2CO3.Their structure and properties were characterized by FTIR,differential scanning calorimetry,thermogravimetry,etc.While maintaining high glass transition temperature,excellent heat-resistant and mechanical properties of phenolphthalein based polyarylethersulfone,the solubility of the polymers prepared were improved greatly.The results indicate that the polymers may have potential applications for gas separation membrane.
1996, 13(6): 93-94
Abstract:
With H2TiO3,H2O2,NH3,MgCl2·6H2O as reactants the nanometer scale MgTi2O5 powder was prepared by chemical coprecipitation.We confirmed that the optimum mole ratio of H2TiO3,H2O2 and NH3 was 1:8:2 and studied the reaction mechanism preliminarily.The TEM and XRD were used to investigate the particle diameter and phase of the powder respectively.
With H2TiO3,H2O2,NH3,MgCl2·6H2O as reactants the nanometer scale MgTi2O5 powder was prepared by chemical coprecipitation.We confirmed that the optimum mole ratio of H2TiO3,H2O2 and NH3 was 1:8:2 and studied the reaction mechanism preliminarily.The TEM and XRD were used to investigate the particle diameter and phase of the powder respectively.
1996, 13(6): 95-97
Abstract:
The pvT behavior and temperature dependence of thermal conductivity and specific heat of phenolphthalein poly(ether ketone)(PEK-C) at constant pressure were investigated.The Spencer-Gilmore equation of PEK-C was estimated.The glass transition temperature rises as the pressure goes up,and at higher pressure an obvious glass transition zone exists in pvT curves.The temperature dependence of thermal conductivity and specific heat is slight.
The pvT behavior and temperature dependence of thermal conductivity and specific heat of phenolphthalein poly(ether ketone)(PEK-C) at constant pressure were investigated.The Spencer-Gilmore equation of PEK-C was estimated.The glass transition temperature rises as the pressure goes up,and at higher pressure an obvious glass transition zone exists in pvT curves.The temperature dependence of thermal conductivity and specific heat is slight.
1996, 13(6): 98-100
Abstract:
The liquid crystalline compound azobenzene with terminal vinyl group (AzoC6C11)and its complex with Pd(Ⅱ) were synthesized by an improved method and characterized by elemental analysis,IR,UV and ESCA.The liquid crystallinity was studied by polarizing microscopic observation and DSC analysis.The complex was shown to be smetic thermotropical liquid crystal.
The liquid crystalline compound azobenzene with terminal vinyl group (AzoC6C11)and its complex with Pd(Ⅱ) were synthesized by an improved method and characterized by elemental analysis,IR,UV and ESCA.The liquid crystallinity was studied by polarizing microscopic observation and DSC analysis.The complex was shown to be smetic thermotropical liquid crystal.
