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1987 Volume 4 Issue 2
1987, 4(2): 1-4
Abstract:
A number of thermosets of liquid chloroprene-hydroxyethyl methacrylate copolymer (CP-co-HEMA) modified epoxy resin were prepared. The mechanical properties of the resin were improved after modification. The shear strength of the modified system began to drop when CP-co-HEMA content is more than 30%. The data of the experiments carried out by monitoring with IR and Curelastometer indicatad that during the curing the etheri fication of primary hydroxyl groups of CP-co-HEMA with epoxy groups and the self-polymerization of epoxy groups occur simultaneously and the etherification appeared to bring about an improvement in the mechanical properties of the thermosets thus obtained. The effects of the curing conditions and CP-co-HEMA content on morphology were studied.It was found that high temperature is in favour of microphase separation and when the curing temperature is low thermodynamic diffusion of the system is a dominant factor.
A number of thermosets of liquid chloroprene-hydroxyethyl methacrylate copolymer (CP-co-HEMA) modified epoxy resin were prepared. The mechanical properties of the resin were improved after modification. The shear strength of the modified system began to drop when CP-co-HEMA content is more than 30%. The data of the experiments carried out by monitoring with IR and Curelastometer indicatad that during the curing the etheri fication of primary hydroxyl groups of CP-co-HEMA with epoxy groups and the self-polymerization of epoxy groups occur simultaneously and the etherification appeared to bring about an improvement in the mechanical properties of the thermosets thus obtained. The effects of the curing conditions and CP-co-HEMA content on morphology were studied.It was found that high temperature is in favour of microphase separation and when the curing temperature is low thermodynamic diffusion of the system is a dominant factor.
1987, 4(2): 5-11
Abstract:
Zacang-Chaka salt lake is a typical borate salt lake located in the west part of Xizang autonomous region. PRC. The contents of potassium, boron and lithium there are found higher than those in the other salt lake on Qinghai-Xizang plateau.During evaporation at 25℃, the lake brine crystallizes through steps what "metastable phase diagram" obtained from laboratory indicates. After crystallization of carnallite, high content of boron remained in the concentrated brine. From it boric acid can be separated out by acidification with hydrochloric acid.
Zacang-Chaka salt lake is a typical borate salt lake located in the west part of Xizang autonomous region. PRC. The contents of potassium, boron and lithium there are found higher than those in the other salt lake on Qinghai-Xizang plateau.During evaporation at 25℃, the lake brine crystallizes through steps what "metastable phase diagram" obtained from laboratory indicates. After crystallization of carnallite, high content of boron remained in the concentrated brine. From it boric acid can be separated out by acidification with hydrochloric acid.
1987, 4(2): 12-16
Abstract:
An accelerated cyclic test for the positive electrode in lead-acid battery has been carried out for studying the effect of some additives on the behaviour of the positive active materials. Two mixed additives selected was found to be more effective, with which the capacity of the active materials was enhanced by 10-15% and the number of the charge-discharge cycles was increased from 19 to 26. The structure and electrochemical properties of the active materials have been investigated by the x-ray differaction, scanning electron microscopy and cyclic voltammetric measurements.It was shown that addition of cobalt ion increases the content of a-PbO2,addition of phosphate makes the crystallite of the active materials finer, but addition of silici-de and fibre only partly strengthens the mechanical property of the material. The effect of PO43-, Co2+ ions on cyclic voltammetry of the lead positive electrode has been discussed as well.
An accelerated cyclic test for the positive electrode in lead-acid battery has been carried out for studying the effect of some additives on the behaviour of the positive active materials. Two mixed additives selected was found to be more effective, with which the capacity of the active materials was enhanced by 10-15% and the number of the charge-discharge cycles was increased from 19 to 26. The structure and electrochemical properties of the active materials have been investigated by the x-ray differaction, scanning electron microscopy and cyclic voltammetric measurements.It was shown that addition of cobalt ion increases the content of a-PbO2,addition of phosphate makes the crystallite of the active materials finer, but addition of silici-de and fibre only partly strengthens the mechanical property of the material. The effect of PO43-, Co2+ ions on cyclic voltammetry of the lead positive electrode has been discussed as well.
1987, 4(2): 17-21
Abstract:
In this paper the study of propylene dimerization catalyzed by β-diketonatə complexes of light rare-earth metals is presented catalyst Pr (acac)3·H2O/Et3Al2 Cl3/PPh3 showed higher activity of 1200-1300 molC3-/molPr.h and conversion rate of 50-60% in dimerization under the reaction conditions Pr(acac)3·H2O, 0.05-0.3mmol; Al/Pr ratio, 30-50; P/Pr ratio, 3-6 and temperature 60-80℃. For systems RE(acac)3/Et3Al2Cl3/PPh3 and Pr(β-diketonates)3·H2O/Et3 Al2Cl3/PPh3,the catalyst activity decreased in the following order:for rare earths:Ce~Pr > La > Nd > Sm for ligands:hfacac > acac > DBM. All catalyst systems studied gave a close weight percentage of products:methylpen-tenes of 64-66% and linear hexenes of 24.1-26.4 with dimer selectivity of 77-93.3%.
In this paper the study of propylene dimerization catalyzed by β-diketonatə complexes of light rare-earth metals is presented catalyst Pr (acac)3·H2O/Et3Al2 Cl3/PPh3 showed higher activity of 1200-1300 molC3-/molPr.h and conversion rate of 50-60% in dimerization under the reaction conditions Pr(acac)3·H2O, 0.05-0.3mmol; Al/Pr ratio, 30-50; P/Pr ratio, 3-6 and temperature 60-80℃. For systems RE(acac)3/Et3Al2Cl3/PPh3 and Pr(β-diketonates)3·H2O/Et3 Al2Cl3/PPh3,the catalyst activity decreased in the following order:for rare earths:Ce~Pr > La > Nd > Sm for ligands:hfacac > acac > DBM. All catalyst systems studied gave a close weight percentage of products:methylpen-tenes of 64-66% and linear hexenes of 24.1-26.4 with dimer selectivity of 77-93.3%.
1987, 4(2): 22-25
Abstract:
Synthetic conditions of β, ω-dihydroxyl polystyrene were studied. Effects of different difunctional anionic initiators and solvents on the anionic polymerization of styrene, especially on the molecular weight distribution, were compared. The reaction between living polystyrene and ethylene oxide was investigated and the association of polystyrene anions has been discussed.
Synthetic conditions of β, ω-dihydroxyl polystyrene were studied. Effects of different difunctional anionic initiators and solvents on the anionic polymerization of styrene, especially on the molecular weight distribution, were compared. The reaction between living polystyrene and ethylene oxide was investigated and the association of polystyrene anions has been discussed.
1987, 4(2): 26-30
Abstract:
The effect of Co60γ-ray radiation on spherulites, lamellae and crystallites etc.of melt-crystallized high density polyethylene was studied with small angle light scattering,small angle x-tay scattering (SAXS) and wide angle x-ray diffraction techniques. It has been shown that there is a tendency to preserve the contour and optical anisotropy of spherulites in irradiation samples afrer melting and recrystallization due to radiation-induced cross-linking. The higher the radiation dose. the stronger the tendency to preserve. Lamellae preserve their own profile, although crystalline damage takes place within lamellae due to irradiation. The damage of the crystalline lamellae cannot be explained vrith "lamellae surface damage" mechanism suggested by Keller. A "lamellae cored damage" mechanism has to be suggested and could give a more satisfactory explaination of the SAXS results.
The effect of Co60γ-ray radiation on spherulites, lamellae and crystallites etc.of melt-crystallized high density polyethylene was studied with small angle light scattering,small angle x-tay scattering (SAXS) and wide angle x-ray diffraction techniques. It has been shown that there is a tendency to preserve the contour and optical anisotropy of spherulites in irradiation samples afrer melting and recrystallization due to radiation-induced cross-linking. The higher the radiation dose. the stronger the tendency to preserve. Lamellae preserve their own profile, although crystalline damage takes place within lamellae due to irradiation. The damage of the crystalline lamellae cannot be explained vrith "lamellae surface damage" mechanism suggested by Keller. A "lamellae cored damage" mechanism has to be suggested and could give a more satisfactory explaination of the SAXS results.
1987, 4(2): 31-35
Abstract:
The adsorption isotherms of H2PdCl4 and 6 competitive adsorbates, acetic, propionic butyric, malonic, citric and maleic acids on Al2O3 have been investigated. They are all fiffed in with the langmuir adsorption isotherm. The results indicated that the impregnation kinetics of H2PdCl4 on Al2O3 was effected by the pH value of impregnation solution and the competitive adsorbates. Addition of competitive adsorbates was able to chauge the UV absorption spectrum of H2PdCl4 solution. It is suggested that there should be an interaction between H2PdCl4 and competitive adsorbates.
The adsorption isotherms of H2PdCl4 and 6 competitive adsorbates, acetic, propionic butyric, malonic, citric and maleic acids on Al2O3 have been investigated. They are all fiffed in with the langmuir adsorption isotherm. The results indicated that the impregnation kinetics of H2PdCl4 on Al2O3 was effected by the pH value of impregnation solution and the competitive adsorbates. Addition of competitive adsorbates was able to chauge the UV absorption spectrum of H2PdCl4 solution. It is suggested that there should be an interaction between H2PdCl4 and competitive adsorbates.
1987, 4(2): 36-41
Abstract:
The extraction mechanism of H2SO4 has been determined with the methods of slopeand constant mole. The results are as follows:At low aqueous H2SO4 concentrations:RNH2(o)+2H++SO42-==(RNH3)2SO4(o) (1)At high aqueous H2SO4 concentrations:RNH2(o)+H++HSO4==(RNH3)·HSO4(o) (2) or (RNH3)2SO4(o)+H2SO4==2(RNH3·HSO4) The composition of the extracted complexes determined by saturated method is(RNH3)2SO4·2.5Hz O and (RNH3)·HSO4·2H2O. In the plot of E% (extraction coefficient) VS Z(atomie number of rare earth element) atypical tetrad effect is found. The position of Y(Ⅲ) in the plots changes with H2SO4concentration and it lies between Yb and Lu or after Lu. The extraction mechanism of Ln(Ⅲ) and Fe(Ⅲ) under different aqueous H2SO4concentrations is as follows:At low aqueous H2SO4 concentrations 1.5(RNH3)2SO4(o)+M3++1.5SO42-==(RNH3)3M(SO4)3(0) (3)At high aqueous H2SO4 concentrations 1.5(RNH3·HSO4)2(o)+M3++1.5SO42-==)RNH3)3M(SO4)3(o)+1.5H2SO4 (4)where M3+ is Nd(Ⅲ), Er(Ⅲ) or Fe(Ⅲ). The composition of the extracted complex is (RNH3)3Nd(SO4)3·1.5H2O at low aqueousacidity. However, it may be ((RNH3)2Nd(SO4)3+RNH3·HSO4)·2H2O at high aqueousacidities. The extraction mechanism of Th(Ⅳ) at low aqueous acidities is as follows:Th4++2SO42-+2(RNH3)2SO4(o)==(RNH3)4Th(SO4)4(o) (5) 1gk3x=10.44
The extraction mechanism of H2SO4 has been determined with the methods of slopeand constant mole. The results are as follows:At low aqueous H2SO4 concentrations:RNH2(o)+2H++SO42-==(RNH3)2SO4(o) (1)At high aqueous H2SO4 concentrations:RNH2(o)+H++HSO4==(RNH3)·HSO4(o) (2) or (RNH3)2SO4(o)+H2SO4==2(RNH3·HSO4) The composition of the extracted complexes determined by saturated method is(RNH3)2SO4·2.5Hz O and (RNH3)·HSO4·2H2O. In the plot of E% (extraction coefficient) VS Z(atomie number of rare earth element) atypical tetrad effect is found. The position of Y(Ⅲ) in the plots changes with H2SO4concentration and it lies between Yb and Lu or after Lu. The extraction mechanism of Ln(Ⅲ) and Fe(Ⅲ) under different aqueous H2SO4concentrations is as follows:At low aqueous H2SO4 concentrations 1.5(RNH3)2SO4(o)+M3++1.5SO42-==(RNH3)3M(SO4)3(0) (3)At high aqueous H2SO4 concentrations 1.5(RNH3·HSO4)2(o)+M3++1.5SO42-==)RNH3)3M(SO4)3(o)+1.5H2SO4 (4)where M3+ is Nd(Ⅲ), Er(Ⅲ) or Fe(Ⅲ). The composition of the extracted complex is (RNH3)3Nd(SO4)3·1.5H2O at low aqueousacidity. However, it may be ((RNH3)2Nd(SO4)3+RNH3·HSO4)·2H2O at high aqueousacidities. The extraction mechanism of Th(Ⅳ) at low aqueous acidities is as follows:Th4++2SO42-+2(RNH3)2SO4(o)==(RNH3)4Th(SO4)4(o) (5) 1gk3x=10.44
1987, 4(2): 42-45
Abstract:
The electrochemical reduction of C2H2 to C2H4 in 0.1M NaClO4 DMF solution containing FeCl2 and K2MoS4 has been investigated by using potentiostatic electrolysis, cyclic voltammetry and a.c.impedance methods. The results showed that the ferrous-molybdate systems exhibited an appreciable electrocatalytic activity and high selectivity in reducing C2H2 to C2H4 when the potential of the graphite electrode was at-1.50V (vs.SCE). It was suggested that the reaction Mo(Ⅵ)→Mo(Ⅴ) takes place at -0.5——1.0V and the reaction Mo(Ⅴ) to Mo(Ⅲ) at -1.0——1.5V,which proceeds through a consecutive electron transfer mechanism, forming a complex of Mo(Ⅲ) as electorcatalytically active species, faciliating the electron transfer of the reaction.
The electrochemical reduction of C2H2 to C2H4 in 0.1M NaClO4 DMF solution containing FeCl2 and K2MoS4 has been investigated by using potentiostatic electrolysis, cyclic voltammetry and a.c.impedance methods. The results showed that the ferrous-molybdate systems exhibited an appreciable electrocatalytic activity and high selectivity in reducing C2H2 to C2H4 when the potential of the graphite electrode was at-1.50V (vs.SCE). It was suggested that the reaction Mo(Ⅵ)→Mo(Ⅴ) takes place at -0.5——1.0V and the reaction Mo(Ⅴ) to Mo(Ⅲ) at -1.0——1.5V,which proceeds through a consecutive electron transfer mechanism, forming a complex of Mo(Ⅲ) as electorcatalytically active species, faciliating the electron transfer of the reaction.
1987, 4(2): 46-50
Abstract:
The single crystal of potassium praseodymium metaphosphate (KPrP4O12) has been obtained by evaporation-solution method and its β type structure has been determined by x-ray diffraction method using MoKα radiation.The crystal structure analysis characterized this structure as monoclinic with space group C2/c and cell parameters a=7.913(2), b=12.489(3), c=10.659(3)Å, P=110.48(2)°and z=4. The basic structure units are P4O124- rings arranged in layers along the c axis. Pr3+ located between layers is bonded to surrounding eight oxygens. The average distance between praseodymium and coordinating oxygens is 2.468Å.
The single crystal of potassium praseodymium metaphosphate (KPrP4O12) has been obtained by evaporation-solution method and its β type structure has been determined by x-ray diffraction method using MoKα radiation.The crystal structure analysis characterized this structure as monoclinic with space group C2/c and cell parameters a=7.913(2), b=12.489(3), c=10.659(3)Å, P=110.48(2)°and z=4. The basic structure units are P4O124- rings arranged in layers along the c axis. Pr3+ located between layers is bonded to surrounding eight oxygens. The average distance between praseodymium and coordinating oxygens is 2.468Å.
1987, 4(2): 51-55
Abstract:
The MWD of alkyd resins and its relation to the physical properties of the resins have been studied by means of HPGPC, VPO, acid value and Gardner's tube viscosity measurements. The resins were synthesized using solid acid as catalyst The results show that for both the resins obtained either with or without catalyst the MWD changes in similar way during thc esterification and log d (degree of distributione appears to have good linear relation with the degree of reaction. The good linear relation was also found between Mn and d, as well as between log ηG and Mw. The use of the catalyst greatly reduces the reaction time and temperature when the identical Mw and MWD are desired. The alkyd resins obtained catalytically have a better solubility andlonger potlife due to their lower viscosity. They have higher Mw and better drying pro-perties and high hardness value in comparison with those obtained without catalyst.
The MWD of alkyd resins and its relation to the physical properties of the resins have been studied by means of HPGPC, VPO, acid value and Gardner's tube viscosity measurements. The resins were synthesized using solid acid as catalyst The results show that for both the resins obtained either with or without catalyst the MWD changes in similar way during thc esterification and log d (degree of distributione appears to have good linear relation with the degree of reaction. The good linear relation was also found between Mn and d, as well as between log ηG and Mw. The use of the catalyst greatly reduces the reaction time and temperature when the identical Mw and MWD are desired. The alkyd resins obtained catalytically have a better solubility andlonger potlife due to their lower viscosity. They have higher Mw and better drying pro-perties and high hardness value in comparison with those obtained without catalyst.
1987, 4(2): 56-60
Abstract:
Thermal expansion coefficient and dynamic mechanical properties in terms of the storage modulus E', loss modulus E" and the loss tangent of a crosslinked multiblock copolymer of hydroxy-terminated polybutadiene and polymethyl methacrylate were investigated. E' and E" were calculated according to the single relaxation time model.The thermodynamic parameters were presented. The molecular weight between crosslinking points MC was calculated about 945. The characteristic damping behavior shows that this polymer is a semicompatible multiblock copolymer with excellent mechanical damping.
Thermal expansion coefficient and dynamic mechanical properties in terms of the storage modulus E', loss modulus E" and the loss tangent of a crosslinked multiblock copolymer of hydroxy-terminated polybutadiene and polymethyl methacrylate were investigated. E' and E" were calculated according to the single relaxation time model.The thermodynamic parameters were presented. The molecular weight between crosslinking points MC was calculated about 945. The characteristic damping behavior shows that this polymer is a semicompatible multiblock copolymer with excellent mechanical damping.
1987, 4(2): 61-64
Abstract:
The crystal of diethylthanolammonium bis (o-diphenol) antimonate (Ⅲ)belongs to orthorhombic space group P212121 with unit cell constants:a=9.096Å, b=11.636Å, c=17.786Å and Z=4. The coordinates of Sb atoms were derived from three-dimensional Patterson function and the locations of non-hydrogen atoms from succesive Fourier and difference Fourier syntheses.The structure was refined to R=0.0326, Rw=0.041 for 2106 independent reflections. It was considered that Sb atom makes use of four sp3d hybrid orbitals to conbine with four O Atoms in formation of a pesudo-trigonal bipyramidal configuration.
The crystal of diethylthanolammonium bis (o-diphenol) antimonate (Ⅲ)belongs to orthorhombic space group P212121 with unit cell constants:a=9.096Å, b=11.636Å, c=17.786Å and Z=4. The coordinates of Sb atoms were derived from three-dimensional Patterson function and the locations of non-hydrogen atoms from succesive Fourier and difference Fourier syntheses.The structure was refined to R=0.0326, Rw=0.041 for 2106 independent reflections. It was considered that Sb atom makes use of four sp3d hybrid orbitals to conbine with four O Atoms in formation of a pesudo-trigonal bipyramidal configuration.
1987, 4(2): 65-67
Abstract:
The electrochemical deposition of La and RE Metals on liquid Aluminium cathode have been measured by Linear sweep voltammetry. Experiments show that depolarization action took place on liquid AL cathode during electrodeposition of La or RE.
The electrochemical deposition of La and RE Metals on liquid Aluminium cathode have been measured by Linear sweep voltammetry. Experiments show that depolarization action took place on liquid AL cathode during electrodeposition of La or RE.
1987, 4(2): 68-70
Abstract:
CBr4-LCV (Leuco Crystal Violet) free radical film, a representative free radical photographic material,is unstable in storage. In this paper the reason of the unstability of CBr4-LCV system and the effect of the stabilizer s-41 were studied by ESR measurement. The result showed that the hot-induced free radical probably plays an important role in fog production during the storage.
CBr4-LCV (Leuco Crystal Violet) free radical film, a representative free radical photographic material,is unstable in storage. In this paper the reason of the unstability of CBr4-LCV system and the effect of the stabilizer s-41 were studied by ESR measurement. The result showed that the hot-induced free radical probably plays an important role in fog production during the storage.
1987, 4(2): 71-73
Abstract:
The title compounds(Ⅲa, R1=H, R2=NO2, Ⅲb, R1=NO2,R2=H, Ⅲc,R1=Cl,R2=NO2,Ⅲb, R1=Br,R2=NO2, Ⅲe, R1=R2=NO2) were prepared by condensation of 1-octyl-3,3-dimethyl-2-methyleneindoline (Ⅰ) and substituted salicylaldehydes (Ⅱ) in anhydrous ethanol. Photochromic properties of these compounds were investigated by UV/VIS spectra measurement and photochromic film obtained from Ⅲa-e Compounds Ⅲa and Ⅲc-e are found to be good photochromic reagents.
The title compounds(Ⅲa, R1=H, R2=NO2, Ⅲb, R1=NO2,R2=H, Ⅲc,R1=Cl,R2=NO2,Ⅲb, R1=Br,R2=NO2, Ⅲe, R1=R2=NO2) were prepared by condensation of 1-octyl-3,3-dimethyl-2-methyleneindoline (Ⅰ) and substituted salicylaldehydes (Ⅱ) in anhydrous ethanol. Photochromic properties of these compounds were investigated by UV/VIS spectra measurement and photochromic film obtained from Ⅲa-e Compounds Ⅲa and Ⅲc-e are found to be good photochromic reagents.
1987, 4(2): 74-76
Abstract:
The interaction between Michler's ketone and chlorine-containing polymers has been studied by means of UV-VIS spectroscopy. No Michler's ketone-polymer charge transfer complex in the ground state was found.There appeared only a red shift of Michler's ketone in region of 365 nm. The degree of the red shift depends on the content of chlorine in the polymer. Upon exposure of the film consisting of Michler's ketone and polymers with various Cl content to a high-pressare Hg lamp a decrease of the~365nm peak bas been observed. The rate of decrease is directly proportional to the weight percent of the chlorine in the polymer. The same results have been obtained when the film is fumed with HCl gas. The absorption peak returned to a certain extent when the exposed films were kept at 50℃. The spectral response curve was found in a good coincidence with the Michler's ketone absorption spectrum. For spectral sensitization of Michler's ketone in the acidsensitive film the first step considered is the Michler's ketone in an excited state formed after the ketone has absorbed light energy.
The interaction between Michler's ketone and chlorine-containing polymers has been studied by means of UV-VIS spectroscopy. No Michler's ketone-polymer charge transfer complex in the ground state was found.There appeared only a red shift of Michler's ketone in region of 365 nm. The degree of the red shift depends on the content of chlorine in the polymer. Upon exposure of the film consisting of Michler's ketone and polymers with various Cl content to a high-pressare Hg lamp a decrease of the~365nm peak bas been observed. The rate of decrease is directly proportional to the weight percent of the chlorine in the polymer. The same results have been obtained when the film is fumed with HCl gas. The absorption peak returned to a certain extent when the exposed films were kept at 50℃. The spectral response curve was found in a good coincidence with the Michler's ketone absorption spectrum. For spectral sensitization of Michler's ketone in the acidsensitive film the first step considered is the Michler's ketone in an excited state formed after the ketone has absorbed light energy.
1987, 4(2): 77-80
Abstract:
Metathetical reaction of rare earth chloride and sodium 10-undecenoic salt gave a number of precipitates with chemical composition of REA3·nH2O(A represents the deprotonated form of the acid). 15 such a compound have been prepared and reported in this paper. They are all insoluble in common organic solvents except chloroform. The conductivities of the salts in chloroform show that they are all non-electrolytes. IR spectra suggest that they are mainly ionic compounds. Antibacterial activities of cerium 10-undecenoic salt also have been tested.
Metathetical reaction of rare earth chloride and sodium 10-undecenoic salt gave a number of precipitates with chemical composition of REA3·nH2O(A represents the deprotonated form of the acid). 15 such a compound have been prepared and reported in this paper. They are all insoluble in common organic solvents except chloroform. The conductivities of the salts in chloroform show that they are all non-electrolytes. IR spectra suggest that they are mainly ionic compounds. Antibacterial activities of cerium 10-undecenoic salt also have been tested.
1987, 4(2): 81-83
Abstract:
Poly(trimethylvinyloxysilane) (Ⅰ) was synthesed by polymeric reaction of polyvinylalcohol with chlorotrimethlylsilane in DMF. The active thin composite membrane for oxygen enrichment was cast from the solution of (Ⅰ) onto a porous polypropylene support (Duragard 2400). crooss-sectionnal SEMs of the composite membrans showed that the thickness of the active thin layer was aboat 1μm. (Ⅰ) has excellent performance:permeability Po2=1.18×10-4)cm3cm/cm2·sec·cmHg, separation factor of oxygen from nitrogen αN2θ2=2.93. The performance of oxygen enrichment changes slightly when the composite membranes was aged for three months at room temperature., Poly(trimethylvinyloxysilane) (Ⅰ) was synthesed by polymeric reaction of polyvinylalcohol with chlorotrimethlylsilane in DMF. The active thin composite membrane for oxygen enrichment was cast from the solution of (Ⅰ) onto a porous polypropylene support (Duragard 2400). crooss-sectionnal SEMs of the composite membrans showed that the thickness of the active thin layer was aboat 1μm. (Ⅰ) has excellent performance:permeability Po2=1.18×10-4)cm3cm/cm2·sec·cmHg, separation factor of oxygen from nitrogen αN2θ2=2.93. The performance of oxygen enrichment changes slightly when the composite membranes was aged for three months at room temperature.
Poly(trimethylvinyloxysilane) (Ⅰ) was synthesed by polymeric reaction of polyvinylalcohol with chlorotrimethlylsilane in DMF. The active thin composite membrane for oxygen enrichment was cast from the solution of (Ⅰ) onto a porous polypropylene support (Duragard 2400). crooss-sectionnal SEMs of the composite membrans showed that the thickness of the active thin layer was aboat 1μm. (Ⅰ) has excellent performance:permeability Po2=1.18×10-4)cm3cm/cm2·sec·cmHg, separation factor of oxygen from nitrogen αN2θ2=2.93. The performance of oxygen enrichment changes slightly when the composite membranes was aged for three months at room temperature., Poly(trimethylvinyloxysilane) (Ⅰ) was synthesed by polymeric reaction of polyvinylalcohol with chlorotrimethlylsilane in DMF. The active thin composite membrane for oxygen enrichment was cast from the solution of (Ⅰ) onto a porous polypropylene support (Duragard 2400). crooss-sectionnal SEMs of the composite membrans showed that the thickness of the active thin layer was aboat 1μm. (Ⅰ) has excellent performance:permeability Po2=1.18×10-4)cm3cm/cm2·sec·cmHg, separation factor of oxygen from nitrogen αN2θ2=2.93. The performance of oxygen enrichment changes slightly when the composite membranes was aged for three months at room temperature.
