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1986 Volume 3 Issue 4
1986, 3(4): 1-5
Abstract:
In this work polyimide was synthesized via nucleophilic displacement polycondensation of dischlorophthalimide diphenyl ether with dianion of bisphenol. The dianion was generated by the conventional method with aqueous sodium hydroxide. Study was made on the influence of the change of variables as well as the structure of the monomer on the polycondensation. The results indicate that the ease of the reaction generally depends on the electron density of the phenoxide and the ability of the positive charge of the reactive site to invite the nucleophile as well as the solubility of the polymer thus obtained.It appears difficult to get a high molecular weight product from bisphenol A although the phenoxide ion of bisphenol A has the strong nucleophilicity and the polymer obtained therefrom has the good solubility. With the consideration that the phenoxide with the strong nucleophilicity would at the same time have the strong ability to form hydrogen bonding with the trace water in the system. High molecular weight polymer with ηi=0.55dl/g(DMAC, 30℃) was obtained from the polycondensation of bisphenol A and bis(4-chlorophthalimide) diphenyl ether via multi-stage removal of water from the system.The copolycondensation of several monomers was conducted.The thermal stability of the homo-or copolymers have been studied preliminarily.
In this work polyimide was synthesized via nucleophilic displacement polycondensation of dischlorophthalimide diphenyl ether with dianion of bisphenol. The dianion was generated by the conventional method with aqueous sodium hydroxide. Study was made on the influence of the change of variables as well as the structure of the monomer on the polycondensation. The results indicate that the ease of the reaction generally depends on the electron density of the phenoxide and the ability of the positive charge of the reactive site to invite the nucleophile as well as the solubility of the polymer thus obtained.It appears difficult to get a high molecular weight product from bisphenol A although the phenoxide ion of bisphenol A has the strong nucleophilicity and the polymer obtained therefrom has the good solubility. With the consideration that the phenoxide with the strong nucleophilicity would at the same time have the strong ability to form hydrogen bonding with the trace water in the system. High molecular weight polymer with ηi=0.55dl/g(DMAC, 30℃) was obtained from the polycondensation of bisphenol A and bis(4-chlorophthalimide) diphenyl ether via multi-stage removal of water from the system.The copolycondensation of several monomers was conducted.The thermal stability of the homo-or copolymers have been studied preliminarily.
1986, 3(4): 6-12
Abstract:
With the catalyst system, FeCl3-(i-C4H9)3Al-phen, (cis-1, 4-1, 2)equibinary polybutadiene was obtained at the polymerization temperature of -30-50℃. By gas-chromatographic analysis of the ozonolysis product of the polymer and 13C-NMR determination it was found that the sequence distribution was not of alternating type. The sequence distribution of the polymer at high polymerization temperature appeared near the Bernoullian statistical and at low temperature it deviated from the random distribution model,The polymerization mechanism has been discussed briefly。
With the catalyst system, FeCl3-(i-C4H9)3Al-phen, (cis-1, 4-1, 2)equibinary polybutadiene was obtained at the polymerization temperature of -30-50℃. By gas-chromatographic analysis of the ozonolysis product of the polymer and 13C-NMR determination it was found that the sequence distribution was not of alternating type. The sequence distribution of the polymer at high polymerization temperature appeared near the Bernoullian statistical and at low temperature it deviated from the random distribution model,The polymerization mechanism has been discussed briefly。
1986, 3(4): 13-16
Abstract:
Solid coordination compound of uranyl nitrate with biuret as UO2(BuH2)4(NO3)2 has been prepared in absolute ethanol.It was characterized by infrared spectra, differential fhermal analysis and thermogravimetric analysis, x-ray powder diffraction and electrical conductance measurements.
Solid coordination compound of uranyl nitrate with biuret as UO2(BuH2)4(NO3)2 has been prepared in absolute ethanol.It was characterized by infrared spectra, differential fhermal analysis and thermogravimetric analysis, x-ray powder diffraction and electrical conductance measurements.
1986, 3(4): 17-21
Abstract:
Based on the experimental results of adsorption and wettability, it is concluded that the adsorption of sodium oleate on γ-Fe2O3 from aqueous solution is of multilayer. The molecules in the first layer are chemisorbed with their hydrocarbon chains extending outward. At higher concentration the second adsorption layer forms and converts the particle surface into hydrophilic again. The wettability of particle surface was found to be related directly to the stability of bothe aqueous and nonaqueous suspensions.
Based on the experimental results of adsorption and wettability, it is concluded that the adsorption of sodium oleate on γ-Fe2O3 from aqueous solution is of multilayer. The molecules in the first layer are chemisorbed with their hydrocarbon chains extending outward. At higher concentration the second adsorption layer forms and converts the particle surface into hydrophilic again. The wettability of particle surface was found to be related directly to the stability of bothe aqueous and nonaqueous suspensions.
1986, 3(4): 22-25
Abstract:
The rheological property of liquid hydroxy-terminated polybutadiene (HTPB) was studied as a function of shear rate,temperature and its molecular weight. Measurements were made in the temperature from 15 to 70℃ and shear rate range from 0 to 2279 s.-1. The flow behavior of HTPB is found to be essentially Newtonian. When bulk viscosity is below 1 Pa. sec. and shear rate below 650 s-1., but it is also a non-Newtonian under other conditions.The results concerning the relationship between bulk viscosity and temperature are following the empirical equation:logηa=A+B/T, when the molecular weight of HTPB is 1,000-5,600.The relation between bulk viscosity and number average molecular weight was established as ηa=2.09×10-8Mn2·52 and ηa=1.14×10-8Mn2·55 at 20 and 25℃, respectively.
The rheological property of liquid hydroxy-terminated polybutadiene (HTPB) was studied as a function of shear rate,temperature and its molecular weight. Measurements were made in the temperature from 15 to 70℃ and shear rate range from 0 to 2279 s.-1. The flow behavior of HTPB is found to be essentially Newtonian. When bulk viscosity is below 1 Pa. sec. and shear rate below 650 s-1., but it is also a non-Newtonian under other conditions.The results concerning the relationship between bulk viscosity and temperature are following the empirical equation:logηa=A+B/T, when the molecular weight of HTPB is 1,000-5,600.The relation between bulk viscosity and number average molecular weight was established as ηa=2.09×10-8Mn2·52 and ηa=1.14×10-8Mn2·55 at 20 and 25℃, respectively.
1986, 3(4): 26-29
Abstract:
The deactivation mechanism of Fe-Sb-W oxides catalyst for ammoxidation of propylene has been studied by ESR.The amount of coke deposited on the surface of catalyst and the changes of structure of the catalyst were determined simultaneously. It was shown that the reaction FeSbO4+e→α-Fe2O3+Sb2O3 took place when the amount of deposited coke exceeded a certain limit and the active structure in the surface of the catalyst was deteriorated.The catalyst was then deactivated seriously,the conversion of propylene and yield of acrylonitrile were only 40% and 9% respectively, while themain product was CO2.
The deactivation mechanism of Fe-Sb-W oxides catalyst for ammoxidation of propylene has been studied by ESR.The amount of coke deposited on the surface of catalyst and the changes of structure of the catalyst were determined simultaneously. It was shown that the reaction FeSbO4+e→α-Fe2O3+Sb2O3 took place when the amount of deposited coke exceeded a certain limit and the active structure in the surface of the catalyst was deteriorated.The catalyst was then deactivated seriously,the conversion of propylene and yield of acrylonitrile were only 40% and 9% respectively, while themain product was CO2.
1986, 3(4): 30-34
Abstract:
The extraction of palladium(Ⅱ) with quaternary ammonium salt N263 in n-octane from hydrochloric acid medium has been studied at 25±1℃. The experimental results indicate that the extraction is an anion exchange process:HPdCl4=+ACl(o)=AHPdCl4(o)+Cl (Ⅰ) PdCl42-+2ACL(o)=A2PdCl4(o)+2Cl- (Ⅱ) where ACl and (O) represent N263 and organic phase respectively. Equation(Ⅰ) takes place at higher acidity but with the lowering of the acidity,equation(Ⅱ) becomes predominant.The experimental results also show that the dimer species of Pd(Ⅱ) is formedin the organic phase with the increasing of Pd(Ⅱ)in it.The influences of temperature and added (n-octanol) on the extraction of Pd(Ⅱ) were also discussed.
The extraction of palladium(Ⅱ) with quaternary ammonium salt N263 in n-octane from hydrochloric acid medium has been studied at 25±1℃. The experimental results indicate that the extraction is an anion exchange process:HPdCl4=+ACl(o)=AHPdCl4(o)+Cl (Ⅰ) PdCl42-+2ACL(o)=A2PdCl4(o)+2Cl- (Ⅱ) where ACl and (O) represent N263 and organic phase respectively. Equation(Ⅰ) takes place at higher acidity but with the lowering of the acidity,equation(Ⅱ) becomes predominant.The experimental results also show that the dimer species of Pd(Ⅱ) is formedin the organic phase with the increasing of Pd(Ⅱ)in it.The influences of temperature and added (n-octanol) on the extraction of Pd(Ⅱ) were also discussed.
1986, 3(4): 35-41
Abstract:
The crystal and molecular structure of[Eu(NO3)3]4(C12H24O6)3 have been determined from single-crystal x-ray diffraction data. The complex crystallizes in the monoclinic space group C2/m with Z=2.Lattice parameters are:a=28.772(6), b=11.142(2), c=12.024(2)Å, β=112.63(2)°.The structure was solved by Patterson and Fourier techniques and refined by least-squares techniques to R=0.063 for 1667 reflections. The structure contains three crystallographically distinct ions in the ratio 1:1:2:(1)[Eu(NO3)6]3- with C2h symmetry, (2)[Eu(NO3)2(C12H24O6)]+ with the same symmetry, (3)[Eu(NO3)2(C12H24O6)]+ with a disordered polyether on a C1 symmetry site.The two positions of the disordered polyether are staggered by 32°.
The crystal and molecular structure of[Eu(NO3)3]4(C12H24O6)3 have been determined from single-crystal x-ray diffraction data. The complex crystallizes in the monoclinic space group C2/m with Z=2.Lattice parameters are:a=28.772(6), b=11.142(2), c=12.024(2)Å, β=112.63(2)°.The structure was solved by Patterson and Fourier techniques and refined by least-squares techniques to R=0.063 for 1667 reflections. The structure contains three crystallographically distinct ions in the ratio 1:1:2:(1)[Eu(NO3)6]3- with C2h symmetry, (2)[Eu(NO3)2(C12H24O6)]+ with the same symmetry, (3)[Eu(NO3)2(C12H24O6)]+ with a disordered polyether on a C1 symmetry site.The two positions of the disordered polyether are staggered by 32°.
1986, 3(4): 42-47
Abstract:
The dioxane complexes of cerium(Ⅳ), Ce(C4H8O2)4Cl4 or HCe(C4H8O2)4Cl5 were prepared by gradually dissolving dried cerium (Ⅳ) hydroxide in dioxane (C4H8O2)and then saturating with dried HCl gas. The formed solid complex was mixed with nitrogen-containing compounds (L), resulting a series of new complexes of ammonium pentachlorocerate (Ⅳ) (HL) Ce (C4H8O2)xCL5 (L=8-hydroxy quinoline, imidazole,o-phenanthroline,pyridine, β-naphthoquinoline,phenazine; x=1,2,3,4). The complexes were characterized by elemental analyses, infrared spectra, ultra-violet spectra,thermal analysis and photoelectron spectra. The effects of the variety of nitrogencontaining ligands on the thermal stabilities of the complexes bave been primarily studied.
The dioxane complexes of cerium(Ⅳ), Ce(C4H8O2)4Cl4 or HCe(C4H8O2)4Cl5 were prepared by gradually dissolving dried cerium (Ⅳ) hydroxide in dioxane (C4H8O2)and then saturating with dried HCl gas. The formed solid complex was mixed with nitrogen-containing compounds (L), resulting a series of new complexes of ammonium pentachlorocerate (Ⅳ) (HL) Ce (C4H8O2)xCL5 (L=8-hydroxy quinoline, imidazole,o-phenanthroline,pyridine, β-naphthoquinoline,phenazine; x=1,2,3,4). The complexes were characterized by elemental analyses, infrared spectra, ultra-violet spectra,thermal analysis and photoelectron spectra. The effects of the variety of nitrogencontaining ligands on the thermal stabilities of the complexes bave been primarily studied.
1986, 3(4): 48-50
Abstract:
A new iodine heterocyclic compound, 8-oxo-diquino(5, 6-b; 6', 5'-e)-pyriodonium [Ⅲ] compound, white needles prims(m·p·221-2℃),was prepared in about 68% yield by treating 6,6'-diquinolyl oxide[Ⅱ] with iodosyl sulfate in concentrated sulfuric acid,following by pyridine[Ⅲ] The structures of[Ⅱ] and[Ⅲ] were confirmed by IR,1HNMR, MS and elemental analysis.
A new iodine heterocyclic compound, 8-oxo-diquino(5, 6-b; 6', 5'-e)-pyriodonium [Ⅲ] compound, white needles prims(m·p·221-2℃),was prepared in about 68% yield by treating 6,6'-diquinolyl oxide[Ⅱ] with iodosyl sulfate in concentrated sulfuric acid,following by pyridine[Ⅲ] The structures of[Ⅱ] and[Ⅲ] were confirmed by IR,1HNMR, MS and elemental analysis.
1986, 3(4): 51-53
Abstract:
The intrinsic viscosity, number average molecular weight and molecular weight distribution of a number of polydisperse cis-polybutadiene samples polymerized with lanthanide catalyst were determined by viscosimetry, osmometry and size exclusion chromatography.The procedures of the data treatment for the calibration of the SEC column,correction for axial dispersion and iterative calculation of the viscosity average molecular weights were given. The monodisperse Mark-Houwink equation of Ln-PB was obtained by linear regression between the experimental intrinsic viscosity and the calculated viscosity average molecular weight of the polydisperse samples.
The intrinsic viscosity, number average molecular weight and molecular weight distribution of a number of polydisperse cis-polybutadiene samples polymerized with lanthanide catalyst were determined by viscosimetry, osmometry and size exclusion chromatography.The procedures of the data treatment for the calibration of the SEC column,correction for axial dispersion and iterative calculation of the viscosity average molecular weights were given. The monodisperse Mark-Houwink equation of Ln-PB was obtained by linear regression between the experimental intrinsic viscosity and the calculated viscosity average molecular weight of the polydisperse samples.
1986, 3(4): 54-57
Abstract:
The model of the fractional counter current extraction (FCCE) is modified based on the study of the extraction mechanism. In this model 2n equations for the equilibrium acidity (H(I)=H0-nX:(I)) and extractant concentration (Z(I)=Z0-nY:(I)) are substituted into the FCCE model proposed by the authors earlier (1) and the number of the equations can be reduced from 2n (m+1) to 2nm. An improvement in the restriction and iteration for the solution is taken, making the physical meaning of the solution more accurate and thus the stability of convergence. A mathmatical simulation for HEH(EHP)-kerosene-HNO3-(Sm-Gd)(NO3)3FCCE system is given and the calculated values are more fit with the experimental data than in earlier work. The influences of the extraction conditions on the separation are also discussed. It is shown that this model can be applied to computer aided design.
The model of the fractional counter current extraction (FCCE) is modified based on the study of the extraction mechanism. In this model 2n equations for the equilibrium acidity (H(I)=H0-nX:(I)) and extractant concentration (Z(I)=Z0-nY:(I)) are substituted into the FCCE model proposed by the authors earlier (1) and the number of the equations can be reduced from 2n (m+1) to 2nm. An improvement in the restriction and iteration for the solution is taken, making the physical meaning of the solution more accurate and thus the stability of convergence. A mathmatical simulation for HEH(EHP)-kerosene-HNO3-(Sm-Gd)(NO3)3FCCE system is given and the calculated values are more fit with the experimental data than in earlier work. The influences of the extraction conditions on the separation are also discussed. It is shown that this model can be applied to computer aided design.
1986, 3(4): 58-59
Abstract:
Auger electron spectroscopy was used to study the activity loss of DSA (Dimensionally Stable Anode) made of Ti-Ru oxide in H2SO4 solution. It is proposed on the basis of the experimental data that under the accelerated life test conditions the loss of DSA activity results from the dissolution of active Ru on the electrode surface.
Auger electron spectroscopy was used to study the activity loss of DSA (Dimensionally Stable Anode) made of Ti-Ru oxide in H2SO4 solution. It is proposed on the basis of the experimental data that under the accelerated life test conditions the loss of DSA activity results from the dissolution of active Ru on the electrode surface.
1986, 3(4): 60-61
Abstract:
The results of WAXD, SAXS and Laue photographs of 3,4-polyisoprene prepared under different condition and elongation ratio are presented. It is found that decrease of polymerization temperature increases the crystallinity of the polymer. Different nitrogen containing donors used as additive in the catalyst system fairely influence the crystallization of 3,4-PI.For the oriented samples, the degree of crystallinity and the values of long period increase, but the crystallite size decreases with increase of the elongation ratio.Some (hko) and one stronger (hkl) plane diffractions were observed.It is concluded 3,4-PI belongs to the non-homogeneity particle system with particle radius of 35-164Å.
The results of WAXD, SAXS and Laue photographs of 3,4-polyisoprene prepared under different condition and elongation ratio are presented. It is found that decrease of polymerization temperature increases the crystallinity of the polymer. Different nitrogen containing donors used as additive in the catalyst system fairely influence the crystallization of 3,4-PI.For the oriented samples, the degree of crystallinity and the values of long period increase, but the crystallite size decreases with increase of the elongation ratio.Some (hko) and one stronger (hkl) plane diffractions were observed.It is concluded 3,4-PI belongs to the non-homogeneity particle system with particle radius of 35-164Å.
1986, 3(4): 62-64
Abstract:
The solubilities of the ternary system La(NO3)3·4H2O-B15C5-(CH3)2CO at 18℃ have been determined by the semimicro method for phase equilibrium study.The results indicated that only one complex La(NO3)3·B15C5·4H2O formed in the system, Its composition has been examined by chemical analysis spectrophotometry and gas chromatography.
The solubilities of the ternary system La(NO3)3·4H2O-B15C5-(CH3)2CO at 18℃ have been determined by the semimicro method for phase equilibrium study.The results indicated that only one complex La(NO3)3·B15C5·4H2O formed in the system, Its composition has been examined by chemical analysis spectrophotometry and gas chromatography.
1986, 3(4): 65-68
Abstract:
The interfacial tension γ of cyclohexane/water interface has been determined by sessile drop method as a function of log concentration of PLURONIC copolymers(L61,L64, and F68).The influences of temperatures (10°, 20° and 35℃),etthylene oxide contents in the polymers as well as added salt (25% NaNO3) on the γ-log C plots have been investigated. The γ-log C plots over the 0.5-1000 ppm range are convex with respect to the log C axis for all three PLURONIC copolymers used in this work.In this respect the trend is opposite to that of low molecular weight surfactants below the CMC.The reason why the Gibbs adsorption equation,at least in its usual form, may not be applied in describing macromolecular solution has been discussed briefly.
The interfacial tension γ of cyclohexane/water interface has been determined by sessile drop method as a function of log concentration of PLURONIC copolymers(L61,L64, and F68).The influences of temperatures (10°, 20° and 35℃),etthylene oxide contents in the polymers as well as added salt (25% NaNO3) on the γ-log C plots have been investigated. The γ-log C plots over the 0.5-1000 ppm range are convex with respect to the log C axis for all three PLURONIC copolymers used in this work.In this respect the trend is opposite to that of low molecular weight surfactants below the CMC.The reason why the Gibbs adsorption equation,at least in its usual form, may not be applied in describing macromolecular solution has been discussed briefly.
1986, 3(4): 69-71
Abstract:
The melting points of eight known compounds have been determined by DTA at the temperature ranging from 50℃ to -150℃. The results are accurate to ±1℃. The melting points of dioxane and cyclohexane,as reported in the literature, are 11℃ and 6.5℃, but another ones have been found by this method at 1℃ and -86℃,respectively. It is considered to be related to the conformations of the two compounds. Phase diagrams for two component system have also been obtained using low temperature DTA technique.
The melting points of eight known compounds have been determined by DTA at the temperature ranging from 50℃ to -150℃. The results are accurate to ±1℃. The melting points of dioxane and cyclohexane,as reported in the literature, are 11℃ and 6.5℃, but another ones have been found by this method at 1℃ and -86℃,respectively. It is considered to be related to the conformations of the two compounds. Phase diagrams for two component system have also been obtained using low temperature DTA technique.
1986, 3(4): 72-74
Abstract:
The calculated results by INDO method show that in the PrCl3(OC4H8)3 comlex the bond orders of Pr-Cl bond are decreased and the energies of the molecular orbitals corresponding to them are increased. The results imply a charge transfer from O to Pr caused by coordination, leading to decreasing the Pr-Cl bond energy,and the reduction of the charge difference between Pr and Cl would increase the covalent percentage of Pr-Cl bond.It is expected that the alkylation reaction may be then carried out favorably and the complex activation would be selective for Pr-Cl bond due to the formation of dipolymer.
The calculated results by INDO method show that in the PrCl3(OC4H8)3 comlex the bond orders of Pr-Cl bond are decreased and the energies of the molecular orbitals corresponding to them are increased. The results imply a charge transfer from O to Pr caused by coordination, leading to decreasing the Pr-Cl bond energy,and the reduction of the charge difference between Pr and Cl would increase the covalent percentage of Pr-Cl bond.It is expected that the alkylation reaction may be then carried out favorably and the complex activation would be selective for Pr-Cl bond due to the formation of dipolymer.
1986, 3(4): 75-77
Abstract:
Five new dithiocarbamates were synthesized by the condensation of carbon disulfide with polyamino-compounds:H4NS2CNH
NHCS2NH4(Ⅰ), 108℃(dec.) H2N
NHCS2NH4 (Ⅱ), 90℃(dec.) H2N
NHCS2NH4 (Ⅲ),105℃(dec.) H3+NCH2CH2NHCH2CH2NHCS2-(Ⅳ), 146℃(dec.) H3+NCH2CH2NHCS2-(Ⅴ), 109℃(dec.) The dithiocarbamates were characterized by IR,13C-NMR and UV spectra.
Five new dithiocarbamates were synthesized by the condensation of carbon disulfide with polyamino-compounds:H4NS2CNH
NHCS2NH4(Ⅰ), 108℃(dec.) H2NNHCS2NH4 (Ⅱ), 90℃(dec.) H2NNHCS2NH4 (Ⅲ),105℃(dec.) H3+NCH2CH2NHCH2CH2NHCS2-(Ⅳ), 146℃(dec.) H3+NCH2CH2NHCS2-(Ⅴ), 109℃(dec.) The dithiocarbamates were characterized by IR,13C-NMR and UV spectra.
