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1995 Volume 12 Issue 3
1995, 12(3): 1-4
Abstract:
A ptirple-red conversion film on stainless steel was formed by cathodic electrode-position from molybdate-phosphate solution. This film displayed good thermostability. The results of XPS and AES analysis showed that the thickness of the film was 94.4nm and Mo existed as Mo (Ⅵ) in the surface of the film, but as Mo(Ⅵ) and Mo(Ⅳ) in the internal layer of the film. The relative atomic percent content of the film obtained from the elemental com-position constant region of the depth profile curves by AES was O 54.8%, Mo 30.5%,P 11.2% and Fe 3.5% respectively. The cyclevoltammetric oxidation peak also revealed the M0(Ⅳ) in the internal layer of the film.
A ptirple-red conversion film on stainless steel was formed by cathodic electrode-position from molybdate-phosphate solution. This film displayed good thermostability. The results of XPS and AES analysis showed that the thickness of the film was 94.4nm and Mo existed as Mo (Ⅵ) in the surface of the film, but as Mo(Ⅵ) and Mo(Ⅳ) in the internal layer of the film. The relative atomic percent content of the film obtained from the elemental com-position constant region of the depth profile curves by AES was O 54.8%, Mo 30.5%,P 11.2% and Fe 3.5% respectively. The cyclevoltammetric oxidation peak also revealed the M0(Ⅳ) in the internal layer of the film.
1995, 12(3): 5-8
Abstract:
Interacting Ru(OAc)2(Ph3P) with dppm (bis(diphenylphosphino)methane) in re-fluxing toluene gave Ru(OAc)2(Ph3P)(dppm) and Ru(OAc)2(dppm)2 in yields of 79% and 8l%, respectively. 1H NMR study carried out at various temperatures showed that the two acetates are coordinated to the central Ru(Ⅱ) in forms of monodentate and didentate. 31P NMR and X-ray diffractometric results revealed the fac-configuration of phosphine ligands. Under hydrogen pressures of 1.0~4.0MPa and temperatures 30~70℃, the title complexes showed a catalytic activity to the selective hydrogenation of acrylic acid and styrene.
Interacting Ru(OAc)2(Ph3P) with dppm (bis(diphenylphosphino)methane) in re-fluxing toluene gave Ru(OAc)2(Ph3P)(dppm) and Ru(OAc)2(dppm)2 in yields of 79% and 8l%, respectively. 1H NMR study carried out at various temperatures showed that the two acetates are coordinated to the central Ru(Ⅱ) in forms of monodentate and didentate. 31P NMR and X-ray diffractometric results revealed the fac-configuration of phosphine ligands. Under hydrogen pressures of 1.0~4.0MPa and temperatures 30~70℃, the title complexes showed a catalytic activity to the selective hydrogenation of acrylic acid and styrene.
1995, 12(3): 9-12
Abstract:
Protonation constants of the title ligand as well as stability constants of its com-plexes with rare earth elements were determined by pH potentiometric titration in the physio-logical conditions and at 25℃,I=0.10mol/L respectively. The results indicate that the rare earth can form 1:1 coordination compounds with glycyl-L-leucine at the studied range of pH. There is an obvious "tetrad effect" in the system. Yttrium position and the effect of peptide bond on the complex stability were discussed.
Protonation constants of the title ligand as well as stability constants of its com-plexes with rare earth elements were determined by pH potentiometric titration in the physio-logical conditions and at 25℃,I=0.10mol/L respectively. The results indicate that the rare earth can form 1:1 coordination compounds with glycyl-L-leucine at the studied range of pH. There is an obvious "tetrad effect" in the system. Yttrium position and the effect of peptide bond on the complex stability were discussed.
1995, 12(3): 13-17
Abstract:
The complexes of 4'-bromo-5'-nitrobenzo-15-crown-5(L) with rare earth have been synthesized and characterized by elemental analysis, IR, UV, TG-DTA, molar conduc-tance and X-ray powder diffration analyses. The complexes have compositions of RE(NO3)3·L(RE=La~Nd), Sm(NO3)3·L·H2O and Eu(NO3)3·L·CH3CN·4H2O respectively with the coordination number of the rare earth cation in the complexes for La,Ce,Pr,and Nd being eleven. In the complexes with samarium and europium the crown ethers are coordi-nated with Sm3+ or Eu3+ via water molecules.
The complexes of 4'-bromo-5'-nitrobenzo-15-crown-5(L) with rare earth have been synthesized and characterized by elemental analysis, IR, UV, TG-DTA, molar conduc-tance and X-ray powder diffration analyses. The complexes have compositions of RE(NO3)3·L(RE=La~Nd), Sm(NO3)3·L·H2O and Eu(NO3)3·L·CH3CN·4H2O respectively with the coordination number of the rare earth cation in the complexes for La,Ce,Pr,and Nd being eleven. In the complexes with samarium and europium the crown ethers are coordi-nated with Sm3+ or Eu3+ via water molecules.
1995, 12(3): 18-22
Abstract:
The oxidative coupling of ethanol stimulated by CO2 laser on the surface of Cu2 (PO4)(OH) and Pb3(PO4)2 has been studied using XRD and IR techniques. The results showed that the distribution of reaction products depends strongly on the chemisorption types of ethanol:1,4-butanediol was formed via the methyl-adsorbed ethanol molecules, while the hydroxyl-adsorbed one gave to ethene. The vibrational structures of the surface of solid meterials are the basic factor affecting the efficiency of laser photon energy. The higher efficiency of laser photon energy in the case of libethenite appeared due to the greater differ-ence in frequecies between P=O and O-Cu-O bonds.
The oxidative coupling of ethanol stimulated by CO2 laser on the surface of Cu2 (PO4)(OH) and Pb3(PO4)2 has been studied using XRD and IR techniques. The results showed that the distribution of reaction products depends strongly on the chemisorption types of ethanol:1,4-butanediol was formed via the methyl-adsorbed ethanol molecules, while the hydroxyl-adsorbed one gave to ethene. The vibrational structures of the surface of solid meterials are the basic factor affecting the efficiency of laser photon energy. The higher efficiency of laser photon energy in the case of libethenite appeared due to the greater differ-ence in frequecies between P=O and O-Cu-O bonds.
1995, 12(3): 23-27
Abstract:
The orientation and relaxation of a crosslinked and poled polymer based on the re-action of glycerin monoether of 4-[(p-nitrophenyl)azo]phenol with biuret of hexamethylene diisocyanate have been studied by UV-Vis spectra and second harmonic generation(SHG) techniques. Second order nonlinear susceptibility χ2, second harmonic coefficient d33 and electro-optic coefficient γ33 were determined. The d33 of the crosslinked and poled polymer was in the range of 10-8~10-7esu and kept constant for a period of 100h after poling and crosslinking.
The orientation and relaxation of a crosslinked and poled polymer based on the re-action of glycerin monoether of 4-[(p-nitrophenyl)azo]phenol with biuret of hexamethylene diisocyanate have been studied by UV-Vis spectra and second harmonic generation(SHG) techniques. Second order nonlinear susceptibility χ2, second harmonic coefficient d33 and electro-optic coefficient γ33 were determined. The d33 of the crosslinked and poled polymer was in the range of 10-8~10-7esu and kept constant for a period of 100h after poling and crosslinking.
1995, 12(3): 28-31
Abstract:
A series of triazol compounds have been synthesized by reaction of aryloxyacetic acid with 1-(1H-1,2,4-triazol-1-yl)-1-bromo-3,3-dimethyl-2-butanone in the presence of tri-ethyl amine. The structures of the compounds have been confirmed by IR, 1H NMR, MS and elemental analysis. The biologicaI test showed that some compounds have a high biologi-cal activity to weeds,wheat coleoptile,and some have a fungicidal activity.
A series of triazol compounds have been synthesized by reaction of aryloxyacetic acid with 1-(1H-1,2,4-triazol-1-yl)-1-bromo-3,3-dimethyl-2-butanone in the presence of tri-ethyl amine. The structures of the compounds have been confirmed by IR, 1H NMR, MS and elemental analysis. The biologicaI test showed that some compounds have a high biologi-cal activity to weeds,wheat coleoptile,and some have a fungicidal activity.
1995, 12(3): 32-35
Abstract:
The static electrorheological properties of suspensions containing doped polyani-line(PAn) particles,pretreated with alkaline agent,in insulating oil No.2 under direct cur-rent high electric field were studied as functions of dielectric constants, conductivity (σ),vol-ume fraction of the particles as well as applied electric field strength. The results showed that the PAn particles of the same σ pretreated by ammonia water possessed higher dielectric constants than those pretreated by aqueous NaOH. In the former case yield stress of the sus-pension increased nonlinearly with dipolar coefficient square when σ of PAn was low enough, i.e. σ≤1.0×10-7S/cm, while in the latter case a maximum yield stress occurred. As a re-sult anhydrous suspensions with high electrorheological activity can be obtained using PAn particles pretreated with alkaline agent to a certain pH value.
The static electrorheological properties of suspensions containing doped polyani-line(PAn) particles,pretreated with alkaline agent,in insulating oil No.2 under direct cur-rent high electric field were studied as functions of dielectric constants, conductivity (σ),vol-ume fraction of the particles as well as applied electric field strength. The results showed that the PAn particles of the same σ pretreated by ammonia water possessed higher dielectric constants than those pretreated by aqueous NaOH. In the former case yield stress of the sus-pension increased nonlinearly with dipolar coefficient square when σ of PAn was low enough, i.e. σ≤1.0×10-7S/cm, while in the latter case a maximum yield stress occurred. As a re-sult anhydrous suspensions with high electrorheological activity can be obtained using PAn particles pretreated with alkaline agent to a certain pH value.
1995, 12(3): 36-39
Abstract:
The high temperature sulfation of CaO with SO2 has been investigated by TG method under vacuum. Experimental data indicated that the sulfation process was a two-stage reaction, a very fast surface reaction with an activation energy of 36.7kJ/mol followed by a product-layer diffusion controlled reaction with an activation energy of 75.2kJ/mol. The initial period was about 7s. This process of sulfation was affected by limestone type, micro structure, particle size and temperature, while the SO2 concentration hardly affected the sulfation. A 59% CaO conversion was achieved in 30s at 1000℃ and 1×102pa.
The high temperature sulfation of CaO with SO2 has been investigated by TG method under vacuum. Experimental data indicated that the sulfation process was a two-stage reaction, a very fast surface reaction with an activation energy of 36.7kJ/mol followed by a product-layer diffusion controlled reaction with an activation energy of 75.2kJ/mol. The initial period was about 7s. This process of sulfation was affected by limestone type, micro structure, particle size and temperature, while the SO2 concentration hardly affected the sulfation. A 59% CaO conversion was achieved in 30s at 1000℃ and 1×102pa.
1995, 12(3): 40-42
Abstract:
The miscibility and cocrystallization of blends consisted of high density polyethy-lene(HDPE) and (ethylene-propylene-octene-1) copolymer(EPO) has been studied by DSC and WAXD methods. Only a single melting or cooling peak was found in DSC curves for all blends, showing an existence of cocrystalline interaction. The crystal parameter and crys-tallinity of the blends are in dependence of the composition of the blends, revealing the com-patibility of the system.
The miscibility and cocrystallization of blends consisted of high density polyethy-lene(HDPE) and (ethylene-propylene-octene-1) copolymer(EPO) has been studied by DSC and WAXD methods. Only a single melting or cooling peak was found in DSC curves for all blends, showing an existence of cocrystalline interaction. The crystal parameter and crys-tallinity of the blends are in dependence of the composition of the blends, revealing the com-patibility of the system.
1995, 12(3): 43-47
Abstract:
The dissolution process of oxychlorides in water has been followed by pH and chlorine ion potentiometric determinations. The concentrations of Mg2+, Cl-,and OH- in soluble samples were determined and the solid samples were characterized by physical me-thods. The experimental data of the C~t curves have been fitted to kinetic equations. The Ksp and thermodynamics functions have been calculated.
The dissolution process of oxychlorides in water has been followed by pH and chlorine ion potentiometric determinations. The concentrations of Mg2+, Cl-,and OH- in soluble samples were determined and the solid samples were characterized by physical me-thods. The experimental data of the C~t curves have been fitted to kinetic equations. The Ksp and thermodynamics functions have been calculated.
1995, 12(3): 48-51
Abstract:
The title complexes Ln(Val)Cl3·6H2O (Ln=La,Nd,Sm,Gd,Er) have been synthesized in aqueous solution. The compositions of the complexes were determined by ele-mental analysis and EDTA titration. The infrared spectra of the complexes were measured with principal spectral bands being assigned. The results showed that the valine molecules are zwitterions in the complexes and coordinate to rare earth ions through carboxyl groups, and the six water molecules coordinate to rare earth ion too. The La ang Nd complexes may be one dimensional chain complexes of infinite length and the others dinuclear complexes.
The title complexes Ln(Val)Cl3·6H2O (Ln=La,Nd,Sm,Gd,Er) have been synthesized in aqueous solution. The compositions of the complexes were determined by ele-mental analysis and EDTA titration. The infrared spectra of the complexes were measured with principal spectral bands being assigned. The results showed that the valine molecules are zwitterions in the complexes and coordinate to rare earth ions through carboxyl groups, and the six water molecules coordinate to rare earth ion too. The La ang Nd complexes may be one dimensional chain complexes of infinite length and the others dinuclear complexes.
1995, 12(3): 52-56
Abstract:
Polysiloxane-acrylic composite latexes having core-shell structure were prepared stepwisely by seeded emulsion polymerization. The effects of emulgent's coverage extent on latex particle surface,addition method of emulgent and ratio of monomers on the formation of latex particles were investigated. The results showed that the emulgent amount on the particle surface of polysiloxane emulsions played an important role on the formation of the la-tex particles having core-shell structure. When the emulgent coverage on the surface of polysiloxane particles was less 40%, the polysiloxane-acrylic latexes where most particles possess core-shell structure may be produced.
Polysiloxane-acrylic composite latexes having core-shell structure were prepared stepwisely by seeded emulsion polymerization. The effects of emulgent's coverage extent on latex particle surface,addition method of emulgent and ratio of monomers on the formation of latex particles were investigated. The results showed that the emulgent amount on the particle surface of polysiloxane emulsions played an important role on the formation of the la-tex particles having core-shell structure. When the emulgent coverage on the surface of polysiloxane particles was less 40%, the polysiloxane-acrylic latexes where most particles possess core-shell structure may be produced.
1995, 12(3): 57-60
Abstract:
The extraction of chromium(Ⅵ) from sulfate medium with primary amine N1923 has been studied by the distribution method and IR spectrography at 298K.
The extraction of chromium(Ⅵ) from sulfate medium with primary amine N1923 has been studied by the distribution method and IR spectrography at 298K.
1995, 12(3): 61-63
Abstract:
The scanning electron microscopy, X-ray diffractometry and electrochemical tech-niques were used to study the surface structure and catalytic activity of highly dispersed plat-inum supported on glassy carbon electrode. The results demonstrated that after high temper-ature treatment the dispersed platinum showed a tendency of monoorientation on the surface of glassy carbon, and yieldied large size microcrystals with regular morphology. The high temperature treated Pt/GC was stable and possessed a relatively high catalytic activity to-wards methanol oxidation.
The scanning electron microscopy, X-ray diffractometry and electrochemical tech-niques were used to study the surface structure and catalytic activity of highly dispersed plat-inum supported on glassy carbon electrode. The results demonstrated that after high temper-ature treatment the dispersed platinum showed a tendency of monoorientation on the surface of glassy carbon, and yieldied large size microcrystals with regular morphology. The high temperature treated Pt/GC was stable and possessed a relatively high catalytic activity to-wards methanol oxidation.
1995, 12(3): 64-66
Abstract:
The synergistic extraction of rare earth(Ⅲ) including La, Nd,Y,Gd,Yb from aqueous mineral acid solution (H2SO4,HCl, HNO3) by isopropyl phosphonic acid mono(1-hexyl-4-ethyl) octyl ester (PT-2, HL) with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP, HA) in benzeiie has been investigated. The compositions of the synergistic ex-tracted complexes and the equilibrium constants were determined and calculated respectively. The relationship between structures of the extractants and synergistic effects has been discussed. The mechanism of the synergistic extraction has been discussed also.
The synergistic extraction of rare earth(Ⅲ) including La, Nd,Y,Gd,Yb from aqueous mineral acid solution (H2SO4,HCl, HNO3) by isopropyl phosphonic acid mono(1-hexyl-4-ethyl) octyl ester (PT-2, HL) with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP, HA) in benzeiie has been investigated. The compositions of the synergistic ex-tracted complexes and the equilibrium constants were determined and calculated respectively. The relationship between structures of the extractants and synergistic effects has been discussed. The mechanism of the synergistic extraction has been discussed also.
1995, 12(3): 67-69
Abstract:
The distillation residue in the preparation of ethyl lactate was found to be a mix-ture of polyethyl lactate and lactides from the IR and EIMS results.
The distillation residue in the preparation of ethyl lactate was found to be a mix-ture of polyethyl lactate and lactides from the IR and EIMS results.
1995, 12(3): 70-72
Abstract:
The interactions of lanthanium(Ⅲ) and terbium(Ⅲ) ions with bovine serum albu-mine(BSA) in an aqueous solution of hexamethylene-tetramine-HCl buffer and 0.1mol/L NaCl (pH=6.3) have been studied by UV-Vis,IR,CD and fluorescence spectroscopies. Three strong and more than five weak binding sites were found in BSA complex. The sec-ondary structure of BSA was slightly disturbed by coordination with rare earth ions. Groups in BSA molecule coordinated with rare earth ions are the β-,γ-carboxyls from the side chains of Asp and Glu residues and the carbonyls from the peptide bonds of BSA.
The interactions of lanthanium(Ⅲ) and terbium(Ⅲ) ions with bovine serum albu-mine(BSA) in an aqueous solution of hexamethylene-tetramine-HCl buffer and 0.1mol/L NaCl (pH=6.3) have been studied by UV-Vis,IR,CD and fluorescence spectroscopies. Three strong and more than five weak binding sites were found in BSA complex. The sec-ondary structure of BSA was slightly disturbed by coordination with rare earth ions. Groups in BSA molecule coordinated with rare earth ions are the β-,γ-carboxyls from the side chains of Asp and Glu residues and the carbonyls from the peptide bonds of BSA.
1995, 12(3): 73-75
Abstract:
A complex of (C6H5)Yb(C9H7)·2THF(Ⅰ) has been synthesized by reacting a Grignard-type reagent C6H5YbI with KC9H7 in THF. It is a first Yb(Ⅱ) complex containing both π-ligand(indenyl) and σ-ligand(phenhyl). The similar reaction carried out in 1,2-dimethoxyethane(DME) gave (C6H5)Yb(C9H7)·DME(Ⅱ). Treatment of(Ⅰ) with diox-ane yielded (C6H5)Yb(C9H7)·THF·(1/2)Dioxane(Ⅲ). The three complexes(Ⅰ), (Ⅱ), and (Ⅲ) were analyzed by elemental analysis,IR,MS and 1H NMR measurements.
A complex of (C6H5)Yb(C9H7)·2THF(Ⅰ) has been synthesized by reacting a Grignard-type reagent C6H5YbI with KC9H7 in THF. It is a first Yb(Ⅱ) complex containing both π-ligand(indenyl) and σ-ligand(phenhyl). The similar reaction carried out in 1,2-dimethoxyethane(DME) gave (C6H5)Yb(C9H7)·DME(Ⅱ). Treatment of(Ⅰ) with diox-ane yielded (C6H5)Yb(C9H7)·THF·(1/2)Dioxane(Ⅲ). The three complexes(Ⅰ), (Ⅱ), and (Ⅲ) were analyzed by elemental analysis,IR,MS and 1H NMR measurements.
1995, 12(3): 76-78
Abstract:
A self-dispersed cationic polyurethane dispersion was prepared with epoxy and quarternary ammonium groups in macromolecule chain. The dispersion can be used as a tex-tile finisher to improve the wettability, machanical strength and permanent antistatic proper-ty of textile.
A self-dispersed cationic polyurethane dispersion was prepared with epoxy and quarternary ammonium groups in macromolecule chain. The dispersion can be used as a tex-tile finisher to improve the wettability, machanical strength and permanent antistatic proper-ty of textile.
1995, 12(3): 79-81
Abstract:
Potassium ion selcctive PVC membrane eiectrodes based on chalcone crown ethers wcre prepared and their electrode behaviour was evaluated. The electrodes exhibited good se-lectivty of potassium.
Potassium ion selcctive PVC membrane eiectrodes based on chalcone crown ethers wcre prepared and their electrode behaviour was evaluated. The electrodes exhibited good se-lectivty of potassium.
1995, 12(3): 82-84
Abstract:
Aphis alarm pheromone analogous (E)-2-ethyl-6,10-dimethyl-1,5,9-unde-cantriene was synthesized by reacting ethyl copper with 6,10-dimethylundecandien-1-yne, which was prepared by reacting CH≡C-H2MgBr with brominated prodtict of citronel-lol.
Aphis alarm pheromone analogous (E)-2-ethyl-6,10-dimethyl-1,5,9-unde-cantriene was synthesized by reacting ethyl copper with 6,10-dimethylundecandien-1-yne, which was prepared by reacting CH≡C-H2MgBr with brominated prodtict of citronel-lol.
1995, 12(3): 85-87
Abstract:
The complexes (phen)4Ln(TCNQ)4(H2O) (Ln=La,Nd) have been synthesized and characterized by elemental analysis. IR spectra、UV-Vis spectra、1H NMR and ESR spectra. The powder conductivities of the complexes at room temperature are of 4.6~5.3×10-2Ω-1cm-1.
The complexes (phen)4Ln(TCNQ)4(H2O) (Ln=La,Nd) have been synthesized and characterized by elemental analysis. IR spectra、UV-Vis spectra、1H NMR and ESR spectra. The powder conductivities of the complexes at room temperature are of 4.6~5.3×10-2Ω-1cm-1.
1995, 12(3): 88-90
Abstract:
The fluorescence spectra of blends of ethylene terephthalate-caprolactone copoly-mer(TCL) with polyhydroxy ether of bisphenol-A(PH) are reported. A broad symmetric emission band without fine structure at about 450nm was observed. The peak is attributed to the exciplex emission from chromophores in TCL and PH and is in relation with the miscibili-ty behaviour of the blends.
The fluorescence spectra of blends of ethylene terephthalate-caprolactone copoly-mer(TCL) with polyhydroxy ether of bisphenol-A(PH) are reported. A broad symmetric emission band without fine structure at about 450nm was observed. The peak is attributed to the exciplex emission from chromophores in TCL and PH and is in relation with the miscibili-ty behaviour of the blends.
1995, 12(3): 91-93
Abstract:
The adsorption on sulfidized WGS (water gas shift) catalyst NiMoK/Al2O3 has been studied by pulse gas chromatography. The changes of entropy and enthalpy of H2O ad-sorption were obtained from the retention volume determined at various temperatures. The results show that the △Ha and △Sa on sulfidized catalyst were greater than that of the oxi-dized catalyst. Furthermore, △Ha and △Sa of catalyst increase with the sulfidation tempera-ture. It is thought that the higher the sulfidation temperature, the more the adsorption sites of H2O on the surface of catalyst, and the weaker the adsorbability.
The adsorption on sulfidized WGS (water gas shift) catalyst NiMoK/Al2O3 has been studied by pulse gas chromatography. The changes of entropy and enthalpy of H2O ad-sorption were obtained from the retention volume determined at various temperatures. The results show that the △Ha and △Sa on sulfidized catalyst were greater than that of the oxi-dized catalyst. Furthermore, △Ha and △Sa of catalyst increase with the sulfidation tempera-ture. It is thought that the higher the sulfidation temperature, the more the adsorption sites of H2O on the surface of catalyst, and the weaker the adsorbability.
1995, 12(3): 94-96
Abstract:
The racemic sex pheromone of Japanese beetle was synthesized by the addition of Z-decen-1-yl cuprate to succinic anhydride in 3 steps in an overall yield up to 60% and the Z-form purity was over 98%.
The racemic sex pheromone of Japanese beetle was synthesized by the addition of Z-decen-1-yl cuprate to succinic anhydride in 3 steps in an overall yield up to 60% and the Z-form purity was over 98%.
1995, 12(3): 97-99
Abstract:
The crystallization and melting behaviour of poly(ethylene oxide-co-propylene ox-ide) and its LiClO4 salt complex were studied. It was found that the plain copolymers are still crystallizable thotigh the degree of crystallinity has been deeply suppressed owing to the presence of the non-crystallizable propylene oxide component. However,the LiClO4 adduct was hardly to crystallize especially in fast cooling. A detailed examination on the heating and cooling rate dependence of the Tm,△Hm,Tc,△Hc and cold crystallization phenomenon of the specimens was made.
The crystallization and melting behaviour of poly(ethylene oxide-co-propylene ox-ide) and its LiClO4 salt complex were studied. It was found that the plain copolymers are still crystallizable thotigh the degree of crystallinity has been deeply suppressed owing to the presence of the non-crystallizable propylene oxide component. However,the LiClO4 adduct was hardly to crystallize especially in fast cooling. A detailed examination on the heating and cooling rate dependence of the Tm,△Hm,Tc,△Hc and cold crystallization phenomenon of the specimens was made.
1995, 12(3): 100-102
Abstract:
The catalytic selective reduction of nitrogen monooxide by methane on γ-Al2O3 and γ-Al2O3-ZSM-5 supported with Pt and Pd has been investigated. For catalysts supported on γ-Al2O3 a higher activity and nitrogen selectivity appeared at 350~400℃, for catalysts supported on γ-Al2O3-ZSM-5 they appeared at 400~500℃. The bimetallic catalysts showed a better catalytic activity than monometallic ones.
The catalytic selective reduction of nitrogen monooxide by methane on γ-Al2O3 and γ-Al2O3-ZSM-5 supported with Pt and Pd has been investigated. For catalysts supported on γ-Al2O3 a higher activity and nitrogen selectivity appeared at 350~400℃, for catalysts supported on γ-Al2O3-ZSM-5 they appeared at 400~500℃. The bimetallic catalysts showed a better catalytic activity than monometallic ones.
1995, 12(3): 103-104
Abstract:
The Knoevenagel condensation of aromatic aldehydes with ethyl cyanoacetate or cyanoacetamide has been carried out smoothly in the presence of potassium fluoride on alumi-na in high yield of products,and only the E isomers of the products were obtained.
The Knoevenagel condensation of aromatic aldehydes with ethyl cyanoacetate or cyanoacetamide has been carried out smoothly in the presence of potassium fluoride on alumi-na in high yield of products,and only the E isomers of the products were obtained.
1995, 12(3): 105-106
Abstract:
The polymerization of acrylonitrile by[(t-BuCp)2NdCH3]2 has been carried out. The influence of the polymerization conditions on the catalytic activity,molecular weight and microstructure of polymers was investigated.
The polymerization of acrylonitrile by[(t-BuCp)2NdCH3]2 has been carried out. The influence of the polymerization conditions on the catalytic activity,molecular weight and microstructure of polymers was investigated.
1995, 12(3): 107-108
Abstract:
A practical method for preparation of triammonium tetrahydrogen molybdophos-phate (AHMP) is proposed by reacting Na3P(S)O3 with ammonium molybdate. The ex-change capacity of AHMP for Li+, Na+,K+, Rb+, Cs+, and Ag+ has been evaluated.
A practical method for preparation of triammonium tetrahydrogen molybdophos-phate (AHMP) is proposed by reacting Na3P(S)O3 with ammonium molybdate. The ex-change capacity of AHMP for Li+, Na+,K+, Rb+, Cs+, and Ag+ has been evaluated.
1995, 12(3): 109-110
Abstract:
The wood powder treated with a mixture of sulfuric-diethylamine-dimethyl sul-foxide (SO2-DEA-DMSO) can reach a high esterification degree when it is then esterified with a mixture of pyridine and acetic anhydride in the conditions of high temperature, high quantity of esterification agent and long reaction time. The esterification degree is relatively low if the wood powder is treated with polyformaldehyde-DMSO (PMO-DMSO) due to the decreased activity of hydroxyl groups in cellulose as result of chemical destrustion of ligno-cellulose during solvent treatment.
The wood powder treated with a mixture of sulfuric-diethylamine-dimethyl sul-foxide (SO2-DEA-DMSO) can reach a high esterification degree when it is then esterified with a mixture of pyridine and acetic anhydride in the conditions of high temperature, high quantity of esterification agent and long reaction time. The esterification degree is relatively low if the wood powder is treated with polyformaldehyde-DMSO (PMO-DMSO) due to the decreased activity of hydroxyl groups in cellulose as result of chemical destrustion of ligno-cellulose during solvent treatment.
1995, 12(3): 111-112
Abstract:
The thermal behavior and mechanical property of PET/PBT blend fibers with dif-ferent draw ratio have been studied. Two independent melting peaks corresponding to that of pure PET and PBT fiber were observed in DSC curves of blend fibers. Blend fibers of low draw ratio showed two Tgs, but only single Tg for that of high draw ratio. The values of ini-tial modulus of the blend fiber possesses an additivity.
The thermal behavior and mechanical property of PET/PBT blend fibers with dif-ferent draw ratio have been studied. Two independent melting peaks corresponding to that of pure PET and PBT fiber were observed in DSC curves of blend fibers. Blend fibers of low draw ratio showed two Tgs, but only single Tg for that of high draw ratio. The values of ini-tial modulus of the blend fiber possesses an additivity.
1995, 12(3): 113-114
Abstract:
Diethylmalonate was synthcsized by carbonylation in the presence of Co2(CO)8 and dibenzo-30-crown-10 in 100% yield. The reaction conditions were examined.
Diethylmalonate was synthcsized by carbonylation in the presence of Co2(CO)8 and dibenzo-30-crown-10 in 100% yield. The reaction conditions were examined.
1995, 12(3): 115-116
Abstract:
The catalytic hydroformylation of 1-hexene by polyalumazane-ruthenium-lan-thanum complex has been investigated. Lanthanum in the complex plays as a promoter of the catalyst.
The catalytic hydroformylation of 1-hexene by polyalumazane-ruthenium-lan-thanum complex has been investigated. Lanthanum in the complex plays as a promoter of the catalyst.
1995, 12(3): 117-118
Abstract:
In this paper, the blend of polyethersulfone and phenoxy has been prepared by melt mixing in a brabender-like apparatus, the mechanical properties and transition behav-iors have been characterized by tensile test, torsional braid analysis, etc., the miscibility of polyethersulfone and phenoxy has been discussed.
In this paper, the blend of polyethersulfone and phenoxy has been prepared by melt mixing in a brabender-like apparatus, the mechanical properties and transition behav-iors have been characterized by tensile test, torsional braid analysis, etc., the miscibility of polyethersulfone and phenoxy has been discussed.
