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1996 Volume 13 Issue 5
1996, 13(5): 1-4
Abstract:
Effects of pressure, reaction temperature, concentration of catalyst and promoter on the synthesis of diethyl formamide(DEF) by catalytic carbonylation of diethylamine in liquid phase have been examined, and the optimal conditions of carbonylation have been determined. The experimental results have revealed that the partial pressure of carbon monoxide(PCO) has a marked effect on the reaction rate and the rate of DEF formation increases with the increase of the partial pressure of CO. The concentration of catalyst has a little influence on the reaction rate, but the carbonylation can not take place without catalyst. The propylene oxide(PO) additive has a strong promoter effect on sodium methoxide catalyst,and the promoter effect on the catalyst is directly proportional to the concentration of PO promoter.
Effects of pressure, reaction temperature, concentration of catalyst and promoter on the synthesis of diethyl formamide(DEF) by catalytic carbonylation of diethylamine in liquid phase have been examined, and the optimal conditions of carbonylation have been determined. The experimental results have revealed that the partial pressure of carbon monoxide(PCO) has a marked effect on the reaction rate and the rate of DEF formation increases with the increase of the partial pressure of CO. The concentration of catalyst has a little influence on the reaction rate, but the carbonylation can not take place without catalyst. The propylene oxide(PO) additive has a strong promoter effect on sodium methoxide catalyst,and the promoter effect on the catalyst is directly proportional to the concentration of PO promoter.
1996, 13(5): 5-9
Abstract:
Eighteen novel symmetrical and unsymmetrical oxadiazoles and their N,N'-diacylhydrazine precursors have been synthesized and characterized by elemental analysis,IR,1H NMR and MS. Their insecticidal and antibiotic activities have also been measured and some are found to have strong bioactivities.
Eighteen novel symmetrical and unsymmetrical oxadiazoles and their N,N'-diacylhydrazine precursors have been synthesized and characterized by elemental analysis,IR,1H NMR and MS. Their insecticidal and antibiotic activities have also been measured and some are found to have strong bioactivities.
1996, 13(5): 10-13
Abstract:
The chemical modification of poly(2,6-dimethyl-1,4-phenylene oxide)(PPO) has been carried out by incorporating nitro or amino groups in the PPO backbone. The obtained maximum monosubstitution value is 95% or 65% respectively. The effects of reaction conditions on the functional group contents in PPO were discussed. The modified PPO obtained was characterized by FT-IR、1H NMR spectroscopy, nitrogen analysis, solubility test and X-ray diffraction study.
The chemical modification of poly(2,6-dimethyl-1,4-phenylene oxide)(PPO) has been carried out by incorporating nitro or amino groups in the PPO backbone. The obtained maximum monosubstitution value is 95% or 65% respectively. The effects of reaction conditions on the functional group contents in PPO were discussed. The modified PPO obtained was characterized by FT-IR、1H NMR spectroscopy, nitrogen analysis, solubility test and X-ray diffraction study.
1996, 13(5): 14-16
Abstract:
Ten new title compounds were synthesized by condensation of thiophosphoryl chlorides and 2-sodium alcoholate-6-substitutent-3, 4-dihydrofuroquinolines, the latter being prepared from the reduction of corresponding 2-oxo compounds with sodium hydride. Their structures were confirmed by 1H NMR, MS, and elemental analysis. Some of them have good antifungous activity to pellicularia sasakii of rice.
Ten new title compounds were synthesized by condensation of thiophosphoryl chlorides and 2-sodium alcoholate-6-substitutent-3, 4-dihydrofuroquinolines, the latter being prepared from the reduction of corresponding 2-oxo compounds with sodium hydride. Their structures were confirmed by 1H NMR, MS, and elemental analysis. Some of them have good antifungous activity to pellicularia sasakii of rice.
1996, 13(5): 17-20
Abstract:
In an aqueous solution and under the sensitization of acridine yellow(AY) or acridine orange(AO), the photoisomerization of bicyclo[2.2.1] hepta-2, 5-diene-2, 3-dicarboxylic acid(N) was investigated. The quantum yields of sensitized photoisomerizations for AY and AO are 0.33 and 0.31, respectively. Since the reaction medium is water which is safe and inexpensive, the sensitizers can harvest sunlight effectively and the preparation of water-soluble norbornadiene derivative is very easy, this photo reaction system is promising for solar energy storage. A mechanism involving electron transfer was proposed from the analysis of fluorescence quenching and thermodynamic discussion.
In an aqueous solution and under the sensitization of acridine yellow(AY) or acridine orange(AO), the photoisomerization of bicyclo[2.2.1] hepta-2, 5-diene-2, 3-dicarboxylic acid(N) was investigated. The quantum yields of sensitized photoisomerizations for AY and AO are 0.33 and 0.31, respectively. Since the reaction medium is water which is safe and inexpensive, the sensitizers can harvest sunlight effectively and the preparation of water-soluble norbornadiene derivative is very easy, this photo reaction system is promising for solar energy storage. A mechanism involving electron transfer was proposed from the analysis of fluorescence quenching and thermodynamic discussion.
1996, 13(5): 21-24
Abstract:
poly(2,5-dimethoxyaniline) film electrodes were prepared by electrochemical method. Metallic platinum microparticles were dispersed into poly(2,5-dimethoxyaniline) matrix by cyclic voltammetry. The electrocatalytic activity of the film electrode was studied for electrooxidation of methanol in protonic acid. It is shown that the incorporation of platinum microparticles into the polymer matrix results in a further ten-fold increase in activity as compared with naked platinum electrodes.The preparation temperature of poly(2,5-dimethoxyaniline) film has a pronounced influence on the electrochemical behaviour. Some important factors which affect electrochemical reactions were discussed.
poly(2,5-dimethoxyaniline) film electrodes were prepared by electrochemical method. Metallic platinum microparticles were dispersed into poly(2,5-dimethoxyaniline) matrix by cyclic voltammetry. The electrocatalytic activity of the film electrode was studied for electrooxidation of methanol in protonic acid. It is shown that the incorporation of platinum microparticles into the polymer matrix results in a further ten-fold increase in activity as compared with naked platinum electrodes.The preparation temperature of poly(2,5-dimethoxyaniline) film has a pronounced influence on the electrochemical behaviour. Some important factors which affect electrochemical reactions were discussed.
1996, 13(5): 25-28
Abstract:
The morphology, structure and properties of ternary blends VECTRA, PEEK,TOBC-PEEK were investigated using WAXD, SEM and mechanical test. With interfacial adhersion, the liquid crystalline polymer(LCP) could form microfiber in certain extent and disperse into the matrix of PEEK. The strength and modulus increased and reached the maximum in the blend containing 20% VECTRA. The crystallization behavior of the blend was obviously affected by the addition of block copolymer. SEM photographs showed that the high content of LCP possessed "core-shell" structure.
The morphology, structure and properties of ternary blends VECTRA, PEEK,TOBC-PEEK were investigated using WAXD, SEM and mechanical test. With interfacial adhersion, the liquid crystalline polymer(LCP) could form microfiber in certain extent and disperse into the matrix of PEEK. The strength and modulus increased and reached the maximum in the blend containing 20% VECTRA. The crystallization behavior of the blend was obviously affected by the addition of block copolymer. SEM photographs showed that the high content of LCP possessed "core-shell" structure.
1996, 13(5): 29-32
Abstract:
A series of 1-(p-toluenesulfonyl)-2-phenoxy-3-aryl-4-phenyl-1,4,2-diazaphospholidin-5-one-2-oxides (2) has been synthesized by the. Mannich-type reaction of 1-phenyl-3-(ptoluenesulfonyl) urea(1), substituted benzaldehydes and triphenyl phosphite in anhydrous toluene. The side reactions were discussed. The structures of new compounds were characterized by 1H NMR, 31P NMR, elemental analysis, MS and IR spectra. The results of preliminary bioassay showed that the compound 2 possesses good selective herbicidal activity against rape.
A series of 1-(p-toluenesulfonyl)-2-phenoxy-3-aryl-4-phenyl-1,4,2-diazaphospholidin-5-one-2-oxides (2) has been synthesized by the. Mannich-type reaction of 1-phenyl-3-(ptoluenesulfonyl) urea(1), substituted benzaldehydes and triphenyl phosphite in anhydrous toluene. The side reactions were discussed. The structures of new compounds were characterized by 1H NMR, 31P NMR, elemental analysis, MS and IR spectra. The results of preliminary bioassay showed that the compound 2 possesses good selective herbicidal activity against rape.
1996, 13(5): 33-36
Abstract:
A series of oxymethylene-linked polyoxyethylene-polyoxypropylene multiblock copolymer were synthesized by condensing CH2Cl2, with poly (ethylene glycol)(PEG), poly(propylene glycol) and telechelic dihydroxy-polystyrene(THPS) in the presene of KOH power. The multiblock copolymers exhibit good emulsifying properties and good phase transfer catalystic properties in Williamson reaction.
A series of oxymethylene-linked polyoxyethylene-polyoxypropylene multiblock copolymer were synthesized by condensing CH2Cl2, with poly (ethylene glycol)(PEG), poly(propylene glycol) and telechelic dihydroxy-polystyrene(THPS) in the presene of KOH power. The multiblock copolymers exhibit good emulsifying properties and good phase transfer catalystic properties in Williamson reaction.
1996, 13(5): 37-40
Abstract:
This article is focused on the synthesis of interpenetrating polymer network (IPN) of epoxy resin and polyacrylic ester which can be used as the material of stone sculptures along hills preservation. The primary and subsidiary factors that influence the coacervation rate, emulsion stability,waterproofness, and water absorption rate of emulsion adhesive film were discussed, and the technological conditions were then optimized. The product was tested by infrared absorption spectroscopy and basic property analysis.
This article is focused on the synthesis of interpenetrating polymer network (IPN) of epoxy resin and polyacrylic ester which can be used as the material of stone sculptures along hills preservation. The primary and subsidiary factors that influence the coacervation rate, emulsion stability,waterproofness, and water absorption rate of emulsion adhesive film were discussed, and the technological conditions were then optimized. The product was tested by infrared absorption spectroscopy and basic property analysis.
1996, 13(5): 41-43
Abstract:
A series of polyurethanes and poly(styrene-methyl methacrylate-methacrylic acid) interpenetrating polymer networks(IPNs) were characterized using stress-strain analysis,dynamic mechanical spectroscopy, transmission electron microscopy and thermal behavior measurements. The results of dynamic mechanical behavior and morphology show that the phase separation of the IPNs is serious.The IPNs have two Tg values with different extent of shift, indicating the mixing of two components in some extent. The formation of IPNs has improved their mechanical properties. It is suggested that the Si-MMA-MAA segments act as radical scavengers in the polyurethane degradation.
A series of polyurethanes and poly(styrene-methyl methacrylate-methacrylic acid) interpenetrating polymer networks(IPNs) were characterized using stress-strain analysis,dynamic mechanical spectroscopy, transmission electron microscopy and thermal behavior measurements. The results of dynamic mechanical behavior and morphology show that the phase separation of the IPNs is serious.The IPNs have two Tg values with different extent of shift, indicating the mixing of two components in some extent. The formation of IPNs has improved their mechanical properties. It is suggested that the Si-MMA-MAA segments act as radical scavengers in the polyurethane degradation.
1996, 13(5): 44-47
Abstract:
In this paper the surface properties of MgO and SrO were investigated by means of temperature-programmed desorption. The results show that there are two types of both basic sites and acidic sites on MgO catalyst, while only one type strong basic sites on SrO catalyst. These basic sites, acidic sites and their synergistic action have different effect on the decomposition of isopropanol. On MgO, propene results from the elimination of water from isopropanol over strong acidic sites and acetone comes from the dehydrogenation of isopropanol over strong basic sites in cooperation with acidic sites. On SrO, acetone is the sole product resulted from the dehydrogenation of isopropanol under the action of very strong basic sites.
In this paper the surface properties of MgO and SrO were investigated by means of temperature-programmed desorption. The results show that there are two types of both basic sites and acidic sites on MgO catalyst, while only one type strong basic sites on SrO catalyst. These basic sites, acidic sites and their synergistic action have different effect on the decomposition of isopropanol. On MgO, propene results from the elimination of water from isopropanol over strong acidic sites and acetone comes from the dehydrogenation of isopropanol over strong basic sites in cooperation with acidic sites. On SrO, acetone is the sole product resulted from the dehydrogenation of isopropanol under the action of very strong basic sites.
1996, 13(5): 48-51
Abstract:
The extraction of Ni(Ⅱ) from 0.100 mol/L CH3COO(H,Na) with HDEHP in different diluents, such as benzene,toluene,n-hexane, cyclohexane, CCl4 and chloroform, has been studied. The species formed in the extraction and the extraction machanism have been examined by means of IR spectra. It shows that the complex formed in chloroform is different from that formed in other diluents. The effect of diluents is discussed. The extraction equilibrium constants and the extraction distribution are correlated with the physical constants and(or) experimental parameters of diluents, respectively. The effect of temperature has also been investigated, and the thermodynamic constants △G0, △H0 and △S0 at 298 K are obtained.
The extraction of Ni(Ⅱ) from 0.100 mol/L CH3COO(H,Na) with HDEHP in different diluents, such as benzene,toluene,n-hexane, cyclohexane, CCl4 and chloroform, has been studied. The species formed in the extraction and the extraction machanism have been examined by means of IR spectra. It shows that the complex formed in chloroform is different from that formed in other diluents. The effect of diluents is discussed. The extraction equilibrium constants and the extraction distribution are correlated with the physical constants and(or) experimental parameters of diluents, respectively. The effect of temperature has also been investigated, and the thermodynamic constants △G0, △H0 and △S0 at 298 K are obtained.
1996, 13(5): 52-55
Abstract:
Solid state chlorinated polyethylene(CPE) was used as compatibilizer for PVC/LLDPE blends. The effects of the composition of blends and the molecular structure of CPE on mechanical properties of the blends were investigated. The mechanism of CPE as a compatibilizer for PVC/LLDPE blends was interpreted by correlating the structure of CPE with morphology of the blends revealed by SEM, TEM and DMA. The experimental results showed that the compatibility between PVC and LLDPE and the mechanical properties of the blends were improved by the addition of CPE.
Solid state chlorinated polyethylene(CPE) was used as compatibilizer for PVC/LLDPE blends. The effects of the composition of blends and the molecular structure of CPE on mechanical properties of the blends were investigated. The mechanism of CPE as a compatibilizer for PVC/LLDPE blends was interpreted by correlating the structure of CPE with morphology of the blends revealed by SEM, TEM and DMA. The experimental results showed that the compatibility between PVC and LLDPE and the mechanical properties of the blends were improved by the addition of CPE.
1996, 13(5): 56-57
Abstract:
Hydrothermal treatment was successfully used to prepare pure nanocrystalline ZnS and CdS from respective amorphous sulfides. XRD indicated that both products were of cubic phase. The electron microscopy image showed that the average particle size of ZnS and CdS was about 7 nm and 5 nm respectively. The ZnS and CdS powders have narrow particle size distribution and ZnS possesses good IR transmittance in the range of 400 to 5000 cm-1.
Hydrothermal treatment was successfully used to prepare pure nanocrystalline ZnS and CdS from respective amorphous sulfides. XRD indicated that both products were of cubic phase. The electron microscopy image showed that the average particle size of ZnS and CdS was about 7 nm and 5 nm respectively. The ZnS and CdS powders have narrow particle size distribution and ZnS possesses good IR transmittance in the range of 400 to 5000 cm-1.
1996, 13(5): 58-60
Abstract:
The mechanism of multicomponent oxide bismuth vanadomolybdate catalysts for the seldctive oxidation of propane to acrolein has been investigated by IR spectroscopy. The results of IR spectra show that when cation vacancies are introduced randomly in the lattice by replacing V5+ with Mo6+ in the scheelite oxides Bi1-x/3)V1-xMoxO4, some of the oxygen combined with Bi cation are released and the tetrahedron Mo(V)O4 may be distorted to some extent. The formation of the shared structure Mo-O-V makes it possible for lattice oxygen ions to diffuse into the bulk of catalyst. The Mo=O double bond, which plays an important role in selective oxidation, has formed by introducing cation vacancies when x is 0.45,namely in Bi0.85V0.55Mo0.45O4 catalyst. The synergistic effect between Mo=O double bond and stronger Bi-O-V bond accounts for the better catalytic performance of this catalyst.
The mechanism of multicomponent oxide bismuth vanadomolybdate catalysts for the seldctive oxidation of propane to acrolein has been investigated by IR spectroscopy. The results of IR spectra show that when cation vacancies are introduced randomly in the lattice by replacing V5+ with Mo6+ in the scheelite oxides Bi1-x/3)V1-xMoxO4, some of the oxygen combined with Bi cation are released and the tetrahedron Mo(V)O4 may be distorted to some extent. The formation of the shared structure Mo-O-V makes it possible for lattice oxygen ions to diffuse into the bulk of catalyst. The Mo=O double bond, which plays an important role in selective oxidation, has formed by introducing cation vacancies when x is 0.45,namely in Bi0.85V0.55Mo0.45O4 catalyst. The synergistic effect between Mo=O double bond and stronger Bi-O-V bond accounts for the better catalytic performance of this catalyst.
1996, 13(5): 61-63
Abstract:
The TiO2 semiconductor film on Al2O3 and glass substrates was prepared by homogeneous precipitation with titanyl sulfate and urea as raw materials. Under low concentration of TiOSO4 the increase of urea concentration could accelerate the formation of the film.The thickness of the film prepared at 70~80℃ for 1 h and calcined at 600℃ for 0.5 h (1 cycle) was over 0.2 μm while the thickness obtained by 4 cycles was over 0.8μm. The adhesion of the film was good. After calcining at 1000℃ for 0.5 h in H2 the film was crystallized into rutile phase having a square resistance of 1.3×104 Ω/□.
The TiO2 semiconductor film on Al2O3 and glass substrates was prepared by homogeneous precipitation with titanyl sulfate and urea as raw materials. Under low concentration of TiOSO4 the increase of urea concentration could accelerate the formation of the film.The thickness of the film prepared at 70~80℃ for 1 h and calcined at 600℃ for 0.5 h (1 cycle) was over 0.2 μm while the thickness obtained by 4 cycles was over 0.8μm. The adhesion of the film was good. After calcining at 1000℃ for 0.5 h in H2 the film was crystallized into rutile phase having a square resistance of 1.3×104 Ω/□.
1996, 13(5): 64-66
Abstract:
The influence of acrylonitrile-grafted wood fiber on the phycical-mechanical properties of polyvinyl chloride-wood fiber composites was studied. The grafted wood fiber improved the tensile strength and impact strength of composites. Generally, the impact strngth improved along with the increase in grafting ratio. The effect of the concentration of wood fiber on mechanical properties of composites was studied.
The influence of acrylonitrile-grafted wood fiber on the phycical-mechanical properties of polyvinyl chloride-wood fiber composites was studied. The grafted wood fiber improved the tensile strength and impact strength of composites. Generally, the impact strngth improved along with the increase in grafting ratio. The effect of the concentration of wood fiber on mechanical properties of composites was studied.
1996, 13(5): 67-69
Abstract:
Four derivatives of friedelin were synthesized by chemical transformation of friedelin in order to investigate their bioactivities and develop highly anti-inflammatory agents.
Four derivatives of friedelin were synthesized by chemical transformation of friedelin in order to investigate their bioactivities and develop highly anti-inflammatory agents.
1996, 13(5): 70-72
Abstract:
Thermal stability of tungstophosphoric heteropoly complexes containing NbO2 with Dawson structure is studied. The total loss of crystallization water occurs below 200℃. The anhydrous acids decompose at 600℃ or so. The XPS determination shows that the electron binding energy of Nb3d5/2 decreases with the increasing number of substituted NbO2 groups.
Thermal stability of tungstophosphoric heteropoly complexes containing NbO2 with Dawson structure is studied. The total loss of crystallization water occurs below 200℃. The anhydrous acids decompose at 600℃ or so. The XPS determination shows that the electron binding energy of Nb3d5/2 decreases with the increasing number of substituted NbO2 groups.
1996, 13(5): 73-75
Abstract:
A golden yellow conversion film was obtained by immersing zinc deposit specimens into Na8[(HEDP)2Mo5O21]·5H2O solution (HEDP, CH3C
). Several factors including concentration, PH, temperature of the treating solution and the treating time affecting the anticorrosion efficiency of the conversion film were investigated. The accelerated corrosion test proved that the film possesses a good corrosion resistance. The composition of the film and the valence states of elements in the film were determined by XPS and AES.The results showed that the relative atomic percent content of the film was Zn 17.84%,O 50.28%,C 7.42%,Mo 18.00% and P 6.44%.Mo existed as Mo(Ⅵ),Mo(Ⅴ),Mo(Ⅲ) and Mo, while Zn existed as various species of Zn(Ⅱ) in the film.
A golden yellow conversion film was obtained by immersing zinc deposit specimens into Na8[(HEDP)2Mo5O21]·5H2O solution (HEDP, CH3C
). Several factors including concentration, PH, temperature of the treating solution and the treating time affecting the anticorrosion efficiency of the conversion film were investigated. The accelerated corrosion test proved that the film possesses a good corrosion resistance. The composition of the film and the valence states of elements in the film were determined by XPS and AES.The results showed that the relative atomic percent content of the film was Zn 17.84%,O 50.28%,C 7.42%,Mo 18.00% and P 6.44%.Mo existed as Mo(Ⅵ),Mo(Ⅴ),Mo(Ⅲ) and Mo, while Zn existed as various species of Zn(Ⅱ) in the film.
1996, 13(5): 76-78
Abstract:
Copolymerization of ethylene/hexene-1 has been carried out by using a TiCl4/SiO2-MgCl2 catalyst. Results show that the rate of copolymerization is higher than that of ethylene homopolymerization. The phenomenon is explained from the viewpoint of unsteady diffusion kinetics of heterogeneous Ziegler-Natta catalysts. The density of ethylene/hexene-1 copolymer obtained reaches the range of very low density polyethylene. The thermal behavior and sequence length distribution of copolymers have been characterized by DSC and 13C NMR.
Copolymerization of ethylene/hexene-1 has been carried out by using a TiCl4/SiO2-MgCl2 catalyst. Results show that the rate of copolymerization is higher than that of ethylene homopolymerization. The phenomenon is explained from the viewpoint of unsteady diffusion kinetics of heterogeneous Ziegler-Natta catalysts. The density of ethylene/hexene-1 copolymer obtained reaches the range of very low density polyethylene. The thermal behavior and sequence length distribution of copolymers have been characterized by DSC and 13C NMR.
1996, 13(5): 79-81
Abstract:
The hydrothermal decomposition process of nesquehonite and the effects of decomposition conditions on the composition of products have been studied. The nesquehonite decomposes quickly in water. It first decomposes into protohydromagnesite, then dypingite appears in a mixture with protohydromagnesite, and finally the hydromagnesite is produced;i. e. via a two-intermediate path. It is a result different from those observed in other studies and may have some guiding significance for the actual production.
The hydrothermal decomposition process of nesquehonite and the effects of decomposition conditions on the composition of products have been studied. The nesquehonite decomposes quickly in water. It first decomposes into protohydromagnesite, then dypingite appears in a mixture with protohydromagnesite, and finally the hydromagnesite is produced;i. e. via a two-intermediate path. It is a result different from those observed in other studies and may have some guiding significance for the actual production.
1996, 13(5): 82-84
Abstract:
The surface-enhanced NIR-FT-Raman spectra of two vitamin B drugs in-situ recorded from thin layer chromatographic(TLC) plate are reported. The in-situ identification of TLC spots from 3 μg-drug reveals similar main spectral feature as that of solid samples. In addition, the sensitivity enhancement has been improved greatly by using silver colloid activated thin layer chromatographic spots.
The surface-enhanced NIR-FT-Raman spectra of two vitamin B drugs in-situ recorded from thin layer chromatographic(TLC) plate are reported. The in-situ identification of TLC spots from 3 μg-drug reveals similar main spectral feature as that of solid samples. In addition, the sensitivity enhancement has been improved greatly by using silver colloid activated thin layer chromatographic spots.
1996, 13(5): 85-87
Abstract:
A kinetic approach and other informations were employed to study the mechanism of Cd ashing and atomization when NH4H2PO4 was used as a modifier. During the pyrolysis stage Cdx(PO3)n produced and a large amount of NH4H2PO4 dehydrated to form metaphosphate with chain or ring shape. This may result in the physical embedment of Cd. So both chemical and physical factors lead to the rise of the pyrolysis temperature. During the atomization stage, the analyte atomization was considered to be governed by the decomposition of this meta phosphate.
A kinetic approach and other informations were employed to study the mechanism of Cd ashing and atomization when NH4H2PO4 was used as a modifier. During the pyrolysis stage Cdx(PO3)n produced and a large amount of NH4H2PO4 dehydrated to form metaphosphate with chain or ring shape. This may result in the physical embedment of Cd. So both chemical and physical factors lead to the rise of the pyrolysis temperature. During the atomization stage, the analyte atomization was considered to be governed by the decomposition of this meta phosphate.
1996, 13(5): 88-90
Abstract:
Miscibility and mechanical properties of blends of linear low density polyethylene(LLDPE) and conventional low density polyethylene(LDPE) were studied by differencial scanning calorimetry(DSC), wide angle X-ray diffraction, dynamic mechanical analysis and static mechanical property measurements. Three endothermic peaks are evident in the DSC traces of the blends, suggesting the formation of a new partly cocrystallized phase. The dynamic mechanical relaxation behaviour of the LLDPE/LDPE blends was found to be close to both components in the vicinities of γ and β regions whereas the blends are dominated by the LLDPE component at the high temperature α regions. The improvement in mechanical properties of the blends has been attributed to the partial cocrystallization between the components in the crystalline phase and the miscibility in the amorphous phase.
Miscibility and mechanical properties of blends of linear low density polyethylene(LLDPE) and conventional low density polyethylene(LDPE) were studied by differencial scanning calorimetry(DSC), wide angle X-ray diffraction, dynamic mechanical analysis and static mechanical property measurements. Three endothermic peaks are evident in the DSC traces of the blends, suggesting the formation of a new partly cocrystallized phase. The dynamic mechanical relaxation behaviour of the LLDPE/LDPE blends was found to be close to both components in the vicinities of γ and β regions whereas the blends are dominated by the LLDPE component at the high temperature α regions. The improvement in mechanical properties of the blends has been attributed to the partial cocrystallization between the components in the crystalline phase and the miscibility in the amorphous phase.
1996, 13(5): 91-93
Abstract:
A series of hydrogen-bonded polyaryletherketone copolymers was synthesized by the reaction of a mixture of phenolphthalein and 3,3'-bis (4-hydroxyphenyl)-isobenzopyrrolidone with equivalent mole of bis (4-nitrophenyl)ketone using anhydrous K2CO3 as catalyst and DMSO as solvent. The intermolecular hydrogen bond in the copolymers prepared was confirmed from FTIR spectra at different temperature. Compared with unmodified phenolphthalein based polyaryletherketone(PEK-C), the introduction of lactam ring groups onto PEK-C backbone led to a significantly higher glass transition temperature, better chemical solvent-resistant property and excellent mechanical tensile property.
A series of hydrogen-bonded polyaryletherketone copolymers was synthesized by the reaction of a mixture of phenolphthalein and 3,3'-bis (4-hydroxyphenyl)-isobenzopyrrolidone with equivalent mole of bis (4-nitrophenyl)ketone using anhydrous K2CO3 as catalyst and DMSO as solvent. The intermolecular hydrogen bond in the copolymers prepared was confirmed from FTIR spectra at different temperature. Compared with unmodified phenolphthalein based polyaryletherketone(PEK-C), the introduction of lactam ring groups onto PEK-C backbone led to a significantly higher glass transition temperature, better chemical solvent-resistant property and excellent mechanical tensile property.
1996, 13(5): 94-96
Abstract:
The reaction of chitosan with 2, 3-epoxypropyl trimethylammonium chloride in neutral condition gave 2-hydroxyl-3-trimethyl(ammonio)propyl chitosan chloride. The effects of reaction time on the wetting ability were studied. The chitosan derivatives show good hygroscopic property and moisture retentiveness like hyaluronic acid. They have good solubility in water and good compatibility with non-ionic and cationic surfactants.
The reaction of chitosan with 2, 3-epoxypropyl trimethylammonium chloride in neutral condition gave 2-hydroxyl-3-trimethyl(ammonio)propyl chitosan chloride. The effects of reaction time on the wetting ability were studied. The chitosan derivatives show good hygroscopic property and moisture retentiveness like hyaluronic acid. They have good solubility in water and good compatibility with non-ionic and cationic surfactants.
1996, 13(5): 97-99
Abstract:
The kinetic study showed that the water content has an important effect on the hydrolysis rate of phthalimidyl benzene sulphonyl chloride(Phisyl-Cl). The PH of the reaction medium should be higher than 8.0 and 9.0 for derivatization with primary and secondary amines respectively. The hydrolysis of PhisyI-Cl is inhibited by adding solid NaHCO3 instead of its saturated solution to the medium to promote derivatization.
The kinetic study showed that the water content has an important effect on the hydrolysis rate of phthalimidyl benzene sulphonyl chloride(Phisyl-Cl). The PH of the reaction medium should be higher than 8.0 and 9.0 for derivatization with primary and secondary amines respectively. The hydrolysis of PhisyI-Cl is inhibited by adding solid NaHCO3 instead of its saturated solution to the medium to promote derivatization.
1996, 13(5): 100-102
Abstract:
Phenylthiourea was reacted with trichlorophosphine and aldehydes(ketones) to produce 3-phenyl-4-chloro-4-oxo-1,3,4-diazaphospholidin-2-thione(Ⅰ). The compounds Ⅰ were then reacted with phenols to produce the titled compounds Ⅲ. The structures of compounds Ⅲ were comfirmed by 1H NMR,31P NMR and elemental analysis. The biological tests found that compounds Ⅲ have good selective herbicidal activities.
Phenylthiourea was reacted with trichlorophosphine and aldehydes(ketones) to produce 3-phenyl-4-chloro-4-oxo-1,3,4-diazaphospholidin-2-thione(Ⅰ). The compounds Ⅰ were then reacted with phenols to produce the titled compounds Ⅲ. The structures of compounds Ⅲ were comfirmed by 1H NMR,31P NMR and elemental analysis. The biological tests found that compounds Ⅲ have good selective herbicidal activities.
1996, 13(5): 103-105
Abstract:
A noval extraction system was introduced using trioctylamine as extractant and xylene or kerosene as diluent. This system exhibited high oxidation resistance without interfacial emulsification, therefore, the so-called third phase was not produced in the extraction process. Various factors influencing the extraction effectiveness were discussed. The experimental results of Cr(Ⅵ) recovery from waste water of high concentration Cr(Ⅵ) were reported.
A noval extraction system was introduced using trioctylamine as extractant and xylene or kerosene as diluent. This system exhibited high oxidation resistance without interfacial emulsification, therefore, the so-called third phase was not produced in the extraction process. Various factors influencing the extraction effectiveness were discussed. The experimental results of Cr(Ⅵ) recovery from waste water of high concentration Cr(Ⅵ) were reported.
1996, 13(5): 106-108
Abstract:
3-Aryl-1(2H, 4H)-acridones and the related acridine-fused pyridine and pyrimidines were synthesized. The structures of all compounds obtained were characterized by elemental analysis, IR and 1H NMR spectra. Some of the compounds show significant analgesic activity.
3-Aryl-1(2H, 4H)-acridones and the related acridine-fused pyridine and pyrimidines were synthesized. The structures of all compounds obtained were characterized by elemental analysis, IR and 1H NMR spectra. Some of the compounds show significant analgesic activity.
1996, 13(5): 109-111
Abstract:
The principal components analysis performed on the centered data was used to study the near-infrared transflectance reflectance spectra of milk. It eliminated the interference of water. The new variables identified the characteristic wavelengths of fat, protein and lactose very well. The spectral range 2030~2350 nm was studied by principal components analysis. The principal component regression was used to predict the concentrations of fat,protein and lactose of the samples with standard predicted errors 1.61,1.94,2.08 g/L respectively.
The principal components analysis performed on the centered data was used to study the near-infrared transflectance reflectance spectra of milk. It eliminated the interference of water. The new variables identified the characteristic wavelengths of fat, protein and lactose very well. The spectral range 2030~2350 nm was studied by principal components analysis. The principal component regression was used to predict the concentrations of fat,protein and lactose of the samples with standard predicted errors 1.61,1.94,2.08 g/L respectively.
1996, 13(5): 112-113
Abstract:
In this paper, the growth rate constants(k) of five bacteria have been determined at different temperatures. From these results a linear equation √k=a+bT can be established for the bacterial growth.
In this paper, the growth rate constants(k) of five bacteria have been determined at different temperatures. From these results a linear equation √k=a+bT can be established for the bacterial growth.
1996, 13(5): 114-115
Abstract:
The thermal power-time curves of the promoter action of Astragalus membranaceus for the E. coli, S. aureus and B. subtilis have been determined by using a thermal activity monitor. The growth rate constants at different concentrations of Astregalus membranaceus have also been calculated. From K~C data, optimum concentrations of the drugs have been obtained.
The thermal power-time curves of the promoter action of Astragalus membranaceus for the E. coli, S. aureus and B. subtilis have been determined by using a thermal activity monitor. The growth rate constants at different concentrations of Astregalus membranaceus have also been calculated. From K~C data, optimum concentrations of the drugs have been obtained.
1996, 13(5): 116-118
Abstract:
The gas permeation behavior of several new Cardo polyarylethersulfones containing different alkyl substituents on the backbone benzene rings was studied. The variation of permeation and diffusion coefficients with temperature followed Arrhenius equation within the temperature range of 30℃~100℃.The permeation coefficient increased with the rise of temperature, while the selection factor decreased correspondingly. The introduction of isopropyl groups resulted in a significant increase in gas permeation coefficient. In particular,the permeation coefficient and selection factor were found to grow simultaneously when the four hydrogen atoms per repeat unit were replaced with methyl groups.
The gas permeation behavior of several new Cardo polyarylethersulfones containing different alkyl substituents on the backbone benzene rings was studied. The variation of permeation and diffusion coefficients with temperature followed Arrhenius equation within the temperature range of 30℃~100℃.The permeation coefficient increased with the rise of temperature, while the selection factor decreased correspondingly. The introduction of isopropyl groups resulted in a significant increase in gas permeation coefficient. In particular,the permeation coefficient and selection factor were found to grow simultaneously when the four hydrogen atoms per repeat unit were replaced with methyl groups.
