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2000 Volume 17 Issue 4
2000, 17(4): 349-352
Abstract:
Two series of sulfonylureas containing 4-substituted pyrimidine were synthesized from 2-amino-4-substituted pyrimidine, respectively, with 2-methoxycarbonyl benzyl sulfonamide and oxalyl chloride, as well as with 1-methyl-4-ethoxycarbonyl-5-pyrazolyl sulfonamide and ethylchloroformate. Their structures were confirmed by elemental analysis, 1H NMR, some were identified by IR and MS. Some of the sulfonylureas showed good herbicidal activity.
Two series of sulfonylureas containing 4-substituted pyrimidine were synthesized from 2-amino-4-substituted pyrimidine, respectively, with 2-methoxycarbonyl benzyl sulfonamide and oxalyl chloride, as well as with 1-methyl-4-ethoxycarbonyl-5-pyrazolyl sulfonamide and ethylchloroformate. Their structures were confirmed by elemental analysis, 1H NMR, some were identified by IR and MS. Some of the sulfonylureas showed good herbicidal activity.
2000, 17(4): 353-357
Abstract:
Polyether-g-polysiloxane copolymers were prepared through hydrosilylation and used as a modifier for epoxy resin. The results indicated that the static friction coefficient of the cured epoxy resin was effectively reduced by the incorporation of the copolymers, and the contact angle with water enhanced. The morphology and surface properties of the cured epoxy resin depended mainly on the structure and content of polyether chains in the graft copolymers, as well as the level of the copolymer. The surface composition of the cured epoxy resin was analyzed by XPS. It was suggested that remarkable enrichment of the polysiloxane chain on the surface of the cured epoxy resin was responsible for the improvement of the surface properties.
Polyether-g-polysiloxane copolymers were prepared through hydrosilylation and used as a modifier for epoxy resin. The results indicated that the static friction coefficient of the cured epoxy resin was effectively reduced by the incorporation of the copolymers, and the contact angle with water enhanced. The morphology and surface properties of the cured epoxy resin depended mainly on the structure and content of polyether chains in the graft copolymers, as well as the level of the copolymer. The surface composition of the cured epoxy resin was analyzed by XPS. It was suggested that remarkable enrichment of the polysiloxane chain on the surface of the cured epoxy resin was responsible for the improvement of the surface properties.
2000, 17(4): 358-361
Abstract:
Tungstocobaltphosphate and tungstonickelphosphate containing polypyrrole (H3PW11MO40-PPY)(M=W,Co,Ni;PPY=polypyrrole) were synthesized by electrochemical deposition and the corresponding film modified glassy carbon electrodes were prepared. The electrochemical properties of the electrodes were investigated.
Tungstocobaltphosphate and tungstonickelphosphate containing polypyrrole (H3PW11MO40-PPY)(M=W,Co,Ni;PPY=polypyrrole) were synthesized by electrochemical deposition and the corresponding film modified glassy carbon electrodes were prepared. The electrochemical properties of the electrodes were investigated.
2000, 17(4): 362-365
Abstract:
The magnetization intensification of bacterial breeding and preoxidation with Thiobacillus Ferrooxidians on the arsenal gold ores from Shaerbulake in Xingjiang Autonomous Region P.R.C. has been studied. The results showed that the 9 K culture medium prepared with magnetized water can promote T.f. breeding and leaching. Magnetization intensified bacterial preoxidation promoted the dissolution of oxygen and mineral ingredients in magnetized water and changed the molecular geometry of water without necessity of any chemcial reagents.
The magnetization intensification of bacterial breeding and preoxidation with Thiobacillus Ferrooxidians on the arsenal gold ores from Shaerbulake in Xingjiang Autonomous Region P.R.C. has been studied. The results showed that the 9 K culture medium prepared with magnetized water can promote T.f. breeding and leaching. Magnetization intensified bacterial preoxidation promoted the dissolution of oxygen and mineral ingredients in magnetized water and changed the molecular geometry of water without necessity of any chemcial reagents.
2000, 17(4): 366-370
Abstract:
The superfine of ternary NiO-La2O3-Al2O3 aerogel catalysts were prepared by sol-gel method in combination with supercritical drying(SCD) technique. The BET, TEM, XRD, DTA and IR measurement results showed that the aerogel was similiar with the single Al2O3 or binary NiO-Al2O3 aerogel in surface area, apparent density, pore size distribution and structure, but exhibited a better quality. The ternany is easier to crystallize and form NiAl2O4 spinal structure and have a stronger adsorbability.
The superfine of ternary NiO-La2O3-Al2O3 aerogel catalysts were prepared by sol-gel method in combination with supercritical drying(SCD) technique. The BET, TEM, XRD, DTA and IR measurement results showed that the aerogel was similiar with the single Al2O3 or binary NiO-Al2O3 aerogel in surface area, apparent density, pore size distribution and structure, but exhibited a better quality. The ternany is easier to crystallize and form NiAl2O4 spinal structure and have a stronger adsorbability.
2000, 17(4): 371-374
Abstract:
The synthesis of a ligand, T-oxo pentanedioic acid-2,4-dinitrobenzene hydrazone(H2LPN), and its five rare earth (La,Pr,Nd,Eu and Gd) complexes are reported. The complexes are characterized by element analysis, IR, UV and 1H NMR spectra, thermal analysis. Besides, the relaxivity of Gd3+ complex was determined by INVREC.Au program, using inversion recovery pulse sequences.
The synthesis of a ligand, T-oxo pentanedioic acid-2,4-dinitrobenzene hydrazone(H2LPN), and its five rare earth (La,Pr,Nd,Eu and Gd) complexes are reported. The complexes are characterized by element analysis, IR, UV and 1H NMR spectra, thermal analysis. Besides, the relaxivity of Gd3+ complex was determined by INVREC.Au program, using inversion recovery pulse sequences.
2000, 17(4): 375-378
Abstract:
Twelve di-n-butyltin(Ⅳ) complexes of bisdithiocarbamate (n-C4H9)2Sn-(S2CNRR')2 were synthesized and characterized by elemental analysis, IR, UV, 1H NMR and TG-DTA measurements. The results revealed the dithiocarbamate ligands are in bidentate coordination with Sn. Preliminary in vitro biological activity tests showed some of them were obviously effective against P388 cells.
Twelve di-n-butyltin(Ⅳ) complexes of bisdithiocarbamate (n-C4H9)2Sn-(S2CNRR')2 were synthesized and characterized by elemental analysis, IR, UV, 1H NMR and TG-DTA measurements. The results revealed the dithiocarbamate ligands are in bidentate coordination with Sn. Preliminary in vitro biological activity tests showed some of them were obviously effective against P388 cells.
2000, 17(4): 379-382
Abstract:
Cu/ZnO/Al2O3 catalysts with different compositions were prepared for hydrogenation of maleic anhydride to V-butyrolactone at atmospheric pressure. Results showed that the difference in activity and selectivity of the catalysts was in relation to the molar ratio of Cu to Zn and calcining temperature of the catalysts in preparation, which affected the surface characters and amount of spinel-type phase. XRD and TPR techniques have been used to investigate the experimental results.
Cu/ZnO/Al2O3 catalysts with different compositions were prepared for hydrogenation of maleic anhydride to V-butyrolactone at atmospheric pressure. Results showed that the difference in activity and selectivity of the catalysts was in relation to the molar ratio of Cu to Zn and calcining temperature of the catalysts in preparation, which affected the surface characters and amount of spinel-type phase. XRD and TPR techniques have been used to investigate the experimental results.
2000, 17(4): 383-386
Abstract:
Li1+xV3O8 was synthesized from Li2CO3 and NH4VO3 at 300℃. The relationships between molar ratio of Li/V in raw materials and element distribution in products were studied. The XRD and SEM results revealed that Li1+xV3O8 synthesized at 300℃ had a lower crystallinity and smaller particle size than that obtained at 680℃ and also had higher discharge capacity and discharge voltage.
Li1+xV3O8 was synthesized from Li2CO3 and NH4VO3 at 300℃. The relationships between molar ratio of Li/V in raw materials and element distribution in products were studied. The XRD and SEM results revealed that Li1+xV3O8 synthesized at 300℃ had a lower crystallinity and smaller particle size than that obtained at 680℃ and also had higher discharge capacity and discharge voltage.
2000, 17(4): 387-391
Abstract:
The chronoamperometry was used to study the powdery microelectrode made of spherical Ni(OH)2. The effects of doping elements on the proton diffusion coefficients DH were investigated for anode and cathode processes at 25℃. The results showed that in comparison with pure Ni(OH)2 the anode process diffusion coefficients (D0) of Ni(OH)2 doped with Co, Co+Zn and Ca were increased a little and those of doped with Zn, Fe and Mg decreased. In contrast, the cathode diffusion coefficients (DR) of Ni(OH)2 doped with Co and Ca were almost doubled and that doped with Fe and Mg were reduced to one fourth as compared with that of pure Ni(OH)2. Doping of Cd only had a very small effect on the DH for both anode and cathode. It appeared that doping of Co, Ca tends to increase the anode proton diffusion velocity, while doping of Fe and Mg tends to decrease the cathode diffusion velocity. The DH of the anode process were found to the 2 orders of magnitude higher than that of the cathode process (10-12 vs 10-10 cm2/s).
The chronoamperometry was used to study the powdery microelectrode made of spherical Ni(OH)2. The effects of doping elements on the proton diffusion coefficients DH were investigated for anode and cathode processes at 25℃. The results showed that in comparison with pure Ni(OH)2 the anode process diffusion coefficients (D0) of Ni(OH)2 doped with Co, Co+Zn and Ca were increased a little and those of doped with Zn, Fe and Mg decreased. In contrast, the cathode diffusion coefficients (DR) of Ni(OH)2 doped with Co and Ca were almost doubled and that doped with Fe and Mg were reduced to one fourth as compared with that of pure Ni(OH)2. Doping of Cd only had a very small effect on the DH for both anode and cathode. It appeared that doping of Co, Ca tends to increase the anode proton diffusion velocity, while doping of Fe and Mg tends to decrease the cathode diffusion velocity. The DH of the anode process were found to the 2 orders of magnitude higher than that of the cathode process (10-12 vs 10-10 cm2/s).
2000, 17(4): 392-396
Abstract:
A silica supportedμ-dialkoxo bridged dicopper(Ⅱ) complex catalyst Cu2(OEt)2/SiO2 was synthesized by the method of grafting metal ions. The bidentate coordination mode of Cu(Ⅱ) ions and the existance of dinuclear structure on the SiO2 surface were confirmed by complexation titration and spectral analyses. The magnetic moment data of Cu2(OEt)2/SiO2 revealed that there are strong antiferromagnetic couplings between the Cu(Ⅱ) ions on the surface of SiO2. Chemical absorption towards CO2 and ethylene oxide(EO) by the catalyst was studied by using molecualr probing-IR technique and CO2 and EO molecules are supposed to be chemisorbed in the form of briged structure under synergistic actions of Lewis acid and Lewis base sites on the surface. Under the action of the catalyst CO2 and EO could be catalytically reacted to give ethylene carbonate at 100~120℃.
A silica supportedμ-dialkoxo bridged dicopper(Ⅱ) complex catalyst Cu2(OEt)2/SiO2 was synthesized by the method of grafting metal ions. The bidentate coordination mode of Cu(Ⅱ) ions and the existance of dinuclear structure on the SiO2 surface were confirmed by complexation titration and spectral analyses. The magnetic moment data of Cu2(OEt)2/SiO2 revealed that there are strong antiferromagnetic couplings between the Cu(Ⅱ) ions on the surface of SiO2. Chemical absorption towards CO2 and ethylene oxide(EO) by the catalyst was studied by using molecualr probing-IR technique and CO2 and EO molecules are supposed to be chemisorbed in the form of briged structure under synergistic actions of Lewis acid and Lewis base sites on the surface. Under the action of the catalyst CO2 and EO could be catalytically reacted to give ethylene carbonate at 100~120℃.
2000, 17(4): 397-400
Abstract:
The influence of Al2O3·3H2O on flame-retardation of its mixture with cured epoxy resin was briefly investigated by thermogravimetry and oxygen index determination. The results showed that Al2O3·3H2O losses 2 molecules of its crystal water quickly at 200~310℃, becoming an active alumina, which is capable of transfer the resin into a flame-retarding compound at higher temperatures. The flame-retardation of the mixture is likely due to the synergistic reactions of Al2O3·3H2O with epoxy resin at high temperatures.
The influence of Al2O3·3H2O on flame-retardation of its mixture with cured epoxy resin was briefly investigated by thermogravimetry and oxygen index determination. The results showed that Al2O3·3H2O losses 2 molecules of its crystal water quickly at 200~310℃, becoming an active alumina, which is capable of transfer the resin into a flame-retarding compound at higher temperatures. The flame-retardation of the mixture is likely due to the synergistic reactions of Al2O3·3H2O with epoxy resin at high temperatures.
2000, 17(4): 401-404
Abstract:
The extraction and stripping of In(Ⅲ ) and Fe(Ⅲ ) with di(2-ethylhexyl) phosphoric acid (P204), 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (P507), Cyanex 923 (a mixture of trialkyla ted phosphine oxides) and the binary mixtures of P204 with Cyanex 923, trialkyl phosphine oxide (TRPO) and tributyl phosphonate (TBP) at different aqueous acidities have been studied. The extraction yield of In (Ⅲ ) was found slightly decreased, but its stripping yield increased when Cyanex 923 was added to P204. The IR spectrometry was used to elucida te the extractio n mechanism by P204, Cyanex 923, and P204-Cyanex 923 mix ture, loaded indium and iron.
The extraction and stripping of In(Ⅲ ) and Fe(Ⅲ ) with di(2-ethylhexyl) phosphoric acid (P204), 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (P507), Cyanex 923 (a mixture of trialkyla ted phosphine oxides) and the binary mixtures of P204 with Cyanex 923, trialkyl phosphine oxide (TRPO) and tributyl phosphonate (TBP) at different aqueous acidities have been studied. The extraction yield of In (Ⅲ ) was found slightly decreased, but its stripping yield increased when Cyanex 923 was added to P204. The IR spectrometry was used to elucida te the extractio n mechanism by P204, Cyanex 923, and P204-Cyanex 923 mix ture, loaded indium and iron.
2000, 17(4): 405-408
Abstract:
A phosphono carboxylic acid cotelomer(POCA) was prepared from acrylic acid(AA), 2-acrylamido-2-methylpropane sulfonic acid(AMPS), NaH2PO2 and Na2S2O8. The optimum synthetic conditions were: m(AA)/m(AMPS)=3:1, concentration of NaH2PO2=15%,concentration of Na2S2O8=2.5%, temperature 110℃, time 4 hours. The product showed a better scale inhibiting and dispersing property than HEDP(hydroxyethylidene bisphosphonic acid) and HPMA(hydrolytic polymaleic anhydride).
A phosphono carboxylic acid cotelomer(POCA) was prepared from acrylic acid(AA), 2-acrylamido-2-methylpropane sulfonic acid(AMPS), NaH2PO2 and Na2S2O8. The optimum synthetic conditions were: m(AA)/m(AMPS)=3:1, concentration of NaH2PO2=15%,concentration of Na2S2O8=2.5%, temperature 110℃, time 4 hours. The product showed a better scale inhibiting and dispersing property than HEDP(hydroxyethylidene bisphosphonic acid) and HPMA(hydrolytic polymaleic anhydride).
2000, 17(4): 409-410
Abstract:
An assignment of the IR bands for a free substituted phthalocyanine H2[Pc-(OC8H17)8], its sandwich-type neodymium(Ⅲ) double- and triple-decker complex, Nd[Pc(OC8H17)8]2 and (Pc)Nd[Pc(OC8H17)8]Nd[Pc(OC8H17)8] has been done. It is found that in H2[Pc(OC8H17)8] and (Pc)Nd[Pc(OC8H17)8]Nd[Pc(OC8H17)8] the characteristic IR peaks appeared at 1330 cm-1(w), 1380 cm-1(s) and 1070~1080 cm-1 (rs) for bivalent phthalocynine anions: Pc2- or Pc(OC8H17)82-, and in Nd[Pc(OC8H17)8]2 the characteristic peaks appeared at 1315 cm-1 (rs) and 1380 cm-1 (s) were assigned for single phthalocyanine anion free radical.
An assignment of the IR bands for a free substituted phthalocyanine H2[Pc-(OC8H17)8], its sandwich-type neodymium(Ⅲ) double- and triple-decker complex, Nd[Pc(OC8H17)8]2 and (Pc)Nd[Pc(OC8H17)8]Nd[Pc(OC8H17)8] has been done. It is found that in H2[Pc(OC8H17)8] and (Pc)Nd[Pc(OC8H17)8]Nd[Pc(OC8H17)8] the characteristic IR peaks appeared at 1330 cm-1(w), 1380 cm-1(s) and 1070~1080 cm-1 (rs) for bivalent phthalocynine anions: Pc2- or Pc(OC8H17)82-, and in Nd[Pc(OC8H17)8]2 the characteristic peaks appeared at 1315 cm-1 (rs) and 1380 cm-1 (s) were assigned for single phthalocyanine anion free radical.
2000, 17(4): 411-413
Abstract:
Aluminium nitride AlN(100) thin films have been successfully deposited on Si(111) substrates by reactive magnetron sputtering technique. The films have been characterized by XRD to determine their crystalline preferential orientation. The results show that the experimental parameters including total pressure of working gas(N2+Ar), N2 partial pressure, target power and the distance from target to substrate affected crystal orientation, deposition rate, and grain size of AlN thin film. The effects of sputtering time and the substrate temperature on AlN film structure have also been investigated. The optimum experimental parameters for AlN(100) thin film deposition are given.
Aluminium nitride AlN(100) thin films have been successfully deposited on Si(111) substrates by reactive magnetron sputtering technique. The films have been characterized by XRD to determine their crystalline preferential orientation. The results show that the experimental parameters including total pressure of working gas(N2+Ar), N2 partial pressure, target power and the distance from target to substrate affected crystal orientation, deposition rate, and grain size of AlN thin film. The effects of sputtering time and the substrate temperature on AlN film structure have also been investigated. The optimum experimental parameters for AlN(100) thin film deposition are given.
2000, 17(4): 414-416
Abstract:
The urushiol-tyrosine resin(UTR) was synthesized from tyrosine and gasoline solution of urushiol by using anhydrous AlCl3 as catalyst. Its structure has been studied by IR, UV and DTA. The UTR-Cu was obtained by impregnation of UTR in Cu2+ solution. The polyphenol oxidase obtained from banana was immobilized on UTR-Cu complexes. The immobilized oxidase(UTR-Cu-En) had an activity of 1.1 A/(min·g), that is, 6.5 times greater than that of oxidase immobilized on active carbon. A possible structure of the UTR Cu immobilized enzyme is suggested.
The urushiol-tyrosine resin(UTR) was synthesized from tyrosine and gasoline solution of urushiol by using anhydrous AlCl3 as catalyst. Its structure has been studied by IR, UV and DTA. The UTR-Cu was obtained by impregnation of UTR in Cu2+ solution. The polyphenol oxidase obtained from banana was immobilized on UTR-Cu complexes. The immobilized oxidase(UTR-Cu-En) had an activity of 1.1 A/(min·g), that is, 6.5 times greater than that of oxidase immobilized on active carbon. A possible structure of the UTR Cu immobilized enzyme is suggested.
2000, 17(4): 417-419
Abstract:
The Multi-wall Carbon Nanotubes (MWNTs) were prepared by catalytic deco-mposition of methane at 600℃. The raw products of MWNTs were heated for different time in the air at 500℃. The qualitative and semi-quantitative phase analyses of the samples were performed by XRD measurements. The morphology of the samples were observed by transmission electron microscope and their specific surface areas were measured. After the MWNTs were heated for 4 hours, their walls became clean and thinner, i.e., the inner diameters became larger and the outer ones became smaller. And their dispersing extent was improved. But calcining method could not eliminate the metals and their oxides existing in the samples.
The Multi-wall Carbon Nanotubes (MWNTs) were prepared by catalytic deco-mposition of methane at 600℃. The raw products of MWNTs were heated for different time in the air at 500℃. The qualitative and semi-quantitative phase analyses of the samples were performed by XRD measurements. The morphology of the samples were observed by transmission electron microscope and their specific surface areas were measured. After the MWNTs were heated for 4 hours, their walls became clean and thinner, i.e., the inner diameters became larger and the outer ones became smaller. And their dispersing extent was improved. But calcining method could not eliminate the metals and their oxides existing in the samples.
2000, 17(4): 420-421
Abstract:
Title indazolone compound was synthesized starting from O-aminobenzoic acid. The optimum conditions of preparation are given in this paper. It is a many-sided, safe and efficient plant growth regulator and in application in the field the yield of corn and wheat has been increased by 20% and 10%, respectively.
Title indazolone compound was synthesized starting from O-aminobenzoic acid. The optimum conditions of preparation are given in this paper. It is a many-sided, safe and efficient plant growth regulator and in application in the field the yield of corn and wheat has been increased by 20% and 10%, respectively.
2000, 17(4): 422-423
Abstract:
An enzymo-spectrophotometric method was proposed based on the catalytic reaction of acetaldehyde and nicotinamide adenine dinucleotide(NADH) by alcohol dehydrogenase(ADH). The change of the absorbance of NADH was determined for calculating the velocity of the enzymatic reaction. Linear calibration graphs were obtained for acetaldehyde in the range of 0.2~10 mg/L, with a detection limit of 0.16 mg/L. The effects of the pH and interferences from metal cations, formaldehyde and n-butylaldehyde on the reaction were examined. The method was simple, rapid and sensitive.
An enzymo-spectrophotometric method was proposed based on the catalytic reaction of acetaldehyde and nicotinamide adenine dinucleotide(NADH) by alcohol dehydrogenase(ADH). The change of the absorbance of NADH was determined for calculating the velocity of the enzymatic reaction. Linear calibration graphs were obtained for acetaldehyde in the range of 0.2~10 mg/L, with a detection limit of 0.16 mg/L. The effects of the pH and interferences from metal cations, formaldehyde and n-butylaldehyde on the reaction were examined. The method was simple, rapid and sensitive.
2000, 17(4): 424-426
Abstract:
The corn starch was modified by reaction with isooctyl acrylate(IA) using BPO as initiator. It is found by XRD and IR that the graft copolymerization takes place at the amorphous region of starch. The effects of reaction temperature on the monomer conversion, grafting ratio and grafting efficiency were investigated.
The corn starch was modified by reaction with isooctyl acrylate(IA) using BPO as initiator. It is found by XRD and IR that the graft copolymerization takes place at the amorphous region of starch. The effects of reaction temperature on the monomer conversion, grafting ratio and grafting efficiency were investigated.
2000, 17(4): 427-429
Abstract:
The thermal degradation kinetics of chlorinated natural rubber(CNR) at constant heating rate has been studied. The results indicate that the thermal degradation of CNR is a one-step reaction and the degradation temperature is directly propotional to the heating rate, but the thermal degradation rate is less affected by the heating rate. The main reaction in thermal degradation is dehydrochlorination with an activation energy closing to that of the dehydrochlorination of PVC.
The thermal degradation kinetics of chlorinated natural rubber(CNR) at constant heating rate has been studied. The results indicate that the thermal degradation of CNR is a one-step reaction and the degradation temperature is directly propotional to the heating rate, but the thermal degradation rate is less affected by the heating rate. The main reaction in thermal degradation is dehydrochlorination with an activation energy closing to that of the dehydrochlorination of PVC.
2000, 17(4): 430-432
Abstract:
Poly(propargyl alcohol)(POHP) and poly(propargyl acetate)(PPAT) were prepared by using palladium acetylide catalysts [Pd(C-CCH2OR)2(PPh3)2] (R=H,OC2H5) and doped with FeCl3 or H2SO4 as humidity sensing materials. The doped polymers were found to have good humidity sensitivity as the impedance variation covered about two orders of magnitute (104~106Ω) at RH% ranged from 11% to 96%. The effects of polymer structures on the humidity sensing behavior were compared.
Poly(propargyl alcohol)(POHP) and poly(propargyl acetate)(PPAT) were prepared by using palladium acetylide catalysts [Pd(C-CCH2OR)2(PPh3)2] (R=H,OC2H5) and doped with FeCl3 or H2SO4 as humidity sensing materials. The doped polymers were found to have good humidity sensitivity as the impedance variation covered about two orders of magnitute (104~106Ω) at RH% ranged from 11% to 96%. The effects of polymer structures on the humidity sensing behavior were compared.
2000, 17(4): 433-435
Abstract:
T-Methyldopa is determined by linear sweep voltammetry on a carbon paste electrode in 0.1 mol/L H2SO4. The peak potential of anode is 0.677 V(vs SCE). A good linear range of T-methyldopa is in 5.0×10-7~1.0×10-4 mol/L. The detection limit is 2.5×10-7 mol/L. The recovery is 95.0%~103.7% and RSD is 2.8%(n=12). The electrode reaction of T-methyldopa is an irreversible process with two electrons and two protons on the carbon paste electrode.
T-Methyldopa is determined by linear sweep voltammetry on a carbon paste electrode in 0.1 mol/L H2SO4. The peak potential of anode is 0.677 V(vs SCE). A good linear range of T-methyldopa is in 5.0×10-7~1.0×10-4 mol/L. The detection limit is 2.5×10-7 mol/L. The recovery is 95.0%~103.7% and RSD is 2.8%(n=12). The electrode reaction of T-methyldopa is an irreversible process with two electrons and two protons on the carbon paste electrode.
2000, 17(4): 436-438
Abstract:
The pressure-sensitive adhesives were prepared from copolymers of butyl acryalte, iso-octyl acrylate with vinyl acetate. The effects of monomer ratio, solvent and initiator amount, and copolymerization time on the property of the adhesive were investigated. The initial adhesion and sustaining adhesion of the adhesives were found dependent on the monomer ratio and amount of solvent used.
The pressure-sensitive adhesives were prepared from copolymers of butyl acryalte, iso-octyl acrylate with vinyl acetate. The effects of monomer ratio, solvent and initiator amount, and copolymerization time on the property of the adhesive were investigated. The initial adhesion and sustaining adhesion of the adhesives were found dependent on the monomer ratio and amount of solvent used.
2000, 17(4): 439-441
Abstract:
A series of 1-substituted phenoxyacetyl-4-aroyl thiosemicarbazides were synthe-sized by reaction of aroylisothiocyanate with (substituted) phenoxyacetic acid hydrazides under solid-liquid phase transfer catalysis condition. The preliminary bioassay results showed that some of the compounds have good antibiotic activity and plant growth regulation activity. The compounds were characterized by elemental analysis, IR and 1H NMR.
A series of 1-substituted phenoxyacetyl-4-aroyl thiosemicarbazides were synthe-sized by reaction of aroylisothiocyanate with (substituted) phenoxyacetic acid hydrazides under solid-liquid phase transfer catalysis condition. The preliminary bioassay results showed that some of the compounds have good antibiotic activity and plant growth regulation activity. The compounds were characterized by elemental analysis, IR and 1H NMR.
2000, 17(4): 442-443
Abstract:
The properties of 2,4-bis(2-allylphenoxy)-6-N,N-dialkylamino-1,3,5-triazine(alkyl=CH3(BAPDMT),C2H5(BAPDET)) and bis(4-maleimidodiphenyl) methane(BMDPM) copolymers were stu-died. The results showed that the triazine monomers could improve the impact strength and shear strength of BMDPM homopolymer without strongly decreasing the heat resistance of the resin. The better results were obtained when the molar ratio of BMDPM to triazine was 4:1.
The properties of 2,4-bis(2-allylphenoxy)-6-N,N-dialkylamino-1,3,5-triazine(alkyl=CH3(BAPDMT),C2H5(BAPDET)) and bis(4-maleimidodiphenyl) methane(BMDPM) copolymers were stu-died. The results showed that the triazine monomers could improve the impact strength and shear strength of BMDPM homopolymer without strongly decreasing the heat resistance of the resin. The better results were obtained when the molar ratio of BMDPM to triazine was 4:1.
2000, 17(4): 444-446
Abstract:
Thirty acylthiosemicarbazide derivatives(Ⅰ) were synthesized by addition reaction of 5-aryl-2-furoyl isothiocyanate(Ⅲ) with aroylhydrazines(Ⅱ). Their compositions and structures were confirmed by elemental analysis, IR and 1H NMR spectrometry measurements. The plant growth effects of these compounds on rice and cucumber have been tested preliminarily.
Thirty acylthiosemicarbazide derivatives(Ⅰ) were synthesized by addition reaction of 5-aryl-2-furoyl isothiocyanate(Ⅲ) with aroylhydrazines(Ⅱ). Their compositions and structures were confirmed by elemental analysis, IR and 1H NMR spectrometry measurements. The plant growth effects of these compounds on rice and cucumber have been tested preliminarily.
2000, 17(4): 447-449
Abstract:
The styrene(St)-butyl acrylate(BA) copolymer was first prepared as seed emulsion and the final latex of St-BA-MA was then obtained from it with methyl acrylate(MA). The hollow polymer particles were obtained from poly(St-BA-MA) in the presence of dodecyl sulfonic sodium through alkaline and acid treatments. In this paper the effects of pH value, temperature and time of acid treatment on the hollow structure of polymer particles were investigated. The results showed that the largest hollow size can be obtained when acid treatment conditions were: pH 2.5, 85℃ and 3 hours.
The styrene(St)-butyl acrylate(BA) copolymer was first prepared as seed emulsion and the final latex of St-BA-MA was then obtained from it with methyl acrylate(MA). The hollow polymer particles were obtained from poly(St-BA-MA) in the presence of dodecyl sulfonic sodium through alkaline and acid treatments. In this paper the effects of pH value, temperature and time of acid treatment on the hollow structure of polymer particles were investigated. The results showed that the largest hollow size can be obtained when acid treatment conditions were: pH 2.5, 85℃ and 3 hours.
2000, 17(4): 450-452
Abstract:
The silica/polymer nanocomposites were obtained via in situ ultraviolet light irra diation of the dispersion system containing epoxylacrylate, aminoacrylate, 1,6-hexanediol diacry late, sensitizer 1173 and 20 nm silica particles. The results showed that the hardness, tensile strength and modulus of the nanocomposites were increased with increasing silica content. The silica nanocomposite with 2.5%(wt) of silica had pencil hardness of grade 6, tensile strength of 50 MPa and modulus of 1640 MPa. The initial thermal decomposition temperature of the nanocomposite was increased considerably at <400 K and decreased at >600 K. The thermal decomposition loss was 83.4% at near 800 K. The nanocomposites showed a strong ultraviolet absorbency in region of 200~400 nm and the absorbency at 400~800 nm increased with increasing silica content. the transmittance at 400 nm was 25% and fluorescence at 700 nm was observed when the composite was excited with 365 nm wave.
The silica/polymer nanocomposites were obtained via in situ ultraviolet light irra diation of the dispersion system containing epoxylacrylate, aminoacrylate, 1,6-hexanediol diacry late, sensitizer 1173 and 20 nm silica particles. The results showed that the hardness, tensile strength and modulus of the nanocomposites were increased with increasing silica content. The silica nanocomposite with 2.5%(wt) of silica had pencil hardness of grade 6, tensile strength of 50 MPa and modulus of 1640 MPa. The initial thermal decomposition temperature of the nanocomposite was increased considerably at <400 K and decreased at >600 K. The thermal decomposition loss was 83.4% at near 800 K. The nanocomposites showed a strong ultraviolet absorbency in region of 200~400 nm and the absorbency at 400~800 nm increased with increasing silica content. the transmittance at 400 nm was 25% and fluorescence at 700 nm was observed when the composite was excited with 365 nm wave.
2000, 17(4): 453-455
Abstract:
The graft copolymerization of methylacrylate onto gelatin initiated by persulfate-urea redox system was studied. The effects of reaction parameters such as copolymerization temperature, copolymerization time, concentrations of initiator, monomer and gelatin on the grafting percentage(G), grafting efficiency(E) and total yield(Y) were investigated. The molecular weight of PMA branch and its intrinsic viscosity were determined.
The graft copolymerization of methylacrylate onto gelatin initiated by persulfate-urea redox system was studied. The effects of reaction parameters such as copolymerization temperature, copolymerization time, concentrations of initiator, monomer and gelatin on the grafting percentage(G), grafting efficiency(E) and total yield(Y) were investigated. The molecular weight of PMA branch and its intrinsic viscosity were determined.
2000, 17(4): 456-458
Abstract:
Some macroreticular adsorption resins were used for decolorization of vitamin B6 in aqueous solution. The results show that the resins with higher specific surface have a higher decolorizing efficiency. The decolorizing process of resin AB-8 was more rapid. Resin H103 had high decolorizing efficiency, but wasn't easily regenerated. Treatment of crude Vitamin B6 solution by adsorbent ToH allows for multiple regeneration cycles without loss of decolorization properties. The decolorization of the crude Vitamin B6 was 85%.
Some macroreticular adsorption resins were used for decolorization of vitamin B6 in aqueous solution. The results show that the resins with higher specific surface have a higher decolorizing efficiency. The decolorizing process of resin AB-8 was more rapid. Resin H103 had high decolorizing efficiency, but wasn't easily regenerated. Treatment of crude Vitamin B6 solution by adsorbent ToH allows for multiple regeneration cycles without loss of decolorization properties. The decolorization of the crude Vitamin B6 was 85%.
2000, 17(4): 459-461
Abstract:
Pyridine, CO and SO2 were used as probes to characterize the mixed oxides Al2O3/SiO2 by TPD technique. XRD study showed mullite was the major composition of the mixed oxides. The tail gases were analyzed by gas chromatography. The results showed that the nanocrystal mixed oxides exhibited a good adsorbability for pyridine, CO and SO2. During desorption of pyridine and CO, CO2 was detected in desorbed mixtures and in the case of SO2 solid sulphur was found.
Pyridine, CO and SO2 were used as probes to characterize the mixed oxides Al2O3/SiO2 by TPD technique. XRD study showed mullite was the major composition of the mixed oxides. The tail gases were analyzed by gas chromatography. The results showed that the nanocrystal mixed oxides exhibited a good adsorbability for pyridine, CO and SO2. During desorption of pyridine and CO, CO2 was detected in desorbed mixtures and in the case of SO2 solid sulphur was found.
2000, 17(4): 462-464
Abstract:
A dendritic oligophenylene in yield of 48% has been synthesized via cross coupling reaction of phenyl boronic acid with 1,3,5-tris(3,5-dibromophenyl)benzene catalyzed by the ligandless palladium chloride in mixture of water/toluene/THF in the presence of tetrabutylammonium bromide. The yield per coupling(y/c) was 88%.
A dendritic oligophenylene in yield of 48% has been synthesized via cross coupling reaction of phenyl boronic acid with 1,3,5-tris(3,5-dibromophenyl)benzene catalyzed by the ligandless palladium chloride in mixture of water/toluene/THF in the presence of tetrabutylammonium bromide. The yield per coupling(y/c) was 88%.
