Login In
2004 Volume 21 Issue 3
2004, 21(3): 217-222
Abstract:
Chitosan in which the N-acetylglucosamine moiety is a structural feature found in glucosaminoglycans and gelatin is the partially denatured derivative of collagen. They exhibit related bioactivities as their precursor. The recent achievements on the chitosan-gelatin network based biomaterials are reviewed is this paper covers preparations of membrane, scaffold, surfaces modifier in tissue engineering as well as the utilization of N-alkylated chitosan as non-viral vector for DNA delivery. These biomaterials have promising perspectives in skin, cartilage, bone tissue engineering and gene therapy.
Chitosan in which the N-acetylglucosamine moiety is a structural feature found in glucosaminoglycans and gelatin is the partially denatured derivative of collagen. They exhibit related bioactivities as their precursor. The recent achievements on the chitosan-gelatin network based biomaterials are reviewed is this paper covers preparations of membrane, scaffold, surfaces modifier in tissue engineering as well as the utilization of N-alkylated chitosan as non-viral vector for DNA delivery. These biomaterials have promising perspectives in skin, cartilage, bone tissue engineering and gene therapy.
2004, 21(3): 223-226
Abstract:
The chemical pattern recognition method has been applied t0 377 kinds of saturated ethers and alcohols in NIST62 mass spectral database. Based on block variables thought, available information about classification was drawn from several series of classifers by orthogonal computation and canonical correlation analysis(CCA), the discriminant least square models were thus set up to classify these ether and alcohol samples. The error probability for optimum model was about 1.06%, with cross validation error probability being about 1.36%.
The chemical pattern recognition method has been applied t0 377 kinds of saturated ethers and alcohols in NIST62 mass spectral database. Based on block variables thought, available information about classification was drawn from several series of classifers by orthogonal computation and canonical correlation analysis(CCA), the discriminant least square models were thus set up to classify these ether and alcohol samples. The error probability for optimum model was about 1.06%, with cross validation error probability being about 1.36%.
2004, 21(3): 227-230
Abstract:
The chemical microetching on copper surface with three-dimensional(3D) gear-like molds was realized by confined etchant layer technique(CELT). By using effective chemical etching and scavenging system(HNO3+NaOH) and the optimized experimental parameters, such as the etching time, etching current density, concentration of etchant or scavenger, the etched patterns were obtained, which is close to negative copy of the mold. The etched micro-patterns characterized by SEM and AFM demonstrates that CELT can be applied to the 3D-microstructure replication on copper surface.
The chemical microetching on copper surface with three-dimensional(3D) gear-like molds was realized by confined etchant layer technique(CELT). By using effective chemical etching and scavenging system(HNO3+NaOH) and the optimized experimental parameters, such as the etching time, etching current density, concentration of etchant or scavenger, the etched patterns were obtained, which is close to negative copy of the mold. The etched micro-patterns characterized by SEM and AFM demonstrates that CELT can be applied to the 3D-microstructure replication on copper surface.
2004, 21(3): 231-234
Abstract:
The amorphous NiB catalyst was prepared by introducing decomposition of electroless nickel plating solution with Ag+. Two supported amorphous NiB alloys on beta zeolite powder were prepared by electroless plating, one the zeolite powder was impregnated with AgNO3 solution(noted as NiB/A-BETA), another not(noted as NiB/N-BETA). Their physical properties were excemined by ICP, XRD, TEM. Their catalytic activities were evaluated in the hydrogenation of sulfolene. The shape of NiB/A-BETA amorphous alloy particles was close to a radiant semi-sphere with average particle size ranged from 100 nm to 120 nm. NiB/A-BETA showed higher activity in hydrogenation of sulfulene.
The amorphous NiB catalyst was prepared by introducing decomposition of electroless nickel plating solution with Ag+. Two supported amorphous NiB alloys on beta zeolite powder were prepared by electroless plating, one the zeolite powder was impregnated with AgNO3 solution(noted as NiB/A-BETA), another not(noted as NiB/N-BETA). Their physical properties were excemined by ICP, XRD, TEM. Their catalytic activities were evaluated in the hydrogenation of sulfolene. The shape of NiB/A-BETA amorphous alloy particles was close to a radiant semi-sphere with average particle size ranged from 100 nm to 120 nm. NiB/A-BETA showed higher activity in hydrogenation of sulfulene.
2004, 21(3): 235-238
Abstract:
Thermoplastic starch was prepared from corn-starch in a batch-mixer in the presence of glycerol, urea and water. The effects of glycerol and urea amounts on the plasticity of thermoplastic starch were studied. The crystallinity change of starch samples was studied by XRD. The results showed that the crystalline structure of the starch was destroyed during processing, and an easy processing thermoplastic starch was obtained. The crystallinity of thermoplastic starch decreased with the increase of urea amount. Increasing glycerol amount results in the loss of tensile strength, but the enhancement of elongation at break of the product. When the mass ratio of glycerol to starch was 0.20~0.40, the apparent viscosity decreased with increase in glycerol amount, and all of the thermoplastic starches become pseudoplastic fluids. The thermoplastic starch exibited better biodegradability than news paper. The thermoplastic starch/polyethylene blends can be blown into transparent films.
Thermoplastic starch was prepared from corn-starch in a batch-mixer in the presence of glycerol, urea and water. The effects of glycerol and urea amounts on the plasticity of thermoplastic starch were studied. The crystallinity change of starch samples was studied by XRD. The results showed that the crystalline structure of the starch was destroyed during processing, and an easy processing thermoplastic starch was obtained. The crystallinity of thermoplastic starch decreased with the increase of urea amount. Increasing glycerol amount results in the loss of tensile strength, but the enhancement of elongation at break of the product. When the mass ratio of glycerol to starch was 0.20~0.40, the apparent viscosity decreased with increase in glycerol amount, and all of the thermoplastic starches become pseudoplastic fluids. The thermoplastic starch exibited better biodegradability than news paper. The thermoplastic starch/polyethylene blends can be blown into transparent films.
2004, 21(3): 239-242
Abstract:
Reactions of dichloroarylphosphine(1a~1c) with PSCl3 gave corresponding arylthiophosphonic dichlorides(2a~2c), which after hydrazinolyzation gave arylthiophosphonic dihydrazides(3a~3c). Reactions of 3a~3c with glycosyl isothiocyanates(4a~4e) in benzene gave corresponding N,N'-di(glycosylthioureylene) arylthiophosphonic diamides(5a~5e,6a~6e,7a~7e). Their structures were confirmed by IR, 1H NMR, 31P NMR, MS and elemental analysis. The glycosyl isothiocyanates 4a~4e were prepared by the reaction of α-D-glycosyl bromides with Pb(SCN)2. The biological activities of the representative compounds have been examined.
Reactions of dichloroarylphosphine(1a~1c) with PSCl3 gave corresponding arylthiophosphonic dichlorides(2a~2c), which after hydrazinolyzation gave arylthiophosphonic dihydrazides(3a~3c). Reactions of 3a~3c with glycosyl isothiocyanates(4a~4e) in benzene gave corresponding N,N'-di(glycosylthioureylene) arylthiophosphonic diamides(5a~5e,6a~6e,7a~7e). Their structures were confirmed by IR, 1H NMR, 31P NMR, MS and elemental analysis. The glycosyl isothiocyanates 4a~4e were prepared by the reaction of α-D-glycosyl bromides with Pb(SCN)2. The biological activities of the representative compounds have been examined.
2004, 21(3): 243-246
Abstract:
A new nitrogen-containing heterocyclic pyrethroid library was designed and constructed using combinatorial parallel synthesis. To evaluate the library synthesis, some sampled compounds in the library were identified by HRMS and their purities were estimated by GC analysis. All compounds in the library were screened by fungicidal activity tests in vitro and in vivo. The results showed that, AD7 has ED501.0×10-7% against RHIZSO in 9 kinds of ED50 tests in vitro, meanwhile, some compounds have ED50<1.0×10-6% against the test targets. While the library was tested in vivo, majority of the fungicidal activities of the compounds were focused on PHYTIN and ALTESO.
A new nitrogen-containing heterocyclic pyrethroid library was designed and constructed using combinatorial parallel synthesis. To evaluate the library synthesis, some sampled compounds in the library were identified by HRMS and their purities were estimated by GC analysis. All compounds in the library were screened by fungicidal activity tests in vitro and in vivo. The results showed that, AD7 has ED501.0×10-7% against RHIZSO in 9 kinds of ED50 tests in vitro, meanwhile, some compounds have ED50<1.0×10-6% against the test targets. While the library was tested in vivo, majority of the fungicidal activities of the compounds were focused on PHYTIN and ALTESO.
2004, 21(3): 247-250
Abstract:
Amphiphilic diblock copolymers(PEDLLA) were synthesized from D,L-lactic acid and methoxy-polyethylene glycol by meltingpolycondensation. PEDLLA nanomicelles were prepared by nanoprecipitation technique and characterized by DLS, 1H NMR, pyrene monomer probe fluorescence technology and UV spectrometry. Micelles obtained were of core-shell structure and nano sized. The size of micelles was influenced by the molecular weight of polyactic acid(PDLLA) segment and PEDLLA concentration in organic solvent. The critical micelle concentrations of PEDLLA were less than 2.43×10-6 mol/L and decreased with increase in the molecular weight of PDLLA segment.
Amphiphilic diblock copolymers(PEDLLA) were synthesized from D,L-lactic acid and methoxy-polyethylene glycol by meltingpolycondensation. PEDLLA nanomicelles were prepared by nanoprecipitation technique and characterized by DLS, 1H NMR, pyrene monomer probe fluorescence technology and UV spectrometry. Micelles obtained were of core-shell structure and nano sized. The size of micelles was influenced by the molecular weight of polyactic acid(PDLLA) segment and PEDLLA concentration in organic solvent. The critical micelle concentrations of PEDLLA were less than 2.43×10-6 mol/L and decreased with increase in the molecular weight of PDLLA segment.
2004, 21(3): 251-255
Abstract:
The Pt microelectrode(φ=0.1 mm), made by abrasive polishing method with Bi2O3 powder was used to study cyclic voltammetric performance of Bi2O3 particles in alkaline solutions. The electrochemical measurments could be more quickly carried out than that by using composite electrode and cavity microelectrode. The SEM results showed the Bi2O3 particles were still present on the abrasive microelectrode after immersing in 9 mol/L KOH for 15 h and 10 times voltammetric cycling. The redox potential and current of main cycle voltammograms are comparably identical for both abrasive microelectrode and cavity microelectrode. It was found that OH- concentration could influence CV performance of Bi2O3, indicating that OH- is involved in the electrochemical reaction of Bi2O3. So the plateau peak on CV curves reported in some literatures can be explained in terms of the continuous change of OH- concentration in the cavity of microelectrode, no plateau was observed with disk-like abrasive microelectrode.
The Pt microelectrode(φ=0.1 mm), made by abrasive polishing method with Bi2O3 powder was used to study cyclic voltammetric performance of Bi2O3 particles in alkaline solutions. The electrochemical measurments could be more quickly carried out than that by using composite electrode and cavity microelectrode. The SEM results showed the Bi2O3 particles were still present on the abrasive microelectrode after immersing in 9 mol/L KOH for 15 h and 10 times voltammetric cycling. The redox potential and current of main cycle voltammograms are comparably identical for both abrasive microelectrode and cavity microelectrode. It was found that OH- concentration could influence CV performance of Bi2O3, indicating that OH- is involved in the electrochemical reaction of Bi2O3. So the plateau peak on CV curves reported in some literatures can be explained in terms of the continuous change of OH- concentration in the cavity of microelectrode, no plateau was observed with disk-like abrasive microelectrode.
2004, 21(3): 256-260
Abstract:
Four heteropoly isomers α-K6[SiW11TiO40]·xH2O and βi-K6[SiW11TiO40]·xH2O(βi=β1,β2,β3) were synthesized and characterized by elemental analysis, IR, UV spectrometry, polarography, cyclic voltammetry and 183W NMR. The 183W NMR results suggested that tungsten atoms are in six chemical enviroments for α,β1,β3-isomers and in nine chemical enviroments for β2-isomer, indicating compounds formed are all mono-substituted heteropoly complexes of Keggin structure. The order of polarographic half-wave potential E1/2 of the heteropoly anions was as follows:β2 > β1 > β3 > α. Their reduction processes involved an one-electron reduction of Ti(Ⅳ) and a pair of two-electron reduction of W(Ⅵ). The synthesized isomers showed better catalytic activity in epoxidation of maleic acid with H2O2 and the β-isomer was higher than α-isomer in catalytic activity.
Four heteropoly isomers α-K6[SiW11TiO40]·xH2O and βi-K6[SiW11TiO40]·xH2O(βi=β1,β2,β3) were synthesized and characterized by elemental analysis, IR, UV spectrometry, polarography, cyclic voltammetry and 183W NMR. The 183W NMR results suggested that tungsten atoms are in six chemical enviroments for α,β1,β3-isomers and in nine chemical enviroments for β2-isomer, indicating compounds formed are all mono-substituted heteropoly complexes of Keggin structure. The order of polarographic half-wave potential E1/2 of the heteropoly anions was as follows:β2 > β1 > β3 > α. Their reduction processes involved an one-electron reduction of Ti(Ⅳ) and a pair of two-electron reduction of W(Ⅵ). The synthesized isomers showed better catalytic activity in epoxidation of maleic acid with H2O2 and the β-isomer was higher than α-isomer in catalytic activity.
2004, 21(3): 261-265
Abstract:
A magnetic photocatalyst(TiO2/SiO2/Fe3O4) where Fe3O4 was coated by SiO2 film as magnetic matrix, has been prepared by sol-gel method and characterized by XPS, XRD, TEM, IR and UV-Vis spectrometry. The photocatalytic activity of the material has been tested on decomposable substrate Orange-Ⅱ under UV-light or sunlight illumination. The results in decoloration show that an amorphous SiO2 film present between Fe3O4 and TiO2 can significantly improve the decoloration of Orange-Ⅱ from 73.1% to 99.8%.
A magnetic photocatalyst(TiO2/SiO2/Fe3O4) where Fe3O4 was coated by SiO2 film as magnetic matrix, has been prepared by sol-gel method and characterized by XPS, XRD, TEM, IR and UV-Vis spectrometry. The photocatalytic activity of the material has been tested on decomposable substrate Orange-Ⅱ under UV-light or sunlight illumination. The results in decoloration show that an amorphous SiO2 film present between Fe3O4 and TiO2 can significantly improve the decoloration of Orange-Ⅱ from 73.1% to 99.8%.
2004, 21(3): 266-270
Abstract:
Avidin and biotin are widely used in biology due to the high affinity between them. In some cases anti-biotin antibodies are used in stead of avidin. In this paper, the kinetic characters of anti-biotin antibody and biotinylated bovine serum albumin(BSA) were studied by biomolecular interaction analysis(BIA) technique based on surface plasma resonance(SPR). The association rate constant, dissociation rate constant and affinity constant between anti-biotin antibody and biotinylated BSA were found to be 2.59×104L/(mol·s), 3.77×10-3s-1 and 6.86×106 L/mol, respectively.
Avidin and biotin are widely used in biology due to the high affinity between them. In some cases anti-biotin antibodies are used in stead of avidin. In this paper, the kinetic characters of anti-biotin antibody and biotinylated bovine serum albumin(BSA) were studied by biomolecular interaction analysis(BIA) technique based on surface plasma resonance(SPR). The association rate constant, dissociation rate constant and affinity constant between anti-biotin antibody and biotinylated BSA were found to be 2.59×104L/(mol·s), 3.77×10-3s-1 and 6.86×106 L/mol, respectively.
2004, 21(3): 271-275
Abstract:
MnZn ferrite nanosized particles are synthesized by using a hydrothermal method. Effects of the added amount of La3+, Nd3+, Ti4+ and multi-elements on the particle size and shape and structure of the products are investigated. The results show that the particle size of Ti-doped MnZn ferrite powders is increased obviously and even over 100 nm when the mass fraction of Ti4+ exceeds 1.0%, but the addition of La3+ or Nd3+ has not obvious effect on the particle size of nano-MnZn ferrite powders. The TEM micrographs give homogeneous hexagonal crystallites when the mass fraction of La3+ is 1.2%, indicating that such an amount of La3+ ions have great influence on the crystallization of the hydrothermal process and can change and improve the growth of crystallites. In the samples doped with 0.4% La3+ or Nd3+ other phases besides the spinel are observed, but it is not in the case of multi-element doping. The spinel characteristic peaks in IR spectrum of nano-MnZn ferrite sample with dopants is found to be moved to lower frequency as compared with that of the undoped, implying that the distribution of the ions in MnZn has been influenced by the introduction of doping ions into the paracorystalline phase of the ferrite.
MnZn ferrite nanosized particles are synthesized by using a hydrothermal method. Effects of the added amount of La3+, Nd3+, Ti4+ and multi-elements on the particle size and shape and structure of the products are investigated. The results show that the particle size of Ti-doped MnZn ferrite powders is increased obviously and even over 100 nm when the mass fraction of Ti4+ exceeds 1.0%, but the addition of La3+ or Nd3+ has not obvious effect on the particle size of nano-MnZn ferrite powders. The TEM micrographs give homogeneous hexagonal crystallites when the mass fraction of La3+ is 1.2%, indicating that such an amount of La3+ ions have great influence on the crystallization of the hydrothermal process and can change and improve the growth of crystallites. In the samples doped with 0.4% La3+ or Nd3+ other phases besides the spinel are observed, but it is not in the case of multi-element doping. The spinel characteristic peaks in IR spectrum of nano-MnZn ferrite sample with dopants is found to be moved to lower frequency as compared with that of the undoped, implying that the distribution of the ions in MnZn has been influenced by the introduction of doping ions into the paracorystalline phase of the ferrite.
2004, 21(3): 276-280
Abstract:
Based on the simple harmonic vibration model of mechanic vibration theory the inherent frequencies of forty anionic surfactant molecules being taken as a multi-freedom spring-mass vibration systems are calculated. And based on their two molecular structure description symbols, fundamental frequency(ω0) and sum-frequency(∑ωi), the QSPR models are established for critical micelle concentration of the surfactants:logCMC=A0+A1ωo+A2∑ωi. The obtained models all have good correlations with r>0.99, and have good predications with the mean absolute error 0.058 8 and the mean relative error 0.031 6.
Based on the simple harmonic vibration model of mechanic vibration theory the inherent frequencies of forty anionic surfactant molecules being taken as a multi-freedom spring-mass vibration systems are calculated. And based on their two molecular structure description symbols, fundamental frequency(ω0) and sum-frequency(∑ωi), the QSPR models are established for critical micelle concentration of the surfactants:logCMC=A0+A1ωo+A2∑ωi. The obtained models all have good correlations with r>0.99, and have good predications with the mean absolute error 0.058 8 and the mean relative error 0.031 6.
2004, 21(3): 281-285
Abstract:
Six liquid crystal compounds of trans-cyclohexyltolan-type with lateral fluorines R1PF2TR2(6) were synthesized via cis-trans isomerization of cyclohexane intermediates(3,3') in dichloroethane-AlCl3 medium with the yield of 35%, much higher than expected(13%). The catalytic mechanisms of the cis-trans cyclohexyl isomerization and the cross-coupling reaction promoted by Pd(Ⅱ) are discussed. All of the compounds were identified by IR, 1H NMR and MS. The results showed that the end compounds 6 exhibit higher optical anisotropy(Δn) and thermal stability in the liquid crystal composition of PCH, and indicated that the lateral fluorine atoms in the molecular structure restrain the Δn value, giving promising applications of these compounds in liquid crystal display.
Six liquid crystal compounds of trans-cyclohexyltolan-type with lateral fluorines R1PF2TR2(6) were synthesized via cis-trans isomerization of cyclohexane intermediates(3,3') in dichloroethane-AlCl3 medium with the yield of 35%, much higher than expected(13%). The catalytic mechanisms of the cis-trans cyclohexyl isomerization and the cross-coupling reaction promoted by Pd(Ⅱ) are discussed. All of the compounds were identified by IR, 1H NMR and MS. The results showed that the end compounds 6 exhibit higher optical anisotropy(Δn) and thermal stability in the liquid crystal composition of PCH, and indicated that the lateral fluorine atoms in the molecular structure restrain the Δn value, giving promising applications of these compounds in liquid crystal display.
2004, 21(3): 286-290
Abstract:
The polystyrene(PS) hybrid materials were obtained by the in situ polymerization from a gel by mixing of styrene and praseodymium triisooctanyl oxide Pr(i-C8) in the absence of water. The materials have been characterized by FT-TR, TG-DTA, DMTA, ESEM, UV and fluorescence spectrometry. The process avoids the aggregation of rare earth in the materials. The introduction of praseodymium triisooctanyl oxide improves the heat resistance and fluorescence intensity of the hybrid. The materials with 4.0%(mass fraction) praseodymium have better transparency. ESEM reveals the crosslinked network structure of PS hybrid material.
The polystyrene(PS) hybrid materials were obtained by the in situ polymerization from a gel by mixing of styrene and praseodymium triisooctanyl oxide Pr(i-C8) in the absence of water. The materials have been characterized by FT-TR, TG-DTA, DMTA, ESEM, UV and fluorescence spectrometry. The process avoids the aggregation of rare earth in the materials. The introduction of praseodymium triisooctanyl oxide improves the heat resistance and fluorescence intensity of the hybrid. The materials with 4.0%(mass fraction) praseodymium have better transparency. ESEM reveals the crosslinked network structure of PS hybrid material.
2004, 21(3): 291-295
Abstract:
The reaction extent of organic phase, as well as the degree of hydrolysis and condensation reactions of inorganic phase of UV-curable polyurethane acrylate/silica hybrid(PUA-TMSPM)/SiO2 material were examined by means of solid-state 13C and 29SiCP/MAS NMR. The results showed that the conversion of acrylate double bond was almost complete on UV irradiation. Solid-state 29SiCP/MAS NMR spectra revealed that there were no unreacted TEOS and TMSPM and the mean condensation degree of the silanes of the hybrid material was 0.80.
The reaction extent of organic phase, as well as the degree of hydrolysis and condensation reactions of inorganic phase of UV-curable polyurethane acrylate/silica hybrid(PUA-TMSPM)/SiO2 material were examined by means of solid-state 13C and 29SiCP/MAS NMR. The results showed that the conversion of acrylate double bond was almost complete on UV irradiation. Solid-state 29SiCP/MAS NMR spectra revealed that there were no unreacted TEOS and TMSPM and the mean condensation degree of the silanes of the hybrid material was 0.80.
2004, 21(3): 296-300
Abstract:
The effects Ag(Ⅰ), Fe(Ⅲ), Mn(Ⅶ) and Ce(Ⅳ) concentrations and pH value on the photocatalytic reaction of NO2- in TiO2 suspension system were studied. The results showed that most of the metal ions studied have stronger synergistic catalytic property, among them the Fe(Ⅲ) in mass fraction greater than 0.25% of TiO2 and acidity of the system pH=4 showed considerably stronger synergistic catalytic property, and Ce(Ⅳ) showed an obvious inhibition effect on the TiO2 photocatalytic oxidation of NO2-.
The effects Ag(Ⅰ), Fe(Ⅲ), Mn(Ⅶ) and Ce(Ⅳ) concentrations and pH value on the photocatalytic reaction of NO2- in TiO2 suspension system were studied. The results showed that most of the metal ions studied have stronger synergistic catalytic property, among them the Fe(Ⅲ) in mass fraction greater than 0.25% of TiO2 and acidity of the system pH=4 showed considerably stronger synergistic catalytic property, and Ce(Ⅳ) showed an obvious inhibition effect on the TiO2 photocatalytic oxidation of NO2-.
2004, 21(3): 301-304
Abstract:
The high reactive flame retardant polyether polyol(HIROL) for polyurethane resin was synthesized by copolymerization of epoxy propane(EP), oxirane(EO), pentabromophenyl glycidyl ether(PBPGE) and glycerol, using BF3·THF as catalyst. The effects of catalyst dosage, reagent ratio, feeding mode and copolymerization time on the physical property and product yield were examined. The results indicated that the oxygen index of soft PU foam containing 23%(mass) HIROL reached 28.5, when the mole ratio of EO:EP:PBPGE was 2:7:1 in HIROL preparation and increased to 32, when additional 6%(mass) dimethyl methyl phosphonate(DMMP) was compounded in PU foam.
The high reactive flame retardant polyether polyol(HIROL) for polyurethane resin was synthesized by copolymerization of epoxy propane(EP), oxirane(EO), pentabromophenyl glycidyl ether(PBPGE) and glycerol, using BF3·THF as catalyst. The effects of catalyst dosage, reagent ratio, feeding mode and copolymerization time on the physical property and product yield were examined. The results indicated that the oxygen index of soft PU foam containing 23%(mass) HIROL reached 28.5, when the mole ratio of EO:EP:PBPGE was 2:7:1 in HIROL preparation and increased to 32, when additional 6%(mass) dimethyl methyl phosphonate(DMMP) was compounded in PU foam.
2004, 21(3): 305-308
Abstract:
High-density polyethylene(HDPE) was oxidized in oxygen atmosphere under γ-ray irradiation to give γ-HDPE, which was then blended with polyamide 6(PA-6). The aggregation structure of γ-HDPE/PA-6 blends and the relationships between the blend structure and its barrier property have been studied by SEM, DSC and TGA. The SEM results show that the γ-irradiation changes the compatibility of PA-6 with γ-HDPE, and in all blends studied 7γ-HDPE/PA-6 has the best compatibility. The results of DSC show that the interaction between the chains of γ-HDPE and PA-6 are affected by the HDPE chain structure, and the strongest interaction occurs in 7γ-HDPE/PA-6 blend. The increase of the compatibility and chain interaction in 7γ-HDPE/PA-6 blend lead its better barrier property to xylene than HDPE, HDPE/PA-6 and others γ-HDPE/PA-6 blends. The oil absorption ratio of 7γ-HDPE/PA-6 blends decreased about 30% and 26%, respectively, in comparison with pure HDPE and HDPE/PA-6 blend.
High-density polyethylene(HDPE) was oxidized in oxygen atmosphere under γ-ray irradiation to give γ-HDPE, which was then blended with polyamide 6(PA-6). The aggregation structure of γ-HDPE/PA-6 blends and the relationships between the blend structure and its barrier property have been studied by SEM, DSC and TGA. The SEM results show that the γ-irradiation changes the compatibility of PA-6 with γ-HDPE, and in all blends studied 7γ-HDPE/PA-6 has the best compatibility. The results of DSC show that the interaction between the chains of γ-HDPE and PA-6 are affected by the HDPE chain structure, and the strongest interaction occurs in 7γ-HDPE/PA-6 blend. The increase of the compatibility and chain interaction in 7γ-HDPE/PA-6 blend lead its better barrier property to xylene than HDPE, HDPE/PA-6 and others γ-HDPE/PA-6 blends. The oil absorption ratio of 7γ-HDPE/PA-6 blends decreased about 30% and 26%, respectively, in comparison with pure HDPE and HDPE/PA-6 blend.
2004, 21(3): 309-312
Abstract:
The colored chitin has been isolated from silkworm chrysalis with protein being extracted off with NaOH solution. The decolorization of the colored silkworm chrysalis chitin was performed by aq. H2O2 solution treatment. The conditions for taking off protein are as follows:m(5%NaOH):m(silkworm chrysalis residue)=80:30, 70℃ and 2 h. The calcium containg salts can be taken off completely with 3%HCl in conditions of 2 h, 25℃ and m(3%HCl):m(silkworm chrysalis residue)=8:3. The colored crude chitin without protein and salts can be decolored by H2O2 treatment in conditions of 65~70℃, pH 8.5±0.5, 5 h and m(30%H2O2):m(silkworm chrysalis residue)=130:50. The yield of white chitin is 25% with whiteness above 30%. It suggested that H2O2 oxidizes the sulfur of cysteine present in the system of iron-sulfur center and and the cytochromes and changes it into sulfoxides, causing the chemical bond between the chromoprotein and the chitin to be broken and chromoprotein to be separated.
The colored chitin has been isolated from silkworm chrysalis with protein being extracted off with NaOH solution. The decolorization of the colored silkworm chrysalis chitin was performed by aq. H2O2 solution treatment. The conditions for taking off protein are as follows:m(5%NaOH):m(silkworm chrysalis residue)=80:30, 70℃ and 2 h. The calcium containg salts can be taken off completely with 3%HCl in conditions of 2 h, 25℃ and m(3%HCl):m(silkworm chrysalis residue)=8:3. The colored crude chitin without protein and salts can be decolored by H2O2 treatment in conditions of 65~70℃, pH 8.5±0.5, 5 h and m(30%H2O2):m(silkworm chrysalis residue)=130:50. The yield of white chitin is 25% with whiteness above 30%. It suggested that H2O2 oxidizes the sulfur of cysteine present in the system of iron-sulfur center and and the cytochromes and changes it into sulfoxides, causing the chemical bond between the chromoprotein and the chitin to be broken and chromoprotein to be separated.
2004, 21(3): 313-315
Abstract:
Beta-aminobutyric acid(BABA) was used as a leading compound for its induced plant resistance activity. The synthesis of twelve new N-phenyl-3-N'-benzyloxycarbonyl-β-aminobutanamides are reported in this paper. Their structures were confirmed by elemental analysis and 1H NMR.
Beta-aminobutyric acid(BABA) was used as a leading compound for its induced plant resistance activity. The synthesis of twelve new N-phenyl-3-N'-benzyloxycarbonyl-β-aminobutanamides are reported in this paper. Their structures were confirmed by elemental analysis and 1H NMR.
2004, 21(3): 316-318
Abstract:
It is well known that hydrogen peroxide in dilute H2SO4 solution discolorizes bromocresol purple, while oxalic acid can sensitively inhibit the discoloration reaction or slow the reaction rate. The kinetic beha-vior of the inhibition reaction has been investigated and a kinetic spectrometric method for determination of trace oxalic acid was developed with detection limit 2.8×10-8 g/mL and the linear range of the determination was 0~8×10-7 g/mL oxalic acid. ε430=1.50×105L/(mol·cm). The method has been satisfactorily applied to the determination of trace oxalic acid in fruits, greens and cereals.
It is well known that hydrogen peroxide in dilute H2SO4 solution discolorizes bromocresol purple, while oxalic acid can sensitively inhibit the discoloration reaction or slow the reaction rate. The kinetic beha-vior of the inhibition reaction has been investigated and a kinetic spectrometric method for determination of trace oxalic acid was developed with detection limit 2.8×10-8 g/mL and the linear range of the determination was 0~8×10-7 g/mL oxalic acid. ε430=1.50×105L/(mol·cm). The method has been satisfactorily applied to the determination of trace oxalic acid in fruits, greens and cereals.
2004, 21(3): 319-321
Abstract:
Four N'-tert-butyl-N-substituted chrysanthemoyl urea derivatives have been synthesized through "substructure link way":substituted chrysanthemoyl chlorides were directly reacted with tert-butyl urea at about 40℃ in the presence of acetonitrile. The structures of the target compounds(2a~2d) were characte-rized by 1H NMR, IR and elemental analysis. The preliminary bioactivity tests showed that compound 2d was active against Cucumber, Chenopodium, Radish and Sorgham. The inhibitory percentage to the root was over 70% and it was also active against the growth of stalks. Compound 2b showed a considerable insecticidal activity.
Four N'-tert-butyl-N-substituted chrysanthemoyl urea derivatives have been synthesized through "substructure link way":substituted chrysanthemoyl chlorides were directly reacted with tert-butyl urea at about 40℃ in the presence of acetonitrile. The structures of the target compounds(2a~2d) were characte-rized by 1H NMR, IR and elemental analysis. The preliminary bioactivity tests showed that compound 2d was active against Cucumber, Chenopodium, Radish and Sorgham. The inhibitory percentage to the root was over 70% and it was also active against the growth of stalks. Compound 2b showed a considerable insecticidal activity.
2004, 21(3): 322-324
Abstract:
Three Mn(Ⅲ) complexes of chiral porphyrin-nicotine compounds were synthesized from tetrasubstited phorphrius and chiral nicotine, as well as maganees acetate in DMF. The complexes were characterized by UV, IR, 1H NMR, MS and elemental analysis. They are expected to have, simultaneously, chiral induction and phase transformation functions for catalysis reactions.
Three Mn(Ⅲ) complexes of chiral porphyrin-nicotine compounds were synthesized from tetrasubstited phorphrius and chiral nicotine, as well as maganees acetate in DMF. The complexes were characterized by UV, IR, 1H NMR, MS and elemental analysis. They are expected to have, simultaneously, chiral induction and phase transformation functions for catalysis reactions.
