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2005 Volume 22 Issue 6
2005, 22(6): 581-585
Abstract:
A method to determine simultaneously two active components in amoxicillin and potassium clavulanate tablets by capillary electrophoresis with high frequency conductivity detection was established.The key effective factors for the separation and determination were studied and the best analysis conditions were obtained.The amoxicillin and potassium clavulanate could be optimally separated and detected in the running medium of 1.0 mmol/L Na2HPO4+0.5 mmol/L NaH2PO4(pH=8.0) at a separation voltage of 20.0 kV.Under the optimal conditions,the sample separation and detection only take 6 min,the determined peaks have good shapes,and the linear concentration range is from 3.0×10-6 g/mL to 160.0×10-6 g/mL for amoxi-cillin (r=0.997) and from 2.0×10-6 g/mL to 150.0×10-6 g/mL for potassium clavulanate (r=0.998).The detection limits are 1.5×10-6 g/mL and 8.0×10-6 g/mL,and the recovery rates are 97.0%~101.0% and 97.7%~98.7% for amoxicillin and potassium clavulanate,respectively.
A method to determine simultaneously two active components in amoxicillin and potassium clavulanate tablets by capillary electrophoresis with high frequency conductivity detection was established.The key effective factors for the separation and determination were studied and the best analysis conditions were obtained.The amoxicillin and potassium clavulanate could be optimally separated and detected in the running medium of 1.0 mmol/L Na2HPO4+0.5 mmol/L NaH2PO4(pH=8.0) at a separation voltage of 20.0 kV.Under the optimal conditions,the sample separation and detection only take 6 min,the determined peaks have good shapes,and the linear concentration range is from 3.0×10-6 g/mL to 160.0×10-6 g/mL for amoxi-cillin (r=0.997) and from 2.0×10-6 g/mL to 150.0×10-6 g/mL for potassium clavulanate (r=0.998).The detection limits are 1.5×10-6 g/mL and 8.0×10-6 g/mL,and the recovery rates are 97.0%~101.0% and 97.7%~98.7% for amoxicillin and potassium clavulanate,respectively.
2005, 22(6): 586-589
Abstract:
Two novel derivatives of 2-naphthalenemethyl benzimidazole were prepared from the reaction of ferrocenesulfonylchloride with the corresponding 2-naphthalenemethyl benzimidazole.The new compounds were characterized by means of elemental analysis,MS and 1H NMR.The crystal structure of compound 2a was determined by X-ray diffraction.The 2a crystals are triclinic with space group P1,and the unit cell parameters are a=0.890 55(10) nm,b=0.970 34(10) nm,c=1.461 0(2) nm,α=101.542(2)°,β=95.811(2)°,γ=109.780(10)°,V=1.144 3(2) nm3,Z=2,F(000)=526,Mr=507.39,Dc1.473 Mg/m3,μ=1.016 mm-1,R1=0.038 6,wR2=0.097 9.The antimicrobial activities of the two novel compounds against five fungicides are superior to that of 50% carbendazim wet powder.
Two novel derivatives of 2-naphthalenemethyl benzimidazole were prepared from the reaction of ferrocenesulfonylchloride with the corresponding 2-naphthalenemethyl benzimidazole.The new compounds were characterized by means of elemental analysis,MS and 1H NMR.The crystal structure of compound 2a was determined by X-ray diffraction.The 2a crystals are triclinic with space group P1,and the unit cell parameters are a=0.890 55(10) nm,b=0.970 34(10) nm,c=1.461 0(2) nm,α=101.542(2)°,β=95.811(2)°,γ=109.780(10)°,V=1.144 3(2) nm3,Z=2,F(000)=526,Mr=507.39,Dc1.473 Mg/m3,μ=1.016 mm-1,R1=0.038 6,wR2=0.097 9.The antimicrobial activities of the two novel compounds against five fungicides are superior to that of 50% carbendazim wet powder.
Electrooxidation of Ethanol on Highly Preferred Orientation (220) Nickel Electrode in Alkaline Media
2005, 22(6): 590-594
Abstract:
Ni electrodes with highly preferred orentation (220) were obtained by means of potentiostatic electrodeposition in the solution containing 1.0 mol/L NiSO4 and 0.5 mol/L H3BO3.The Ni electrode deposited at-1.25 V for 60 min was examined with X-ray diffraction.The result shows that Ni electrode exhibits highly preferred orientation with a texture degree of 92%.The mechanism and catalytic activity of ethanol oxidation on the highly preferred orientation (220) Ni electrode were studied with cyclic voltammetry and in situ FTIR spectroscopy.The results show that the Ni electrode has electrocatalytic activity for the oxdation of ethanol.The main product of ethanol oxidation on the Ni electrode is CH3COO-.The kinetic equation of ethanol electrooxidation was derived.The kinetic parameters were determined with the polarization curves.The rate constant k1 for the oxidation of Ni(Ⅱ) to Ni(Ⅲ) is 4.9×10-13 exp(0.52FE/RT) and the rate constant (k2) for the oxidation of ethanol by Ni(Ⅲ) is 5.7×10-6 L/(mol·s).
Ni electrodes with highly preferred orentation (220) were obtained by means of potentiostatic electrodeposition in the solution containing 1.0 mol/L NiSO4 and 0.5 mol/L H3BO3.The Ni electrode deposited at-1.25 V for 60 min was examined with X-ray diffraction.The result shows that Ni electrode exhibits highly preferred orientation with a texture degree of 92%.The mechanism and catalytic activity of ethanol oxidation on the highly preferred orientation (220) Ni electrode were studied with cyclic voltammetry and in situ FTIR spectroscopy.The results show that the Ni electrode has electrocatalytic activity for the oxdation of ethanol.The main product of ethanol oxidation on the Ni electrode is CH3COO-.The kinetic equation of ethanol electrooxidation was derived.The kinetic parameters were determined with the polarization curves.The rate constant k1 for the oxidation of Ni(Ⅱ) to Ni(Ⅲ) is 4.9×10-13 exp(0.52FE/RT) and the rate constant (k2) for the oxidation of ethanol by Ni(Ⅲ) is 5.7×10-6 L/(mol·s).
2005, 22(6): 595-599
Abstract:
β-Cyclodextrin (β-CD) exhibits a pair of reversible peaks in the second order differential simple oscillgraphic voltammogram in a 0.2 mol/L NaOH solution,and the peak height decreases with the increase in the concentration of the inclusion complex of amoxicillin-β-CD.Based on the oscillographic characteristic of amoxicillin-β-CD,a second order differential simple oscillgraphic voltammetry method for determination of amoxicillin in capsule is presented.A linear response was observed in the range of 2.5×10-6~3.0×10-5 mol/L with a correlation coefficient of -0.997 9 and a detection limit of 1.0×10-6 mol/L for amoxi-cillin.The relative standard deviation (RSD) for the determination of 1.5×10-5 mol/L amoxicillin was 2.3% (n=5),and the average recovery rate was 100.1% (n=5).In addition,the inclusion ratio and inclusion constant (K) of amoxicillin-β-CD determined by the Job method were 1:1 and 6.0×105,respectively.
β-Cyclodextrin (β-CD) exhibits a pair of reversible peaks in the second order differential simple oscillgraphic voltammogram in a 0.2 mol/L NaOH solution,and the peak height decreases with the increase in the concentration of the inclusion complex of amoxicillin-β-CD.Based on the oscillographic characteristic of amoxicillin-β-CD,a second order differential simple oscillgraphic voltammetry method for determination of amoxicillin in capsule is presented.A linear response was observed in the range of 2.5×10-6~3.0×10-5 mol/L with a correlation coefficient of -0.997 9 and a detection limit of 1.0×10-6 mol/L for amoxi-cillin.The relative standard deviation (RSD) for the determination of 1.5×10-5 mol/L amoxicillin was 2.3% (n=5),and the average recovery rate was 100.1% (n=5).In addition,the inclusion ratio and inclusion constant (K) of amoxicillin-β-CD determined by the Job method were 1:1 and 6.0×105,respectively.
2005, 22(6): 600-604
Abstract:
Quaternary ammonium Gemini surfactants (C12-s-C12·2Br)(s=2,3,4,6) and alkyl ammonium bromide (CmTXABr),both carrying positive charge on the head group,form mixed micelle in aqueous solution.The micellazation is close to ideal mixing and does not show synergism.In the mixed system of C12-s-C12·2Br/C12TMABr,the critical mixed micell concentration (cmcT) gradually increases with the increase of the number of methylene (s) in the spacer from 2 to 4 and reaches a maximum at s=4,then the cmcT slightly decreases with s further increasing to 6,which is similar to the dependence of cmc on s in single component C12-s-C12·2Br aqueous solution.The mixed micellization is promoted with increasing the alkyl chain length of CmTMABr from 12 to 16 or the head-group size of C12TXABr from three methyl to three propyl.In the mixed systems with equal mole ratio of C12-2-C12·2Br/CmTXABr,the cmcT's were 1.30(s=2/C12TMABr),1.25(s=2/C14TMABr),0.96(s=2/C16TMABr),1.27(s=2/C12TEABr) and 1.21(s=2/C12TBABr) mmol/L,respectively.
Quaternary ammonium Gemini surfactants (C12-s-C12·2Br)(s=2,3,4,6) and alkyl ammonium bromide (CmTXABr),both carrying positive charge on the head group,form mixed micelle in aqueous solution.The micellazation is close to ideal mixing and does not show synergism.In the mixed system of C12-s-C12·2Br/C12TMABr,the critical mixed micell concentration (cmcT) gradually increases with the increase of the number of methylene (s) in the spacer from 2 to 4 and reaches a maximum at s=4,then the cmcT slightly decreases with s further increasing to 6,which is similar to the dependence of cmc on s in single component C12-s-C12·2Br aqueous solution.The mixed micellization is promoted with increasing the alkyl chain length of CmTMABr from 12 to 16 or the head-group size of C12TXABr from three methyl to three propyl.In the mixed systems with equal mole ratio of C12-2-C12·2Br/CmTXABr,the cmcT's were 1.30(s=2/C12TMABr),1.25(s=2/C14TMABr),0.96(s=2/C16TMABr),1.27(s=2/C12TEABr) and 1.21(s=2/C12TBABr) mmol/L,respectively.
2005, 22(6): 605-609
Abstract:
A new zirconia-based stationary phase (DPZ) was prepared from zirconia modified with dodecyla-mine-N,N-dimethylenephosphonic acid (DDPA).The surface coverage of DDPA was 3.3 μmol/m2 when DPZ was modified under reflux,and only 0.64 μmol/m2 when DPZ was just impregnated in a DDPA solution (without refluxing).The results of color reaction of zirconia with ammonium molybdate indicate that,in both cases,DDPA adsorbed on zirconia via the combination of one phosphonic group with zirconia,and another phosphonic group was free.The mechanism was studied in detail based on the influence of methanol content and pH of mobile phase on the capacity factors of the acidic compounds.The free phosphonic groups shielded most of the Lewis-acid sites on the surface of zirconia and imparted negative charges on the surface at high pH,resulting in excellent resolution for phenols and a great improvement for the separation of benzoic acids.
A new zirconia-based stationary phase (DPZ) was prepared from zirconia modified with dodecyla-mine-N,N-dimethylenephosphonic acid (DDPA).The surface coverage of DDPA was 3.3 μmol/m2 when DPZ was modified under reflux,and only 0.64 μmol/m2 when DPZ was just impregnated in a DDPA solution (without refluxing).The results of color reaction of zirconia with ammonium molybdate indicate that,in both cases,DDPA adsorbed on zirconia via the combination of one phosphonic group with zirconia,and another phosphonic group was free.The mechanism was studied in detail based on the influence of methanol content and pH of mobile phase on the capacity factors of the acidic compounds.The free phosphonic groups shielded most of the Lewis-acid sites on the surface of zirconia and imparted negative charges on the surface at high pH,resulting in excellent resolution for phenols and a great improvement for the separation of benzoic acids.
2005, 22(6): 610-614
Abstract:
A novel pyridinium salt with a donor/π-conjugated system/acceptor (D-π-A) structure was synthesized and characterized by IR spectrometry,elemental analysis,thermogravimatric and X-ray diffraction analyses.The single- and two- photon induced fluorescence of the compound were studied.The nonlinear optical properties of the compound were investigated by virtue of 1 064 nm picosecond laser beam,and the results show that the novel pyridinium salt has a TPA coefficient of β=0.104 7 cm/GW,a TPA cross-section of σ=3.247 3×10-46 cm4·s·photon-1,and the overall conversion efficiency was 1.9% at the pump energy level of 1.677 mJ.The crystallographic data for the structural analysis were deposited with the Cambridge Crystallographic Data Center,CCDC no.242507.
A novel pyridinium salt with a donor/π-conjugated system/acceptor (D-π-A) structure was synthesized and characterized by IR spectrometry,elemental analysis,thermogravimatric and X-ray diffraction analyses.The single- and two- photon induced fluorescence of the compound were studied.The nonlinear optical properties of the compound were investigated by virtue of 1 064 nm picosecond laser beam,and the results show that the novel pyridinium salt has a TPA coefficient of β=0.104 7 cm/GW,a TPA cross-section of σ=3.247 3×10-46 cm4·s·photon-1,and the overall conversion efficiency was 1.9% at the pump energy level of 1.677 mJ.The crystallographic data for the structural analysis were deposited with the Cambridge Crystallographic Data Center,CCDC no.242507.
2005, 22(6): 615-618
Abstract:
A new schiff-base compound,[NiL]ClO4(1),was synthesized and characterized,where L represents the 1:1 condensation product of salicylaldehyde with diethyltriamine.The crystal structure of compound 1 shows that the Ni2+ ion in the NiL+ moiety bonded with one O atom and three N atoms of the schiff-base ligand,L-,and exhibits a near square coordination geometry.The H-bonding interaction between neighboring NiL+ and ClO4- ions do not form H-bonding network.The temperature dependence of magnetic susceptibility (1.8~300 K) indicates that compound 1 is diamagnetic.The compound with stoichiometry of [NiL][FeⅡFeⅢ(ox)3](2) was prepared by mixing the aqueous solutions of compound 1,K3[Fe(ox)3]·3H2O and FeSO4·7H2O under N2 atmosphere at ambient temperature.The IR spectrum of compound 2 illustrates that all the oxalate groups function as bridging groups,and compound 2 is actually a coordination polymer.The magnetic susceptibility measurement result at 1.8~300 K shows that this polymer possesses the anti-ferromagnetic ordering at below 11 K;the magnetic behavior above 60 K can be explained by the Curie-Weiss law,and the best fit for the magnetic susceptibility data at above 65 K gives a Curie-Weiss constant of 10.40(2) emu·K/mol and a Weiss temperature -22.9(4)K,respectively.
A new schiff-base compound,[NiL]ClO4(1),was synthesized and characterized,where L represents the 1:1 condensation product of salicylaldehyde with diethyltriamine.The crystal structure of compound 1 shows that the Ni2+ ion in the NiL+ moiety bonded with one O atom and three N atoms of the schiff-base ligand,L-,and exhibits a near square coordination geometry.The H-bonding interaction between neighboring NiL+ and ClO4- ions do not form H-bonding network.The temperature dependence of magnetic susceptibility (1.8~300 K) indicates that compound 1 is diamagnetic.The compound with stoichiometry of [NiL][FeⅡFeⅢ(ox)3](2) was prepared by mixing the aqueous solutions of compound 1,K3[Fe(ox)3]·3H2O and FeSO4·7H2O under N2 atmosphere at ambient temperature.The IR spectrum of compound 2 illustrates that all the oxalate groups function as bridging groups,and compound 2 is actually a coordination polymer.The magnetic susceptibility measurement result at 1.8~300 K shows that this polymer possesses the anti-ferromagnetic ordering at below 11 K;the magnetic behavior above 60 K can be explained by the Curie-Weiss law,and the best fit for the magnetic susceptibility data at above 65 K gives a Curie-Weiss constant of 10.40(2) emu·K/mol and a Weiss temperature -22.9(4)K,respectively.
2005, 22(6): 619-623
Abstract:
A novel hepta-coordinated organotin complex[(4-F-C6H4CH2)2Sn(3-O2CC5H4N)2(4-F-C6H4-C 2H5OH)]n was synthesized from the reaction of[(4-F-C6H4CH2)3Sn]2O with 3-pyridinecarboxylic acid and characterized by means of elementary analysis,IR and 1H NMR.The crystal structure was determined by single crystal X-ray diffraction study.The crystal belongs to the monoclinic system with space group P2(1)/c,a=1.763 4(12) nm,b=1.277 6(9) nm,c=1.360 6(9) nm,β=96.991(11)°,Z=4,V=3.043(4) nm 3,Dc=1.575 g/cm3,μ=0.904 mm-1,F(000)=1 456,R1=0.040 5,wR2=0.068 2.In the complex,the tin atom is hepta-coordinated in a distorted pentagonal bipyramid including a bridging pyridyl N atom,by which the one-dimensional infinite chain is formed.The antitumor activity tests for the human tumor cell lines MCF-7 and WiDr show that this complex exhibits a good bioactivity.
A novel hepta-coordinated organotin complex[(4-F-C6H4CH2)2Sn(3-O2CC5H4N)2(4-F-C6H4-C 2H5OH)]n was synthesized from the reaction of[(4-F-C6H4CH2)3Sn]2O with 3-pyridinecarboxylic acid and characterized by means of elementary analysis,IR and 1H NMR.The crystal structure was determined by single crystal X-ray diffraction study.The crystal belongs to the monoclinic system with space group P2(1)/c,a=1.763 4(12) nm,b=1.277 6(9) nm,c=1.360 6(9) nm,β=96.991(11)°,Z=4,V=3.043(4) nm 3,Dc=1.575 g/cm3,μ=0.904 mm-1,F(000)=1 456,R1=0.040 5,wR2=0.068 2.In the complex,the tin atom is hepta-coordinated in a distorted pentagonal bipyramid including a bridging pyridyl N atom,by which the one-dimensional infinite chain is formed.The antitumor activity tests for the human tumor cell lines MCF-7 and WiDr show that this complex exhibits a good bioactivity.
2005, 22(6): 624-629
Abstract:
A dimethylbenzene-compatible TDI-trimer modified by n-butanol was synthesized,and used to prepare paints with different acrylic polyol resins.The paints prepared with the modified TDI-trimer have smaller and more uniform particles than those prepared with unmodified TDI-trimer.Good TDI-trimer was obtained when the reaction temperature was 60℃,the mole ratio of -NCO to -OH was 10:1 and a new catalyst made in house was used.In the modified TDI-trimer,the solid content was about 50%.The tolerance of the modified TDI-trimer to dimethylbenzene was over 2.3 and free TDI in the sample was less than 1.5%.The thermal stability of the TDI-trimer was determined by thermogravimetric analysis (TGA).The thermal stability improved as -NCO/-OH ratio increased,and was not influenced by the type of the catalyst.However,the thermal stability increased when the content of the catalyst increased.
A dimethylbenzene-compatible TDI-trimer modified by n-butanol was synthesized,and used to prepare paints with different acrylic polyol resins.The paints prepared with the modified TDI-trimer have smaller and more uniform particles than those prepared with unmodified TDI-trimer.Good TDI-trimer was obtained when the reaction temperature was 60℃,the mole ratio of -NCO to -OH was 10:1 and a new catalyst made in house was used.In the modified TDI-trimer,the solid content was about 50%.The tolerance of the modified TDI-trimer to dimethylbenzene was over 2.3 and free TDI in the sample was less than 1.5%.The thermal stability of the TDI-trimer was determined by thermogravimetric analysis (TGA).The thermal stability improved as -NCO/-OH ratio increased,and was not influenced by the type of the catalyst.However,the thermal stability increased when the content of the catalyst increased.
2005, 22(6): 630-633
Abstract:
The hydroxy of the chiral source D-mannitol was protected via the formation of acetal and benzyl ether,and then chiral synthon 4 was prepared after the deprotection and oxygenolysis of the protected D-mannitol.Eight new (R)-3-O-acyl-2-O-benzyl-glycerodialkyl phosphates 7a~7h were synthesized from chiral synthon 4 via the introduction of fatty acyl group with different chain length,deprotection and coupling with dialkyl phosphorochloridate.Owing to the acyl migration during the preparation,the compounds 7a~7h may be racemized to some extent,which is especially obvious in the preparation of compound 7d.The structures of the targeted molecules were confirmed by 1H NMR and elemental analysis,and their specific rotation powers were measured.
The hydroxy of the chiral source D-mannitol was protected via the formation of acetal and benzyl ether,and then chiral synthon 4 was prepared after the deprotection and oxygenolysis of the protected D-mannitol.Eight new (R)-3-O-acyl-2-O-benzyl-glycerodialkyl phosphates 7a~7h were synthesized from chiral synthon 4 via the introduction of fatty acyl group with different chain length,deprotection and coupling with dialkyl phosphorochloridate.Owing to the acyl migration during the preparation,the compounds 7a~7h may be racemized to some extent,which is especially obvious in the preparation of compound 7d.The structures of the targeted molecules were confirmed by 1H NMR and elemental analysis,and their specific rotation powers were measured.
2005, 22(6): 634-637
Abstract:
A glass-slide was coated with a film of Fe3+-H doped titanium dioxide by sol-gel method and microwave plasma-deposition technique.The film was calcined and an excellent TiO2 photo-catalyst was obtained.It was found that the catalytic activity for the degradation of alizarin red of Fe-H/TiO2 was better than that of Fe-TiO2 under UV light or visible light when the mass percent of Fe3+ doped was 0.1%,and the efficiency of the visible light was increased.The absorption peaks of Fe-H/TiO2 with 0.1% doped-Fe3+ not only were more than that of other TiO2 but also showed red shift.The XRD spectra show that Fe-H/TiO2 with 0.1% doped-Fe3+ obtained separately at 500℃ and 550℃ kept the anatase crystal system and the average size of the anatase crystals were 12.9 nm and 17.3 nm,respectively.
A glass-slide was coated with a film of Fe3+-H doped titanium dioxide by sol-gel method and microwave plasma-deposition technique.The film was calcined and an excellent TiO2 photo-catalyst was obtained.It was found that the catalytic activity for the degradation of alizarin red of Fe-H/TiO2 was better than that of Fe-TiO2 under UV light or visible light when the mass percent of Fe3+ doped was 0.1%,and the efficiency of the visible light was increased.The absorption peaks of Fe-H/TiO2 with 0.1% doped-Fe3+ not only were more than that of other TiO2 but also showed red shift.The XRD spectra show that Fe-H/TiO2 with 0.1% doped-Fe3+ obtained separately at 500℃ and 550℃ kept the anatase crystal system and the average size of the anatase crystals were 12.9 nm and 17.3 nm,respectively.
2005, 22(6): 638-642
Abstract:
Silane coupling agent (MAPS) was used to introduce polymerizable groups (MMA) on phosphors' surface to form organic encapsulation for SrAl2O4:Eu2+,Dy3+phosphors.IR,SEM and TEM showed that the encapsulation film,which is composed of poly (methyl methacrylate) modified by silane,is a dense reticulation with a thickness of 20~30 nm.The water-resistance and oil absorption measurement results and persistent luminescent properties indicated that the encapsulated SrAl2O4:Eu2+,Dy3+phosphors had better water-resistance performance and lower oil absorption amount,and maintained good persistent photoluminescence properties.The fluorescence intensity and afterglow life of the phosphors were respectively reduced to 93% and 95% of that of the phosphor before organic encapsulation.
Silane coupling agent (MAPS) was used to introduce polymerizable groups (MMA) on phosphors' surface to form organic encapsulation for SrAl2O4:Eu2+,Dy3+phosphors.IR,SEM and TEM showed that the encapsulation film,which is composed of poly (methyl methacrylate) modified by silane,is a dense reticulation with a thickness of 20~30 nm.The water-resistance and oil absorption measurement results and persistent luminescent properties indicated that the encapsulated SrAl2O4:Eu2+,Dy3+phosphors had better water-resistance performance and lower oil absorption amount,and maintained good persistent photoluminescence properties.The fluorescence intensity and afterglow life of the phosphors were respectively reduced to 93% and 95% of that of the phosphor before organic encapsulation.
2005, 22(6): 643-646
Abstract:
Proper conditions for the esterification reaction of starch with maleic anhydride were presented after examining the effects of several factors such as reaction temperature,reaction time,the ratio of reactants and water content on the degree of carboxylation (DC) and the degree of substitution (DS) of the product.With 6 mL of pyridine as the catalyst,6 g of starch were reacted with 6 g of maleic anhydride in the mixed solvent of 7 mL of water and 30 mL of N,N-dimethylformamide at 30℃ for 9 h,and the starch-half-ester was obtained.It was found that DC and DS of the starch-half-ester were 34.7% and 0.868,respectively.In addition,the carboxylic derivate of the starch was prepared through an alternative route.Initiated with 1.5 g K2S2O8,12 g of starch were allowed to react with 10 g of maleic acid in 30 mL of water at 95℃ for 4 h.DC and DS of the derivate were 42.7% and 1.22,respectively.The structures of the two derivates were verified with FTIR.The X-ray diffraction analysis results show that the crystallinities of the two derivates are lower than that of starch.
Proper conditions for the esterification reaction of starch with maleic anhydride were presented after examining the effects of several factors such as reaction temperature,reaction time,the ratio of reactants and water content on the degree of carboxylation (DC) and the degree of substitution (DS) of the product.With 6 mL of pyridine as the catalyst,6 g of starch were reacted with 6 g of maleic anhydride in the mixed solvent of 7 mL of water and 30 mL of N,N-dimethylformamide at 30℃ for 9 h,and the starch-half-ester was obtained.It was found that DC and DS of the starch-half-ester were 34.7% and 0.868,respectively.In addition,the carboxylic derivate of the starch was prepared through an alternative route.Initiated with 1.5 g K2S2O8,12 g of starch were allowed to react with 10 g of maleic acid in 30 mL of water at 95℃ for 4 h.DC and DS of the derivate were 42.7% and 1.22,respectively.The structures of the two derivates were verified with FTIR.The X-ray diffraction analysis results show that the crystallinities of the two derivates are lower than that of starch.
2005, 22(6): 647-651
Abstract:
2-Butenedioic acid (z)-monophenyl ester and its solid rare earth complexes REL3·4H2O(RE=La3+,Ce3+,Sm3+,Eu3+,Gd3+,Tb3+,Y3+) were synthesized and characterized by means of elemental analysis,TG-DTA,IR and NMR.The results show that the frequency differences (Δν)(100~124 cm-1) of the carboxylic stretching in the complexes were much smaller than that in the corresponding sodium salt NaL (about 196 cm-1),which indicates that the carboxylic groups in the complexes coordinate to the rare earth ions in the form of a bidentate ligand.The νC=O of the ester groups in the complexes shifted to higher wave numbers in the 1 740~1 743 cm-1 region,which suggests that the ethereal oxygen in the complexes coordinates to RE3+,but the carbonyl oxygen of the ester does not take part in the coordination.The NMR study has proved this conclusion.In the four water molecules,just one coordinates to the cation.The fluorescence spectra of the complexes in solid state were also studied.The strong fluorescence emitting peaks at 617 nm for Eu3+ and 545 nm for Tb3+ observed could be attributed to the effective energy transfer between the ligand triplet levels and the emitting levels of the Eu3+ and Tb3+.
2-Butenedioic acid (z)-monophenyl ester and its solid rare earth complexes REL3·4H2O(RE=La3+,Ce3+,Sm3+,Eu3+,Gd3+,Tb3+,Y3+) were synthesized and characterized by means of elemental analysis,TG-DTA,IR and NMR.The results show that the frequency differences (Δν)(100~124 cm-1) of the carboxylic stretching in the complexes were much smaller than that in the corresponding sodium salt NaL (about 196 cm-1),which indicates that the carboxylic groups in the complexes coordinate to the rare earth ions in the form of a bidentate ligand.The νC=O of the ester groups in the complexes shifted to higher wave numbers in the 1 740~1 743 cm-1 region,which suggests that the ethereal oxygen in the complexes coordinates to RE3+,but the carbonyl oxygen of the ester does not take part in the coordination.The NMR study has proved this conclusion.In the four water molecules,just one coordinates to the cation.The fluorescence spectra of the complexes in solid state were also studied.The strong fluorescence emitting peaks at 617 nm for Eu3+ and 545 nm for Tb3+ observed could be attributed to the effective energy transfer between the ligand triplet levels and the emitting levels of the Eu3+ and Tb3+.
2005, 22(6): 652-656
Abstract:
The flame retardancy of N-P-epoxy resin modified by aluminum hydroxide was investigated,and the effects of thermal decomposition temperature and aluminum hydroxide content were analyzed.The resin formulation was optimized through an orthogonal design of experiments.After it was thermally treated,the thermal decomposition temperature of aluminum hydroxide could be raised from 195.35℃ to 242.15℃.The flamability of the aluminum hydroxide modified N-P-epoxy resin was V0,and the oxygen index of LOI was 36%~37% when the mass ratio of epoxy resin and aluminum hydroxide was 100:(77.5~85),and the phosphor content was 2.8% and nitrogen content 1.6%.
The flame retardancy of N-P-epoxy resin modified by aluminum hydroxide was investigated,and the effects of thermal decomposition temperature and aluminum hydroxide content were analyzed.The resin formulation was optimized through an orthogonal design of experiments.After it was thermally treated,the thermal decomposition temperature of aluminum hydroxide could be raised from 195.35℃ to 242.15℃.The flamability of the aluminum hydroxide modified N-P-epoxy resin was V0,and the oxygen index of LOI was 36%~37% when the mass ratio of epoxy resin and aluminum hydroxide was 100:(77.5~85),and the phosphor content was 2.8% and nitrogen content 1.6%.
2005, 22(6): 657-660
Abstract:
Using stannous octoate (ZnOct2) as the catalyst,poly (D,L-lactic acid)(PDLLA) was synthesized.The effects of catalyst amount,polymerization temperature and time on the molecular weight of PDLLA were studied.The optimal conditions were as follows:mass fraction of ZnOct2 0.5%,reaction temperature 170℃,reaction time 7 h.The degradation of PDLLA in normal saline was explored,and the degradation products were characterized by XRD.The results showed that during the degradation process,insoluble oligomers were produced first,and then soluble oligomers and D,L-lactide were produced,and the material lost mass rapidly,and finally PDLLA degraded completely.
Using stannous octoate (ZnOct2) as the catalyst,poly (D,L-lactic acid)(PDLLA) was synthesized.The effects of catalyst amount,polymerization temperature and time on the molecular weight of PDLLA were studied.The optimal conditions were as follows:mass fraction of ZnOct2 0.5%,reaction temperature 170℃,reaction time 7 h.The degradation of PDLLA in normal saline was explored,and the degradation products were characterized by XRD.The results showed that during the degradation process,insoluble oligomers were produced first,and then soluble oligomers and D,L-lactide were produced,and the material lost mass rapidly,and finally PDLLA degraded completely.
2005, 22(6): 661-664
Abstract:
The separation of mercury in a microemulsion composed of OP-10/iso-pentanol/cyclohexane/NaOH was studied.When 0.03 mol/L triisooctylamine (TIOA) in the membrane phase,0.03 mol/L NaOH in the stripping phase,and 0.05 mol/L HCl and 0.10 mol/L KBr in the feed phase were used,the percent extraction of Hg(Ⅱ) was more than 98%.Under the chosen conditions,Hg(Ⅱ) could be completely separated from Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Mn(Ⅱ),Cd(Ⅱ) and Pb(Ⅱ).
The separation of mercury in a microemulsion composed of OP-10/iso-pentanol/cyclohexane/NaOH was studied.When 0.03 mol/L triisooctylamine (TIOA) in the membrane phase,0.03 mol/L NaOH in the stripping phase,and 0.05 mol/L HCl and 0.10 mol/L KBr in the feed phase were used,the percent extraction of Hg(Ⅱ) was more than 98%.Under the chosen conditions,Hg(Ⅱ) could be completely separated from Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Mn(Ⅱ),Cd(Ⅱ) and Pb(Ⅱ).
2005, 22(6): 665-668
Abstract:
Water-based Fe3O4 magnetic fluid was prepared by chemical co-precipitation in the presence of a surfactant PEG-4000.The effects of preparation conditions such as pH value,n(Fe3+)/n(Fe2+),temperature and PEG mass concentration on the formation and the stability of the magnetic fluid were investigated.The results show that under the conditions of pH value between 12 and 13,n(Fe3+):n(Fe2+)=1.75:1~2:1,PEG mass concentration of 50 g/L and temperature 60℃,the water-based magnetic fluid was obtained with strong magnetism and good stability.The TEM image shows that the particles of the magnetic fluid were square with an average size of about (20±5) nm.The magnetic fluid did not show obvious sedimentation trend in 48 hours without external magnetic field.The magnetic susceptibility of the magnetic fluid powder was measured by means of a magnetic balance,and the results show that the magnetic susceptibility was high,and increased with the increase of the magnetic field strength,which shows that the Fe3O4 nanoparticles were paramagnetic.
Water-based Fe3O4 magnetic fluid was prepared by chemical co-precipitation in the presence of a surfactant PEG-4000.The effects of preparation conditions such as pH value,n(Fe3+)/n(Fe2+),temperature and PEG mass concentration on the formation and the stability of the magnetic fluid were investigated.The results show that under the conditions of pH value between 12 and 13,n(Fe3+):n(Fe2+)=1.75:1~2:1,PEG mass concentration of 50 g/L and temperature 60℃,the water-based magnetic fluid was obtained with strong magnetism and good stability.The TEM image shows that the particles of the magnetic fluid were square with an average size of about (20±5) nm.The magnetic fluid did not show obvious sedimentation trend in 48 hours without external magnetic field.The magnetic susceptibility of the magnetic fluid powder was measured by means of a magnetic balance,and the results show that the magnetic susceptibility was high,and increased with the increase of the magnetic field strength,which shows that the Fe3O4 nanoparticles were paramagnetic.
2005, 22(6): 669-672
Abstract:
Methylacetylcarboethoxycyclohexanone was synthesized via nitro-reduction from methylnitroethylcarboethoxycyclohexanone,which was produced from methylcarboethoxycyclohexenone and nitroethane by Michael addition.The total yield of the two reactions reached about 42%.The effect of the catalyst on the two reactions was studied.The results show that the optimum catalysts for the Michael addition and the nitro-reduction were tetrabutylammoniumfloride and titanium trichloride,and the yields of the addition product and the reduction product were 54% and 78%,respectively.The structures of the compounds were charac-terized by elemental analysis,IR,1H NMR,and MS.
Methylacetylcarboethoxycyclohexanone was synthesized via nitro-reduction from methylnitroethylcarboethoxycyclohexanone,which was produced from methylcarboethoxycyclohexenone and nitroethane by Michael addition.The total yield of the two reactions reached about 42%.The effect of the catalyst on the two reactions was studied.The results show that the optimum catalysts for the Michael addition and the nitro-reduction were tetrabutylammoniumfloride and titanium trichloride,and the yields of the addition product and the reduction product were 54% and 78%,respectively.The structures of the compounds were charac-terized by elemental analysis,IR,1H NMR,and MS.
2005, 22(6): 673-675
Abstract:
Nano SiO2 modified natural rubber latex treated by ultrasonic and special dispersing agent was used to prepare medical gloves,and the mechanical and aging properties of the product were investigated.The results show that the tensile strength of the glove with 0.5% (mass fraction) nano SiO2 was 20.2 MPa when the contrast was 15.9 MPa.After 2% (mass fraction) nano SiO2 was filled in the latex,the tensile strength of the product increased to 25.5 MPa.With the increase of the nano SiO2 content,strength at 300% and 500% elongation of the products increased gradually.Addition of nano SiO2 particles didn't change the elongation at break and elasticity of the glove.After 33 hours aging in hot air at 100℃,the tensile strength of the glove with 2% (mass fraction) nano SiO2 was as high as 12.7 MPa.
Nano SiO2 modified natural rubber latex treated by ultrasonic and special dispersing agent was used to prepare medical gloves,and the mechanical and aging properties of the product were investigated.The results show that the tensile strength of the glove with 0.5% (mass fraction) nano SiO2 was 20.2 MPa when the contrast was 15.9 MPa.After 2% (mass fraction) nano SiO2 was filled in the latex,the tensile strength of the product increased to 25.5 MPa.With the increase of the nano SiO2 content,strength at 300% and 500% elongation of the products increased gradually.Addition of nano SiO2 particles didn't change the elongation at break and elasticity of the glove.After 33 hours aging in hot air at 100℃,the tensile strength of the glove with 2% (mass fraction) nano SiO2 was as high as 12.7 MPa.
2005, 22(6): 676-678
Abstract:
Studies on mineral Chinese medicine Xuan Jing Shi were made by means of XRD,SEM,ICP,TG and DSC.The mineral's phase,crystal size,surface shape,elemental content and thermal dissolution were determined.The results indicate that Xuan Jing Shi is mainly made up of CaSO4·2H2O.Its particle shape is slice and the particles pile up closely.The crystal size was 31.1 nm and the surface area 8.9×105 cm2/g.When heated,two water molecules were losted in one step.There are plenty of trace elements Zn,Mn,Co,Cu,Mo in Xuan Jing Shi.Above results may serve as a base for quality evaluation of the medicine.
Studies on mineral Chinese medicine Xuan Jing Shi were made by means of XRD,SEM,ICP,TG and DSC.The mineral's phase,crystal size,surface shape,elemental content and thermal dissolution were determined.The results indicate that Xuan Jing Shi is mainly made up of CaSO4·2H2O.Its particle shape is slice and the particles pile up closely.The crystal size was 31.1 nm and the surface area 8.9×105 cm2/g.When heated,two water molecules were losted in one step.There are plenty of trace elements Zn,Mn,Co,Cu,Mo in Xuan Jing Shi.Above results may serve as a base for quality evaluation of the medicine.
2005, 22(6): 679-681
Abstract:
The influences of the concentration and generation of polyamidoamine dendrimer,the ratio of dodecanoic acid to toluene,and pH in the water phase on the extraction yield of helianthine were systematically studied by selecting helianthine as the guest molecule and electrostatic self-assembled PAMAM as the host.The experimental results show that the extraction yield of helianthine increased with the increase of the generation and concentration of the polyamidoamine dendrimer.When the mass ratio of dodecanoic acid to toluene was 1:10,pH value was 7.3,the extraction yield of helianthine was the maximum.When the concentrations of 1.0,2.0 and 3.0 generations of polyamidoamine dendrimer were all 0.21 mmol/L,their self-assembled dendrimers of 1.0,2.0 and 3.0 generations of polyamidoamine dendrimer with dodecanoic acid exhibited the corresponding maximal extraction yields of helianthine,i.e.,6.04%,41.61% and 68.50%,respectively.The action mechanism of the host-guest molecule in the phase transfer system is analyzed.
The influences of the concentration and generation of polyamidoamine dendrimer,the ratio of dodecanoic acid to toluene,and pH in the water phase on the extraction yield of helianthine were systematically studied by selecting helianthine as the guest molecule and electrostatic self-assembled PAMAM as the host.The experimental results show that the extraction yield of helianthine increased with the increase of the generation and concentration of the polyamidoamine dendrimer.When the mass ratio of dodecanoic acid to toluene was 1:10,pH value was 7.3,the extraction yield of helianthine was the maximum.When the concentrations of 1.0,2.0 and 3.0 generations of polyamidoamine dendrimer were all 0.21 mmol/L,their self-assembled dendrimers of 1.0,2.0 and 3.0 generations of polyamidoamine dendrimer with dodecanoic acid exhibited the corresponding maximal extraction yields of helianthine,i.e.,6.04%,41.61% and 68.50%,respectively.The action mechanism of the host-guest molecule in the phase transfer system is analyzed.
2005, 22(6): 682-684
Abstract:
An RP-HPLC method was used to determine the content of berberine hydrochloride in Fuyanxiao tablets on a Diamonsil C18 column.The mobile phase was a CH3CN/KH2P04 (volume ratio 30:70) mixture of pH=3,and the average rate of recovery of berberine hydrochloricde was 98.18%,with a RSD of 0.92% (n=5).The method is simple and accurate,and can be used for the quality control in the production of Fuyanxiao tablet.
An RP-HPLC method was used to determine the content of berberine hydrochloride in Fuyanxiao tablets on a Diamonsil C18 column.The mobile phase was a CH3CN/KH2P04 (volume ratio 30:70) mixture of pH=3,and the average rate of recovery of berberine hydrochloricde was 98.18%,with a RSD of 0.92% (n=5).The method is simple and accurate,and can be used for the quality control in the production of Fuyanxiao tablet.
Supercritical CO2 Assisted Preparation of Polystyrene/nylon1010 Blend and Its Crystalline Morphology
2005, 22(6): 685-687
Abstract:
Polystyrene/nylon1010 blend was prepared with supercritical CO2 as the monomer/initiator carrier.The aggregation structures of both nylon1010 treated by supercritical CO2 and the blend were studied.The results reveal that the crystallinity of the blend decreased a little as the PS content increased;there were apparent bacillary or fruticose crystalline on the surface of treated nylon1010 and PS/nylon1010 blend.
Polystyrene/nylon1010 blend was prepared with supercritical CO2 as the monomer/initiator carrier.The aggregation structures of both nylon1010 treated by supercritical CO2 and the blend were studied.The results reveal that the crystallinity of the blend decreased a little as the PS content increased;there were apparent bacillary or fruticose crystalline on the surface of treated nylon1010 and PS/nylon1010 blend.
2005, 22(6): 688-690
Abstract:
Low molecular weight N-succinyl-chitosans with different degrees of substitution were synthesized by controlling reaction temperature,reaction time,and the molar ratio of the low molecular weight chitosan to succinic anhydride.The structure of the low molecular weight N-succinyl-chitosan was characterized by infrared spectroscopy (IR),by which -COCH2CH2COOH was proved to be introduced to the -NH2 of the low molecular weight chitosan.The moisture adsorption and moisture retention capacities of the low molecular weight chitosan derivatives with different degrees of substitution were investigated.The results indicate that the moisture adsorption and moisture retention capacities of the low molecular weight N-succinyl-chitosan increase with the increase of the degree of substitution.When the degree of substitution is greater than 38%,the derivatives have better moisture adsorption and moisture retention capacities than hyaluronic acid.
Low molecular weight N-succinyl-chitosans with different degrees of substitution were synthesized by controlling reaction temperature,reaction time,and the molar ratio of the low molecular weight chitosan to succinic anhydride.The structure of the low molecular weight N-succinyl-chitosan was characterized by infrared spectroscopy (IR),by which -COCH2CH2COOH was proved to be introduced to the -NH2 of the low molecular weight chitosan.The moisture adsorption and moisture retention capacities of the low molecular weight chitosan derivatives with different degrees of substitution were investigated.The results indicate that the moisture adsorption and moisture retention capacities of the low molecular weight N-succinyl-chitosan increase with the increase of the degree of substitution.When the degree of substitution is greater than 38%,the derivatives have better moisture adsorption and moisture retention capacities than hyaluronic acid.
2005, 22(6): 691-693
Abstract:
The effect of isocyanates (TDI,MDI,PAPI) on the adhesion of EPDM rubber was studied.The results indicate that isocyanates affect the adhesion strength obviously.After carbon-white,sulfur,accelerator and zinc oxide were added to EPDM,the adhesion strengths were 1.922 MPa at 0.4% TDI,1.830 MPa at 0.4% MDI,and 1.937 MPa at 0.4% PAPI,respectively.The EPDM rubber with PAPI has the highest adhesion strength.
The effect of isocyanates (TDI,MDI,PAPI) on the adhesion of EPDM rubber was studied.The results indicate that isocyanates affect the adhesion strength obviously.After carbon-white,sulfur,accelerator and zinc oxide were added to EPDM,the adhesion strengths were 1.922 MPa at 0.4% TDI,1.830 MPa at 0.4% MDI,and 1.937 MPa at 0.4% PAPI,respectively.The EPDM rubber with PAPI has the highest adhesion strength.
2005, 22(6): 694-696
Abstract:
The deamination reaction of[Ni(NH3)6]Cl2 was studied by using the non-isothermal TG method.The data from the non-isothermal experiments were analyzed by means of ACHAR and COATS-REDFERN methods.It was found that the integral kinetic equation and differential coefficient kinetic eqution for the deamination of[Ni(NH3)6C]I2 were f(α)=[-ln(1-α)]-1,g(α)=α+(1-α)ln(1-α),activation energies were E1=81.223 6 kJ/mol,E2=189.634 2 kJ/mol;pre-exponential factor A1=4.10×109/s,A2=7.02×1022/s,and kinetic compensation effect equation ln A1=3.519 6E1+5.378 2;ln A2=3.457 3E2+4.804 5.
The deamination reaction of[Ni(NH3)6]Cl2 was studied by using the non-isothermal TG method.The data from the non-isothermal experiments were analyzed by means of ACHAR and COATS-REDFERN methods.It was found that the integral kinetic equation and differential coefficient kinetic eqution for the deamination of[Ni(NH3)6C]I2 were f(α)=[-ln(1-α)]-1,g(α)=α+(1-α)ln(1-α),activation energies were E1=81.223 6 kJ/mol,E2=189.634 2 kJ/mol;pre-exponential factor A1=4.10×109/s,A2=7.02×1022/s,and kinetic compensation effect equation ln A1=3.519 6E1+5.378 2;ln A2=3.457 3E2+4.804 5.
