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2005 Volume 22 Issue 10
2005, 22(10): 1045-1049
Abstract:
The synthesis of 6-methyl-2-N,N-diethylaminopyrimidinol(2) from diethylgunidine nitrate(1) and diketene was studied.After nitration and then chlorization of 2,4-chloro-5-nitropyrimidine(4<) was obtained,and a novel series of 5-nitro-4-(substituted-phenoxy or phenylthio)pyrimidines(5) were prepared via the(reaction) of 4 and substituted phenols or phenylthiols.Furthermore,a new reaction between the methyl mercaptoacetate derivative of 4(6) and hydrazine,which yields pyrimidinyl hydrazine(8) in which the thio-acetoacetic acid methyl ester behaves as a leaving group under the nucleophinlic attack.The structures of all of the compounds were confirmed by 1H NMR,IR,MS,and elemental analysis.The preliminary bioassay indicated that some of the compounds showed moderate herbicidal,fungicidal and anti-TMV activities.
The synthesis of 6-methyl-2-N,N-diethylaminopyrimidinol(2) from diethylgunidine nitrate(1) and diketene was studied.After nitration and then chlorization of 2,4-chloro-5-nitropyrimidine(4<) was obtained,and a novel series of 5-nitro-4-(substituted-phenoxy or phenylthio)pyrimidines(5) were prepared via the(reaction) of 4 and substituted phenols or phenylthiols.Furthermore,a new reaction between the methyl mercaptoacetate derivative of 4(6) and hydrazine,which yields pyrimidinyl hydrazine(8) in which the thio-acetoacetic acid methyl ester behaves as a leaving group under the nucleophinlic attack.The structures of all of the compounds were confirmed by 1H NMR,IR,MS,and elemental analysis.The preliminary bioassay indicated that some of the compounds showed moderate herbicidal,fungicidal and anti-TMV activities.
2005, 22(10): 1050-1054
Abstract:
The UV absorption spectra of eleven chitosan derivatives,for example O-cyanoethyl chitosan and N-benzyl chitosan,were obtained.In dilute solution,the UV-Vis absorption spectra of all these derivatives cover the ultraviolet B region(280~320 nm).The UV-Vis spectra of N-salicylaldehyde modified chitosan and N-cinnamaldehyde modified chitosan cover part of the ultraviolet A region(>320 nm).In concentrated solution,complete spectra cannot be achieved due to the limit of the instrument.With the increase of the concentration,red shift appears in the UV-Vis spectra,which indicates that the state of aggregation has changed.At the critical concentration for the cholesteric liquid crystalline phase,the position of the peak shifts obviously.This phenomenon can be explained by the increase of the interaction of the chromophore induced by the ordered arrangement of the mesophase.Moreover the UV-Vis spectrum of the film of N-benzyl chitosan in liquid crystalline state covers the whole ultraviolet region.The UV-absorption characteristics of these chitosan derivatives show that they may be used as photoprotectants employed in cosmetic and pharmaceutical preparations.
The UV absorption spectra of eleven chitosan derivatives,for example O-cyanoethyl chitosan and N-benzyl chitosan,were obtained.In dilute solution,the UV-Vis absorption spectra of all these derivatives cover the ultraviolet B region(280~320 nm).The UV-Vis spectra of N-salicylaldehyde modified chitosan and N-cinnamaldehyde modified chitosan cover part of the ultraviolet A region(>320 nm).In concentrated solution,complete spectra cannot be achieved due to the limit of the instrument.With the increase of the concentration,red shift appears in the UV-Vis spectra,which indicates that the state of aggregation has changed.At the critical concentration for the cholesteric liquid crystalline phase,the position of the peak shifts obviously.This phenomenon can be explained by the increase of the interaction of the chromophore induced by the ordered arrangement of the mesophase.Moreover the UV-Vis spectrum of the film of N-benzyl chitosan in liquid crystalline state covers the whole ultraviolet region.The UV-absorption characteristics of these chitosan derivatives show that they may be used as photoprotectants employed in cosmetic and pharmaceutical preparations.
2005, 22(10): 1055-1059
Abstract:
A strongly-weakly basic anion-exchange resin was prepared with Triethylenediamine(TEDA) as a amination agent,and the capability of the resin was studied by titration.A comparison study was made on the adsorption behavior for benzoic acid of the resin vs that of the D201 resin and D301R resin,including the static and dynamic adsorption behavior.The results indicated that the pH titration curves of the three resins were not affected by temperature.The titration curve of the new resin is between the curves of the strongly-basic resin D201 and the weakly-basic resin D301R.The amount of benzoic acid adsorbed at equilibrium by this resin was 5.974 451 mmol/g,which was between that for D201(8.432 689 mmol/g) and D301R(5.497 871 mmol/g).At 303 K,the adsorption rate constant of the resin for benzoic acid was(0.030 60 min-1),which was less than that for D201(0.044 89 min-1),and greater than that for D301R(0.026 13 min-1).
A strongly-weakly basic anion-exchange resin was prepared with Triethylenediamine(TEDA) as a amination agent,and the capability of the resin was studied by titration.A comparison study was made on the adsorption behavior for benzoic acid of the resin vs that of the D201 resin and D301R resin,including the static and dynamic adsorption behavior.The results indicated that the pH titration curves of the three resins were not affected by temperature.The titration curve of the new resin is between the curves of the strongly-basic resin D201 and the weakly-basic resin D301R.The amount of benzoic acid adsorbed at equilibrium by this resin was 5.974 451 mmol/g,which was between that for D201(8.432 689 mmol/g) and D301R(5.497 871 mmol/g).At 303 K,the adsorption rate constant of the resin for benzoic acid was(0.030 60 min-1),which was less than that for D201(0.044 89 min-1),and greater than that for D301R(0.026 13 min-1).
2005, 22(10): 1060-1064
Abstract:
Four new complexes were synthesized via reaction of dimethylbiguamide(DMBG) with anhydrous Rare Earth chloride in anhydrous ethanol or Rare Earth acetate in ethanol,and characterized by elemental analysis,ICP,UV,IR,and fluorescence spectroscopy.The formulae of the complexes were established as Nd(DMBG)2(EtO)Cl2(EtO=ethoxy) and Re(DMBG)2(CH3COO)3(Re=Nd(Ⅲ),Sm(Ⅲ)).Their anti-diabetes action on the diabetes mice was observed,and the elimination rates of supraoxide anion free radical on lipid were determinated by ESR.The result shows that Nd(DMBG)2(CH3COO)3 complex exhibits a strong effect in both cases,which implies that its anti-diabetes action may be related to anti-oxidation action or protection effect to membrane damnication.
Four new complexes were synthesized via reaction of dimethylbiguamide(DMBG) with anhydrous Rare Earth chloride in anhydrous ethanol or Rare Earth acetate in ethanol,and characterized by elemental analysis,ICP,UV,IR,and fluorescence spectroscopy.The formulae of the complexes were established as Nd(DMBG)2(EtO)Cl2(EtO=ethoxy) and Re(DMBG)2(CH3COO)3(Re=Nd(Ⅲ),Sm(Ⅲ)).Their anti-diabetes action on the diabetes mice was observed,and the elimination rates of supraoxide anion free radical on lipid were determinated by ESR.The result shows that Nd(DMBG)2(CH3COO)3 complex exhibits a strong effect in both cases,which implies that its anti-diabetes action may be related to anti-oxidation action or protection effect to membrane damnication.
2005, 22(10): 1065-1069
Abstract:
Several bis-quaternary ammonium salts of peroxotungstate and peroxomolybdate,such as PhCH2N-(CH2)6NCH2Ph[W(O2)4]·2H2O,PhCH2N(CH2)6NCH2Ph[WO(O2)2(C2O4)] and PhCH2N(CH2)6-NCH2Ph[MoO(O2)2(C2O4)],have been synthesized and characterized.Their catalytic activities in the oxidation of cyclohexanol and benzyl alcohol with aqueous 30% hydrogen peroxide were investigated.The(results) show that the bis-quaternary ammonium peroxotungstates are excellent catalysts in the oxidation of benzyl alcohol and cyclohexanol under moderate conditions.However,the catalytic activity of bis-quaternary ammonium peroxomolybadates is relatively weak.The yields of benzyl acid,benzaldehyde and cyclohexanone were 93.0%,93.6% and 91.7% respectively.
Several bis-quaternary ammonium salts of peroxotungstate and peroxomolybdate,such as PhCH2N-(CH2)6NCH2Ph[W(O2)4]·2H2O,PhCH2N(CH2)6NCH2Ph[WO(O2)2(C2O4)] and PhCH2N(CH2)6-NCH2Ph[MoO(O2)2(C2O4)],have been synthesized and characterized.Their catalytic activities in the oxidation of cyclohexanol and benzyl alcohol with aqueous 30% hydrogen peroxide were investigated.The(results) show that the bis-quaternary ammonium peroxotungstates are excellent catalysts in the oxidation of benzyl alcohol and cyclohexanol under moderate conditions.However,the catalytic activity of bis-quaternary ammonium peroxomolybadates is relatively weak.The yields of benzyl acid,benzaldehyde and cyclohexanone were 93.0%,93.6% and 91.7% respectively.
2005, 22(10): 1070-1074
Abstract:
A series of iron-doped nano-titania were prepared from titanium tetrachloride precursor via a two-step method involving microwave and conventional heating treatments.The iron-doped nano-titania was characterized with XRD,TEM,UV-Vis and XPS techniques.The results indicated that the iron-doped nano-titania with an average diameter of 10 nm contained anatase as the main phase and rutile phase.It was found that the ferric ion dopant of a proper concentration promoted the formation of the rutile phase,and reduced the crystallite size of anatase.An increase of 0.3 eV in the binding energy of Ti2p was observed after the nano-titania was doped with 0.5%(mole fraction) ferric ions.Moreover,the photoresponse shifted to the visible region for iron-doped nano-titania.Photocatalytic activity was evaluated by measuring the decomposition rates of vitamin B12 exposed to UVA(320~400) radiation.The results indicated that the optimum mole fraction of ferric ions was 0.5% for the iron-doped nano-titania,which doubled the photocatalytic decomposition rate of vitamin B12 compared to that of undoped nano-titania.
A series of iron-doped nano-titania were prepared from titanium tetrachloride precursor via a two-step method involving microwave and conventional heating treatments.The iron-doped nano-titania was characterized with XRD,TEM,UV-Vis and XPS techniques.The results indicated that the iron-doped nano-titania with an average diameter of 10 nm contained anatase as the main phase and rutile phase.It was found that the ferric ion dopant of a proper concentration promoted the formation of the rutile phase,and reduced the crystallite size of anatase.An increase of 0.3 eV in the binding energy of Ti2p was observed after the nano-titania was doped with 0.5%(mole fraction) ferric ions.Moreover,the photoresponse shifted to the visible region for iron-doped nano-titania.Photocatalytic activity was evaluated by measuring the decomposition rates of vitamin B12 exposed to UVA(320~400) radiation.The results indicated that the optimum mole fraction of ferric ions was 0.5% for the iron-doped nano-titania,which doubled the photocatalytic decomposition rate of vitamin B12 compared to that of undoped nano-titania.
2005, 22(10): 1075-1078
Abstract:
A procedure for the preparative isolation of 1-S-[(1Z)-3-hydroxy-1-[(sulfooxy) imino]-4-(pentenyl)]-1-thio-β-D-glucopyanose,potassium salt(progoitrin) from Brassica oleracea rapeseed is reported.The glucosinolates were extracted from Brassica oleracea rapeseed with a 70% methanol solution;then,the extractives were separated and purified to get the glucosinolates on chromatographic column with alumina support;and finally,the glucosinolates were purified by reverse-phase octadecyl(C18) silica support,and progoitrin was obtained as the major content of glucosinolate.The structure of progoitrin was identified on the basis of its physicochemical properties,UV,IR,1H NMR and elemental analysis.Its purity was determined by high performance liquid chromatographic(HPLC) method.The anticarcinogenic effects of mixed glucosinolate and pure progoitrin were measured.The experimental results show that when a dose of 60 mg/kg was administrated,the ratio of inhibitory to S180 sarcoma was 67.3% and 59.5% for mixed glucosinolates and pure progoitrin,respectively.This study suggests that both the mixture of glucosinolates and pure progoitrin in Brassica oleracea rapeseed have potential anticarcinogenic effect as chempreventive agents.
A procedure for the preparative isolation of 1-S-[(1Z)-3-hydroxy-1-[(sulfooxy) imino]-4-(pentenyl)]-1-thio-β-D-glucopyanose,potassium salt(progoitrin) from Brassica oleracea rapeseed is reported.The glucosinolates were extracted from Brassica oleracea rapeseed with a 70% methanol solution;then,the extractives were separated and purified to get the glucosinolates on chromatographic column with alumina support;and finally,the glucosinolates were purified by reverse-phase octadecyl(C18) silica support,and progoitrin was obtained as the major content of glucosinolate.The structure of progoitrin was identified on the basis of its physicochemical properties,UV,IR,1H NMR and elemental analysis.Its purity was determined by high performance liquid chromatographic(HPLC) method.The anticarcinogenic effects of mixed glucosinolate and pure progoitrin were measured.The experimental results show that when a dose of 60 mg/kg was administrated,the ratio of inhibitory to S180 sarcoma was 67.3% and 59.5% for mixed glucosinolates and pure progoitrin,respectively.This study suggests that both the mixture of glucosinolates and pure progoitrin in Brassica oleracea rapeseed have potential anticarcinogenic effect as chempreventive agents.
2005, 22(10): 1079-1082
Abstract:
The inclusion complex(IC) of p-diethynylbenzene(DEB) with β-cyclodextrin was synthesized via different methods and was characterized by 1H NMR spectroscopy,XRD and DSC.The results show that(insoluble) DEB dissolves in D2O after entering the cavity of β-CD,and the DEB molecules in the cavity cause an upfield shift of H-3 and H-5 of β-cyclodextrin in the 1H NMR spectrum.The DSC and XRD analyses indicate that there is no crystalline DEB in the inclusion complex.The presence of DEB in the cavity makes the dehydration peak of β-cyclodextrin shift to lower temperature.The fluorescence spectra of the solid inclusion complex and DEB show that DEB molecules have entered the cavities of β-cyclodextrin either in single or in dimolecular forms.The absence of the emission of solid DEB in the solid-state emission spectrum of the inclusion complex also suggests that complexation can inhibit the π-π stacking of DEB effectively.
The inclusion complex(IC) of p-diethynylbenzene(DEB) with β-cyclodextrin was synthesized via different methods and was characterized by 1H NMR spectroscopy,XRD and DSC.The results show that(insoluble) DEB dissolves in D2O after entering the cavity of β-CD,and the DEB molecules in the cavity cause an upfield shift of H-3 and H-5 of β-cyclodextrin in the 1H NMR spectrum.The DSC and XRD analyses indicate that there is no crystalline DEB in the inclusion complex.The presence of DEB in the cavity makes the dehydration peak of β-cyclodextrin shift to lower temperature.The fluorescence spectra of the solid inclusion complex and DEB show that DEB molecules have entered the cavities of β-cyclodextrin either in single or in dimolecular forms.The absence of the emission of solid DEB in the solid-state emission spectrum of the inclusion complex also suggests that complexation can inhibit the π-π stacking of DEB effectively.
2005, 22(10): 1083-1086
Abstract:
Genistein(G) has the effects of anti-tumour and anti-arteriosclerosis.It can also reduce plasma lipid and kill various cancer cells without damaging the normal cells.Nevertheless,its medical application is much restricted because of its poor solubility in water and fat.In this study,its two new water-soluble derivatives,genistein-3'-sodium sulfonate(G1) and genistein-3',6-disodium sulfonate(G2),were prepared via sulfation and column chromatography separation.The structures of the two compounds were identified by means of IR and 1H NMR.At the same time,the inhibitory ratios of G,G1 and G2 against lipid peroxidation were determined.The results show that G1 and G2 not only have stronger anti-peroxidation activity for lipids than G,but also have good water solubilities.
Genistein(G) has the effects of anti-tumour and anti-arteriosclerosis.It can also reduce plasma lipid and kill various cancer cells without damaging the normal cells.Nevertheless,its medical application is much restricted because of its poor solubility in water and fat.In this study,its two new water-soluble derivatives,genistein-3'-sodium sulfonate(G1) and genistein-3',6-disodium sulfonate(G2),were prepared via sulfation and column chromatography separation.The structures of the two compounds were identified by means of IR and 1H NMR.At the same time,the inhibitory ratios of G,G1 and G2 against lipid peroxidation were determined.The results show that G1 and G2 not only have stronger anti-peroxidation activity for lipids than G,but also have good water solubilities.
2005, 22(10): 1087-1091
Abstract:
2-Cyclopentlybenzimidazole was synthesized via the reaction of o-phenylenediamine and cyclopentlyacetic acid under microwave.Three new compounds were obtained from the reaction of ferrocenesulfonylchloride and the benzimidazoles.The new compounds were characterized by means of 1HNMR,MS,and elemental analysis,and their inhibition activities against five microbes were tested in comparison with the 50% carbendazim wet powder.
2-Cyclopentlybenzimidazole was synthesized via the reaction of o-phenylenediamine and cyclopentlyacetic acid under microwave.Three new compounds were obtained from the reaction of ferrocenesulfonylchloride and the benzimidazoles.The new compounds were characterized by means of 1HNMR,MS,and elemental analysis,and their inhibition activities against five microbes were tested in comparison with the 50% carbendazim wet powder.
2005, 22(10): 1092-1095
Abstract:
The adsorption behavior of NH4+-pretreated clinoptilolite for potassium ions was studied.The effects of competing cations were investigated.The results indicate that NH4+-pretreated clinoptilolite adsorbed potassium ions with high adsorption capacity.The adsorption behavior of the NH4+-pretreated clinoptilolite deviated from the original trend at the equivalent fraction of K+ in the clinoptilolite YK+=0.5 due to the effect of potassium concentration.The presence of competing cations,mainly sodium ions,surpressed the exchange capacity for potassium,in particular the ratio of potassium ions to sodium ions directly influenced the selec-tivity of potassium on the NH4+-pretreated clinoptilolite.
The adsorption behavior of NH4+-pretreated clinoptilolite for potassium ions was studied.The effects of competing cations were investigated.The results indicate that NH4+-pretreated clinoptilolite adsorbed potassium ions with high adsorption capacity.The adsorption behavior of the NH4+-pretreated clinoptilolite deviated from the original trend at the equivalent fraction of K+ in the clinoptilolite YK+=0.5 due to the effect of potassium concentration.The presence of competing cations,mainly sodium ions,surpressed the exchange capacity for potassium,in particular the ratio of potassium ions to sodium ions directly influenced the selec-tivity of potassium on the NH4+-pretreated clinoptilolite.
2005, 22(10): 1096-1099
Abstract:
Five Polyimides(PIs) were prepared from 3,3'-dihydroxy-4,4'-diamino-biphenyl(HAB) and 3,3',4,4'-biphenyltetra-carboxylic dianhydride(BPDA),pyromellitic dianhydride(PMDA),or their mixtures by condensation,and then dehydration-imidization.The derivative thermogravimetry(DTG) of the thermogravimetric analysis(TGA) showed 2 heat decomposition peaks,upon which the heat decomposition process can be considered as two-staged——the formation of Polybenzoxazoles(PBOs) and then the decomposition of PBOs.The DTG curves of the PI films treated at 500℃ for 1 h under nitrogen showed only one peak,which indicated that PIs can be sufficiently converted into PBO.The structures of the PIs and the PBOs were characterized by FTIR.The heat resistance(HR) of PBOs,indicated by the decomposition onset temperature Td,was better than that of PIs by 100~170℃.HR of PMDA-HAB PBO was better than that of BPDA-HAB PBO.HR of HAB-BPDA-PMDA PBOs with different BPDA/PMDA molar ratios was better than that of BPDA-HAB PBO or PMDA-HAB PBO.The HAB-BPDA-PMDA PBO with molar ratio of 1:0.25:0.75 showed the best HR.
Five Polyimides(PIs) were prepared from 3,3'-dihydroxy-4,4'-diamino-biphenyl(HAB) and 3,3',4,4'-biphenyltetra-carboxylic dianhydride(BPDA),pyromellitic dianhydride(PMDA),or their mixtures by condensation,and then dehydration-imidization.The derivative thermogravimetry(DTG) of the thermogravimetric analysis(TGA) showed 2 heat decomposition peaks,upon which the heat decomposition process can be considered as two-staged——the formation of Polybenzoxazoles(PBOs) and then the decomposition of PBOs.The DTG curves of the PI films treated at 500℃ for 1 h under nitrogen showed only one peak,which indicated that PIs can be sufficiently converted into PBO.The structures of the PIs and the PBOs were characterized by FTIR.The heat resistance(HR) of PBOs,indicated by the decomposition onset temperature Td,was better than that of PIs by 100~170℃.HR of PMDA-HAB PBO was better than that of BPDA-HAB PBO.HR of HAB-BPDA-PMDA PBOs with different BPDA/PMDA molar ratios was better than that of BPDA-HAB PBO or PMDA-HAB PBO.The HAB-BPDA-PMDA PBO with molar ratio of 1:0.25:0.75 showed the best HR.
2005, 22(10): 1100-1103
Abstract:
The nonisothermal crystallization kinetics of poly(ε-caprolactone)(PCL) in PCL/silica(SiO2) non-covalently coupled organic-inorganic hybrids was investigated by means of differential scanning calorimetry(DSC).The results show that the mechanism of the nucleation and growth of the PCL nonisothermal crystallization in the hybrids are related to the composition of the hybrids and their structural micro-environmental effect.Under the same crystallinity,the F(T) value of a 60:40(mass fraction) TEOS/PCL hybrid(sample) was 7.42 K·minn/(m-1),whose crystallization rate was the highest.On the one hand,the inorganic nano-component(viz.SiO2) could act as a nucleating agent to facilitate the crystallization of PCL in the hybrids.On the other hand,the intermolecular hydrogen bonding and the SiO2 network in the hybrids also confine the crystallization of PCL.
The nonisothermal crystallization kinetics of poly(ε-caprolactone)(PCL) in PCL/silica(SiO2) non-covalently coupled organic-inorganic hybrids was investigated by means of differential scanning calorimetry(DSC).The results show that the mechanism of the nucleation and growth of the PCL nonisothermal crystallization in the hybrids are related to the composition of the hybrids and their structural micro-environmental effect.Under the same crystallinity,the F(T) value of a 60:40(mass fraction) TEOS/PCL hybrid(sample) was 7.42 K·minn/(m-1),whose crystallization rate was the highest.On the one hand,the inorganic nano-component(viz.SiO2) could act as a nucleating agent to facilitate the crystallization of PCL in the hybrids.On the other hand,the intermolecular hydrogen bonding and the SiO2 network in the hybrids also confine the crystallization of PCL.
2005, 22(10): 1104-1107
Abstract:
The present paper covers the synthesis and characterization of a novel polyetherimide(PEI-A).The BMI resin microspheres with a diameter of 3~5 μm were prepared by curing the blend of bis(4-malei-(midediphenyl)) methane(BMI monomer) and 2,2'-diallyl bisphenol A(DBA) with 10%~50% PEI-A by means of reaction-induced phase separation(160℃ for 8 h,185℃ for 2 h,200℃ for 10 h).The morphologies of the blends and the BMI resin microspheres were investigated by virtue of SEM.The size and size distribution of the BMI resin microsphere particle were characterized via LPS.The result shows that the system of PEI-A/(BMI monomer and DBA) is suitable to preparing BMI resin microspheres of micrometer size.With increase of the PEI-A content,bismaleimide resin microsphere particle size decreases,but the particle size distribution fluctuates in a wide-narrow-wide pattern.
The present paper covers the synthesis and characterization of a novel polyetherimide(PEI-A).The BMI resin microspheres with a diameter of 3~5 μm were prepared by curing the blend of bis(4-malei-(midediphenyl)) methane(BMI monomer) and 2,2'-diallyl bisphenol A(DBA) with 10%~50% PEI-A by means of reaction-induced phase separation(160℃ for 8 h,185℃ for 2 h,200℃ for 10 h).The morphologies of the blends and the BMI resin microspheres were investigated by virtue of SEM.The size and size distribution of the BMI resin microsphere particle were characterized via LPS.The result shows that the system of PEI-A/(BMI monomer and DBA) is suitable to preparing BMI resin microspheres of micrometer size.With increase of the PEI-A content,bismaleimide resin microsphere particle size decreases,but the particle size distribution fluctuates in a wide-narrow-wide pattern.
2005, 22(10): 1108-1111
Abstract:
Glyoxal,organic silane coupling agents,and dodecyl succinic anhydride(DDSA) latex were used to treat tapioca starch individually.When 10 g of starch was mixed with 0.3 g of catalyst,and 4.5 mL of the crosslinking agent for 35 min at 40℃,the crosslinked starch exhibited a rate of water uptake of 19.48% which was less than that of tapioca starch;when starch was 10 g,KH-570 was 8 mL,and the pH was controlled at 8.5,the water uptake ratio of the coupled starch thus-produced was 20.85%;when the volume of DDSA was 7.5 mL,m(DDSA):m(MS-1):m(H2O) was 1:25:46,and the pH was controlled at 8,the water uptake of the esterified starch was 26.62%.After the treatment,the hydrophilicity of the starch was(reduced) because of the decrease of -OH groups,which was validated by FTIR.
Glyoxal,organic silane coupling agents,and dodecyl succinic anhydride(DDSA) latex were used to treat tapioca starch individually.When 10 g of starch was mixed with 0.3 g of catalyst,and 4.5 mL of the crosslinking agent for 35 min at 40℃,the crosslinked starch exhibited a rate of water uptake of 19.48% which was less than that of tapioca starch;when starch was 10 g,KH-570 was 8 mL,and the pH was controlled at 8.5,the water uptake ratio of the coupled starch thus-produced was 20.85%;when the volume of DDSA was 7.5 mL,m(DDSA):m(MS-1):m(H2O) was 1:25:46,and the pH was controlled at 8,the water uptake of the esterified starch was 26.62%.After the treatment,the hydrophilicity of the starch was(reduced) because of the decrease of -OH groups,which was validated by FTIR.
2005, 22(10): 1112-1116
Abstract:
A series of twin-tailed hydrophobically associating water-soluble terpolymers poly(acrylamide/sodium acrylate/dioctylacrylamide)[P(AM/NaAA/DiC8AM)] were synthesized by micell copolymerization.These polymer systems were characterized by FTIR and 1H NMR.Their viscosity behavior was examined.When c(total monomers)=1.70~3.20 mol/L,x(DiC8AM)=0.05%~0.40% and SMR=70~25,the(intrinsic) viscosity values [η] of the terpolymers,which were in the range of 3.67~26.38 dL/g,increased with the increase of the total monomer concentration and the decrease of the hydrophobe mole fraction at 30℃ and in 1 mol/L NaCl aqueous solution while the Huggins constant KH and average coil density ρequ,which were in the ranges of 0.220~3.90 and 0.116~0.681 g/dL respectively,decreased.In the 19 334 μg/g(saline) solution,the apparent viscosity of the terpolymer increased,but the critical association concentration(decreased) with the increase of the total monomer concentration and the hydrophobe mole fraction,and the(decrease) of SMR.The experimental results show that the properties and the association behavior of the terpolymers are pronouncedly dependent on the [η] and the hydrophobe mole fraction of the polymer,as well as the block length and the distribution of the hydrophobe in the polymer chain.
A series of twin-tailed hydrophobically associating water-soluble terpolymers poly(acrylamide/sodium acrylate/dioctylacrylamide)[P(AM/NaAA/DiC8AM)] were synthesized by micell copolymerization.These polymer systems were characterized by FTIR and 1H NMR.Their viscosity behavior was examined.When c(total monomers)=1.70~3.20 mol/L,x(DiC8AM)=0.05%~0.40% and SMR=70~25,the(intrinsic) viscosity values [η] of the terpolymers,which were in the range of 3.67~26.38 dL/g,increased with the increase of the total monomer concentration and the decrease of the hydrophobe mole fraction at 30℃ and in 1 mol/L NaCl aqueous solution while the Huggins constant KH and average coil density ρequ,which were in the ranges of 0.220~3.90 and 0.116~0.681 g/dL respectively,decreased.In the 19 334 μg/g(saline) solution,the apparent viscosity of the terpolymer increased,but the critical association concentration(decreased) with the increase of the total monomer concentration and the hydrophobe mole fraction,and the(decrease) of SMR.The experimental results show that the properties and the association behavior of the terpolymers are pronouncedly dependent on the [η] and the hydrophobe mole fraction of the polymer,as well as the block length and the distribution of the hydrophobe in the polymer chain.
2005, 22(10): 1117-1121
Abstract:
The reaction kinetics of polyurethane formation and that of trimerization of isocyanate in a system of polyisocyanurate modified by urethane were studied by FTIR.The results show that the two competing reactions occurred and progressed simultaneously,and the trimerization was found to be first order,and the polyurethane formation was first order with respect to the isocyanate concentration and zero order with respect to the polyol concentration.At the same time,the effects of the catalyst(DMP-30) concentration and the initial reaction temperature on the initial rates of the two reactions were also investigated.The initial rate of the polyurethane formation appeared to be almost linearly dependent on the catalyst concentration.Only when the catalyst concentration reached a certain value,did the initial rate of the trimerization reaction increase greatly with increase in the catalyst concentration;the initial rate of the trimerization reaction increased with increase of the temperature when the temperature was low,but when the temperature was high(>50℃),it decreased with increase of the temperature,while the initial rate of the polyurethane formation always increased with increase of the temperature.
The reaction kinetics of polyurethane formation and that of trimerization of isocyanate in a system of polyisocyanurate modified by urethane were studied by FTIR.The results show that the two competing reactions occurred and progressed simultaneously,and the trimerization was found to be first order,and the polyurethane formation was first order with respect to the isocyanate concentration and zero order with respect to the polyol concentration.At the same time,the effects of the catalyst(DMP-30) concentration and the initial reaction temperature on the initial rates of the two reactions were also investigated.The initial rate of the polyurethane formation appeared to be almost linearly dependent on the catalyst concentration.Only when the catalyst concentration reached a certain value,did the initial rate of the trimerization reaction increase greatly with increase in the catalyst concentration;the initial rate of the trimerization reaction increased with increase of the temperature when the temperature was low,but when the temperature was high(>50℃),it decreased with increase of the temperature,while the initial rate of the polyurethane formation always increased with increase of the temperature.
2005, 22(10): 1122-1126
Abstract:
Magnetic chitosan microspheres were prepared by using glutaradehyde as the cross-linker.The morphology and structure of the microspheres were observed and analyzed.The results show that the magnetic chitosan microspheres were well-shaped spherical with smooth surface,and the average particle size was 0.9 μm with a narrow size distribution.The laccase was immobilized on the magnetic chitosan microspheres.The optimal temperatures for the immobilized enzyme were 10℃ and 55℃,5℃ lower than that of the free enzyme,respectively.The optimal pH for the immobilized enzyme was 3.02,the same as that for free enzyme.After the immobilized enzyme was kept at 60℃ for 210 min,it lost 26% of the initial enzyme activity,while the free enzyme lost 80.6% under the same conditions.After 10 cycles of operation,the immobilized enzyme remained over 80% of its initial activity.Therefore,the catalytic efficiency and storage stability of the laccase were greatly improved after its immobilization on the magnetic chitosan microspheres.
Magnetic chitosan microspheres were prepared by using glutaradehyde as the cross-linker.The morphology and structure of the microspheres were observed and analyzed.The results show that the magnetic chitosan microspheres were well-shaped spherical with smooth surface,and the average particle size was 0.9 μm with a narrow size distribution.The laccase was immobilized on the magnetic chitosan microspheres.The optimal temperatures for the immobilized enzyme were 10℃ and 55℃,5℃ lower than that of the free enzyme,respectively.The optimal pH for the immobilized enzyme was 3.02,the same as that for free enzyme.After the immobilized enzyme was kept at 60℃ for 210 min,it lost 26% of the initial enzyme activity,while the free enzyme lost 80.6% under the same conditions.After 10 cycles of operation,the immobilized enzyme remained over 80% of its initial activity.Therefore,the catalytic efficiency and storage stability of the laccase were greatly improved after its immobilization on the magnetic chitosan microspheres.
2005, 22(10): 1127-1131
Abstract:
A new approach to the "in-cell" indirect electrosynthesis of o-tolualdehyde from o-xylene is reported in this paper.In an aqueous sulfuric acid solution containing V5+ ions,o-xylene was directly eletro-oxidized to o-tolualdehyde in an undivided cell where oxygen was continuously bubbled over the cathodic surface.The experimental conditions affecting the current efficiency for the o-tolualdehyde production,such as H2SO4 concentration,current density,electrolytic temperature,reaction time,V5+ concentration,and surfactant CTAB,were determined.The results show that the maximum current efficiency for o-tolualdehyde production was 155.20%.The current efficiency remained ~150% even when the aqueous solution separated from the electrolysis mixture was recycled for four times.
A new approach to the "in-cell" indirect electrosynthesis of o-tolualdehyde from o-xylene is reported in this paper.In an aqueous sulfuric acid solution containing V5+ ions,o-xylene was directly eletro-oxidized to o-tolualdehyde in an undivided cell where oxygen was continuously bubbled over the cathodic surface.The experimental conditions affecting the current efficiency for the o-tolualdehyde production,such as H2SO4 concentration,current density,electrolytic temperature,reaction time,V5+ concentration,and surfactant CTAB,were determined.The results show that the maximum current efficiency for o-tolualdehyde production was 155.20%.The current efficiency remained ~150% even when the aqueous solution separated from the electrolysis mixture was recycled for four times.
2005, 22(10): 1132-1136
Abstract:
A series of waterborne polyurethane(WPU) emulsions with montmorillonite(MMT),toluene diisocyanate,dimethylolpropionic acid,γ-aminopropyltriethoxysilane and polyoxypropylene glycol etc.as the starting materials were prepared via the intercalative polymerization method.The X-ray diffraction and SEM results showed that the gallery distance of the montmorillonite was about 5.19 nmin the WPU matrix.Silane coupling agent and montmorillonite had mutual improvement effect for modifying the WPU.As 1%(mass fraction) MMT and 2%(mass fraction) coupling agent were introduced,compared with those of WPU without modification,the tensile strength and the elongation at break increased by 69.7% and 17.6%,respectively,and the water absorption rate decreased by 48.7%.
A series of waterborne polyurethane(WPU) emulsions with montmorillonite(MMT),toluene diisocyanate,dimethylolpropionic acid,γ-aminopropyltriethoxysilane and polyoxypropylene glycol etc.as the starting materials were prepared via the intercalative polymerization method.The X-ray diffraction and SEM results showed that the gallery distance of the montmorillonite was about 5.19 nmin the WPU matrix.Silane coupling agent and montmorillonite had mutual improvement effect for modifying the WPU.As 1%(mass fraction) MMT and 2%(mass fraction) coupling agent were introduced,compared with those of WPU without modification,the tensile strength and the elongation at break increased by 69.7% and 17.6%,respectively,and the water absorption rate decreased by 48.7%.
2005, 22(10): 1137-1140
Abstract:
A new type of ZnO/conjugated polymer(P) complex particles was successfully designed and prepared from the precursors PVC and ZnCl2,and used as a catalyst to decolorize dye methylene blue(MB).Under natural light and at room temperature,the catalytic activity of ZnO was dramatically enhanced by the modification with this P,and MB could be fully decolorized within 5 min.When m(ZnCl2):m(PVC) was about 3:1,the ZnO/P complex catalyst could be reused for 6 times with a high activity.The complex catalyst was also characterized by IR and UV-Vis techniques,and the results show that P was a conjugated polymer with active groups and linked to ZnO by Zn-O-C bond.The doping of P greatly extends the photo response region of ZnO.
A new type of ZnO/conjugated polymer(P) complex particles was successfully designed and prepared from the precursors PVC and ZnCl2,and used as a catalyst to decolorize dye methylene blue(MB).Under natural light and at room temperature,the catalytic activity of ZnO was dramatically enhanced by the modification with this P,and MB could be fully decolorized within 5 min.When m(ZnCl2):m(PVC) was about 3:1,the ZnO/P complex catalyst could be reused for 6 times with a high activity.The complex catalyst was also characterized by IR and UV-Vis techniques,and the results show that P was a conjugated polymer with active groups and linked to ZnO by Zn-O-C bond.The doping of P greatly extends the photo response region of ZnO.
2005, 22(10): 1141-1144
Abstract:
A series of polyurethane adhesives were prepared by using MDI-BDO as the hard-segment and PBA as the soft-segment.In order to control the crystallinity of the hard and soft segments,1,2-PG and PNA,which contain dissymmetrical and symmetrical side methyl groups respectively,were incorporated into the hard-segment and the soft-segment respectively.The influences of the changes of the soft-segment and the hard-segment structures and their contents on the crystallinity,micro-phase separation,mechanical properties and adhesive strength were studied by DSC,WAXD,and SEM.The results show that the introduction of PNA reduced the crystallinity of the soft-and the hard-segment simultaneously,and increased the micro-phase separation.The crystallinity and micro-phase separation of the hard-segments decreased upon the introduction of 1,2-PG,and the tensile strength decreased with the increased content of 1,2-PG;however,the adhesive strength increased from 16.8 N/cm to 18.1 N/cm.When the hard-segment content increased from 23% to 31%,the tensile strength of polyurethane adhesive was enhanced from 25.6 MPa to 37.1 MPa,but the elasticity declined.
A series of polyurethane adhesives were prepared by using MDI-BDO as the hard-segment and PBA as the soft-segment.In order to control the crystallinity of the hard and soft segments,1,2-PG and PNA,which contain dissymmetrical and symmetrical side methyl groups respectively,were incorporated into the hard-segment and the soft-segment respectively.The influences of the changes of the soft-segment and the hard-segment structures and their contents on the crystallinity,micro-phase separation,mechanical properties and adhesive strength were studied by DSC,WAXD,and SEM.The results show that the introduction of PNA reduced the crystallinity of the soft-and the hard-segment simultaneously,and increased the micro-phase separation.The crystallinity and micro-phase separation of the hard-segments decreased upon the introduction of 1,2-PG,and the tensile strength decreased with the increased content of 1,2-PG;however,the adhesive strength increased from 16.8 N/cm to 18.1 N/cm.When the hard-segment content increased from 23% to 31%,the tensile strength of polyurethane adhesive was enhanced from 25.6 MPa to 37.1 MPa,but the elasticity declined.
2005, 22(10): 1145-1148
Abstract:
A water soluble fluorescent monomer,4-methoxy-N-(2-N',N'-dimethylaminoethyl) naphthalimide allyl chloride quaternary ammonium salt was synthesized from 4-bromo-1,8-naphthalic anhydride and 2-dimethylaminoethylamine.The optimum reaction conditions were obtained by experiments.The structure of the product was characterized by IR,1H NMR,MS and elementary analysis.The optical properties of the product,such as ultraviolet-visible spectrum and fluorescent spectrum were determined and studied.
A water soluble fluorescent monomer,4-methoxy-N-(2-N',N'-dimethylaminoethyl) naphthalimide allyl chloride quaternary ammonium salt was synthesized from 4-bromo-1,8-naphthalic anhydride and 2-dimethylaminoethylamine.The optimum reaction conditions were obtained by experiments.The structure of the product was characterized by IR,1H NMR,MS and elementary analysis.The optical properties of the product,such as ultraviolet-visible spectrum and fluorescent spectrum were determined and studied.
2005, 22(10): 1149-1151
Abstract:
1-Chloro-3-(2'-ethoxyethoxy)-propane was prepared from 3-chloro-propanol and ethoxy-ethene with dichloroacetic acid as the catalyst and a yield of 96.2%.3-(2'-Ethoxyethoxy)propyl lithium was(then) synthesised from 1-chloro-3-(2'-ethoxyethoxy)-propane and lithium-sodium alloy in a high yield(86%) in a high vacuum reactor.It can be used as an anion polymerization initiator.
1-Chloro-3-(2'-ethoxyethoxy)-propane was prepared from 3-chloro-propanol and ethoxy-ethene with dichloroacetic acid as the catalyst and a yield of 96.2%.3-(2'-Ethoxyethoxy)propyl lithium was(then) synthesised from 1-chloro-3-(2'-ethoxyethoxy)-propane and lithium-sodium alloy in a high yield(86%) in a high vacuum reactor.It can be used as an anion polymerization initiator.
2005, 22(10): 1152-1154
Abstract:
The molecular structures,molecular weights,viscocities and moduli of thermal aged and thermal oxidative aged epoxidized natural rubber(ENR) were determined by means of FTIR,GPC and RPA.It was found that the decrease in the IR absorption intensity of the epoxy was more obvious than that of the C=C bond,and the molecular weight and the dynamic rheological behavior had changed.Mn and Mw were reduced respectively by 26% and 5% after thermal oxidative aging.After thermal aging,however,Mn was reduced by 2% only,and Mw increased by 6%.The molecular weight distribution broadened from 3.18 for ENR to 3.43 for the thermal aged ENR and 4.05 for the thermal oxidative aged ENR.The decrement of η* of the thermal aged ENR with rising shear rate was larger than that of the unaged ENR,but for the thermal oxidative ENR the decrement of η* was lower compared with the unaged ENR.G' of the thermal aged ENR decreased slightly and G' of the thermal oxidative aged ENR was obvious lower than that of the unaged ENR in the low frequency range.In the high frequency range,G' of the thermal aged ENR was larger than that of the unaged ENR,and G' of the thermal oxidative ENR increased to the same level as that of the unaged ENR.
The molecular structures,molecular weights,viscocities and moduli of thermal aged and thermal oxidative aged epoxidized natural rubber(ENR) were determined by means of FTIR,GPC and RPA.It was found that the decrease in the IR absorption intensity of the epoxy was more obvious than that of the C=C bond,and the molecular weight and the dynamic rheological behavior had changed.Mn and Mw were reduced respectively by 26% and 5% after thermal oxidative aging.After thermal aging,however,Mn was reduced by 2% only,and Mw increased by 6%.The molecular weight distribution broadened from 3.18 for ENR to 3.43 for the thermal aged ENR and 4.05 for the thermal oxidative aged ENR.The decrement of η* of the thermal aged ENR with rising shear rate was larger than that of the unaged ENR,but for the thermal oxidative ENR the decrement of η* was lower compared with the unaged ENR.G' of the thermal aged ENR decreased slightly and G' of the thermal oxidative aged ENR was obvious lower than that of the unaged ENR in the low frequency range.In the high frequency range,G' of the thermal aged ENR was larger than that of the unaged ENR,and G' of the thermal oxidative ENR increased to the same level as that of the unaged ENR.
2005, 22(10): 1155-1157
Abstract:
Complexation extraction of p-aminophenol(PAP) with bis(2-ethylhexyl)phosphoric acid(P204),tri-octylamine(TOA) or tri-butyl phosphate(TBP) was studied.The heat of reaction for each extraction was respectively-9.20 kJ/mol,-5.57 kJ/mol,-3.47 kJ/mol.FTIR analysis of the organic phases showed that the extraction mechanism depended on the complexing agent.Lewis acidic complexing agent P204 and Lewis alkaline complexing agent TOA with alkaline functional group -NH2 and acidic functional group -OH of PAP respectively form complexes via ionic association,and neutral complexing agents TBP and TOA with group -OH of PAP via hydrogenbond association.A relationship between the extraction reaction enthalpy and the extraction mechanism was found.
Complexation extraction of p-aminophenol(PAP) with bis(2-ethylhexyl)phosphoric acid(P204),tri-octylamine(TOA) or tri-butyl phosphate(TBP) was studied.The heat of reaction for each extraction was respectively-9.20 kJ/mol,-5.57 kJ/mol,-3.47 kJ/mol.FTIR analysis of the organic phases showed that the extraction mechanism depended on the complexing agent.Lewis acidic complexing agent P204 and Lewis alkaline complexing agent TOA with alkaline functional group -NH2 and acidic functional group -OH of PAP respectively form complexes via ionic association,and neutral complexing agents TBP and TOA with group -OH of PAP via hydrogenbond association.A relationship between the extraction reaction enthalpy and the extraction mechanism was found.
2005, 22(10): 1158-1160
Abstract:
The condensation reaction of 4-hydroxycoumarin with each of a~h substituted benzalacetones in absolute ethanol gave coumarin analogues which were subsequently converted to their ethyl ethers(cyclocou-marin).The ethers can be quantitatively converted back to the coumarin analogues by acid hydrolysis.Four of them are new substances.The reaction mechanism is discussed in detail.All the products were characterized by HPLC,IR and 1H NMR.Compared with the present process in the literature,the process for the synthesis of the coumarin analogues is obviously improved on the reaction time,temperature,solvent,catalyst,and post-treatment.
The condensation reaction of 4-hydroxycoumarin with each of a~h substituted benzalacetones in absolute ethanol gave coumarin analogues which were subsequently converted to their ethyl ethers(cyclocou-marin).The ethers can be quantitatively converted back to the coumarin analogues by acid hydrolysis.Four of them are new substances.The reaction mechanism is discussed in detail.All the products were characterized by HPLC,IR and 1H NMR.Compared with the present process in the literature,the process for the synthesis of the coumarin analogues is obviously improved on the reaction time,temperature,solvent,catalyst,and post-treatment.
