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2001 Volume 18 Issue 2
2001, 18(2): 87-91
Abstract:
Recent developments in using supercritical carbon dioxide as a solvent for chemical reactions are reviewed.
Recent developments in using supercritical carbon dioxide as a solvent for chemical reactions are reviewed.
2001, 18(2): 92-95
Abstract:
Pyridazinone-carbamate derivatives 5a~5l were synthesized starting from 2-substituted-4,5-dichloro pyridazinones 1 via two routes. One is that 2-substituted-4-chloro-5-hydroxyl pyrida-zinones 2 reacted with U-bromoethyl carbamates to afford compounds 5a and 5b. The other is that 2-substituted-4-chloro-5-(2-amino ethyloxyl)pyridazinones 3 obtained from the reaction of 1 with amino ethanol, reacted with chloroformate to give 5a~5l. Furthermore, the catalytic hydrogenation of 3 gave 2-substituted-5-(2-amino ethyloxyl)pyridazinones 4, which reacted with chloromates to produce compounds 6a~6d at temperatures between -10~-5℃, and to N,N-dicarbamates 7a and 7b at 0~15℃. The reactivity of intermidiates 3 and 4 was also discussed. The preliminary bioassay indicated that almost all of the compounds showed fungicidal activities.
Pyridazinone-carbamate derivatives 5a~5l were synthesized starting from 2-substituted-4,5-dichloro pyridazinones 1 via two routes. One is that 2-substituted-4-chloro-5-hydroxyl pyrida-zinones 2 reacted with U-bromoethyl carbamates to afford compounds 5a and 5b. The other is that 2-substituted-4-chloro-5-(2-amino ethyloxyl)pyridazinones 3 obtained from the reaction of 1 with amino ethanol, reacted with chloroformate to give 5a~5l. Furthermore, the catalytic hydrogenation of 3 gave 2-substituted-5-(2-amino ethyloxyl)pyridazinones 4, which reacted with chloromates to produce compounds 6a~6d at temperatures between -10~-5℃, and to N,N-dicarbamates 7a and 7b at 0~15℃. The reactivity of intermidiates 3 and 4 was also discussed. The preliminary bioassay indicated that almost all of the compounds showed fungicidal activities.
2001, 18(2): 96-99
Abstract:
The nanophase LaCoyMn1-yO3(0≤y≤1) has been prepared by solid state reaction and characterized by XRD, TG/DTA, TEM and atomic absorption spectrometry. The results showed that the compound is of perovskite type and the crystals of some samples are distored, but not collapsed. The AC impedance and magnetic balance results indicated that when y=0.5 the compound has minimum value both in conductivity and magnetic susceptibility, which was interpreted in terms of minimum value of unpaired electron number of the compound at this condition.
The nanophase LaCoyMn1-yO3(0≤y≤1) has been prepared by solid state reaction and characterized by XRD, TG/DTA, TEM and atomic absorption spectrometry. The results showed that the compound is of perovskite type and the crystals of some samples are distored, but not collapsed. The AC impedance and magnetic balance results indicated that when y=0.5 the compound has minimum value both in conductivity and magnetic susceptibility, which was interpreted in terms of minimum value of unpaired electron number of the compound at this condition.
2001, 18(2): 100-103
Abstract:
Three new terephthalato-bridged binuclear chromium(Ⅲ) complexes with the formula[Cr2(TPHA)L4](NO3)4, where L stands for 4,4'-dimethyl-2,2'-bipyridine(Me2bpy); 2,9-dimethyl-1,10-phenanthroline(Me2 phen) and 5-chloro-1,10-phenanthroline(Clphen), repectively and TPHA respresents the terephthalate dianions, have been synthesized and characterized. Based on the elemental analyses, molar conductance and magnetic moments measurements, and spectroscopic studies, extended TPHA-bridged structures consisting of two chromium(Ⅲ) ions, each in an octahedral environment are proposed for these complexes. The variable temperature magnetic susceptibility of was determined at 4~300 K[Cr2(TPHA)(Me2 bpy)4](NO3)4 and the obtained data were simulated by the least square fitting and the equation based on the spin Hamiltonian operator,Ĥ=-2JŜ1Ŝ2, where the exchange integral J=-2.98 cm-1. The result indicates the presence of a weak antiferromagnetic spin-exchange interaction between the metal ions in the binuclear complex.
Three new terephthalato-bridged binuclear chromium(Ⅲ) complexes with the formula[Cr2(TPHA)L4](NO3)4, where L stands for 4,4'-dimethyl-2,2'-bipyridine(Me2bpy); 2,9-dimethyl-1,10-phenanthroline(Me2 phen) and 5-chloro-1,10-phenanthroline(Clphen), repectively and TPHA respresents the terephthalate dianions, have been synthesized and characterized. Based on the elemental analyses, molar conductance and magnetic moments measurements, and spectroscopic studies, extended TPHA-bridged structures consisting of two chromium(Ⅲ) ions, each in an octahedral environment are proposed for these complexes. The variable temperature magnetic susceptibility of was determined at 4~300 K[Cr2(TPHA)(Me2 bpy)4](NO3)4 and the obtained data were simulated by the least square fitting and the equation based on the spin Hamiltonian operator,Ĥ=-2JŜ1Ŝ2, where the exchange integral J=-2.98 cm-1. The result indicates the presence of a weak antiferromagnetic spin-exchange interaction between the metal ions in the binuclear complex.
2001, 18(2): 104-107
Abstract:
Chitosan was degraded by 60Co V-ray irradiation. The degradation kinetics, effect of irradiation on the degree of deacetylation(DE) of chitosan and the main chain scission mechanism have been studied. The results showed that the irradiation degradation of chitosan obeys the rule of random degradation. On irradiaton, DE was slightly raised and some of the C1-O-C4 bonds broke. Terminal groups with structure of W-lactone appeared produced during degradation.
Chitosan was degraded by 60Co V-ray irradiation. The degradation kinetics, effect of irradiation on the degree of deacetylation(DE) of chitosan and the main chain scission mechanism have been studied. The results showed that the irradiation degradation of chitosan obeys the rule of random degradation. On irradiaton, DE was slightly raised and some of the C1-O-C4 bonds broke. Terminal groups with structure of W-lactone appeared produced during degradation.
2001, 18(2): 108-111
Abstract:
Several spherical Ni(OH)2 electrode materials were prepared and characterized by XRD, Raman spectrometry and other experimental methods.The effects of apparent appearance, doping elements and microscopic structure of Ni(OH)2 samples on their charge-discharge performances were discussed. The results showed that the Ni(OH)2 electrodes had good filling and higher charge-discharge property and were characterized by a proper spheroidicity and crystallinity, small grain size and greater cell parameter c. In Raman spectra they gave characteristic peaks at 510 and 3596 cm-1 bands. The XRD and Raman spectrometry appeared an effective tools for evaluation of Ni(OH)2 electrode material.
Several spherical Ni(OH)2 electrode materials were prepared and characterized by XRD, Raman spectrometry and other experimental methods.The effects of apparent appearance, doping elements and microscopic structure of Ni(OH)2 samples on their charge-discharge performances were discussed. The results showed that the Ni(OH)2 electrodes had good filling and higher charge-discharge property and were characterized by a proper spheroidicity and crystallinity, small grain size and greater cell parameter c. In Raman spectra they gave characteristic peaks at 510 and 3596 cm-1 bands. The XRD and Raman spectrometry appeared an effective tools for evaluation of Ni(OH)2 electrode material.
2001, 18(2): 112-115
Abstract:
The crystallization and melting behavior of U-crystal phase in polypropylene(U-PP) with different molecular weight have been studied by DSC and WAXD techniques. All the four U-PP samples with different molecular weight have a common optimum crystallization temperature. The crystallization rate, relative content of U-crystal phase and the crystallinity of all PP samples were found in relation with the molecular weight of the polymer. With increase in molecular weight, the crystallization rate decreases, while the relative content of U-crystal phase and the crystallinity increase.
The crystallization and melting behavior of U-crystal phase in polypropylene(U-PP) with different molecular weight have been studied by DSC and WAXD techniques. All the four U-PP samples with different molecular weight have a common optimum crystallization temperature. The crystallization rate, relative content of U-crystal phase and the crystallinity of all PP samples were found in relation with the molecular weight of the polymer. With increase in molecular weight, the crystallization rate decreases, while the relative content of U-crystal phase and the crystallinity increase.
2001, 18(2): 116-119
Abstract:
The syndiospecific polymerization of styrene was carried out via U-diketonate titanium complex/MAO. The polymerization activity approached to 6.2×105 g/(mol·h) in reaction conditions:catalyst 4.3×10-4 mol/L, molar ratio of aluminum to titanium 500:1, 80℃ and 1 h. The melting temperature of the syndiotactic polystyrene was about 267℃. The effects of molar ratio of aluminum to titanium, concentration of U-diketonate titanium complex and temperature on polymerization were investigated. The polymer was characterized by 13C NMR and DSC. The thermal properties of the syndiotactic polystyrene were discussed.
The syndiospecific polymerization of styrene was carried out via U-diketonate titanium complex/MAO. The polymerization activity approached to 6.2×105 g/(mol·h) in reaction conditions:catalyst 4.3×10-4 mol/L, molar ratio of aluminum to titanium 500:1, 80℃ and 1 h. The melting temperature of the syndiotactic polystyrene was about 267℃. The effects of molar ratio of aluminum to titanium, concentration of U-diketonate titanium complex and temperature on polymerization were investigated. The polymer was characterized by 13C NMR and DSC. The thermal properties of the syndiotactic polystyrene were discussed.
2001, 18(2): 120-124
Abstract:
The properties of polyvinyl alcohol and formalized polyvinyl alcohol aqueous solution were studied and their behavior as a protective colloid for polyvinyl acetate emulsion, especially in freezing-thawing conditions were compared, including the function of graft degree of vinyl acetate on them. The results showed that polyvinyl formal was much preferable of polyvinyl alcohol in this respect. The mechanism of the modification was discussed.
The properties of polyvinyl alcohol and formalized polyvinyl alcohol aqueous solution were studied and their behavior as a protective colloid for polyvinyl acetate emulsion, especially in freezing-thawing conditions were compared, including the function of graft degree of vinyl acetate on them. The results showed that polyvinyl formal was much preferable of polyvinyl alcohol in this respect. The mechanism of the modification was discussed.
2001, 18(2): 125-127
Abstract:
The polymer-supported TiCl4 catalyst was synthesized and the catalytic features in the polymerization of ethylene and copolymerization of ethylene, propylene and butadiene in the presence of cocatalyst(Et3Al) were studied. The supported catalyst and obtained polymers were characterized by IR, DSC, elemental analysis and viscosity molecular weight measurements.
The polymer-supported TiCl4 catalyst was synthesized and the catalytic features in the polymerization of ethylene and copolymerization of ethylene, propylene and butadiene in the presence of cocatalyst(Et3Al) were studied. The supported catalyst and obtained polymers were characterized by IR, DSC, elemental analysis and viscosity molecular weight measurements.
2001, 18(2): 128-130
Abstract:
The substituted indenyl metallocene complexes (1-C6H5CH2 Ind)2 MCl2(M=Ti(1),Zr(2)) and (1-C6H5CH2 Ind)CpMCl2(M=Ti(3),Zr(4)) were synthesized and characterizd by IR、1H NMR, EI-MS and elemental analysis. It is found that the compounds(2) and (4) could be used for catalytic polymerization of ethylene in the presence of MAO with products of [M]Z=(31.4~39.5)×104.
The substituted indenyl metallocene complexes (1-C6H5CH2 Ind)2 MCl2(M=Ti(1),Zr(2)) and (1-C6H5CH2 Ind)CpMCl2(M=Ti(3),Zr(4)) were synthesized and characterizd by IR、1H NMR, EI-MS and elemental analysis. It is found that the compounds(2) and (4) could be used for catalytic polymerization of ethylene in the presence of MAO with products of [M]Z=(31.4~39.5)×104.
2001, 18(2): 131-133
Abstract:
The acrylic polymer emulsion incorporated with keto groups was prepared by conventional method using DAAM(diacetone-acrylamide) as a functional monomer. By mixing the product with polyurethane dispersion containing hydrazing group and hydrazine, separatively, the crosslinkable urethane/acrylate mixed polymer emulsion and the crosslinkable acrylic polymer emulsion were obtained. The crosslinking reaction and the microstructure of the crosslinkable emulsion were studied by FT IR and TEM observation. The film property of the crosslinkable emulsions was found to have a great improvement.
The acrylic polymer emulsion incorporated with keto groups was prepared by conventional method using DAAM(diacetone-acrylamide) as a functional monomer. By mixing the product with polyurethane dispersion containing hydrazing group and hydrazine, separatively, the crosslinkable urethane/acrylate mixed polymer emulsion and the crosslinkable acrylic polymer emulsion were obtained. The crosslinking reaction and the microstructure of the crosslinkable emulsion were studied by FT IR and TEM observation. The film property of the crosslinkable emulsions was found to have a great improvement.
2001, 18(2): 134-136
Abstract:
Eight novel bis(triphenyltin)unsaturated alkylphosphates were synthesized by the reacting corresponding triphenyltin chloride with disodium alkenyl or alkynylphosphates. Their structures were characterized by elemental analyses, IR,1H NMR,119Sn NMR and MS. The bioassay tests showed their high fungicidal activity.
Eight novel bis(triphenyltin)unsaturated alkylphosphates were synthesized by the reacting corresponding triphenyltin chloride with disodium alkenyl or alkynylphosphates. Their structures were characterized by elemental analyses, IR,1H NMR,119Sn NMR and MS. The bioassay tests showed their high fungicidal activity.
2001, 18(2): 137-139
Abstract:
Tungstophosphoric acid pillar double hydroxides with composition of M2Al-PW12[M=Zn2+,Co2+,Ni2+,Mg2+] have been synthesized and their catalytic activities for isobutane-butene alkylation were studied. The results showed that M2Al-PW12 had higher initial activity and selectivity of product, but lower deactivation rate than parent H3PW12 and the activity of the catalysts and selectivity in alkylation appeared in relation with the kinds of elements in double hydroxide.
Tungstophosphoric acid pillar double hydroxides with composition of M2Al-PW12[M=Zn2+,Co2+,Ni2+,Mg2+] have been synthesized and their catalytic activities for isobutane-butene alkylation were studied. The results showed that M2Al-PW12 had higher initial activity and selectivity of product, but lower deactivation rate than parent H3PW12 and the activity of the catalysts and selectivity in alkylation appeared in relation with the kinds of elements in double hydroxide.
2001, 18(2): 140-142
Abstract:
Mg/Al layered double hydroxide(LDH) was treated with stearic acid by a wet method. The modified double hydroxide showed good dispersion and floatation property with their layer structure being remained almost unchanged.
Mg/Al layered double hydroxide(LDH) was treated with stearic acid by a wet method. The modified double hydroxide showed good dispersion and floatation property with their layer structure being remained almost unchanged.
2001, 18(2): 143-145
Abstract:
The photo-electro-catalytic oxidation of methanol in acid solution on Pt-Ru modified and unmodified titanium dioxide film electrodes has been studied. The photo-catalysis current of the OTE/TiO2 electrode and photo-electro-catalysis current of the OTE/TiO2/Pt-Ru electrode both were three order of magnitude larger than that created by the common electrical oxidation. In addition, the effect of Pt-Ru on the current is described. The electrode sensitized by RuL2(NCS)2 showed a broader photoresponse spectral region.
The photo-electro-catalytic oxidation of methanol in acid solution on Pt-Ru modified and unmodified titanium dioxide film electrodes has been studied. The photo-catalysis current of the OTE/TiO2 electrode and photo-electro-catalysis current of the OTE/TiO2/Pt-Ru electrode both were three order of magnitude larger than that created by the common electrical oxidation. In addition, the effect of Pt-Ru on the current is described. The electrode sensitized by RuL2(NCS)2 showed a broader photoresponse spectral region.
2001, 18(2): 146-148
Abstract:
Eight metal cluster compounds have been synthesized from parent compound (_3-CPh)Co3-(CO)9 and triphenylphosphine(arsine,stibine,bismuthine). All the compounds were characterized by elemental analysis and IR spectrometry. They results showed that their catalytic activities for 1-butene hydroformylation and the yields of product both were higher than that of the parent compound in 97% and 20% more, respectively, at reaction conditions of 303.5 K, 0.392 MPa, and for 48 hours. The catalytic activities and the ratio of nor to iso by using PhCCo3(CO)7(APh3)m were increased with increase in the atomic numbers of element A(A=P,As,Sb,Bi).
Eight metal cluster compounds have been synthesized from parent compound (_3-CPh)Co3-(CO)9 and triphenylphosphine(arsine,stibine,bismuthine). All the compounds were characterized by elemental analysis and IR spectrometry. They results showed that their catalytic activities for 1-butene hydroformylation and the yields of product both were higher than that of the parent compound in 97% and 20% more, respectively, at reaction conditions of 303.5 K, 0.392 MPa, and for 48 hours. The catalytic activities and the ratio of nor to iso by using PhCCo3(CO)7(APh3)m were increased with increase in the atomic numbers of element A(A=P,As,Sb,Bi).
2001, 18(2): 149-151
Abstract:
The extraction behavior of Fe(Ⅲ), Cu(Ⅱ), Co(Ⅱ), Mn(Ⅱ), Pb(Ⅱ), Ni(Ⅱ) and Hg(Ⅱ) by microemulsion Triton X-100 (T-(4-(1,1,3,3-tetramethy(butyl)phenyl)-k-hydroxy)poly(oxy-1,2-ethanediyl) in the presence of (NH4)2SO4 and complexing agents were investigated. The results indicated that the complexes of Fe(Ⅲ) with aluminon were almost completely extracted in HAc-NaAc buffered microemulsion while Cu(Ⅱ), Co(Ⅱ), Cd(Ⅱ), Mn(Ⅱ) and Hg(Ⅱ) were not. Quantitative separation of Fe(Ⅲ), Co(Ⅱ) and Mn(Ⅱ) were realized. The extraction mechanism by O/W microemulsion has been discussed.
The extraction behavior of Fe(Ⅲ), Cu(Ⅱ), Co(Ⅱ), Mn(Ⅱ), Pb(Ⅱ), Ni(Ⅱ) and Hg(Ⅱ) by microemulsion Triton X-100 (T-(4-(1,1,3,3-tetramethy(butyl)phenyl)-k-hydroxy)poly(oxy-1,2-ethanediyl) in the presence of (NH4)2SO4 and complexing agents were investigated. The results indicated that the complexes of Fe(Ⅲ) with aluminon were almost completely extracted in HAc-NaAc buffered microemulsion while Cu(Ⅱ), Co(Ⅱ), Cd(Ⅱ), Mn(Ⅱ) and Hg(Ⅱ) were not. Quantitative separation of Fe(Ⅲ), Co(Ⅱ) and Mn(Ⅱ) were realized. The extraction mechanism by O/W microemulsion has been discussed.
2001, 18(2): 152-154
Abstract:
The reaction enthalpy of solid-solid coordination reaction of L-Leucine with copper acetate is determined by solution calorimetry in an isoperibel reaction calorimeter. The calorimetric solvent is the solution of hydrochloric acid(4 mol/L), a new thermochemical cycle is designed. The values of ΔfHmθ=15.64 kJ/mol, ΔfHmθ(trans-Cu(L-Leu)2,s)=-1194.7 kJ/mol are evalcated.
The reaction enthalpy of solid-solid coordination reaction of L-Leucine with copper acetate is determined by solution calorimetry in an isoperibel reaction calorimeter. The calorimetric solvent is the solution of hydrochloric acid(4 mol/L), a new thermochemical cycle is designed. The values of ΔfHmθ=15.64 kJ/mol, ΔfHmθ(trans-Cu(L-Leu)2,s)=-1194.7 kJ/mol are evalcated.
2001, 18(2): 155-157
Abstract:
The solubility variation of the phase system HCl-KCl-H2O at 25℃ is reported when θHK(interactions between two species with the same charge) and JHKCl(interactions among three species) are changed within ±10%. The calculated results indicate that the interactions among the three species are much stronger than that between the two species, whereas the combination of the two kinds of interactions result in great changes of the solubility of the system. This results is important for the salting out technology of the water-salt system.
The solubility variation of the phase system HCl-KCl-H2O at 25℃ is reported when θHK(interactions between two species with the same charge) and JHKCl(interactions among three species) are changed within ±10%. The calculated results indicate that the interactions among the three species are much stronger than that between the two species, whereas the combination of the two kinds of interactions result in great changes of the solubility of the system. This results is important for the salting out technology of the water-salt system.
2001, 18(2): 158-160
Abstract:
Three novel 8-alkyl pyrromethene-BF2 complexes have been synthesized. Their structures were confirmed by IR, MS,1H NMR and elemental analysis. Their spectral behavior have been discussed in terms of UV-Vis and fluorescence spectral results, which indicate compound 4b has a extremely high fluorescence quantum yield.
Three novel 8-alkyl pyrromethene-BF2 complexes have been synthesized. Their structures were confirmed by IR, MS,1H NMR and elemental analysis. Their spectral behavior have been discussed in terms of UV-Vis and fluorescence spectral results, which indicate compound 4b has a extremely high fluorescence quantum yield.
2001, 18(2): 161-162
Abstract:
The dinuclear complex[VO(L)]2(_-O)(H2 L=salicylaldehyde benzoylhydrazone) was synthesized and characterized by elemental analysis, IR, UV, cyclic voltammetry. The results showed that two oxygen atoms and one nitrogen atom of the tridentate hydrazone ligand are coordinated to vanadium(V) atom. The vanadium atom approximates to a distorted square pyramidal coordination sphere. The redox potentials of the title complex in different solvents follow the order:CH2Cl2< CH3CN< DMF.
The dinuclear complex[VO(L)]2(_-O)(H2 L=salicylaldehyde benzoylhydrazone) was synthesized and characterized by elemental analysis, IR, UV, cyclic voltammetry. The results showed that two oxygen atoms and one nitrogen atom of the tridentate hydrazone ligand are coordinated to vanadium(V) atom. The vanadium atom approximates to a distorted square pyramidal coordination sphere. The redox potentials of the title complex in different solvents follow the order:CH2Cl2< CH3CN< DMF.
2001, 18(2): 163-164
Abstract:
Hexachlorocyclotriphosphazene was prepared by reacting ammonium chloride and phosphorus pentachloride in an inert organic solvent at the presence of different metal compounds and pyridine. The conbination of MgCl2·6H2O with pyridine showed an ideal catalytic activity to give hexachlorocyclotriphosphazene in yield of 87% under the suitable conditions. The method is time saving.
Hexachlorocyclotriphosphazene was prepared by reacting ammonium chloride and phosphorus pentachloride in an inert organic solvent at the presence of different metal compounds and pyridine. The conbination of MgCl2·6H2O with pyridine showed an ideal catalytic activity to give hexachlorocyclotriphosphazene in yield of 87% under the suitable conditions. The method is time saving.
2001, 18(2): 165-166
Abstract:
The fisheyes and gels in blowing-extruted polypropylene(PP) films were investigated by GPC, FTIR, TGA and viscosimetry. It is concluded that the decomposition and thermal degradation of specimen during processing are responsible for the fisheyes, while gels are those specimens with larger molecular weight than surroundings.
The fisheyes and gels in blowing-extruted polypropylene(PP) films were investigated by GPC, FTIR, TGA and viscosimetry. It is concluded that the decomposition and thermal degradation of specimen during processing are responsible for the fisheyes, while gels are those specimens with larger molecular weight than surroundings.
2001, 18(2): 167-168
Abstract:
Pd-supported ZSM-5 zeolites prepared through ion exchange technique were used as a dehydrogenation catalyst for synthesis of o-phenylphenol from cyclohexanone. When Si/Al ratio in the catalyst was 85:1 or more, an obvious reduction in attenuation rate of catalyst activity was observed. When the Si/Al ratio was of 17:1 or less, polymer compounds could be formed on the surface of zeolite, that would decrease the dehydrogenation activity due to the reduction of the specific surface area of the catalyst.
Pd-supported ZSM-5 zeolites prepared through ion exchange technique were used as a dehydrogenation catalyst for synthesis of o-phenylphenol from cyclohexanone. When Si/Al ratio in the catalyst was 85:1 or more, an obvious reduction in attenuation rate of catalyst activity was observed. When the Si/Al ratio was of 17:1 or less, polymer compounds could be formed on the surface of zeolite, that would decrease the dehydrogenation activity due to the reduction of the specific surface area of the catalyst.
2001, 18(2): 169-170
Abstract:
The polyimide alignment layer containing trifluoro methyl moiety was synthesized. It is found that the imidization percentage reached 97.2% after one hour heating at 250℃ and the thermal decomposition temperature was 420℃. The high pretilt angles from 6.7~7.8° were acquired by changing the rubbing strength. STN liquid crystal cells with 240° twist angle were fabricated by using this kind of polyimide alignment material. After a series of reliability experiment at certain temperature and humidity, high temperature, low temperature and thermal impact, the power consumption currents of the cells changed little. All the results show that this kind of material is a good alignment material and can be used for STN liquid crystal display.
The polyimide alignment layer containing trifluoro methyl moiety was synthesized. It is found that the imidization percentage reached 97.2% after one hour heating at 250℃ and the thermal decomposition temperature was 420℃. The high pretilt angles from 6.7~7.8° were acquired by changing the rubbing strength. STN liquid crystal cells with 240° twist angle were fabricated by using this kind of polyimide alignment material. After a series of reliability experiment at certain temperature and humidity, high temperature, low temperature and thermal impact, the power consumption currents of the cells changed little. All the results show that this kind of material is a good alignment material and can be used for STN liquid crystal display.
2001, 18(2): 171-172
Abstract:
The title compound 3 was synthesized from diethylguanidine nitrate(2) obtained from diethylamine, CaCN2 and HNO3. The mixture consisted of 0.5 mol 2, 0.55 mol acetonyl propionate, 3 g benzyltriethylammonium chloride, and 44 g NaOH was refluxed for 4 hours to give 85 g 3, in yield 94.6%.
The title compound 3 was synthesized from diethylguanidine nitrate(2) obtained from diethylamine, CaCN2 and HNO3. The mixture consisted of 0.5 mol 2, 0.55 mol acetonyl propionate, 3 g benzyltriethylammonium chloride, and 44 g NaOH was refluxed for 4 hours to give 85 g 3, in yield 94.6%.
