New unsymmetrical diamine monomer containing triaryl imidazole pendent group, 4-[4-（4,5-diphenyl-1H-imidazol-2-y1）phe- noxy]-1,3-benzenediamine, was synthesized via aromatic substitution reaction of 1-chloro-2,4-din...New unsymmetrical diamine monomer containing triaryl imidazole pendent group, 4-[4-（4,5-diphenyl-1H-imidazol-2-y1）phe- noxy]-1,3-benzenediamine, was synthesized via aromatic substitution reaction of 1-chloro-2,4-dinitrobenzene with 4-（4,5- diphenyl-1H-imidazol-2-y1）pbenol, followed by palladium-catalyzed hydrazine reduction. This new monomer was further confirmed by FT-IR, IH NMR and ^13C NMR. Novel polyamides having pendant triaryl imidazole group were prepared by the phosphorylation polycondensation of four commercially aromatic dicarboxylic acids with the prepared diamine. Inherent viscosities of polyamides were in the range 0.42-0.53 dL/g indicating formation of medium molecular weight polymers. Polyamides exhibited glass-transition temperature （Tg） in the range 236-265 ℃. These polymers are essentially amorphous and were soluble in polar aprotic solvents such as DMF, NMP, DMAc. The 10% weight loss temperatures in air atmosphere, measured by TGA were in the range 350-373 ℃ indicating their good thermal stabilities. ？2009 Mousa Ghaemy. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Hairpin pyrrole-imidazole(Py-Im) polyamides are a class of programmable minor-groove binders that recognize pre-determined DNA double helixes with high affinity and specificity. They are capable of regulating gene exp...Hairpin pyrrole-imidazole(Py-Im) polyamides are a class of programmable minor-groove binders that recognize pre-determined DNA double helixes with high affinity and specificity. They are capable of regulating gene expression by modulating the activity of transcription factors. To date, Py-Im polyamides have been successfully applied as a potent tool to disturb DNA functions and considered as a group of promising candidates for the clinical applications. Herein, this review will focus on summarizing the recent advances of Py-Im polyamides from their synthesis to applications via various modifications at the molecular level.展开更多
Three diamine monomers with different derivatives of imidazole heterocyclic ring, aryl ethers and electron withdrawing trifluoromethyl groups in the backbone were synthesized and used in polycodensation reaction with ...Three diamine monomers with different derivatives of imidazole heterocyclic ring, aryl ethers and electron withdrawing trifluoromethyl groups in the backbone were synthesized and used in polycodensation reaction with various aliphatic and aromatic dicarboxylic acids for preparation of a series of novel polyamides （PAs）. The PAs were obtained in high yields and possessed inherent viscosities in the range of 0.26-0.75 dL/g. All of the polymers were amorphous in nature, showed outstanding solubility and could be easily dissolved in amide-type polar aprotic solvents. They showed good thermal stability with glass transition temperatures between 162-302 ℃. Thermogravimetric analysis showed that all polymers were stable, with 10% weight loss recorded above 421 ℃in N2 atmospheres. All the PAs presented fluorescence upon irradiation with ultraviolet light and thus showed promise for applications in electroluminescent devices. The monomers and PAs were also screened for antibacterial activity against Gram positive and Gram negative bacteria.展开更多
An optically active bulky aromatic diacid chiral monomer, （2S）-4-[（4-methyl-2-phthalimidylpentanoylamino）benzoylamino]isophthalic acid （1）, containing a rigid phthalimide and flexible L-leucine pendent group was...An optically active bulky aromatic diacid chiral monomer, （2S）-4-[（4-methyl-2-phthalimidylpentanoylamino）benzoylamino]isophthalic acid （1）, containing a rigid phthalimide and flexible L-leucine pendent group was synthesized in five steps. A fast and clean method for direct polyamidation reaction of monomer 1 with various aromatic diamines under microwave irradiation and conventional heating was performed. The polymerization reactions provided optically active polyamides with high yields and inherent viscosities in the range of 0.36-0.74 dL/g. Their thermal properties were evaluated by thermogravimetric analysis （TGA） and differential scanning calorimetry. TGA thermograms show that the polymers are thermally stable, 10% weight loss temperatures are in excess of 385℃, and char yields at 800℃ are higher than 56%. The data obtained from TGA were used to study the kinetics of thermal decomposition of the resulting polymers. The interpretation of kinetic parameters （E, AH, AS and AG） of thermal decomposition stages was evaluated using Coats and Redfern equation.展开更多
The present work aimed to synthesize a new interesting series of thiazole based polyamides containing diarylidenecyclohexanone moiety 5a-5f using low temperature solution polycondensation technique. The new polymers w...The present work aimed to synthesize a new interesting series of thiazole based polyamides containing diarylidenecyclohexanone moiety 5a-5f using low temperature solution polycondensation technique. The new polymers were synthesized by the reaction of thiazole based monomer namely, bis（2-aminothiazol-4-ylbenzylidene）cyclohexanone 3 with different aliphatic and aromatic diacid chlorides using NMP, and in the presence of anhydrous Li Cl as catalyst. Adipoyl, sebacoyl, oxaloyl, terephthaloyl, isophthaloyl dichlorides and biphenyl dicarbonyl dichloride were used as diacid chlorides. The structure of the model compound 4 as well as the new polymers was confirmed by correct elemental and spectral analyses. The thermal properties of those polymers were evaluated by TGA and DTG measurements and correlated to their structural units, beside X-ray diffraction analysis, solubility and viscometry measurements. The inherent viscosities for the synthesized polymers were in the range 0.6–1.03 d L/g. On the other hand the corrosion inhibitive properties of monomer 3 as well as polyamides 5d and 5f as selected examples were carried out on carbon-steel in 0.5 mol/L H2SO4 at 40 °C. The calculated inhibition efficiency（IE%） for polymer 5d was in the range（82 ± 6）% in all selected concentrations. The best value of IE% was obtained at 1 mg/L to reach 98.24% for polymer 5d and at 0.5 mg/L to reach 87.75% for polymer 5f.展开更多
New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamid...New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamide（DPDAB）, and various aromatic and aliphatic dicarboxylic diacids in NMP using triphenyl phosphate（TPP） and pyridine as catalyst. The diamine and all the prepared polyamides were fully characterized by using FT-IR,~1H-NMR,UV-Vis spectroscopy, fluorimetry and elemental analysis.The inherent viscosity of polyamides ranged from 0.45 dL/g to 0.68 dL/g.All the polymers exhibited solubility in common polar aprotic solvents such as NMP,DMAc,DMF,DMSO,pyridine,HMPA,and even in less polar solvents such as THF and m-cresol at room temperature.Thermal properties of polyamides were evaluated by means of DSC,DMTA and TGA.These polymers showed glass transition temperatures（T_g） in the range of 138-210℃. Their initial decomposition temperature（T_i） varied from 265℃to 310℃under N_2.The dilute solution（0.2 g/dL） of polyamides in DMF exhibited fluorescence emission withλ_（max） in the range of 470-550 nm.展开更多
A novel unsymmetrical fluorinated diamine monomer with kink non-coplanar heterocyclic structures, 1,2-dihydro- 2-（4-amino-2-trifluoromethyophenyo）-4-[4-（4-amino-2-trifluoromethyophenoxy）phenyo]（2H）phthaoazin-1-o...A novel unsymmetrical fluorinated diamine monomer with kink non-coplanar heterocyclic structures, 1,2-dihydro- 2-（4-amino-2-trifluoromethyophenyo）-4-[4-（4-amino-2-trifluoromethyophenoxy）phenyo]（2H）phthaoazin-1-oneo was prepared through the nucleophilic substitution reaction of 1-trifluromethyl-2-chloro-5-nitrobenzene with 1,2-dihydro-4-（4- hydroxyphenyl）（2H）phthalazin-l-one in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd-C. A series of new fluorinated polyarnides were synthesized by the phosphorylation polyamidation of the fluorinated diamine with various dicarboxylic acids. The prepared polymers were obtained in quantitative yields with moderately and high inherent viscosities （0.47-0.87 dL/g）. They were all amorphous and readily soluble in various polar aprotic solvents such as N-methyl-2-pyrrolidone （NMP）, N,N-dimethylformamide （DMF）, N,N-dimethylacctamide （DMAc）, pyridine （Py） and m-cresol at room temperature. These fluorinated polyamides have excellent thermal properties. The glass transition temperatures were all above 300℃. The 5% and 10% weight loss temperatures were in the range of 437-466℃ and 482-525℃ in nitrogen atmosphere, respectively.展开更多
A new diamine containing sulfone,sulfide and amide groups was synthesized via a three-step reaction process. The nucleophilic substitution reaction of 4-aminothiophenol with 4-nitrobenzoyl chloride in the presence of ...A new diamine containing sulfone,sulfide and amide groups was synthesized via a three-step reaction process. The nucleophilic substitution reaction of 4-aminothiophenol with 4-nitrobenzoyl chloride in the presence of propylene oxide (PO) afforded N-(4-mercaptophenyl)-4-nitrobenzamide(MPNB).The catalytic reduction of the nitro group in MPNB to amino group was accomplished by using Pd/C and hydrazine monohydrate to produce 4-amino-N-(4-mercapto phenyl)benzamide(AMPB).Reaction of two moles of AMPB with bis(4-c...展开更多
A potential biodegradable and optically active bulky chiral aromatic amide-imidic diacid monomer,（2S,3S）-5-（3- methyl-2-phthalimidylpentanoylarnino）isophthalic acid（7）,containing a rigid phthalimide and flexible...A potential biodegradable and optically active bulky chiral aromatic amide-imidic diacid monomer,（2S,3S）-5-（3- methyl-2-phthalimidylpentanoylarnino）isophthalic acid（7）,containing a rigid phthalimide and flexible L-isoleucine pendant group was synthesized in three steps.New aromatic polyamides including pendant phthalimido groups and flexible side spacers have been synthesized by direct polycondensation reaction of equimolar amounts of different aromatic diamines with an optically active diacid 7,using N-methyl-2-pyrrolidone（NMP） as a solvent and triphenyl phosphite/CaCl_2/pyridine as a condensing agent.These polyamides were characterized by FTIR,~1H-NMR spectroscopy,specific rotation, thermogravimetric and elemental analysis.The resulting polymers have inherent viscosities in the range of 0.21-0.45 dL/g. Amino acid existence in this backbone results in optically active polymers.Due to introduction of bulky and flexible groups in these polyamides,they show improved solubility in polar aprotic solvents such as NMP and dimethylacetamide and also good thermal stability（10%weight loss temperatures in excess of 330℃,and char yields at 600℃in nitrogen higher than 62%）.展开更多
A series of dimer acid-based polyamides were synthesized by melt-polycondensation of dimer acid and various aromatic diamines, and were characterized by Fourier transform infrared spectrum （FT-IR） and nuclear magnet...A series of dimer acid-based polyamides were synthesized by melt-polycondensation of dimer acid and various aromatic diamines, and were characterized by Fourier transform infrared spectrum （FT-IR） and nuclear magnetic resonance （^1H NMR）. The physical properties of the polyamides, such as glass transition temperature, melting temperature, decomposition temperature and mechanical properties were also investigated. The polyamides＇ intrinsic viscosity ranges from 1.8 dL·g^-1 to 2.2 dL·g^-1, and the melting temperature ranges from 140 ℃ to 181 ℃. The glass transition temperatures, observed from dynamic mechanical analysis, fall in the range of 34.8-48.2 ℃. The physical and mechanical properties of the resultant polyamides are similar to those of the PA1212. The heat resistance and mechanical properties of poly （4, 4′-diphenylsulfone dimeramide） （PSD） and poly（4, 4′-di pb enyl dimeramide） （PPDI） are comparable to those of PA 1212.展开更多
A series of new Schiff base polyamides（PAs） were synthesized by polycondensation of benzilbisthiosemicarbazone diamine（LH6） with different commercially available aliphatic and aromatic diacid chlorides. The monome...A series of new Schiff base polyamides（PAs） were synthesized by polycondensation of benzilbisthiosemicarbazone diamine（LH6） with different commercially available aliphatic and aromatic diacid chlorides. The monomer and all the PAs were characterized by FTIR,^1H-NMR,and elemental analysis.The prepared polyamides showed inherent viscosities in the range of 0.30-0.36 dL/g in DMF at 25℃,indicating their moderate molecular weight.The PAs were completely soluble in aprotic polar solvents such as dimethylformamide（DMF）,N-methylpyrolidone（NMP）, tetrachloroethane（TCE）,dimthylsulfoxide（DMSO） and also in H_2SO_4 and partially soluble in THF,acetone and chloroform at room temperature.Thermal analysis showed that these PAs were practically amorphous and exhibited 10%weight loss above 220℃.展开更多
Aromatic/aliphatic polyamides were synthesized from a diamine monomer, 2,3-bis-p-aminophenylquinoxaline （IV）, based on quinoxaline and various dicarboxylic acids of aliphatic, aromatic and heterocyclic. The diamine ...Aromatic/aliphatic polyamides were synthesized from a diamine monomer, 2,3-bis-p-aminophenylquinoxaline （IV）, based on quinoxaline and various dicarboxylic acids of aliphatic, aromatic and heterocyclic. The diamine and polyamides were characterized by elemental analysis, FTIR and IH-NMR. The solubility of the polyamides was affected by the quinoxaline and heterocyclic groups in the polymer chain. They were all soluble in common organic solvents such as dimethylsulfoxide （DMSO）, N,N-dimethylformamide （DMF） and N-methylpyrolidone （NMP）. The polyamides showed inherent viscosity in the range of 0.25-0.3 dL/g in DMSO at 25℃ and good thermal stability with the char yields in the range of 65%-82% at 600℃ in nitrogen.展开更多
Aliphatic polyamides have been considered as eco-friendly materials,useful for a wide range of applications.However,it still presents obstacle to produce sustainable aliphatic polyamides from abundant renewable source...Aliphatic polyamides have been considered as eco-friendly materials,useful for a wide range of applications.However,it still presents obstacle to produce sustainable aliphatic polyamides from abundant renewable sources.Herein,we describe that 4-hydroxyproline(4-HYP),a renewable resource,was readily converted to its corresponding bicyclic bridged lactam monomers bearing pendant Boc-protected secondary amino group,and oligo-ethylene glycol group.Lithium hexamethyldisilazide(LiHMDS)-mediated polymerization of the resulting monomers exhibited a controlled feature,affording sustainable aliphatic polyamides with number-average molecular weight up to 73 kg/mol and a low molecular weight distribution?<1.28.Overall,this work can lead to a novel kind of functional and sustainable polyamides with potential applications,including degradable plastics,and drug delivery.展开更多
A series of novel mesogenic polyamides containing a flexible pendent side group was synthesized by solution condensation polymerization. The new monomers, diacids and diamines containing flexible elements of different...A series of novel mesogenic polyamides containing a flexible pendent side group was synthesized by solution condensation polymerization. The new monomers, diacids and diamines containing flexible elements of different lengths, were also synthesized and characterized by H-1 NMR, mass spectroscopy and elemental analysis. The polymers were characterized by viscosity measurements, differential scanning calorimetry (DSC), X-ray diffraction and polarizing optical microscopy. These studies revealed that polyamides containing flexible elements of a sufficient length exhibited thermotropic liquid crystalline (LC) properties. The melting temperatures of this series of polymers were: particularly sensitive to the length of the flexible segment on the main chain and that of the flexible pendent ester side chain. Lyotropic LC behaviours were also observed in solution.展开更多
A new synthetic route to polyamides and hydroxyl polyamides was established, based on the selecting (?)-acylation of three novel typical active diesters: the active diester of N-hydroxy- (?) 4-epoxy-5-cyclohexene-2, 3...A new synthetic route to polyamides and hydroxyl polyamides was established, based on the selecting (?)-acylation of three novel typical active diesters: the active diester of N-hydroxy- (?) 4-epoxy-5-cyclohexene-2, 3-dicarboximide( HOEC), such as N, N'-(temphthaloyldioxy) bis(1, 4- epoxy - 5 - cyclohexene- 2, 3 - dicarboximide.) ( PBOEC), N, N'- ( isophthaloyl - dioxy) bis (1,4-epoxy-5-cyclohexene-2, 3-dicarboximide)(IPBOEC) and N, N' -(adipoyldioxy) his (1,4-epoxy-5-cyclohexene-2, 3-dicarboximide) ( ADOEC)with aliphatic diamines and 1,3-diamino-2-hydroxypropane. The polycondensation occurs at room temperature in solution without added catalyst. Dipolar aprotic solvents which include dimethyl sulfoxide, N- methyl - 2- pyrrolidone and dimethylformamide were used as solvents for polymerization. The selective N-acylation of two active diesters was performed as a model reaction study.展开更多
A diamine containing ether and ester units, as basic monomer for the preparation of polyamides, was prepared via three consecutive reactions. Nucleophilic substitution reaction of 1,4-dihydroxy benzene with 4-nitroben...A diamine containing ether and ester units, as basic monomer for the preparation of polyamides, was prepared via three consecutive reactions. Nucleophilic substitution reaction of 1,4-dihydroxy benzene with 4-nitrobenzoyl chloride produced 4-hydroxyphenyl 4-nitrobenzoate （HPNB）. Reduction of nitro groups to amino groups using Fe and HC1 resulted in preparation of 4-hydroxyphenyl 4-aminobenzoate （HPAB）. The diamine was synthesized through nucleophilic substitution reaction of HPAB with 2,6-dichloropyridine. The precursors and diamine were fully characterized by common methods, and the diamine was polycondensed with different diacid chlorides in the presence of an acid scavenger to prepare new polyamides. The polyamides were characterized, and their physical properties including thermal stability and behavior, inherent viscosity and solubility were studied.展开更多
Long chain semiaromatic polyamides with high molecular weight were synthesized by the reactions of undecanediamine with various aromatic diacids,and characterized by fourier transform infrared spectra（FT-IR） and nuc...Long chain semiaromatic polyamides with high molecular weight were synthesized by the reactions of undecanediamine with various aromatic diacids,and characterized by fourier transform infrared spectra（FT-IR） and nuclear magnetic resonance（1H-NMR）.The thermal behaviors were determined by differential scanning calorimetry（DSC） and thermogravimetric analysis（TGA）.The solubility,dynamic mechanical,physical and mechanical properties of the polyamides were also investigated.The experimental results show that the polyamides with high molecular weights are obtained only the PH value of the polyamides salt are in the range of 7.2-7.4.The melting temperatures and the glass transition temperatures of the polyamides increase with the increase of the rigidity of aromatic diacids,and are near to those of poly（nonamethylenetere-phthalamide）（PA9T）.展开更多
Five new optically active polyamides （PAs） 6a-6e were prepared by direct polycondensation reaction of 2-（1,3- isoindolinedione-2-yl）-glutaric acid 4 as a new chiral diacid with various aromatic diamines 5a-Se in a...Five new optically active polyamides （PAs） 6a-6e were prepared by direct polycondensation reaction of 2-（1,3- isoindolinedione-2-yl）-glutaric acid 4 as a new chiral diacid with various aromatic diamines 5a-Se in a medium consisting of triphenyl phosphite （TPP）, calcium chloride, pyridine （Py） and N-methyl-2-pyrrolidone （NMP）. The polycondensation reaction produced a series of polyamids 6a-6e in quantitative yields with inherent viscosities of 0.26-0.39 dL/g. The resulting polymers were fully characterized by means of ^1H-NMR, FT-1R spectroscopy, elemental analysis, inherent viscosity and specific rotation. Thermal properties of these polymers were investigated using thermal gravimetric analysis （TGA） and differential thermal gravimetry （DTG）. Phthalimide rings as a bulky pendent group in the polymer chains disturb the interchain and intrachain interactions and make these PAs readily soluble in polar, aprotic solvents such as N,N-dimethyl acetamide （DMAc）, N,N-dimethyl formamide （DMF）, dimethyl sulfoxide （DMSO）, N-methyl-2-pyrrolidone （NMP） and sulfuric acid.展开更多
Long chain semiaromatic polyamides were synthesized by the reactions of decanediamine with various aromatic diacids and characterized by Fourier transform infrared spectroscopy （FT-IR） and nuclear magnetic resonance...Long chain semiaromatic polyamides were synthesized by the reactions of decanediamine with various aromatic diacids and characterized by Fourier transform infrared spectroscopy （FT-IR） and nuclear magnetic resonance （^1H-NMR）. The thermal behaviors were determined by differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA）. The solubility, dynamic mechanical, physical and mechanical properties of the polyamides have also been investigated. The resultant polyamides have intrinsic viscosity ranging from 1.7 dL/g to 2.1 dL/g. Their melting temperatures range from 305℃ to 343℃, and the glass transition temperatures fall in the range of 125-130℃. The tensile strength of the polyamides is above 100 MPa.展开更多
A novel aromatic diamine,2-（5-（3,5-diaminophenyl）-l,3,4-oxadiazole-2-yl）pyridine（POBD）,containing a pyridine ring and a 1,3,4-oxadiazole moiety,was synthesized.It was used in a polycondensation with various arom...A novel aromatic diamine,2-（5-（3,5-diaminophenyl）-l,3,4-oxadiazole-2-yl）pyridine（POBD）,containing a pyridine ring and a 1,3,4-oxadiazole moiety,was synthesized.It was used in a polycondensation with various aromatic and aliphatic diacid chlorides to generate a series of new aromatic polyamides with pendant 1,3,4-oxadiazole groups.The prepared polyamides were characterized by IR,elemental analysis and through the synthesis of model compounds.Thermophysical properties of the synthesized polyamides have been studied by DSC,TGA and inherent viscosity measurements. Relatively high inherent viscosity values（0.76-1.62 dL/g,in 0.125%H_2SO_4 at 25℃） were observed for these compounds. Number average molecular weight（M_n） of the polymers was measured by vapor phase osmometry（VPO）.The introduction of bulky side chains in the structure of aromatic polyamides led to increased solubility of these polymers in common polar and aprotic solvents,such as DMF,DMSO,NMP and DMAc,which allowed thin films to be cast from polymer solutions. The highest molecular weight（M_n = 51190） was observed for polymer（DC）,which was prepared from pyridine-2,6-dichlorocarbonyl.展开更多
文摘New unsymmetrical diamine monomer containing triaryl imidazole pendent group, 4-[4-（4,5-diphenyl-1H-imidazol-2-y1）phe- noxy]-1,3-benzenediamine, was synthesized via aromatic substitution reaction of 1-chloro-2,4-dinitrobenzene with 4-（4,5- diphenyl-1H-imidazol-2-y1）pbenol, followed by palladium-catalyzed hydrazine reduction. This new monomer was further confirmed by FT-IR, IH NMR and ^13C NMR. Novel polyamides having pendant triaryl imidazole group were prepared by the phosphorylation polycondensation of four commercially aromatic dicarboxylic acids with the prepared diamine. Inherent viscosities of polyamides were in the range 0.42-0.53 dL/g indicating formation of medium molecular weight polymers. Polyamides exhibited glass-transition temperature （Tg） in the range 236-265 ℃. These polymers are essentially amorphous and were soluble in polar aprotic solvents such as DMF, NMP, DMAc. The 10% weight loss temperatures in air atmosphere, measured by TGA were in the range 350-373 ℃ indicating their good thermal stabilities. ？2009 Mousa Ghaemy. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金supported by the Shenzhen Sciences & Technology Innovation Council (Nos. GJHS20170314154409805, GJHS20160331195142827, GJHS20150417103343317, JCYJ201708 1815358196, JCYJ20150401150223649 and JCYJ20170413165 916608)the National Natural Science Foundation of China (Nos. 21672254, 21778068, 21502219 and 21432003)
文摘Hairpin pyrrole-imidazole(Py-Im) polyamides are a class of programmable minor-groove binders that recognize pre-determined DNA double helixes with high affinity and specificity. They are capable of regulating gene expression by modulating the activity of transcription factors. To date, Py-Im polyamides have been successfully applied as a potent tool to disturb DNA functions and considered as a group of promising candidates for the clinical applications. Herein, this review will focus on summarizing the recent advances of Py-Im polyamides from their synthesis to applications via various modifications at the molecular level.
基金partially financially supported by the Research Affairs Division of University of Kurdistan(UOK),Sanandaj(Iran)
文摘Three diamine monomers with different derivatives of imidazole heterocyclic ring, aryl ethers and electron withdrawing trifluoromethyl groups in the backbone were synthesized and used in polycodensation reaction with various aliphatic and aromatic dicarboxylic acids for preparation of a series of novel polyamides （PAs）. The PAs were obtained in high yields and possessed inherent viscosities in the range of 0.26-0.75 dL/g. All of the polymers were amorphous in nature, showed outstanding solubility and could be easily dissolved in amide-type polar aprotic solvents. They showed good thermal stability with glass transition temperatures between 162-302 ℃. Thermogravimetric analysis showed that all polymers were stable, with 10% weight loss recorded above 421 ℃in N2 atmospheres. All the PAs presented fluorescence upon irradiation with ultraviolet light and thus showed promise for applications in electroluminescent devices. The monomers and PAs were also screened for antibacterial activity against Gram positive and Gram negative bacteria.
基金supported by the Research Affairs Division Isfahan University of Technology(IUT),IsfahanNational Elite Foundation(NEF) and Center of Excellency in Sensors and Green Chemistry Research(IUT).
文摘An optically active bulky aromatic diacid chiral monomer, （2S）-4-[（4-methyl-2-phthalimidylpentanoylamino）benzoylamino]isophthalic acid （1）, containing a rigid phthalimide and flexible L-leucine pendent group was synthesized in five steps. A fast and clean method for direct polyamidation reaction of monomer 1 with various aromatic diamines under microwave irradiation and conventional heating was performed. The polymerization reactions provided optically active polyamides with high yields and inherent viscosities in the range of 0.36-0.74 dL/g. Their thermal properties were evaluated by thermogravimetric analysis （TGA） and differential scanning calorimetry. TGA thermograms show that the polymers are thermally stable, 10% weight loss temperatures are in excess of 385℃, and char yields at 800℃ are higher than 56%. The data obtained from TGA were used to study the kinetics of thermal decomposition of the resulting polymers. The interpretation of kinetic parameters （E, AH, AS and AG） of thermal decomposition stages was evaluated using Coats and Redfern equation.
文摘The present work aimed to synthesize a new interesting series of thiazole based polyamides containing diarylidenecyclohexanone moiety 5a-5f using low temperature solution polycondensation technique. The new polymers were synthesized by the reaction of thiazole based monomer namely, bis（2-aminothiazol-4-ylbenzylidene）cyclohexanone 3 with different aliphatic and aromatic diacid chlorides using NMP, and in the presence of anhydrous Li Cl as catalyst. Adipoyl, sebacoyl, oxaloyl, terephthaloyl, isophthaloyl dichlorides and biphenyl dicarbonyl dichloride were used as diacid chlorides. The structure of the model compound 4 as well as the new polymers was confirmed by correct elemental and spectral analyses. The thermal properties of those polymers were evaluated by TGA and DTG measurements and correlated to their structural units, beside X-ray diffraction analysis, solubility and viscometry measurements. The inherent viscosities for the synthesized polymers were in the range 0.6–1.03 d L/g. On the other hand the corrosion inhibitive properties of monomer 3 as well as polyamides 5d and 5f as selected examples were carried out on carbon-steel in 0.5 mol/L H2SO4 at 40 °C. The calculated inhibition efficiency（IE%） for polymer 5d was in the range（82 ± 6）% in all selected concentrations. The best value of IE% was obtained at 1 mg/L to reach 98.24% for polymer 5d and at 0.5 mg/L to reach 87.75% for polymer 5f.
文摘New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamide（DPDAB）, and various aromatic and aliphatic dicarboxylic diacids in NMP using triphenyl phosphate（TPP） and pyridine as catalyst. The diamine and all the prepared polyamides were fully characterized by using FT-IR,~1H-NMR,UV-Vis spectroscopy, fluorimetry and elemental analysis.The inherent viscosity of polyamides ranged from 0.45 dL/g to 0.68 dL/g.All the polymers exhibited solubility in common polar aprotic solvents such as NMP,DMAc,DMF,DMSO,pyridine,HMPA,and even in less polar solvents such as THF and m-cresol at room temperature.Thermal properties of polyamides were evaluated by means of DSC,DMTA and TGA.These polymers showed glass transition temperatures（T_g） in the range of 138-210℃. Their initial decomposition temperature（T_i） varied from 265℃to 310℃under N_2.The dilute solution（0.2 g/dL） of polyamides in DMF exhibited fluorescence emission withλ_（max） in the range of 470-550 nm.
基金This work was financially supported by the National Natural Science Foundation of China (No. 50673031)the Key Natural Science Foundation of Fujian Province (No. E0320003)State Key Laboratory of Polymer Physics and Chemistry in Institute of Chemistry of CAS (No. 200602).
文摘A novel unsymmetrical fluorinated diamine monomer with kink non-coplanar heterocyclic structures, 1,2-dihydro- 2-（4-amino-2-trifluoromethyophenyo）-4-[4-（4-amino-2-trifluoromethyophenoxy）phenyo]（2H）phthaoazin-1-oneo was prepared through the nucleophilic substitution reaction of 1-trifluromethyl-2-chloro-5-nitrobenzene with 1,2-dihydro-4-（4- hydroxyphenyl）（2H）phthalazin-l-one in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd-C. A series of new fluorinated polyarnides were synthesized by the phosphorylation polyamidation of the fluorinated diamine with various dicarboxylic acids. The prepared polymers were obtained in quantitative yields with moderately and high inherent viscosities （0.47-0.87 dL/g）. They were all amorphous and readily soluble in various polar aprotic solvents such as N-methyl-2-pyrrolidone （NMP）, N,N-dimethylformamide （DMF）, N,N-dimethylacctamide （DMAc）, pyridine （Py） and m-cresol at room temperature. These fluorinated polyamides have excellent thermal properties. The glass transition temperatures were all above 300℃. The 5% and 10% weight loss temperatures were in the range of 437-466℃ and 482-525℃ in nitrogen atmosphere, respectively.
文摘A new diamine containing sulfone,sulfide and amide groups was synthesized via a three-step reaction process. The nucleophilic substitution reaction of 4-aminothiophenol with 4-nitrobenzoyl chloride in the presence of propylene oxide (PO) afforded N-(4-mercaptophenyl)-4-nitrobenzamide(MPNB).The catalytic reduction of the nitro group in MPNB to amino group was accomplished by using Pd/C and hydrazine monohydrate to produce 4-amino-N-(4-mercapto phenyl)benzamide(AMPB).Reaction of two moles of AMPB with bis(4-c...
基金supported by the Research Affairs Division Isfahan University of Technology(IUT),IsfahanNational Elite Foundation(NEF) Center of Excellency in Sensors and Green Chemistry Research(IUT)
文摘A potential biodegradable and optically active bulky chiral aromatic amide-imidic diacid monomer,（2S,3S）-5-（3- methyl-2-phthalimidylpentanoylarnino）isophthalic acid（7）,containing a rigid phthalimide and flexible L-isoleucine pendant group was synthesized in three steps.New aromatic polyamides including pendant phthalimido groups and flexible side spacers have been synthesized by direct polycondensation reaction of equimolar amounts of different aromatic diamines with an optically active diacid 7,using N-methyl-2-pyrrolidone（NMP） as a solvent and triphenyl phosphite/CaCl_2/pyridine as a condensing agent.These polyamides were characterized by FTIR,~1H-NMR spectroscopy,specific rotation, thermogravimetric and elemental analysis.The resulting polymers have inherent viscosities in the range of 0.21-0.45 dL/g. Amino acid existence in this backbone results in optically active polymers.Due to introduction of bulky and flexible groups in these polyamides,they show improved solubility in polar aprotic solvents such as NMP and dimethylacetamide and also good thermal stability（10%weight loss temperatures in excess of 330℃,and char yields at 600℃in nitrogen higher than 62%）.
文摘A series of dimer acid-based polyamides were synthesized by melt-polycondensation of dimer acid and various aromatic diamines, and were characterized by Fourier transform infrared spectrum （FT-IR） and nuclear magnetic resonance （^1H NMR）. The physical properties of the polyamides, such as glass transition temperature, melting temperature, decomposition temperature and mechanical properties were also investigated. The polyamides＇ intrinsic viscosity ranges from 1.8 dL·g^-1 to 2.2 dL·g^-1, and the melting temperature ranges from 140 ℃ to 181 ℃. The glass transition temperatures, observed from dynamic mechanical analysis, fall in the range of 34.8-48.2 ℃. The physical and mechanical properties of the resultant polyamides are similar to those of the PA1212. The heat resistance and mechanical properties of poly （4, 4′-diphenylsulfone dimeramide） （PSD） and poly（4, 4′-di pb enyl dimeramide） （PPDI） are comparable to those of PA 1212.
文摘A series of new Schiff base polyamides（PAs） were synthesized by polycondensation of benzilbisthiosemicarbazone diamine（LH6） with different commercially available aliphatic and aromatic diacid chlorides. The monomer and all the PAs were characterized by FTIR,^1H-NMR,and elemental analysis.The prepared polyamides showed inherent viscosities in the range of 0.30-0.36 dL/g in DMF at 25℃,indicating their moderate molecular weight.The PAs were completely soluble in aprotic polar solvents such as dimethylformamide（DMF）,N-methylpyrolidone（NMP）, tetrachloroethane（TCE）,dimthylsulfoxide（DMSO） and also in H_2SO_4 and partially soluble in THF,acetone and chloroform at room temperature.Thermal analysis showed that these PAs were practically amorphous and exhibited 10%weight loss above 220℃.
文摘Aromatic/aliphatic polyamides were synthesized from a diamine monomer, 2,3-bis-p-aminophenylquinoxaline （IV）, based on quinoxaline and various dicarboxylic acids of aliphatic, aromatic and heterocyclic. The diamine and polyamides were characterized by elemental analysis, FTIR and IH-NMR. The solubility of the polyamides was affected by the quinoxaline and heterocyclic groups in the polymer chain. They were all soluble in common organic solvents such as dimethylsulfoxide （DMSO）, N,N-dimethylformamide （DMF） and N-methylpyrolidone （NMP）. The polyamides showed inherent viscosity in the range of 0.25-0.3 dL/g in DMSO at 25℃ and good thermal stability with the char yields in the range of 65%-82% at 600℃ in nitrogen.
基金financially supported by the National Natural Science Foundation of China(Nos.U21A2089 and 51873211)。
文摘Aliphatic polyamides have been considered as eco-friendly materials,useful for a wide range of applications.However,it still presents obstacle to produce sustainable aliphatic polyamides from abundant renewable sources.Herein,we describe that 4-hydroxyproline(4-HYP),a renewable resource,was readily converted to its corresponding bicyclic bridged lactam monomers bearing pendant Boc-protected secondary amino group,and oligo-ethylene glycol group.Lithium hexamethyldisilazide(LiHMDS)-mediated polymerization of the resulting monomers exhibited a controlled feature,affording sustainable aliphatic polyamides with number-average molecular weight up to 73 kg/mol and a low molecular weight distribution?<1.28.Overall,this work can lead to a novel kind of functional and sustainable polyamides with potential applications,including degradable plastics,and drug delivery.
基金This work is supported by the National Natural Science Foundation of China
文摘A series of novel mesogenic polyamides containing a flexible pendent side group was synthesized by solution condensation polymerization. The new monomers, diacids and diamines containing flexible elements of different lengths, were also synthesized and characterized by H-1 NMR, mass spectroscopy and elemental analysis. The polymers were characterized by viscosity measurements, differential scanning calorimetry (DSC), X-ray diffraction and polarizing optical microscopy. These studies revealed that polyamides containing flexible elements of a sufficient length exhibited thermotropic liquid crystalline (LC) properties. The melting temperatures of this series of polymers were: particularly sensitive to the length of the flexible segment on the main chain and that of the flexible pendent ester side chain. Lyotropic LC behaviours were also observed in solution.
文摘A new synthetic route to polyamides and hydroxyl polyamides was established, based on the selecting (?)-acylation of three novel typical active diesters: the active diester of N-hydroxy- (?) 4-epoxy-5-cyclohexene-2, 3-dicarboximide( HOEC), such as N, N'-(temphthaloyldioxy) bis(1, 4- epoxy - 5 - cyclohexene- 2, 3 - dicarboximide.) ( PBOEC), N, N'- ( isophthaloyl - dioxy) bis (1,4-epoxy-5-cyclohexene-2, 3-dicarboximide)(IPBOEC) and N, N' -(adipoyldioxy) his (1,4-epoxy-5-cyclohexene-2, 3-dicarboximide) ( ADOEC)with aliphatic diamines and 1,3-diamino-2-hydroxypropane. The polycondensation occurs at room temperature in solution without added catalyst. Dipolar aprotic solvents which include dimethyl sulfoxide, N- methyl - 2- pyrrolidone and dimethylformamide were used as solvents for polymerization. The selective N-acylation of two active diesters was performed as a model reaction study.
文摘A diamine containing ether and ester units, as basic monomer for the preparation of polyamides, was prepared via three consecutive reactions. Nucleophilic substitution reaction of 1,4-dihydroxy benzene with 4-nitrobenzoyl chloride produced 4-hydroxyphenyl 4-nitrobenzoate （HPNB）. Reduction of nitro groups to amino groups using Fe and HC1 resulted in preparation of 4-hydroxyphenyl 4-aminobenzoate （HPAB）. The diamine was synthesized through nucleophilic substitution reaction of HPAB with 2,6-dichloropyridine. The precursors and diamine were fully characterized by common methods, and the diamine was polycondensed with different diacid chlorides in the presence of an acid scavenger to prepare new polyamides. The polyamides were characterized, and their physical properties including thermal stability and behavior, inherent viscosity and solubility were studied.
文摘Long chain semiaromatic polyamides with high molecular weight were synthesized by the reactions of undecanediamine with various aromatic diacids,and characterized by fourier transform infrared spectra（FT-IR） and nuclear magnetic resonance（1H-NMR）.The thermal behaviors were determined by differential scanning calorimetry（DSC） and thermogravimetric analysis（TGA）.The solubility,dynamic mechanical,physical and mechanical properties of the polyamides were also investigated.The experimental results show that the polyamides with high molecular weights are obtained only the PH value of the polyamides salt are in the range of 7.2-7.4.The melting temperatures and the glass transition temperatures of the polyamides increase with the increase of the rigidity of aromatic diacids,and are near to those of poly（nonamethylenetere-phthalamide）（PA9T）.
文摘Five new optically active polyamides （PAs） 6a-6e were prepared by direct polycondensation reaction of 2-（1,3- isoindolinedione-2-yl）-glutaric acid 4 as a new chiral diacid with various aromatic diamines 5a-Se in a medium consisting of triphenyl phosphite （TPP）, calcium chloride, pyridine （Py） and N-methyl-2-pyrrolidone （NMP）. The polycondensation reaction produced a series of polyamids 6a-6e in quantitative yields with inherent viscosities of 0.26-0.39 dL/g. The resulting polymers were fully characterized by means of ^1H-NMR, FT-1R spectroscopy, elemental analysis, inherent viscosity and specific rotation. Thermal properties of these polymers were investigated using thermal gravimetric analysis （TGA） and differential thermal gravimetry （DTG）. Phthalimide rings as a bulky pendent group in the polymer chains disturb the interchain and intrachain interactions and make these PAs readily soluble in polar, aprotic solvents such as N,N-dimethyl acetamide （DMAc）, N,N-dimethyl formamide （DMF）, dimethyl sulfoxide （DMSO）, N-methyl-2-pyrrolidone （NMP） and sulfuric acid.
文摘Long chain semiaromatic polyamides were synthesized by the reactions of decanediamine with various aromatic diacids and characterized by Fourier transform infrared spectroscopy （FT-IR） and nuclear magnetic resonance （^1H-NMR）. The thermal behaviors were determined by differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA）. The solubility, dynamic mechanical, physical and mechanical properties of the polyamides have also been investigated. The resultant polyamides have intrinsic viscosity ranging from 1.7 dL/g to 2.1 dL/g. Their melting temperatures range from 305℃ to 343℃, and the glass transition temperatures fall in the range of 125-130℃. The tensile strength of the polyamides is above 100 MPa.
基金financially supported by the Graduate Council of the University of Mohaghegh Ardabili(Iran)
文摘A novel aromatic diamine,2-（5-（3,5-diaminophenyl）-l,3,4-oxadiazole-2-yl）pyridine（POBD）,containing a pyridine ring and a 1,3,4-oxadiazole moiety,was synthesized.It was used in a polycondensation with various aromatic and aliphatic diacid chlorides to generate a series of new aromatic polyamides with pendant 1,3,4-oxadiazole groups.The prepared polyamides were characterized by IR,elemental analysis and through the synthesis of model compounds.Thermophysical properties of the synthesized polyamides have been studied by DSC,TGA and inherent viscosity measurements. Relatively high inherent viscosity values（0.76-1.62 dL/g,in 0.125%H_2SO_4 at 25℃） were observed for these compounds. Number average molecular weight（M_n） of the polymers was measured by vapor phase osmometry（VPO）.The introduction of bulky side chains in the structure of aromatic polyamides led to increased solubility of these polymers in common polar and aprotic solvents,such as DMF,DMSO,NMP and DMAc,which allowed thin films to be cast from polymer solutions. The highest molecular weight（M_n = 51190） was observed for polymer（DC）,which was prepared from pyridine-2,6-dichlorocarbonyl.
