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
A novel kind of aromatic diamine, N-（4-（4-（2,6-diphenyl pyridine-4-yl） phenoxy） phenyl）-3,5-diaminobezamide （DPDAB）, was synthesized via aromatic nucleophilic substitution of 3,5-dinitrobenzoylchloride with 4-...A novel kind of aromatic diamine, N-（4-（4-（2,6-diphenyl pyridine-4-yl） phenoxy） phenyl）-3,5-diaminobezamide （DPDAB）, was synthesized via aromatic nucleophilic substitution of 3,5-dinitrobenzoylchloride with 4-（4-（2,6- diphenylpyridine-4-yl）phenoxy）aniline （DPPA）, followed by palladium-catalyzed hydrazine reduction. This monomer was used to prepare polyimides （PIs） based on reaction with several commerically avaiable tetracarboxylic dianhydrides such as pyromellatic dianhydride （PMDA）, benzophenone tetracarboxylic acide dianhydride （BTDA） and bicycle [2.2.2] oct-7-ene- 2, 3,5,6-tetracarboxylic dianhydride （BCDA）. These PIs had inherent viscosity in the range of 0.34-0.76 dL/g and showed good solubility in various aprotic polar solvents. The glass-transition tempratures （Tgs） of the PIs were in the range of 184-302℃, and showed high thermal stability with 10% weight loss in the temperature range of 360-500℃ under nitrogen atmosphere.展开更多
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.
文摘A novel kind of aromatic diamine, N-（4-（4-（2,6-diphenyl pyridine-4-yl） phenoxy） phenyl）-3,5-diaminobezamide （DPDAB）, was synthesized via aromatic nucleophilic substitution of 3,5-dinitrobenzoylchloride with 4-（4-（2,6- diphenylpyridine-4-yl）phenoxy）aniline （DPPA）, followed by palladium-catalyzed hydrazine reduction. This monomer was used to prepare polyimides （PIs） based on reaction with several commerically avaiable tetracarboxylic dianhydrides such as pyromellatic dianhydride （PMDA）, benzophenone tetracarboxylic acide dianhydride （BTDA） and bicycle [2.2.2] oct-7-ene- 2, 3,5,6-tetracarboxylic dianhydride （BCDA）. These PIs had inherent viscosity in the range of 0.34-0.76 dL/g and showed good solubility in various aprotic polar solvents. The glass-transition tempratures （Tgs） of the PIs were in the range of 184-302℃, and showed high thermal stability with 10% weight loss in the temperature range of 360-500℃ under nitrogen atmosphere.
