Polyimides are well known for their high chemical and thermal stability. However, a few polyimide samples have been reported which are completely soluble in such environmentally friendly and common organic solvent as ...Polyimides are well known for their high chemical and thermal stability. However, a few polyimide samples have been reported which are completely soluble in such environmentally friendly and common organic solvent as propyleneglycol monomethyl ether acetate (PGMEA). In this work thermally stable, organosoluble and photocurable acidic polyimides were synthesized by simple and cost effective one-pot solution method. They polyimides obtained by this method showed much higher thermal stability (1 wt% loss temperature 345°C) than melt polymerized polyimides owing to the photocrosslinking reactions by the terminal double bonds.展开更多
A new kind of asymmetrical ether diamine,3,4'-bis(4-aminophenoxy)benzophenone(BABP),was synthesized from the nucleophilic substitution reaction of 4-chloronitrobenzene and 3,4'-dihydroxybenzophenone in the prese...A new kind of asymmetrical ether diamine,3,4'-bis(4-aminophenoxy)benzophenone(BABP),was synthesized from the nucleophilic substitution reaction of 4-chloronitrobenzene and 3,4'-dihydroxybenzophenone in the presence of potassium carbonate,followed by catalytic reduction with SnCl_2-6H_2O and concentrated hydrochloric acid.The prepared diamine was employed in the preparation of a novel polyimide containing asymmetrical diaryl ether segments via the polycondensation of it with BTDA by a two-step method.The resulting polyimide exhibits excellent solubility,film-forming capability and high thermal resistance.展开更多
A series organosoluble and heterocyclic poly(ether-amide)s (PEA)s were synthesized from a new diamine containing pyridine moiety and four aliphatic-aromatic dicarboxylic acids by direct polycondensation reactions....A series organosoluble and heterocyclic poly(ether-amide)s (PEA)s were synthesized from a new diamine containing pyridine moiety and four aliphatic-aromatic dicarboxylic acids by direct polycondensation reactions. Dicarboxilic acids 4a-4d containing ether groups were synthesized in two step reactions. At first, dialdehydes 3a-3d were synthesized from four dibromo alkanes la-ld and 4-hydroxybenzaldehyde 2, then dicarboxilic acids 4a-4d were synthesized from dialdehydes 3a-3d and malonic acid in a solvent free reaction. On the other hand, the new diamine 8 containing pyridine ring was synthesized in two step reactions. The structures of synthesized monomers and polymers were proven by FTIR, NMR spectroscopy and elemental analysis. Also all of the above polymers were fully characterized by inherent viscosity, solubility tests, gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The resulted PEAs have shown good inherent viscosities, solubility and thermal properties.展开更多
Six dicarboxylic acids 3a-3f were synthesized dianhydride 1 with L-aminoacids 2a-2f in a solution of glacial new poly(amide-imide)s PAIs were synthesized from by the reaction of 3,3',4,4'-benzophenonetetracarboxyl...Six dicarboxylic acids 3a-3f were synthesized dianhydride 1 with L-aminoacids 2a-2f in a solution of glacial new poly(amide-imide)s PAIs were synthesized from by the reaction of 3,3',4,4'-benzophenonetetracarboxylic acetic acid/pyridine (Py) at refluxing temperature. Then six the direct polycondensation reaction of [N,N'-(4,4'- carbonyldiphtaloyl)-bis-L-amino diacid]s with 1,5-bis(4-aminophenyl)penta-l,4-dien-3-one (APPD). The polymerization reactions produced a series of new optically active PAls with high yield and good inherent viscosity. Also these PAls are optically active and soluble in various organic solvents chromatography for the separation of enantiomeric mixtures. FTIR and 1H-NMR spectroscopy, elemental analyses, thermogravimetric analysis (TGA). These resulting new polymers can be used in column The resulted polymers were fully characterized by means of inherent viscosity measurements, solubility tests and展开更多
文摘Polyimides are well known for their high chemical and thermal stability. However, a few polyimide samples have been reported which are completely soluble in such environmentally friendly and common organic solvent as propyleneglycol monomethyl ether acetate (PGMEA). In this work thermally stable, organosoluble and photocurable acidic polyimides were synthesized by simple and cost effective one-pot solution method. They polyimides obtained by this method showed much higher thermal stability (1 wt% loss temperature 345°C) than melt polymerized polyimides owing to the photocrosslinking reactions by the terminal double bonds.
基金the financial support from the Natural Science Foundation of Gansu Province(No. 096RJZA047)the Fundamental Research Funds for the Central Universities(No.lzujbky-2011-24)
文摘A new kind of asymmetrical ether diamine,3,4'-bis(4-aminophenoxy)benzophenone(BABP),was synthesized from the nucleophilic substitution reaction of 4-chloronitrobenzene and 3,4'-dihydroxybenzophenone in the presence of potassium carbonate,followed by catalytic reduction with SnCl_2-6H_2O and concentrated hydrochloric acid.The prepared diamine was employed in the preparation of a novel polyimide containing asymmetrical diaryl ether segments via the polycondensation of it with BTDA by a two-step method.The resulting polyimide exhibits excellent solubility,film-forming capability and high thermal resistance.
文摘A series organosoluble and heterocyclic poly(ether-amide)s (PEA)s were synthesized from a new diamine containing pyridine moiety and four aliphatic-aromatic dicarboxylic acids by direct polycondensation reactions. Dicarboxilic acids 4a-4d containing ether groups were synthesized in two step reactions. At first, dialdehydes 3a-3d were synthesized from four dibromo alkanes la-ld and 4-hydroxybenzaldehyde 2, then dicarboxilic acids 4a-4d were synthesized from dialdehydes 3a-3d and malonic acid in a solvent free reaction. On the other hand, the new diamine 8 containing pyridine ring was synthesized in two step reactions. The structures of synthesized monomers and polymers were proven by FTIR, NMR spectroscopy and elemental analysis. Also all of the above polymers were fully characterized by inherent viscosity, solubility tests, gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The resulted PEAs have shown good inherent viscosities, solubility and thermal properties.
文摘Six dicarboxylic acids 3a-3f were synthesized dianhydride 1 with L-aminoacids 2a-2f in a solution of glacial new poly(amide-imide)s PAIs were synthesized from by the reaction of 3,3',4,4'-benzophenonetetracarboxylic acetic acid/pyridine (Py) at refluxing temperature. Then six the direct polycondensation reaction of [N,N'-(4,4'- carbonyldiphtaloyl)-bis-L-amino diacid]s with 1,5-bis(4-aminophenyl)penta-l,4-dien-3-one (APPD). The polymerization reactions produced a series of new optically active PAls with high yield and good inherent viscosity. Also these PAls are optically active and soluble in various organic solvents chromatography for the separation of enantiomeric mixtures. FTIR and 1H-NMR spectroscopy, elemental analyses, thermogravimetric analysis (TGA). These resulting new polymers can be used in column The resulted polymers were fully characterized by means of inherent viscosity measurements, solubility tests and