Synthesis and properties of novel cardo aromatic poly(ether‐benzoxazole)s

Three new bis(ether‐acyl chloride) monomers, 1,1‐bis[4‐(4‐chloroformylphenoxy)phenyl]cyclohexane ( 1a ), 5,5‐bis[4‐(4‐chloroformylphenoxy)phenyl]‐4,7‐methanohexahydroindan ( 1b ), and 9,9‐bis[4‐(4‐chloroformylphenoxy)phenyl]fluorene ( 1c ), were synthesized from readily available compounds. Aromatic polybenzoxazoles bearing ether and cardo groups were obtained by the low‐temperature solution polycondensation of the bis(ether‐acyl chloride)s with three bis(aminophenol)s and the subsequent thermal cyclodehydration of the resultant poly(o‐hydroxy amide)s. The intermediate poly(o‐hydroxy amide)s exhibited inherent viscosities in the range of 0.35–0.71 dL/g. All of the poly(o‐hydroxy amide)s were amorphous and soluble in many organic polar solvents, and most of them could afford flexible and tough films by solvent casting. The poly(o‐hydroxy amide)s exhibited glass‐transition temperatures (T_g's) in the range of 141–169 °C and could be thermally converted into the corresponding polybenzoxazoles approximately in the region of 240–350 °C, as indicated by the DSC thermograms. Flexible and tough films of polybenzoxazoles could be obtained by thermal cyclodehydration of the poly(o‐hydroxy amide) films. All the polybenzoxazoles were amorphous and showed an enhanced T_g but a dramatically decreased solubility as compared with their poly(o‐hydroxy amide) precursors. They exhibited T_g's of 215–272 °C by DSC and showed insignificant weight loss before 500 °C in nitrogen or air. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4014–4021, 2001     

Synthesis and properties of novel aromatic polyhydrazides and poly(amide–hydrazide)s based on the bis(ether benzoic acid)s from hydroquinone and substituted hydroquinones

4,4′‐(1,4‐Phenylenedioxy)dibenzoic acid as well as the 2‐methyl‐, 2‐tert‐butyl‐, or 2‐phenyl‐substituted derivatives of this dicarboxylic acid were synthesized in two main steps from p‐fluorobenzonitrile and hydroquinone or its methyl‐, tert‐butyl‐, or phenyl‐substituted derivatives. Polyhydrazides and poly(amide–hydrazide)s were prepared from these bis(ether benzoic acid)s or their diacyl chlorides with terephthalic dihydrazide, isophthalic dihydrazide, or p‐aminobenzoyl hydrazide by means of the phosphorylation reaction or low‐temperature solution polycondensation. Most of the hydrazide polymers and copolymers are amorphous and readily soluble in various polar solvents such as N‐methyl‐2‐pyrrolidone (NMP) and dimethyl sulfoxide. They could be solution‐cast into transparent, flexible, and tough films. These polyhydrazides and poly(amide–hydrazide)s had T_gs in the range of 167–237°C and could be thermally cyclodehydrated into the corresponding poly(1,3,4‐oxadiazole)s and poly(amide–1,3,4‐oxadiazole)s approximately in the region of 250–350°C, as evidenced by the DSC thermograms. All the tert‐butyl‐substituted oxadiazole polymers and those derived from isophthalic dihydrazide were organic soluble. The thermally converted oxadiazole polymers exhibited T_gs in the range of 208–243°C and did not show significant weight loss before 450°C either in nitrogen or in air. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1169–1181, 1999     

New rigid-rod poly(benzoxazole-imide)s containing chloro-substituted p-phenylene units in the main chain

A series of new poly(o-hydroxy amide-imide)s with high molecular weights were synthesized by low-temperature solution polycondensation from a preformed imide ring and chloro- or dichloro-substituted p-phenylene-containing diacid chlorides of 2,5-bis(trimellitimido)chlorobenzene or 1,4-bis(trimellitimido)-2,5-dichlorobenzene and three bis(o-amino phenol)s. All the poly(o-hydroxy amide-imide)s were readily soluble in a variety of organic solvents such as N-methyl-2-pyrrolidone and N,N-dimethylacetamide. Transparent and flexible films of these polymers were cast from their solutions. The cast films had tensile strengths ranging from 88 to 102 MPa and elongations at break of 8–12%. Subsequent thermal cyclodehydration of the poly(o-hydroxy amide-imide)s afforded novel poly(benzoxazole-imide)s. The poly(benzoxazole-imide)s exhibited glass-transition temperatures in the range of 310–338 °C and were stable up to 500 °C in nitrogen, with 10% weight-loss temperatures recorded between 550 and 570 °C in nitrogen. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4151–4158, 1999     

New poly(amide–imide)s syntheses. XXIII. Synthesis and properties of poly(amide–imide)s derived from 4,4′‐[1,4‐phenylenebis(isopropylidene‐1,4‐phenyleneoxy)]dianiline and various bis(trimellitimide)s

A series of poly(amide–imide)s III_a–m containing flexible isopropylidene and ether groups in the backbone were synthesized by the direct polycondensation of 4,4′‐[1,4‐phenylenebis(isopropylidene‐1,4‐phenyleneoxy)]dianiline (PIDA) with various bis(trimellitimide)s II_a–m in N‐methyl‐2‐pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. The resulting poly(amide–imide)s had inherent viscosities in the range of 0.80–1.36 dL/g. Except for those from the bis(trimellitimide)s of p‐phenylenediamine and benzidine, all the polymers could be cast from DMAc into transparent and tough films. They exhibited excellent solubility in polar solvents. The 10% weight loss temperatures of the polymers in air and in nitrogen were all above 495°C, and their T_g values were in the range of 201–252°C. Some properties of poly(amide–imide)s III were compared with those of the corresponding poly(amide–imide)s V prepared from the bis(trimellitimide) of diamine PIDA and various aromatic diamines. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 69–76, 1999     

Aromatic polybenzoxazoles containing ether–sulfone linkages

A series of poly(o‐hydroxy amide)s having both ether and sulfone linkages in the main chain were synthesized via the low‐temperature solution polycondensation of 4,4′‐[sulfonylbis(1,4‐phenylene)dioxy]dibenzoyl chloride and 4,4′‐[sulfonylbis(2,6‐dimethyl‐1,4‐phenylene)dioxy]dibenzoyl chloride with three bis(o‐aminophenol)s including 4,4′‐diamino‐3,3′‐dihydroxybiphenyl, 3,3′‐diamino‐4,4′‐dihydroxybiphenyl, and 2,2‐bis(3‐diamino‐4‐hydroxyphenyl)hexafluoropropane. Subsequent thermal cyclodehydration of the poly(o‐hydroxy amide)s afforded polyethersulfone benzoxazoles. Most of the poly(o‐hydroxy amide)s were soluble in polar organic solvents such as N‐methyl‐2‐pyrrolidone; however, the polybenzoxazoles without the hexafluoroisopropylidene group were organic‐insoluble. The polybenzoxazoles exhibited glass‐transition temperatures (T_g) in the range of 219–282 °C by DSC and softening temperatures (T_s) of 242–320 °C by thermomechanical analysis. Thermogravimetric analyses indicated that most polybenzoxazoles were stable up to 450 °C in air or nitrogen. The 10% weight loss temperatures were recorded in the ranges of 474–593 °C in air and 478–643 °C in nitrogen. The methyl‐substituted polybenzoxazoles had higher T_g's but lower T_s's and initial decomposition temperatures compared with the corresponding unsubstituted polybenzoxazoles. For a comparative purpose, the synthesis and characterization of a series of sulfonyl polybenzoxazoles without the ether group that derived from 4,4′‐sulfonyldibenzoyl chloride and bis(o‐aminophenol)s were also reported. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2262–2270, 2001     

Synthesis and properties of poly(ether imide)s based on the bis(ether anhydride)s from hydroquinone and its derivatives

Four bis(ether anhydride)s, 4,4′‐(1,4‐phenylenedioxy)diphthalic anhydride (IV), 4,4′‐(2,5‐tolylenedioxy)‐diphthalic anhydride (Me‐IV), 4,4′‐(2‐chloro‐1,4‐phenylenedioxy)diphthalic anhydride (Cl‐IV), and 4,4′‐(2,5‐biphenylenedioxy)diphthalic anhydride (Ph‐IV), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of 4‐nitrophthalonitrile with the potassium phenoxides of hydroquinone and various substituted hydroquinones such as methylhydroquinone, chlorohydroquinone, and phenylhydroquinone in N,N‐dimethylformamide, followed by alkaline hydrolysis and dehydration. Four series of poly(ether imide)s were prepared from bis(ether anhydride)s with various aromatic diamines by a classical two‐step procedure. The inherent viscosities of the intermediate poly(amic acid)s were in the range of 0.40–2.63 dL/g. Except for those derived from p‐phenylenediamine and benzidine, almost all the poly(amic acid)s could be solution‐cast and thermally converted into transparent, flexible, and tough polyimide films. Introduction of the chloro or phenyl substituent leads to a decreased crystallinity and an increased solubility of the polymers. The glass transition temperatures (T_g) of these polyimides were recorded in the range of 204–263°C. In general, the methyl‐ and chloro‐substituted polyimides exhibited relatively higher T_gs, whereas the phenyl‐substituted ones exhibited slightly lower T_gs compared to the corresponding nonsubstituted ones. Thermogravimetric analysis (TG) showed that 10% weight loss temperatures of all the polymers were above 500°C either in nitrogen or in air. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 665–675, 1999     

Syntheses and properties of new aromatic polybenzoxazoles bearing ether and phenylethylidene or 1‐phenyl‐2,2,2‐trifluoroethylidene linkages

Two new bis(ether acyl chloride)s, 1,1‐bis[4‐(4‐chloroformylphenoxy)phenyl]‐1‐phenylethane and 1,1‐bis[4‐(4‐chloroformylphenoxy)phenyl]‐1‐phenyl‐2,2,2‐trifluoroethane, were prepared from readily available reagents. Aromatic polybenzoxazoles with both ether and phenylethylidene or 1‐phenyl‐2,2,2‐trifluoroethylidene linkages between phenylene units were obtained by a conventional two‐step procedure including the low‐temperature solution polycondensation of the bis(ether acyl chloride)s with three bis(o‐aminophenol)s, yielding poly(o‐hydroxyamide) precursors, and subsequent thermal cyclodehydration. The intermediate poly(o‐hydroxyamide)s exhibited inherent viscosities of 0.39–0.98 dL/g. All of the poly(o‐hydroxyamide)s were amorphous and soluble in polar organic solvents such as N,N‐dimethylacetamide, and most of them could afford flexible and tough films via solvent casting. The poly(o‐hydroxyamide)s exhibited glass‐transition temperatures (T_g's) of 129–194 °C and could be thermally converted into corresponding polybenzoxazoles in the solid state at temperatures higher than 300 °C. All the polybenzoxazoles were amorphous and showed an enhanced T_g but a dramatically decreased solubility with to respect to their poly(o‐hydroxyamide) precursors. They exhibited T_g's of 216–236 °C through differential scanning calorimetry and were stable up to 500 °C in nitrogen or air, with 10% weight‐loss temperatures being recorded between 538 and 562 °C in nitrogen or air. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 914–921, 2003     

Synthesis and characterization of phthalazinone containing poly(arylene ether)s via a novel N–C coupling reaction

High‐molecular‐weight poly(phthalazinone)s with very high glass‐transition temperatures (T_g's) were synthesized via a novel N–C coupling reaction. New bisphthalazinone monomers ( 7a–e ) were synthesized from 2‐(4‐chlorobenzoyl) phthalic acid in two steps. Poly(phthalazinone)s, having inherent viscosities in the range of 0.34–0.91 dL/g, were prepared by the reaction of the bis(phthalazinone) monomers with an activated aryl halide in a dipolar aprotic solvent in the presence of potassium carbonate. The poly(phthalazinone)s exhibited T_g's greater than 230 °C. polymer 8b synthesized from diphenyl biphenol and bis(4‐flurophenyl) sulfone demonstrated the highest T_g of 297 °C. Thermal stabilities of the poly(phthalazinone)s were determined by thermogravimetric analysis. All the poly(phthalazinone)s showed a similar pattern of decomposition with no weight loss below 450 °C in nitrogen. The temperatures of 5% weight loss were observed to be about 500 °C. The poly(phthalazinone)s containing 4,4′‐isopropylidenediphenol and 4,4′‐(hexafluoroisopropylidene) diphenol and diphenyl ether linkage were soluble in chlorinated solvents such as chloroform. Other poly‐(phthalazinone)s were soluble in dipolar aprotic solvents such as N,N′‐dimethylacetamide. The soluble poly(phthalazinone)s can be cast as flexible films from solution. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2481–2490, 2003     

Synthesis and characterization of new fluorene‐based poly(ether imide)s

A novel bis(ether anhydride) monomer, 9,9‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]fluorene dianhydride (4), was synthesized from the nitrodisplacement of 4‐nitrophthalonitrile by the bisphenoxide ion of 9,9‐bis(4‐hydroxyphenyl)fluorene (1), followed by alkaline hydrolysis of the intermediate tetranitrile and dehydration of the resulting tetracarboxylic acid. A series of poly(ether imide)s bearing the fluorenylidene group were prepared from the bis(ether anhydride) 4 with various aromatic diamines 5a–i via a conventional two‐stage process that included ring‐opening polyaddition to form the poly(amic acid)s 6a–i followed by thermal cyclodehydration to the polyimides 7a–i. The intermediate poly(amic acid)s had inherent viscosities in the range of 0.39–1.57 dL/g and afforded flexible and tough films by solution‐casting. Except for those derived from p‐phenylenediamine, m‐phenylenediamine, and benzidine, all other poly(amic acid) films could be thermally transformed into flexible and tough polyimide films. The glass transition temperatures (T_g) of these poly(ether imide)s were recorded between 238–306°C with the help of differential scanning calorimetry (DSC), and the softening temperatures (T_s) determined by thermomechanical analysis (TMA) stayed in the range of 231–301°C. Decomposition temperatures for 10% weight loss all occurred above 540°C in an air or a nitrogen atmosphere. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1403–1412, 1999     

Synthesis and properties of poly(ether imide)s derived from 2,7-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride and various aromatic diamines

A naphthalene unit-containing bis(ether anhydride), 2,7-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride, was prepared in three steps starting from the nucleophilic nitrodisplacement reaction of 2,7-dihydroxynaphthalene and 4-nitrophthalonitrile in N,N-dimethylformamide (DMF) solution in the presence of potassium carbonate followed by alkaline hydrolysis of the intermediate bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). High-molar-mass aromatic poly(ether imide)s were synthesized using a conventional two-stage polymerization process from the bis(ether anhydride) and ten aromatic diamines. The intermediate poly(ether amic acid)s had inherent viscosities of 0.95–2.67 dL/g. The films of poly(ether imide)s derived from two rigid diamines, that is, p-phenylenediamine and benzidine, crystallized and embrittled during the thermal imidization process. The other poly(ether imide)s belonged to amorphous materials and could be fabricated into transparent, flexible, and tough films. These poly(ether imide) films had yield strengths of 91–115 MPa, tensile strengths of 89–136 MPa, elongation to break of 11–45%, and initial moduli of 1.7–2.2 GPa. The T_gs of poly(ether imide)s were recorded in the range of 222–256°C depending on the nature of the diamine moiety. All polymers were thermally stable up to 500°C, with 10% weight loss being recorded above 540°C in air and nitrogen atmospheres. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2281–2287, 1997     

Synthesis and properties of poly(ether imide)s derived from 2,6-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride and aromatic diamines

A new naphthalene unit-containing bis(ether anhydride), 2,6-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride, was synthesized in three steps starting from the nucleophilic nitrodisplacement reaction of 2,6-dihydroxynaphthalene and 4-nitrophthalonitrile in N,N-dimethylformamide (DMF) solution in the presence of potassium carbonate, followed by alkaline hydrolysis of the intermediate bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). High-molar-mass aromatic poly(ether imide)s were prepared using a conventional two-step polymerization process from the bis(ether anhydride) and various aromatic diamines. The intermediate poly(ether amic acid)s had inherent viscosities of 0.65–2.03 dL/g. The films of poly(ether imide)s derived from two rigid diamines, i.e. p-phenylenediamine and benzidine, crystallized during the thermal imidization process. The other poly(ether imide)s belonged to amorphous materials and could be fabricated into transparent, flexible, and tough films. These aromatic poly(ether imide) films had yield strengths of 104–131 MPa, tensile strengths of 102–153 MPa, elongation to break of 8–87%, and initial moduli of 1.6–3.2 GPa. The glass transition temperatures (T_g's) of poly(ether imide)s were recorded in the range of 220–277°C depending on the nature of the diamine moiety. All polymers were stable up to 500°C, with 10% weight loss being recorded above 550°C in both air and nitrogen atmospheres. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1657–1665, 1998     

Synthesis and characterization of aromatic poly(ether sulfone imide)s derived from sulfonyl bis(ether anhydride)s and aromatic diamines

Two sulfonyl group-containing bis(ether anhydride)s, 4,4′-[sulfonylbis(1,4-phenylene)dioxy]diphthalic anhydride ( IV ) and 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenylene)dioxy]diphthalic anhydride (Me- IV ), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of the bisphenolate ions of 4,4′-sulfonyldiphenol and 4,4′-sulfonylbis(2,6-dimethylphenol) with 4-nitrophthalonitrile in N,N-dimethylformamide (DMF). High-molar-mass aromatic poly(ether sulfone imide)s were synthesized via a conventional two-stage procedure from the bis(ether anhydride)s and various aromatic diamines. The inherent viscosities of the intermediate poly(ether sulfone amic acid)s were in the ranges of 0.30–0.47 dL/g for those from IV and 0.64–1.34 dL/g for those from Me- IV. After thermal imidization, the resulting two series of poly(ether sulfone imide)s had inherent viscosities of 0.25–0.49 and 0.39–1.19 dL/g, respectively. Most of the polyimides showed distinct glass transitions on their differential scanning calorimetry (DSC) curves, and their glass transition temperatures (T_g) were recorded between 223–253 and 252–288°C, respectively. The results of thermogravimetry (TG) revealed that all the poly(ether sulfone imide)s showed no significant weight loss before 400°C. The methyl-substituted polymers showed higher T_g's but lower initial decomposition temperatures and less solubility compared to the corresponding unsubstituted polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1649–1656, 1998     

Poly(arylene ether)s,poly(arylene thioether)s,and poly(arylene sulfone)s derived from a dihydroxy(imidoarylene) monomer

Novel poly(arylene ether)s, poly(arylene thioether)s, and poly(arylene sulfone)s were synthesized from the dihydroxy(imidoarylene) monomer 1 . The syntheses of poly(arylene ether)s were carried out in DMAc in the presence of anhydrous K₂CO₃ by a nucleophilic substitution reaction between the bisphenol and activated difluoro compounds. Poly(arylene thioether)s were synthesized according to the recently discovered one-pot polymerization reaction between a bis(N,N′-dimethyl-S-carbamate) and activated difluoro compounds in the presence of a mixture of Cs₂CO₃ and CaCO₃. The bis(N,N′-dimethyl-S-carbamate) 3 was synthesized by the thermal rearrangement reaction of bis(N,N′-dimethylthiocarbamate) 2 , which was synthesized from 1 by a phase-transfer catalyzed reaction. The poly(arylene thioether)s were further oxidized to form poly(arylene sulfone)s, which would be very difficult, if not impossible, to synthesize by other methods. All of the polymers described have extremely high T_gs and thermal stability as determined from DSC and TGA analysis. Poly(arylene sulfone)s have the highest T_gs and they are in the range of 298–361°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1201–1208, 1998     

Synthesis and characterization of poly(aryl amide imide)s derived from diphenyltrimellitic anhydride

The synthesis and characterization of a series of novel poly(aryl amide imide)s based on diphenyltrimellitic anhydride are described. The poly(aryl amide imide)s, having inherent viscosities of 0.39–1.43 dL/g in N-methyl-2-pyrrolidinone at 30°C, were prepared by polymerization with aromatic diamines in N,N-dimethylacetamide and subsequent chemical imidization. All the polymers were amorphous, readily soluble in aprotic polar solvents such as DMAC, NMP, dimethylsulfoxide, N,N-dimethylformamide, and m-cresol, and could be cast to form flexible and tough films. The glass transition temperatures were in the range of 284–366°C, and the temperatures for 5% weight loss in nitrogen were above 468°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4541–4545, 1999     

Synthesis and properties of polyimides,polyamides and poly(amide-imide)s from ether diamine having the spirobichroman structure

A novel spirobichroman unit containing dietheramine, 6,6′-bis(4-aminophenoxy)-4,4,4′,4′,7,7′-hexamethyl-2,2′-spirobichroman ( 3 ), was prepared by the nucleophilic substitution of 6,6′-dihydroxy-4,4,4′,4′,7,7′-hexamethyl-2,2′-spirobichroman with p-chloronitrobenzene in the presence of K₂CO₃ followed by hydrazine catalytic reduction of the intermediate dinitro compound. A series of polyimides were synthesized from diamine 3 and various aromatic dianhydrides by a conventional two-stage procedure through the formation of poly(amic-acid)s followed by thermal imidization. The intermediate poly(amic-acid)s had inherent viscosities of 1.00–2.78 dL/g. All the poly-(amic-acid)s could be thermally cyclodehydrated into flexible and tough polyimide films, and some polyimides were soluble in polar solvents such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), and N,N-dimethylformamide (DMF). These polyimides had glass transition temperatures (T_g) in the range of 236–256°C, and 10% weight loss occurred up to 450°C. Furthermore, a series of polyamides and poly(amide-imide)s with inherent viscosities of 0.71–2.29 dL/g were prepared by direct polycondensation of the diamine 3 with various aromatic dicarboxylic acids and imide ring-containing dicarboxylic acids by means of triphenyl phosphite and pyridine. All the polyamides and poly(amide-imide)s were readily soluble in polar solvents such as DMAc, and tough and flexible films could be cast from their DMAc solutions. These polymers had glass transition temperatures in the range of 137–228°C and 10% weight loss temperatures in the range of 419–443°C in air and 404–436°C in nitrogen, respectively. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1487–1497, 1997     

Synthesis of novel poly(thioether‐naphthalimide)s that utilize hydrazine as the diamine

A series of bis(4‐thio‐1,8‐naphthalic anhydride)s and the corresponding bis(N‐amino naphthalimide) derivatives were synthesized from readily available compounds in high yield. A series of novel poly(thioether‐naphthalimide)s, which utilized hydrazine as the diamine, were synthesized by a one‐step polymerization reaction in m‐cresol. Poly(thioether‐naphthalimide)s with inherent viscosities of 0.57–1.73 dL/g were obtained. The polymers were soluble in CHCl₃ and were determined to have high molecular weights by means of gel permeation chromatographic analysis. They were soluble in m‐cresol and could be cast into tough films from m‐cresol solution. The glass‐transition temperature (T_g) values of the polyimides ranged from 320 to 353 °C. Polyimides from the bisphenol dianhydride, derived from 9,9‐bis(4‐hydroxyphenyl)fluorene, did not show a clear transition in the DSC analysis. Degradation temperatures for 5% weight loss all occurred above 430 °C in nitrogen. The series of monomers were successfully copolymerized with each other. Monomers 6a and 7a , containing the bisphenol A moiety, could also be copolymerized with perylenetetracarboxylic dianhydride. These copolymers had high T_g's and were thermally stable. The UV–vis absorption properties of the polymers were also examined. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1040–1050, 2001     

Preparation and properties of new poly(amide‐imide)s based on 1,4‐bis(4‐trimellitimidophenoxy)naphthalene and aromatic diamines

A diimide dicarboxylic acid, 1,4‐bis(4‐trimellitimidophenoxy)naphthalene (1,4‐BTMPN), was prepared by condensation of 1,4‐bis(4‐aminophenoxy)naphthalene and trimellitic anhydride at a 1 : 2 molar ratio. A series of novel poly(amide‐imide)s (IIa–k) with inherent viscosities of 0.72 to 1.59 dL/g were prepared by triphenyl phosphite‐activated polycondensation from the diimide‐diacid 1,4‐BTMPN with various aromatic diamines (Ia–k) in a medium consisting of N‐methyl‐2‐pyrrolidinone (NMP), pyridine, and calcium chloride. The poly(amide‐imide)s showed good solubility in NMP, N,N‐dimethylacetamide, and N,N‐dimethylformamide. The thermal properties of the obtained poly(amide‐imide)s were examined with differential scanning calorimetry and thermogravimetry analysis. The synthesized poly(amide‐imide)s possessed glass‐transition temperatures in the range of 215 to 263°C. The poly(amide‐imide)s exhibited excellent thermal stabilities and had 10% weight losses at temperatures in the range of 538 to 569°C under a nitrogen atmosphere. A comparative study of some corresponding poly(amide‐imide)s also is presented. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1–8, 2000     

New light‐colored poly(ether imide)s based on 2,5‐di‐tert‐butylhydroquinone bis(ether anhydride) and aromatic diamines

A series of poly(ether imide)s (PEIs), III _a–k , with light color and good physical properties were prepared from 1,4‐bis(3,4‐dicarboxypheoxy)‐2,5‐di‐tert‐butylbenzene dianhydride ( I ) with various aromatic diamines ( II _a–k ) via a conventional two‐stage procedure that included a ring‐opening polyaddition to yield poly(amic acid)s (PAA), followed by thermal imidization to the PEI. The intermediate PAA had inherent viscosities in the range of 1.00–1.53 dL g^?1. Most of the PEIs showed excellent solubility in chlorinated solvents such as dichloromethane, chloroform, and m‐cresol, but did not easily dissolve in dimethyl sulfoxide and amide‐type polar solvents. The III series had tensile strengths of 96–116 MPa, an elongation at break of 7–8%, and initial moduli of 2.0–2.5 GPa. The glass‐transition temperatures (T_g) and softening temperatures (T_s's) of the III series were recorded between 232 and 285 °C and 216–279 °C, respectively. The decomposition temperatures for 10% weight loss all occurred above 511 °C in nitrogen and 487 °C in air. The III series showed low dielectric constants (2.71–3.54 at 1 MHz), low moisture absorption (0.18–0.66 wt %), and was light‐colored with a cutoff wavelength below 380 nm and a low yellow index (b^*) values of 7.3–14.8. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1270–1284, 2005     

Facile synthesis of soluble aromatic poly(amide amine)s via C–N coupling reaction: Characterization,thermal, and optical properties

Aromatic poly(amide amine)s (APAAs), as novel high‐performance polymers, have been obtained by the condensation polymerization of N,N'‐bis(4‐bromobenzoyl)‐p‐phenylenediamine with two different primary aromatic diamines via palladium‐catalyzed aryl amination reaction. The structures of the polymers are characterized by means of FTIR, ¹H NMR spectroscopy, and elemental analysis, the results show a good agreement with the proposed structures. DSC and TGA measurements exhibit that polymers possess high glass transition temperature (T_g > 240 °C) and good thermal stability with high decomposition temperatures (T₅ > 400 °C). These novel polymers also display good solubility. In addition, due to its special structure, APAA‐2 is endowed with significantly strong photonic luminescence in N,N‐dimethylformamide and good electroactivity. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4845–4852     

Synthesis and properties of new adamantane‐based poly(ether imide)s

A new adamantane‐based bis(ether anhydride), 2,2‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]adamantane dianhydride, was prepared in three steps starting from nitrodisplacement of 4‐nitrophthalonitrile with the potassium phenolate of 2,2‐bis(4‐hydroxyphenyl)adamantane. A series of adamantane‐containing poly(ether imide)s were prepared from the adamantane‐based bis(ether anhydride) and aromatic diamines by a conventional two‐stage synthesis in which the poly(ether amic acid)s obtained in the first stage were heated stage‐by‐stage at 150–270°C to give the poly(ether imide)s. The intermediate poly(ether amic acid)s had inherent viscosities between 0.56 and 1.92 dL/g. Except for those from p‐phenylenediamine, m‐phenylenediamine, and benzidine, all the poly(ether amic acid) films could be thermally converted into transparent, flexible, and tough poly(ether imide) films. All the poly(ether imide)s showed limited solubility in organic solvents, although they were amorphous in nature as evidenced by X‐ray diffractograms. Glass transition temperatures of these poly(ether imide)s were recorded in the range of 242–317°C by differential scanning calorimetry and of 270–322°C by dynamic mechanical analysis. They exhibited high resistance to thermal degrdation, with 10% weight loss temperatures being recorded between 514–538°C in nitrogen and 511–527°C in air. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1619–1628, 1999