Synthesis of new diacid monomers and poly(amide-imide)s: study of structure–property relationship and applications

Two diimide-diacid monomers 4,4′-bis[4″-(trimellitimido)phenyl isopropylidene-4″′-phenoxy]diphenyl sulfone and 4,4′-bis[4″-(trimellitimido)phenylisopropylidene-4″′-phenoxy] were synthesized. The structures of the monomers were characterized by FT-IR and ¹H-NMR spectroscopy. A series of novel poly(amide-imide)s were prepared from this two diacids and aromatic diamines through phosphorylation reaction. The PAIs were characterized by FT-IR, ¹H-NMR, XRD, TGA, and DSC, solution viscosity, solubility test and electrical properties. Poly(amide-imide)s showed excellent solubility due to the presence of flexible groups and isopropylidene unit in the polymer backbone. They also exhibited good thermal stability and the temperatures at which 10% weight loss occurred in the range 385–465 °C. These PAIs found to have a dielectric constant in the range 3.25–4.20 at 10 kHz and have excellent electrical insulation character and can be used as insulation materials for electrical items operating at elevated temperatures.     

Synthesis and properties of new poly(amide-imide)s based on 2,5-bis(trimellitimido)toluene

Summary A series of new aromatic poly(amide-imide)s were synthesized by the triphenyl phosphite activated polycondensation of the diimide-diacid, 2,5-bis(trimellitimido)toluene (I) with various aromatic diamines. The poly(amide-imide)s had inherent viscosities of 0.69–1.89 dL/g. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents. Transparent, flexible, and tough films of these polymers could be cast from DMAc or NMP solutions. Their cast films had tensile strengths ranging from 76 to 112 MPa, elongations at break from 8 to 31%, and initial moduli from 2.20 to 2.99 GPa. The glass transition temperatures of these polymers were in the range of 253–328°C. Received: 25 September 1998/Revised version: 2 December 1998/Accepted: 8 December 1998     

Synthesis and characterization of new organo-soluble poly(amide-imide)s based on 1,4-bis(trimellitimido)-2,5-dimethylbenzene

Summary A series of new aromatic poly(amide-imide)s were synthesized by the triphenyl phosphite activated polycondensation of the diimide-diacid, 1,4-bis(trimellitimido)-2,5-dimethylbenzene (I), with various aromatic diamines. The poly(amide-imide)s had inherent viscosities of 1.13–2.22 dL/g. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents. Transparent, flexible, and tough films of these polymers could be cast from DMAc or NMP solutions. Their cast films had tensile strengths ranging from 64 to 116 MPa, elongations at break from 6 to 20%, and initial moduli from 2.18 to 3.90 GPa. The glass transition temperatures of these polymers were in the range of 247–324°C. Received: 13 April 1999/Revised version: 28 May 1999/Accepted: 26 June 1999     

Synthesis and properties of flourine-containing polyimides

A series of new flourine-containing polyimides have been synthesized from the condensation of 2,2,-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-amino-phenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, or 2,2bis[4-(4-amino-2-trifluoro-methylphenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane with various aromatic dianhydrides. The electric constant at 1 KHz in the flourine-containing polyimides decreases from 3.51 to 2.72 as flourine content increases. The poly(amic acid)s had inherit viscosities of 0.52–1.23 dL/g, depending on the diamines and dianhydrides. Most of the resulting polymers showed an amorphous nature and afforded flexible and tough films. The amount of moisture absorption decreases as flourine content in polyimides increases. The glass transition temperatures of these polyimides were in the range of 287–328°C, and the 10% weight loss temperatures were above 542°C in the nitrogen. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 609–617, 1997     

Synthesis and properties of poly(amide-imide)s based on 1,5-bis(4-trimellitimido)naphthalene

1,5-Bis(4-trimellitimido)naphthalene (II) was prepared by the condensation reaction of 1,5-naphthalenediamine and trimellitic anhydride. A series of aromatic poly(amide-imide)s (IV _a–o) was synthesized by the direct polycondensation of the diimide-diacid (II) and various aromatic diamines (III _a–o). The reaction utilized triphenyl phosphite and pyridine as condensing agents in the presence of calcium chloride in N-methyl-2-pyrrolidone (NMP). The inherent viscosities of the resulting poly(amide-imide)s were in the range of 0.55∼1.39 dL/g. These polymers were generally soluble in polar solvents, such as N,N-dimethylacetamide (DMAc), NMP, N,N-dimethylformamide (DMF). Flexible and tough poly(amide-imide) films were obtained by casting from a DMAc solution and had tensile strengths of 90∼145 MPa, elongations to break of 5∼13 %, and initial moduli of 2.29∼3.73 GPa. The glass transition temperatures of some poly(amide-imide)s were recorded in the range of 206∼218 °C, and most of the polymers did not show discernible glass transition on their DSC traces. The 10% weight loss temperatures were above 522 °C in nitrogen and above 474 °C in air atmosphere.     

Organosoluble, Low-Colored Fluorinated Polyimides Based on 1,1-Bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane

A novel trifluoromethyl-substituted bis(ether amine) monomer, 1,1-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane, was synthesized that led to a series of novel fluorinated polyimides via chemical imidization route when reacted with various commercially available aromatic tetracarboxylic dianhydrides. These polyimides were highly soluble in a variety of organic solvents such as N-methyl-2-pyrrolidone and N,N -dimethylacetamide, and most of them could afford transparent, low-colored, and tough films. These polyimides exhibited glass-transition temperatures (T _gs) of 227–269 °C and showed no significant decomposition below 500 °C under either nitrogen or air atmosphere. These polyimides had low dielectric constants of 2.87–3.17 at 10 kHz, low water uptake of 0.13%–0.58%, and an ultraviolet-visible absorption cutoff wavelength at 364–410 nm. For a comparative study, a series of analogous polyimides based on 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane were also prepared and characterized.     

Synthesis and Properties of Noncoplanar Rigid-rod Aromatic Polyamides Containing Phenyl or Naphthyl Substituents

A series of novel aromatic polyamides having noncoplanar biphenylene units in the main chain and bulky naphthyl or phenyl pendant group at 2,2′-disubstituted position were prepared from the two rigid-rod aromatic dicarboxylic acid monomers, 2,2′-diphenylbiphenyl-4,4′-dicarboxylic acid (1) and 2,2′-dinaphthylbiphenyl-4,4′-dicarboxylic acid (2), and various aromatic diamines. These polyamides were readily soluble in many organic solvents and showed excellent thermal stability associated with high glass-transition temperatures in the range of 229–292°C. These polymers also exhibited strong UV–Vis absorption bands at 262–353 nm in NMP solution, and their photoluminescence spectra showed maximum bands at 440–462 nm in the purple to blue region. The poly(amine–amide) IId derived from the diamine with triphenylamine moieties revealed excellent electrochromic contrast and coloration efficiency, changing color from the pale yellowish neutral form to green then to the blue oxidized forms when scanning potentials positively from 0.00 to 1.30 V. Figure Graphical Abstract. A series of novel aromatic polyamides having noncoplanar biphenylene units in the main chain and bulky naphthyl or phenyl pendant group at 2,2′-disubstituted position were prepared from the two dicarboxylic acids and various aromatic diamines. These polyamides were readily soluble in many organic solvents and showed excellent thermal stability associated with high glass-transition temperatures in the range of 229–292°C. These polymers also exhibited strong UV–Vis absorption bands at 262–353 nm in NMP solution, and their photoluminescence spectra showed maximum bands at 440–462 nm in the purple to blue region. The poly(amine–amide) IId derived from the diamine with triphenylamine moieties revealed excellent electrochromic contrast and coloration efficiency, changing color from the pale yellowish neutral form to green then to the blue oxidized forms when scanning potentials positively from 0.00 to 1.30 V.     

Synthesis and characterization of new soluble cardo poly(amide-imide)s derived from 2,2-bis[4-(4-trimellitimidophenoxy)phenyl]norbornane

A series of new soluble poly(amide-imide)s were prepared from the diimide-dicarboxylic acid, 2,2-bis[4-(4-trimellitimidophenoxy)phenyl]norbornane, and various diamines by the direct polycondensation in N-methyl-2-pyrrolidinone containing CaCl_2, using triphenyl phosphite and pyridine as condensing agents. All the polymers were obtained in quantitative yields with inherent viscosities of 1.01-1.42 dL g⁻¹. Gel permeation chromatography (GPC) of the polymers showed number-average and weight-average molecular weight up to 67,300 and 118,000, respectively. The poly(amide-imide)s were amorphous and were readily soluble in various solvents such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), pyridine, cyclohexanone and tetrahydrofuran. Tough and flexible films were obtained by casting their DMAc solution. The films had tensile strength of 89-110 MPa and a tensile modulus range of 1.8-2.2 GPa. The glass transition temperatures of the polymers were determined by DSC method and they were in the range of 265-295 °C. The polymers were fairly stable up to a temperature around or above 450 °C, and lose 10% weight in the range of 472-504 °C and 490-520 °C in nitrogen and air, respectively.     

Synthesis and characterization of polyimides based on isopropylidene-containing bis(ether anhydride)s

Two bis(ether anhydride)s, 4,4′-[1,4-phenylenebis(isopropylidene-1,4-phenyleneoxy)]-diphthalic anhydride (IV _a) and 4,4′-[isopropylidenebis(1,4-phenylene)dioxy]diphthalic anhydride (IV _b), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of 4-nitrophthalonitrile with α,α ′-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene (I _a) and 4,4′-isopropylidenediphenol (I _b) in N,N-dimethylformamide (DMF) in the presence of potassium carbonate. The bis(ether anhydride)s IV _a and IV _b were polymerized with various aromatic diamines to obtain two series of poly(ether amic acid)s VI _a–g and VII _a–g with inherent viscosities in the range of 0.30∼0.74 and 0.29∼1.01 dL/g, respectively. The poly(ether amic acid)s were converted to poly(ether imide)s VIII _a–g and IX _a–g by thermal cyclodehydration. Most of the poly(ether imide)s could afford flexible and tough films, and they showed high solubility in polar solvents such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide, and m-cresol. The obtained poly(ether imide) films had tensile strengths of 45∼83 MPa, elongations-to-break of 6∼27%, and initial modulus of 0.6∼1.7 GPa. The T_gs of poly(ether imide)s VIII _a–g and IX _a–g were in the range of 194∼210 and 204∼243 °C, respectively. Thermogravimetric analysis (TG) showed that 10% weight loss temperatures of all the polymers were above 500 °C in both air and nitrogen atomspheres.     

Synthesis and characterization of new optically active poly(amide-imide)s containing 1,3,4-oxadiazole moiety in the main chain

Six new optically active poly(amide-imide)s were synthesized by poly condensation reaction of 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole (8) with six chiral N,N′-(bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic)-bis-l-amino acids (3a–f) in a medium consisting of N-methyl-2-pyrrolidone (NMP), triphenylphosphite (TPP), calcium chloride (CaCl₂), and pyridine. Chiral N,N′-(bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic)-bis-l-amino acids (3a–f) were obtained by the reaction of bicyclo[2.2.2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (1) with two equimolar of l-alanine (2a), l-valine (2b), l-leucine (2c), l-isoleucine (2d), l-phenyl alanine (2e), and l-2-aminobutyric acid (2f) in acetic acid. The poly condensation reaction produced a series of novel poly(amide-imide)s (9a–f) in high yield and with inherent viscosities between 0.30 and 0.52 dL/g. The resulting polymers were characterized by elemental analysis, viscosity measurement, solubility testing, thermo-gravimetric analysis (TGA), ¹H-NMR, and FT-IR techniques.     

New poly(amide–imide)s syntheses. 17. Preparation and properties of poly(amide–imide)s derived from N-phenyl-3,3-bis[4-(4-aminophenoxy)-phenyl]phthalimidine,trimellitic anhydride,and various aromatic diamines

A dicarboxylic acid ( 1 ) bearing two phthalimide rings was prepared by the condensation of N-phenyl-3,3-bis[4-(4-aminophenoxy)phenyl]phthalimidine and trimellitic anhydride. A new family of poly(amide–imide)s having inherent viscosities of 0.65–1.65 dl/g was prepared by the triphenyl phosphite activated polycondensation of the diimide–diacid 1 with various aromatic diamines in a medium consisting of N-methyl-2-pyrrolidone (NMP), pyridine, and calcium chloride. All the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. The soluble poly(amide–imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range 249–340°C and the 10% weight loss temperatures were above 545°C in nitrogen.     

Synthesis and characterization of new poly(ether–ester–imide)s as a generation of soluble and thermally stable polymers

A new-type of dicarboxylic acid 6 was synthesized from the reaction of 1,4-bis[4-aminophenoxy]butane 4 with trimellitic anhydride 5 in a solution of glacial acetic acid/pyridine (Py) at refluxing temperature. 1,4-Bis[4-nitrophenoxy]butane 3 was prepared by reaction of 4-nitrophenol 1 with 1,4-dibromo butane 2 in N,N-dimethylformamide (DMF) solution. Then dinitro 3 was reduced to 1,4-bis[4-aminophenoxy]butane 4 by using 10% Pd–C, ethanol, and hydrazine monohydrate. So six new thermally stable and organosoluble poly(ether–ester–imide)s (PEEIs) 8a–f with good inherent viscosities were synthesized by the direct polycondensation reaction of new 1,4-bis[4-(trimellitimido)phenoxy]butane 6 with several aromatic diols 7a–f through direct polycondensation using tosyl chloride (TsCl)/pyridine (Py)/DMF system as condensing agent. The resulted polymers were fully characterized by means of FTIR and ¹H NMR spectroscopy, elemental analyses, inherent viscosity, solubility tests, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and derivative of thermogravimetric (DTG).     

New aromatic poly(ether-ketone)s containing hexafluoroisopropylidene groups

Summary New aromatic poly(ether-ketone)s containing hexafluoroisopropylidene groups have been prepared by aromatic nucleophylic displacement reaction of the potassium salts of aromatic dihydroxy compounds containing fluoren, 1,3,4-oxadiazole or phenylquinoxaline rings with 2,2-bis[4-(4-fluorobenzoylphenyl)hexafluoropropane. These polymers were readily soluble in various organic solvents such as N,N-dimethylformamide, pyridine, tetrahydrofuran and chloroform and gave flexible films by casting such solutions. Their glass transition temperatures (T_g) were in the range of 189–222°C and they were thermally stable up to 480°C. The polymer films displayed low dielectric constants, in the range of 2.8 – 3.2, and good mecanical properties, with tensile strength in the range of 46 – 61 MPa and elastic modulus of 1.4 – 1.6 GPa. Received: 6 April 2001/Revised version: 31 July 2001/Accepted: 31 July 2001     

Synthesis and characterization of polyamides and poly(amide-imide)s based on ether-sulfone-diamines

A series of polyamides and poly(amide-imide)s were prepared by the direct polycondensation of 4,4′-[sulfonylbis(1,4-phenyleneoxy)]dianiline or 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenyleneoxy)]dianiline with aromatic dicarboxylic acids and phthalimide unit-bearing dicarboxylic acids in a N-methyl-2-pyrrolidone (NMP) solution containing dissolved calcium chloride using triphenyl phosphite and pyridine as condensing agents. The inherent viscosities of the resulting polymers were above 0.45 dL/g and up to 1.70 dL/g. Except for the polyamides derived from terephthalic acid and 4,4′-biphenyldicarboxylic acid, all the other polyamides and all poly(amide-imide)s were readily soluble in polar organic solvents such as NMP, N, N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and m-cresol, and afforded transparent and tough films by solution-casting. Most of the polymers showed distinct glass transition on their differential scanning calorimetry (DSC) traces and their glass transition temperatures (T_g) stayed between 140–264 °C. The methyl-substituted polymers showed higher T_gs than the corresponding unsubstituted counterparts. The results of the thermogravimetry analysis (TGA) revealed that all the methyl-substituted polymers showed lower initial decomposition temperatures than the unsubstituted ones.     

Synthesis and characterization of organosoluble poly(arylate‐imide)s prepared from direct polycondensation of bis(trimellitimide)‐diacids and various bisphenols

Three diimide‐diacids, 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]hexafluoropropane ( I‐A ), 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]propane ( I‐B ), and 5,5′‐bis[4‐ (4‐trimellitimidophenoxy)phenyl]hexahydro‐4,7‐methanoindan ( I‐C ), were prepared by the azeotropic condensation of trimellitic anhydride with three analogous diamines. Three series of alternating aromatic poly(arylate‐imide)s, having inherent viscosities of 0.41–0.82 dL/g, were synthesized from these diimide‐diacids ( I‐A , I‐B , and I‐C ) with various bisphenols by direct polycondensation using diphenyl chlorophosphate and pyridine as condensing agents. All of the polymers were readily soluble in a variety of organic solvents such as N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, and even in the less polar tetrahydrofuran. These polymers could be cast into transparent and tough films, which had strength at break values ranging from 73 to 98 MPa, elongation at break from 6 to 11%, and initial modulus from 1.6 to 2.2 GPa. The softening temperatures of the polymers were recorded at 145–248°C. They had 10% weight loss at a temperature above 450°C and left 35–51% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3818–3825, 2003     

New poly(amide‐imide) syntheses. 24. Synthesis and properties of fluorinated poly(amide‐imide)s based on 2,2‐bis[4‐(trimellitimidophenoxy)phenyl]hexafluoropropane and various aromatic diamines

An imide ring‐performed dicarboxylic acid bearing one hexafluoroisopropylidene and two ether linkages between aromatic rings, 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]hexafluoropropane (II), was prepared from the condensation of 2,2‐bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane and trimellitic anhydride. A novel series of poly(amide‐imide)s having inherent viscosities of 0.72 ∼ 1.86 dL g⁻¹ was prepared by the triphenyl phosphite‐activated polycondensation from the diimide‐diacid (II) with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrolidone, pyridine, and calcium chloride. Several of the resulting polymers were soluble in polar amide solvents, and their solutions could be cast into transparent, thin, flexible films having good tensile properties and high thermal stability. The 10% weight loss temperatures were all above 495°C in air or nitrogen atmosphere, and the glass transition temperatures were in the range of 237°–276°C. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 823–831, 1999     

Synthesis and characterization of novel poly(amide-imide)s derived from N,N’-Bis(p-aminophenyl) terephthalamide

Summary An aromatic diamine monomer, N,N’-bis (p-aminophenyl) terephthalamide (PTP) was synthesized by employing sodium hydride as catalyst, 1,4-phenyleneamine (PDA) and dimethyl terephthalate (DMT) as starting materials. The structure of monomer was characterized by FT-IR, ¹H-NMR and elemental analysis. A series of new poly(amide-imide)s (PAIs) having inherent viscosities of 1.85–2.07 dL/g were synthesized from aromatic diamine PTP with various commercially available aromatic dianhydrides using a standard two-stage process with thermal imidization of poly(amic-acid) (PAA) films. The structure of polymers was respectively investigated by FT-IR. The WAXD patterns indicated an amorphous morphological structure of these polymers. All the new PAIs had good thermal stability with the glass transition temperature of 234–248 °C, the temperatures of 5% and 10% weight loss in nitrogen were in the range of 518–541 °C and 543–564 °C respectively. All PAIs were found to hold outstanding mechanical properties with the tensile strengths of 267.83–326.14 Mpa and Young’s modulus of 4.67–5.83 GPa.     

Modified poly(ether–imide–amide)s with pendent benzazole structures: Synthesis and characterization

Three series of novel modified poly(ether–imide–amide)s (PEIAs) having pendent benzazole units were prepared from diimide–dicarboxylic acids, including 2-[3,5-bis(4-trimellitimidophenoxy) phenyl]benzimidazole, 2-[3,5-bis(4-trimellitimidophenoxy) phenyl]benzoxazole, and 2-[3,5-bis(4-trimellitimidophenoxy) phenyl]benzothiazole, with various diamines by direct polycondensation in N-methyl-2-pyrrolidone with triphenyl phosphite and pyridine as condensing agents. These new diimide–dicarboxylic acids containing ether linkages and benzazole pendent groups were synthesized by the condensation reaction of 5-(2-benzimidazole)-1,3-bis(4-aminophenoxy)benzene, 5-(2-benzoxazole)-1,3-bis(4-aminophenoxy)benzene, or 5-(2-benzothiazole)-1,3-bis(4-aminophenoxy)benzene with trimellitic anhydride, respectively. All of the polymers were obtained in quantitative yields with inherent viscosities of 0.39–0.65 dL/g. For comparative purposes, the corresponding unsubstituted PEIAs were also prepared by the reaction of a diimide–dicarboxylic acid monomer lacking benzazole pendent groups, namely, 3,5-bis(4-trimellitimidophenoxy) phenyl, with the same diamines under similar conditions. The solubilities of the modified PEIAs in common organic solvents and their thermal stability were enhanced compared to those of the corresponding unmodified PEIAs. The glass-transition temperature, 10% weight loss temperature, and char yields at 800°C were 19–31°C, 22–57°C and 4–8% higher, respectively, than those of the unmodified polymers. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and properties of novel phosphorus‐containing poly(ether ether ketone ketone)s

A novel monomer, bis[4‐(4‐fluorobenzoyl)phenyl]phenylphosphine oxide, was synthesized through the reaction of bis(4‐chloroformylphenyl) phenyl phosphine oxide with fluorobenzene. Three poly(ether ether ketone ketone)s derived from bis[4‐(4‐fluorobenzoyl)phenyl]phenylphosphine oxide and different aromatic bisphenols were prepared by aromatic nucleophilic substitution reactions. The resulting polymers had inherent viscosities in the range of 0.55–0.73 dL/g. The structures of the poly(ether ether ketone ketone)s were characterized with Fourier transform infrared and ¹H‐NMR. Thermal analysis indicated that the glass‐transition temperatures of the poly(ether ether ketone ketone)s were higher than 200°C, and the 5% weight loss temperatures in nitrogen were higher than 463°C. All the polymers showed excellent solubility in polar solvents such as N‐methyl‐2‐pyrrolidone, dimethylformamide, and dimethylacetamide and could also be dissolved in chlorinated methane. The polymers afforded transparent and flexible films by solvent casting. Organic phosphorous moieties also imparted good flame‐retardancy to the polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and properties of novel soluble aromatic polyetherimides from 1,1′-bis[4-(3,4-dicarboxyphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane dianhydride and aromatic diamines

New aromatic polyetherimides containing the 1,1′-bis[4-(3,4-dicarboxyphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane dianhydride unit were prepared by a conventional two-step method from 1,1′-bis[4-(3,4-dicarboxyphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane dianhydride and several diamines. This procedure yielded high molecular weight polyetherimides with inherent viscosities of 0.22–1.29 dL/g. Most of the corresponding polyetherimides were soluble in organic solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N,N-dimethylacetamide, and methylene chloride under ambient temperature. The glass transition temperatures (T_g) of these polymers were in the range of 207–264°C and the temperatures of 10% weight loss were over 520°C at a heating rate 20°C/min in nitrogen. © 1996 John Wiley & Sons, Inc.