Novel poly(thiourea‐ether‐imide)s derived from 4,4′‐oxydiphenyl‐bis(thiourea): probing the possibility for high‐temperature applications

Our interest in the fabrication of high‐performance polyimides has led to thiourea‐substituted poly(thiourea‐ether‐imide)s (PTEIs) with good retention of thermal properties along with flame retardancy. A new aromatic monomer, 4,4′‐oxydiphenyl‐bis(thiourea) (ODPBT), was efficiently synthesized and polymerized with various dianhydrides (pyromellitic dianhydride, 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 4,4′‐(hexafluoroisopropylidene)diphthalic dianhydride) via two‐stage chemical imidization to fabricate a series of PTEIs. The structural characterization of ODPBT and the polymers was carried out using Fourier transform infrared, ¹H NMR and ¹³C NMR spectral techniques along with crystallinity, organosolubility, inherent viscosity and gel permeation chromatographic measurements. PTEIs bearing C?S and ? O? moieties in the backbone demonstrated an amorphous nature and were readily soluble in various amide solvents. The novel polymers had inherent viscosities of 1.16–1.23 dL g^?1 and molecular weights of ca 90 783–96 927 g mol^?1. Their thermal stability was substantiated via 10% weight loss in the temperature range 516–530 °C under inert atmosphere. The polyimides had glass transition temperatures of 260–265 °C. Incorporation of thiourea functionalities into polymer backbones is demonstrated to be an effective way to enhance their thermal properties and flame retardancy. Thus, ODPBT can be considered as an excellent candidate for use in the synthesis of high‐performance polymeric materials. Copyright © 2010 Society of Chemical Industry     

Synthesis and characterization of novel aromatic poly(amide‐imide)s derived from 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl or 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl and various aromatic diamines

New aromatic diimide‐dicarboxylic acids having kinked and cranked structures, 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl (2a) and 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl (2b), were synthesized by the reaction of trimellitic anhydride with 2,2′‐bis(4‐aminophenoxy)biphenyl (1a) and 2,2′‐bis(4‐aminophenoxy)‐1,1′‐binaphthyl (1b), respectively. Compounds 2a and 2b were characterized by FT‐IR and NMR spectroscopy and elemental analyses. Then, a series of novel aromatic poly(amide‐imide)s were prepared by the phosphorylation polycondensation of the synthesized monomers with various aromatic diamines. Owing to structural similarity, and a comparison of the characterization data, a model compound was synthesized by the reaction of 2b with aniline. The resulting polymers with inherent viscosities of 0.58–0.97 dl g^?1 were obtained in high yield. The polymers were fully characterized by FT‐IR and NMR spectroscopy. The ultraviolet λ_max values of the poly(amide‐imide)s were also determined. The polymers were readily soluble in polar aprotic solvents. They exhibited excellent thermal stabilities and had 10% weight loss at temperatures above 500 °C under a nitrogen atmosphere. Copyright © 2003 Society of Chemical Industry     

Processable and colorless fluorinated poly(ether imide)s based on an isopropylidene‐containing bis(ether anhydride) and various aromatic bis(ether amine)s bearing trifluoromethyl groups

A series of novel organosoluble and light‐colored fluorinated poly(ether imide)s (PEIs) ( IV ) having inherent viscosities of 0.43–0.59 dL/g were prepared from 4,4′‐[1,4‐phenylenbis(isopropylidene‐1,4‐phenyleneoxy)]diphthalic anhydride ( I ) and various trifluoromethyl‐substituted aromatic bis(ether amine)s by a standard two‐step process with thermal and chemical imidization of poly(amic acid) precursors. These PEIs showed excellent solubility in many organic solvents and could be solution‐cast into transparent and tough films. These films were essentially colorless, with an UV–visible absorption edge of 361–375 nm and a very low b* value (a yellowness index) of 15.3–17.0. They also showed good thermal stability with glass‐transition temperature of 191–248°C, 10% weight loss temperature in excess of 494°C, and char yields at 800°C in nitrogen more than 39%. The thermally cured PEI films showed good mechanical properties with tensile strengths of 83–96 MPa, elongations at break of 8–11%, and initial moduli of 1.7–2.0 GPa. They possessed lower dielectric constants of 3.25–3.72 (1 MHz). In comparison with the V series nonfluorinated PEIs, the IV series showed better solubility, lower color intensity, and lower dielectric constants. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 620–628, 2007     

Synthesis and characterization of polyamides and poly(amide‐imide)s derived from 2,6‐bis(3‐aminophenoxy)benzonitrile or 2,6‐bis(4‐aminophenoxy)benzonitrile

A series of polyamides and poly(amide‐imide)s was prepared by direct polycondensation of ether and nitrile group containing aromatic diamines with aromatic dicarboxylic acids and bis(carboxyphthalimide)s respectively in N‐methyl 2‐pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. New diamines, such as 2,6‐bis(4‐aminophenoxy)benzonitrile and 2,6‐bis(3‐aminophenoxy)benzonitrile, were prepared from 2,6‐dichlorobenzonitrile with 4‐aminophenol and 3‐aminophenol, respectively, in NMP using potassium carbonate. Bis(carboxyphthalimide)s were prepared from the reaction of trimellitic anhydride with various aromatic diamines in N,N′‐dimethyl formamide. The inherent viscosities of the resulting polymers were in the range of 0.27 to 0.93 dl g^?1 in NMP and the glass transition temperatures were between 175 and 298 °C. All polymers were soluble in dipolar aprotic solvents such as dimethylsulfoxide, dimethylacetamide and NMP. All polymers were stable up to 350 °C with a char yield of above 40 % at 900 °C in nitrogen atmosphere. All polymers were found to be amorphous except the polyamide derived from isophthalic acid and the poly(amide‐imide)s derived from diaminodiphenylether and diaminobenzophenone based bis(carboxyphthalimide)s. Copyright © 2004 Society of Chemical Industry     

Synthesis of new poly(amide–imide)s derived from trimellitylimido‐L‐phenylalanine

N‐Trimellitylimido‐L ‐phenylalanine was prepared from the reaction of 1,2,4‐benzenetricarboxylic anhydride with L ‐phenylalanine in N,N‐dimethylformamide solution at refluxing temperature. The direct polycondensation reaction of the monomer imide‐diacid with 4,4′‐diaminodiphenylsulfone, 4,4′‐diaminodiphenylmethane, 1,4‐phenylenediamine, 1,3‐phenylenediamine, 2,4‐diaminotoluene, 4,4′‐diaminodiphenylether and benzidine was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrrolidone, pyridine and calcium chloride. The resulting poly(amide–imide)s, PAIs, having inherent viscosities of 0.21–0.45 dlg^?1 were obtained in high yield. All of the above compounds were fully characterized by IR spectroscopy and elemental analyses. The optical rotation of all PAIs has also been measured. Some structural characterization and physical properties of these new optically active PAIs are reported. © 2001 Society of Chemical Industry     

Novel organosoluble poly(amide‐imide‐imide)s synthesized from new tetraimide‐dicarboxylic acid by condensation with 4,4′‐oxydiphthalic anhydride, 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene,trimellitic anhydride,and various aromatic diamines

A new monomer of tetraimide‐dicarboxylic acid (IV) was synthesized by starting from ring‐opening addition of 4,4′‐oxydiphthalic anhydride, trimellitic anhydride, and 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene at a 1:2:2 molar ratio in N‐methyl‐2‐pyrrolidone (NMP). From this new monomer, a series of novel organosoluble poly(amide‐imide‐imide)s with inherent viscosities of 0.7–0.96 dL/g were prepared by triphenyl phosphite activated polycondensation from the tetraimide‐diacid with various aromatic diamines. All synthesized polymers were readily soluble in a variety of organic solvents such as NMP and N,N‐dimethylacetamide, and most of them were soluble even in less polar m‐cresol and pyridine. These polymers afforded tough, transparent, and flexible films with tensile strengths ranging from 99 to 125 MPa, elongations at break from 12 to 19%, and initial moduli from 1.6 to 2.4 GPa. The thermal properties and stability were also good with glass‐transition temperatures of 236–276°C and thermogravimetric analysis 10 wt % loss temperatures of 504–559°C in nitrogen and 499–544°C in air. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2854–2864, 2006     

Synthesis and characterization of new aromatic poly(amide–imide)s based on 4‐aryl‐2,6‐bis(4‐trimellitimidophenyl) pyridines

New diimide–dicarboxylic acids, ie 4‐phenyl‐2,6‐bis(4‐trimellitimidophenyl)pyridine and 4‐p‐biphenyl‐2,6‐bis‐(4‐trimellitimidophenyl)pyridine, were synthesized by the condensation reaction of 4‐phenyl‐2,6‐bis(4‐aminophenyl)pyridine and 4‐p‐biphenyl‐2,6‐bis(4‐aminophenyl)pyridine with trimellitic anhydride in glacial acetic acid or dimethylformamide. The monomers were fully characterized by FT‐IR and NMR spectroscopies, and elemental analyses. A series of novel poly(amide–imide)s with inherent viscosities of 0.68–0.87 dl g^?1 was prepared from the two diimide–diacids with various aromatic diamines by direct polycondensation. The poly(amide–imide)s were characterized by FT‐IR and NMR spectroscopies. The λ_max data for the resulting poly(amide–imide)s were in the range of 260–292 nm. These polymers exhibited good solubilities in polar aprotic solvents. The 10 % weight loss temperatures are above 485 °C under a nitrogen atmosphere. Copyright © 2004 Society of Chemical Industry     

Synthesis and characterization of novel optically active poly(amide‐imide)s

4,4′‐(Hexafluoroisopropylidene)‐bis‐(phthalic anhydride) (1) was reacted with L ‐leucine (2) in toluene solution at refluxing temperature in the presence of triethylamine and the resulting imide‐acid (4) was obtained in quantitative yield. The compound (4) was converted to the diacid chloride (5) by reaction with thionyl chloride. The polymerization reaction of the imide‐acid chloride (5) with 1,6‐hexamethylenediamine (6a) , benzidine (6b) , 4,4′‐diaminodiphenylmethane (6c) , 1,5‐diaminoanthraquinone (6d) , 4,4′‐sulfonyldianiline (6e) , 3,3′‐diaminobenzophenone (6f) , p‐phenylenediamine (6g) and 2,6‐diaminopyridine (6h) was carried out in chloroform/DMAc solution. The resulting poly(amide‐imide)s were obtained in high yield and are optically active and thermally stable. All of the above compounds were fully characterized by IR, elemental analyses and specific rotation. Some structural characterization and physical properties of those optically active poly(amide‐imide)s are reported. © 1999 Society of Chemical Industry     

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     

Thermally stable polyureas and poly(urea‐imide)s containing zinc and nickel napthtrien complexes

Two new napthtrien metal complexes, MNapth₂trien; where M = Zn and Ni, were synthesized and used for the synthesis of metal‐containing polyureas and poly(urea‐imide)s. MNapth₂trien underwent polymerization reaction with two diisocyanates, namely, 4,4′‐diphenylmethane diisocyanate and isophorone diisocyanate to yield polyureas. Poly(urea‐imide)s were obtained by the synthesis of metal‐containing isocyanate‐terminated polyurea prepolymers from the reaction between MNapth₂trien and excess diisocyanates, which could then undergo further reaction with different dianhydrides. The dianhydrides used were pyromellitic dianhydride and benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride. The polymers were characterized by infrared, nuclear magnetic resonance, elemental analysis, X‐ray diffraction, solubility, and viscosity. Glass transition temperature of the polymers was obtained from differential scanning calorimetry and dynamic mechanical thermal analysis. Thermal stability of polymers was studied by thermogravimetric analysis in air. It was found that the resulting metal‐containing polymers exhibited good thermal stability. Initial decomposition temperatures of the polymers depend on the amount of MNapth₂trien in the polymer composition. Char yields of metal‐containing poly(urea‐imide)s are higher than those of metal‐containing polyureas. Most metal‐containing polymers show good solubility in organic solvents. Shore D hardness test indicates that metal‐containing poly(urea‐imide)s are hard materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of poly(ester‐ether‐imide)s derived from 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene

A series of novel aromatic poly(ester‐ether‐imide)s with inherent viscosity values of 0.44–0.74 dL g^?1 were prepared by the diphenylchlorophosphate‐activated direct polycondensation of an imide ring‐containing diacid namely 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene ( 1 ) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. Owing to comparison of the characterization data, an ester‐containing model compound ( 2 ) was also synthesized by the reaction of 1 with phenol. The model compound 2 and the resulted polymers were fully characterized by FT‐IR and NMR spectroscopy. The ultraviolet λ_max values of the poly(ester‐ether‐imide)s were also determined. The resulting polymers exhibited an excellent organosolubility in a variety of high polar solvents such as N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl sulfoxide, and N‐methyl‐2‐pyrrolidone. They were soluble even in common less polar organic solvents such as pyridine, m‐cresol, and tetrahydrofuran on heating. Crystallinity of the polymers was estimated by means of wide‐angle X‐ray diffraction. The resulted polymers exhibited nearly an amorphous nature. From differential scanning calorimetry thermograms, the polymers showed glass‐transition temperatures between 221 and 245°C. Thermal behaviors of the obtained polymers were characterized by thermogravimetric analysis, and the 10% weight loss temperatures of the poly(ester‐ether‐imide)s were found to be over 410°C in nitrogen. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of new cardo poly(ether imide)s derived from 9,9‐bis [4‐(4‐aminophenoxy)phenyl]xanthene

A series of new cardo poly(ether imide)s bearing flexible ether and bulky xanthene pendant groups was prepared from 9,9‐bis[4‐(4‐aminophenoxy)phenyl]xanthene with six commercially available aromatic tetracarboxylic dianhydrides in N,N‐dimethylacetamide (DMAc) via the poly(amic acid) precursors and subsequent thermal or chemical imidization. The intermediate poly(amic acid)s had inherent viscosities between 0.83 and 1.28 dL/g, could be cast from DMAc solutions and thermally converted into transparent, flexible, and tough poly(ether imide) films which were further characterized by X‐ray and mechanical analysis. All of the poly(ether imide)s were amorphous and their films exhibited tensile strengths of 89–108 MPa, elongations at break of 7–9%, and initial moduli of 2.12–2.65 GPa. Three poly(ether imide)s derived from 4,4′‐oxydiphthalic anhydride, 4,4′‐sulfonyldiphthalic anhydride, and 2,2‐bis(3,4‐dicarboxyphenyl))hexafluoropropane anhydride, respectively, exhibited excellent solubility in various solvents such as DMAc, N,N‐dimethylformamide, N‐methyl‐2‐pyrrolidinone, pyridine, and even in tetrahydrofuran at room temperature. The resulting poly(ether imide)s with glass transition temperatures between 286 and 335°C had initial decomposition temperatures above 500°C, 10% weight loss temperatures ranging from 551 to 575°C in nitrogen and 547 to 570°C in air, and char yields of 53–64% at 800°C in nitrogen. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of new thermally stable poly(ester‐imide)s derived from 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl and 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl and various aromatic dihydroxy compounds

A series of new alternating aromatic poly(ester‐imide)s were prepared by the polycondensation of the preformed imide ring‐containing diacids, 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl (2a) and 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl (2b) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. A model compound (3) was also prepared by the reaction of 2b with phenol, its synthesis permitting an optimization of polymerization conditions. Poly(ester‐imides) were fully characterized by FTIR, UV‐vis and NMR spectroscopy. Both biphenylene‐ and binaphthylene‐based poly(ester‐imide)s exhibited excellent solubility in common organic solvents such as tetrahydrofuran, m‐cresol, pyridine and dichloromethane. However, binaphthylene‐based poly(ester‐imide)s were more soluble than those of biphenylene‐based polymers in highly polar organic solvents, including N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide and dimethyl sulfoxide. From differential scanning calorimetry thermograms, the polymers showed glass‐transition temperatures between 261 and 315 °C. Thermal behaviour of the polymers obtained was characterized by thermogravimetric analysis, and the 10 % weight loss temperatures of the poly(ester‐imide)s was in the range 449–491 °C in nitrogen. Furthermore, crystallinity of the polymers was estimated by means of wide‐angle X‐ray diffraction. The resultant poly(ester‐imide)s exhibited nearly an amorphous nature, except poly(ester‐imide)s derived from hydroquinone and 4,4′‐dihydroxybiphenyl. In general, polymers containing binaphthyl units showed higher thermal stability but lower crystallinity than polymers containing biphenyl units. Copyright © 2005 Society of Chemical Industry     

Preparation and Characterization of 4,4′‐Bis(4‐aminophenoxy)diphenyl Sulfone Based Fluoropoly(ether‐imide)/Organo‐Modified Clay Nanocomposites

A series of fluoropoly(ether‐imide) (6F‐PEI), and [6F‐PEI/montmorillonite (MMT) clay) nanocomposites films were made by thermal curing of respective formulations containing fluoropoly(ether‐amic acid) (6F‐PEAA), synthesized from 2,2′‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 4,4′‐bis(4‐aminophenoxy)diphenyl sulfone (p‐SED), and increasing concentration of p‐SED treated montmorillonite clay (modified MMT clay) at temperature from RT to 350 °C. These films showed excellent solvent resistance as well as very good thermal stability, and increased glass transition (T_g) values with increasing % clay. In addition, these trifluoromethyl groups‐containing nanocomposites films showed sharp lowering of coefficient of thermal expansion (CTE) by 22%. Furthermore, they exhibited increased long‐term thermo‐oxidative stability (TOS), with % weight retention in the range of 86 to 92% in isothermal heating at 300 °C for 300 h in air, reduced water absorption at 100 RH at 50 °C in the range of 0.5 to 1.15%. These data are still much lower than those of neat ULTEM® 1000 and Kapton® H film. The modulus of elasticity is on an average 38% higher for the nanocomposite films relative to neat fluoropoly(ether‐imide) (6FDA + p‐SED), and above non‐fluorinated polyimide films. The surface energy measurement by One‐Liquid and Two‐Liquid method showed a comparable trend of decreasing contact angle. For the nanocomposite films having 15% hydrophobic clay, the contact angle decreased by 21 and 20% for DI‐water and formamide, respectively. The surface energy increase was in the range of 8.21–8.54 mJ/m².

     

A relaxational and conductive study on two poly(ether imide)s

A study of the relaxations and the conductivity of poly(ether imide) (PEI) ULTEM 5000 was carried out. The results were compared with the ones obtained in a previous study of PEI ULTEM 1000. The glass transition temperature was determined by differential scanning calorimetry (DSC). Then, the relaxations of PEI ULTEM 5000 using the thermally stimulated depolarization current technique (TSDC) on conventionally polarized electrets were studied. Owing to the interesting structure indicated by this technique a more detailed analysis of the β relaxation was done using window polarization (WP). It was possible to isolate 7 subrelaxations that we related to their counterparts in PEI ULTEM 1000. WP was also used to compare, one by one, the other relaxations that both materials present. The analysis of the ρ relaxation showed that the space trapping capability is stronger in PEI ULTEM 5000. The role of conductivity was analyzed using open circuit polarized samples and, more quantitatively, using dielectric analysis (DEA) and the dielectric modulus formalism. DEA and dynamic mechanical thermal analysis (DMTA) were also used to obtain information about the polar relaxations, complementary to that obtained by TSDC. Copyright © 2004 Society of Chemical Industry     

Synthesis and characterization of novel poly(amide imide)s based on bis(p‐amidobenzoic acid)‐n‐trimellitylimido‐L‐leucine

N‐Trimellitylimido‐L ‐leucine was reacted with thionyl chloride, and N‐trimellitylimido‐L ‐leucine diacid chloride was obtained in a quantitative yield. The reaction of this diacid chloride with p‐aminobenzoic acid was performed in dry tetrahydrofuran, and bis(p‐amidobenzoic acid)‐N‐trimellitylimido‐L ‐leucine (5) was obtained as a novel optically active aromatic imide–amide diacid monomer in a high yield. The direct polycondensation reaction of the monomer imide–amide diacid 5 with 4,4′‐diaminodiphenylsulfone, 4,4′‐diaminodiphenylether, 1,4‐phenylenediamine, 1,3‐phenylenediamine, 2,4‐diaminotoluene, and benzidine (4,4′‐diaminobiphenyl) was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrolidone, pyridine, and calcium chloride. The resulting novel poly(amide imide)s (PAIs), with inherent viscosities of 0.22–0.52 dL g^?1, were obtained in high yields, were optically active, and had moderate thermal stability. All of the compounds were fully characterized with IR spectroscopy, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAIs are reported. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 35–43, 2002; DOI 10.1002/app.10181     

Poly(imide‐amide)s and poly(imide‐ester)s obtained from N,N′‐(4,4′‐Me,R‐diphthaloyl)‐bis‐glycine acid dichloride (R = Me,Et): Synthesis,characterization, and thermal studies

Poly(imide‐amide)s (PIAs) and poly(imide‐ester)s (PIEs) containing two Si‐atoms in the repeating unit were synthesized from acid dichlorides and diamines and diphenols, respectively. The acid dichlorides were obtained from the dianhydrides, which reacted first with glycine and then with thionyl chloride. The dianhydrides were obtained from the tetramethyl derivatives, which were oxidized to the tetra acids and then the dianhydrides were obtained with acetic anhydride. PIAs were obtained in N,N‐dimethylacetamide solution at low temperature and the PIEs in a CHCl₃ solution. Monomers and polymers were characterized by IR and 1H, 13C, and 29Si‐NMR spectroscopy and the results were in agreement with the proposed structures. The η_inh values were indicative of low molecular weight species and of oligomeric nature. The glass transition (T_g) and thermal decomposition temperatures (TDT) values of PIAs were higher than those of PIEs due to the presence of the aromatic rings of the diamine. The aliphatic groups bonded to the Si atom of the acid dichloride moiety promoted the decrease of the thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and properties of organosoluble poly(ether imide)s containing 4,4′(octahydro-4,7-methano-5H-inden-5-ylidene) cardo group

A series of organosoluble aromatic poly(ether imide)s (PEIs) VIIa-k were synthesized from 4,4′-[(octahydro-4,7-methano-5H-inden-5-ylidene)bis(1,4-phenylene)dioxy] diphthalic dianhydride (IV) and various aromatic diamines. PEIs synthesized through two-stage polymerization had inherent viscosities of 0.51–0.64 dL/g. This series of polymers could also be synthesized from IV and diamines in a small amount of refluxing m-cresol in a one-step process and had inherent viscosities of 0.65–0.87 dL/g. For the low melting point diamines (Vj and Vk), polymers could be obtained by bulk polymerization and had inherent viscosities of 0.36 and 0.41 dL/g. Polymers showed good organosolubility and could be cast into transparent, flexible, and tough polyimide films with good tensile properties. These PEIs had glass transition temperatures among 203–281°C. Thermogravimetric analyses established that these polymers were fairly stable up to 430°C, and the 10% weight loss temperatures were recorded in the range of 473–503°C in nitrogen and 481–512°C in air atmosphere. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 987–996, 1999     

Synthesis and characterization of aromatic/cycloaliphatic poly(amide‐ imide‐imide)s from bis(4‐amino‐ 3,5‐dimethylphenyl) cycloalkane derivatives

A series of novel aromatic diamines containing cycloaliphatic moieties was synthesized by the reaction of cycloalkanones like cyclohexanone and cycloheptanone with 2,6‐dimethylaniline. The tetrimide diacid was synthesized using the prepared diamine with 3,3′,4,4′‐benzophenonetetracarboxylic acid dianhydride/pyromellitic dianhydride and p‐aminobenzoic acid. The polymers were prepared by treating the tetrimide diacid with different aromatic diamines. The structures of the monomers and polymers were identified using elemental analysis and Fourier transform infrared, ¹H NMR and ¹³C NMR spectroscopy. The polymers show excellent solubility. The polymers are amorphous and have high optical transparency. They also show good thermal stability and their T_g value is found to be in the range 268–305 °C. Copyright © 2007 Society of Chemical Industry     

Organosoluble poly(ether imide)s from phthalimidine based and trifluoromethyl substituted bis(ether amine)

A series of new organosoluble and optically transparent poly(ether imide)s (PEIs) were synthesized by the polycondensation of trifluoromethyl substituted and phthalimidine cardo group based bis(ether amine), 3,3‐bis‐[4‐{2′‐trifluoromethyl 4′‐(4″‐aminophenyl)phenoxy}phenyl]‐2‐phenyl‐2, 3‐dihydro‐isoindole‐1‐one with different fluorinated and non‐fluorinated aromatic dianhydrides (2a–e). All the PEIs were well characterized by elemental analysis, NMR, FTIR spectroscopy, and gel permeation chromatography (GPC). The synthesized PEIs showed moderate to high inherent viscosity 0.41–0.61 dL/g and excellent solubility at room temperature in different organic solvents. All the transparent yellow films showed cut‐off length upto 425 nm. They exhibited high tensile strengths upto 98 MPa, excellent thermostability upto 554°C for 5% weight loss, high glass transition temperature upto 327°C, and water uptake value less than 0.6%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009