Synthesis and properties of novel polyamides containing sulfone‐ether linkages and xanthene cardo groups

In order to obtain polyamides with enhanced solubility and processability, as well as good mechanical and thermal properties, several novel polyamides containing sulfone‐ether linkages and xanthene cardo groups based on a new diamine monomer, 9,9‐bis[4‐(4‐aminophenoxy)phenyl]xanthene (BAPX), were investigated. The BAPX monomer was synthesized via a two‐step process consisting of an aromatic nucleophilic substitution reaction of readily available 4‐chloronitrobenzene with 9,9‐bis(4‐hydroxyphenyl)xanthene in the presence of potassium carbonate in N,N‐dimethylformamide, followed by catalytic reduction with hydrazine and Pd/C. Four novel aromatic polyamides containing sulfone‐ether linkages and xanthene cardo groups with inherent viscosities between 0.98 and 1.22 dL g^?1 were prepared by low‐temperature polycondensation of BAPX with 4,4′‐sulfonyldibenzoyl chloride, 4,4′‐[sulfonyl‐bis(4‐phenyleneoxy)]dibenzoyl chloride, 3,3′‐[sulfonyl‐bis(4‐phenyleneoxy)]dibenzoyl chloride and 4,4′‐[sulfonyl‐bis(2,6‐dimethyl‐1,4‐phenyleneoxy)]dibenzoyl chloride in N,N‐dimethylacetamide (DMAc) solution containing pyridine. All these new polyamides were amorphous and readily soluble in various polar solvents such as DMAc and N‐methylpyrrolidone. These polymers showed relatively high glass transition temperatures in the range 238–298 °C, almost no weight loss up to 450 °C in air or nitrogen atmosphere, decomposition temperatures at 10% weight loss ranging from 472 to 523 °C and 465 to 512 °C in nitrogen and air, respectively, and char yields at 800 °C in nitrogen higher than 50 wt%. Transparent, flexible and tough films of these polymers cast from DMAc solution exhibited tensile strengths ranging from 78 to 87 MPa, elongations at break from 9 to 13% and initial moduli from 1.7 to 2.2 GPa. Primary characterization of these novel polyamides shows that they might serve as new candidates for processable high‐performance polymeric materials. Copyright © 2010 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 soluble poly(ester‐imide)s containing noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit

A new diimide–diacid chloride (3) containing a noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit was synthesized by treating 2,2′‐dimethyl‐4,4′‐diamino‐biphenylene with trimellitic anhydride followed by refluxing with thionyl chloride. Various new poly(ester‐imide)s were prepared from 3 with different bisphenols by solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher at 170°C. Inherent viscosities of the poly(ester‐imide)s were found to range between 0.31 and 0.35 dL g^?1. All of the poly(ester‐imide)s, except the one containing pendent adamantyl group 5e, exhibited excellent solubility in the following solvents: N,N‐dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidinone, m‐cresol, o‐chlorophenol, and chloroform. The polymers showed glass‐transition temperatures between 166 and 226°C. The 10% weight loss temperatures of the poly(ester‐imide)s, measured by TGA, were found to be in the range between 415 and 456°C in nitrogen. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2486–2493, 2004     

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     

Synthesis and characterization of highly soluble poly(ether imide)s containing indane moieties in the main chain

A new indane containing unsymmetrical diamine monomer ( 3 ) was synthesized. This diamine monomer leads to a number of novel semifluorinated poly (ether imide)s when reacted with different commercially available dianhydrides like benzene‐1,2,4,5‐tetracarboxylic dianhydride (PMDA), benzophenone‐3,3′, 4,4′‐tetracarboxylic dianhydride (BTDA), 4,4′‐(hexafluoro‐isopropylidene)diphthalic anhydride (6FDA), 4,4′‐oxydiphthalic anhydride (ODPA), and 4,4′‐(4,4′‐Isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) by thermal imidization route. All the poly(ether imide)s showed excellent solubility in several organic solvents such as N‐methylpyrrolidone (NMP), N,N‐dimethylformamide (DMF), N,N‐dimethylacetamide (DMAc), tetrahydrofuran (THF), chloroform (CHCl₃) and dichloromethane (DCM) at room temperature. These light yellow poly (ether imide)s showed very low water absorption (0.19–0.30%) and very good optical transparency. Wide angle X‐ray diffraction measurements revealed that these polymers were amorphous in nature. The polymers exhibited high thermal stability up to 526°C in nitrogen with 5% weight loss, and high glass transition temperature up to 265°C. The polymers exhibited high tensile strength up to 85 MPa, modulus up to 2.5 GPa and elongation at break up to 38%, depending on the exact polymer structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

New poly(amide imide imide)s based on tetraimide dicarboxylic acid condensed from 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride,m‐aminobenzoic acid,and 4,4″‐oxydianiline and various aromatic diamines

A series of new, organosoluble, and light‐colored poly(amide imide imide)s were synthesized from tetraimide dicarboxylic acid ( I ) and various aromatic diamines by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. I was prepared by the azeotropic condensation of 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, m‐aminobenzoic acid, and 4,4′‐oxydianiline at a 2/2/1 molar ratio in N‐methyl‐2‐pyrrolidone (NMP)/toluene. The thin films cast from N,N‐dimethylacetamide (DMAc) had cutoff wavelengths shorter than 400 nm (365–394 nm) and color coordinate b* values between 13.10 and 36.07; these polymers were lighter in color than the analogous poly(amide imide)s and isomeric polymers. All of the polymers were readily soluble in a variety of organic solvents, including NMP, DMAc, N,N‐dimethylformamide, dimethyl sulfoxide, and even less polar dioxane and tetrahydrofuran. The cast films exhibited tensile strengths of 90–104 MPa, elongations at break of 7–22%, and initial moduli of 1.9–2.4 GPa. The glass‐transition temperatures of the polymers were recorded at 274–319°C. They had 10% weight losses at temperatures beyond 520°C and left more than a 50% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 669–679, 2003     

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 and characterization of novel polyaspartimides derived from 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl and various diamines

A novel bismaleimide, 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl, containing noncoplanar 2,2′‐dimethylbiphenylene and flexible ether units in the polymer backbone was synthesized from 2,2′‐dimethyl‐4,4′‐bis(4‐aminophenoxy)biphenyl with maleic anhydride. The bismaleimide was reacted with 11 diamines using m‐cresol as a solvent and glacial acetic acid as a catalyst to produce novel polyaspartimides. Polymers were identified by elemental analysis and infrared spectroscopy, and characterized by solubility test, X‐ray diffraction, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis). The inherent viscosities of the polymers varied from 0.22 to 0.48 dL g⁻¹ in concentration of 1.0 g dL⁻¹ of N,N‐dimethylformamide. All polymers are soluble in N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethylsulfoxide, pyridine, m‐cresol, and tetrahydrofuran. The polymers, except PASI‐4, had moderate glass transition temperature in the range of 188°–226°C and good thermo‐oxidative stability, losing 10% mass in the range of 375°–426°C in air and 357°–415°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 279–286, 1999     

Synthesis and properties of fluorinated aromatic poly(amide imide)s based on 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone and various bis(trimellitimide)s

A CF₃‐containing diamine, 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone ( 2 ), was synthesized from 4,4′‐dihydroxybenzophenone and 2‐chloro‐5‐nitrobenzotrifluoride. Imide‐containing diacids ( 3 and 5B_a – 5B_g ) were prepared by the condensation reaction of aromatic diamines and trimellitic anhydride. Then, two series of novel soluble aromatic poly(amide imide)s (PAIs; 6A_a – 6A_k and 6B_a – 6B_g ) were synthesized from a diamine ( 4A_a – 4A_k or 2 ) with the imide‐containing diacids ( 3 and 5B_a – 5B_g ) via direct polycondensation with triphenyl phosphate and pyridine. The aromatic PAIs had inherent viscosities of 0.74–1.76 dL/g. All of the synthesized polymers showed excellent solubility in amide‐type solvents, such as N‐methyl‐2‐pyrrolidone and N,N‐dimethylacetamide (DMAc), and afforded transparent and tough films by DMAc solvent casting. These polymer films had tensile strengths of 90–113 MPa, elongations at break of 8–15%, and initial moduli of 2.0–2.9 GPa. The glass‐transition temperatures of the aromatic PAIs were in the range 242–279°C. They had 10% weight losses at temperatures above 500°C and showed excellent thermal stabilities. The 6B series exhibited less coloring and showed lower yellowness index values than the corresponding 6A series. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3641–3653, 2006     

Synthesis of aromatic poly(urea‐imide) with heterocyclic side‐chain structure

The poly(urea‐imide) copolymers with inherent viscosity of 0.81–1.08 dL/g were synthesized by reacting aryl ether diamine or its polyurea prepolymer with various diisocyanate‐terminated polyimide prepolymers. The aryl ether diamine was obtained by first nucleophilic substitution of phenolphthalein with p‐chloronitrobenzene in the presence of anhydrous potassium carbonate to form a dinitro aryl ether, and then further hydrogenated to diamine. The polyimide prepolymers were prepared by using 4,4′‐diphenylmethane diisocyanate to react with pyromellitic dianhydride, 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride, or 3,3′,4,4′‐sulfonyldiphthalic anhydride by using the direct one‐pot method to improve their solubility, but without sacrificing thermal property. These copolymers are amorphous and readily soluble in a wide range of organic solvents such as N‐methyl‐2‐pyrrolidone, dimethylimidazole, N,N‐dimethylacetamide, dimethyl sulfoxide, N,N‐dimethylformamide, m‐cresol, and sulfolane. All the poly(urea‐imides) have glass transition temperatures in the range of 205–240°C and show a 10 wt % loss at 326–352°C in nitrogen and 324–350°C in air. The tensile strength, elongation at break, and initial modulus of these copolymer films range from 42 to 79 MPa, 5 to 16%, and 1.23 to 2.02 GPa, respectively. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1719–1730, 1999     

Synthesis and characterization of new poly(amide‐imide)s based on 1,4‐bis(trimellitimido)‐2,5‐dichlorobenzene

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‐dichlorobenzene (I), with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrrolidone (NMP), pyridine, and calcium chloride. The poly(amide‐imide)s had inherent viscosities of 0.88–1.27 dL g⁻¹. The diimide‐diacid monomer (I) was prepared from 2,5‐dichloro‐p‐phenylenediamine with trimellitic anhydride. All the resulting polymers were amorphous and were readily soluble in a variety of organic solvents, including NMP and N,N‐dimethylacetamide. Transparent, flexible, and tough films of these polymers could be cast from N,N‐dimethylacetamide or NMP solutions. Cast films had tensile strengths ranging from 92 to 127 MPa, elongations at break from 4 to 24%, and initial moduli from 2.59 to 3.65 GPa. The glass transition temperatures of these polymers were in the range of 256°–317°C, and the 10% weight loss temperatures were above 430°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 271–278, 1999     

Synthesis and characterization of new rigid‐rod and organosoluble poly(amide–imide)s based on 1,4‐bis(trimellitimido)‐2,3,5,6‐tetramethylbenzene

A series of new aromatic poly(amide–imide)s (PAIs) was synthesized by triphenyl phosphite‐activated polycondensation of the diimide–diacid, 1,4‐bis(trimellitimido)‐2,3,5,6‐tetramethylbenzene (I), with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrrolidone (NMP), pyridine, and calcium chloride. The PAIs had inherent viscosities of 0.82–2.43 dL/g. The diimide–diacid monomer (I) was prepared from 2,3,5,6‐tetramethyl‐p‐phenylenediamine with trimellitic anhydride (TMA). Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents including NMP, N,N‐dimethylacetamide (DMAc), and N,N‐dimethylformamide (DMF). Transparent, flexible, and tough films of these polymers could be cast from DMAc solutions. Their cast films had tensile strengths ranging from 80 to 95 MPa, elongation at break from 10 to 45%, and initial modulus from 2.01 to 2.50 GPa. The 10% weight loss temperatures of these polymers were above 510°C in nitrogen. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1162–1170, 2000     

Synthesis and properties of polyamides based on 5,5′‐bis[4‐(4‐aminophenoxy)phenyl]‐hexahydro‐4,7‐methanoindan

A new diamine 5,5′‐bis[4‐(4‐aminophenoxy)phenyl]‐hexahydro‐4,7‐methanoindan ( 3 ) was prepared through the nucleophilic displacement of 5,5′‐bis(4‐hydroxylphenyl)‐hexahydro‐4,7‐methanoindan ( 1 ) with p‐halonitrobenzene in the presence of K₂CO₃ in N,N‐dimethylformamide (DMF), followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of new polyamides were synthesized by the direct polycondensation of diamine 3 with various aromatic dicarboxylic acids. The polymers were obtained in quantitative yields with inherent viscosities of 0.76–1.02 dl g⁻¹. All the polymers were soluble in aprotic dipolar solvents such as N,N‐dimethylacetamide (DMAc) and N‐methyl‐2‐pyrrolidone (NMP), and could be solution cast into transparent, flexible and tough films. The glass transition temperatures of the polyamides were in the range 245–282 °C; their 10% weight loss temperatures were above 468 °C in nitrogen and above 465 °C in air. © 2000 Society of Chemical Industry     

Highly fluorinated poly(ether‐imide)s derived from 2,2′‐bis(3,4,5‐trifluorophenyl)‐4,4′‐diaminodiphenyl ether and aromatic dianhydrides

A new diamine, 2,2′‐bis(3,4,5‐trifluorophenyl)‐4,4′‐diaminodiphenyl ether (FPAPE) was synthesized through the Suzuki coupling reaction of 2,2′‐diiodo‐4,4′‐dinitrodiphenyl ether with 3,4,5‐trifluorophenylboronic acid to produce 2,2′‐bis(3,4,5‐trifluorophenyl)‐4,4′‐dinitrodiphenyl ether (FPNPE), followed by palladium‐catalyzed hydrazine reduction of FPNPE. FPAPE was then utilized to prepare a novel class of highly fluorinated all‐aromatic poly(ether‐imide)s. The chemical structure of the resulting polymers is well confirmed by infrared and nuclear magnetic resonance spectroscopic methods. Limiting viscosity numbers of the polymer solutions at 25 °C were measured through the extrapolation of the concentrations used to zero. M_n and M_w of these polymers were about 10 000 and 25 000 g mol^?1, respectively. The polymers showed a good film‐forming ability, and some characteristics of their thin films including color and flexibility were investigated qualitatively. An excellent solubility in polar organic solvents was observed. X‐ray diffraction measurements showed that the fluoro‐containing polymers have a nearly amorphous nature. The resulting polymers had T_g values higher than 340 °C and were thermally stable, with 10% weight loss temperatures being recorded above 550 °C. Based on the results obtained, FPAPE can be considered as a promising design to prepare the related high performance polymeric materials. Copyright © 2011 Society of Chemical Industry     

Synthesis and properties of new aromatic poly(ester‐imide)s derived from 4‐p‐biphenyl‐2,6‐bis(4‐trimellitimidophenyl) pyridine and various dihydroxy compounds

A novel class of wholly aromatic poly(ester‐imide)s, having a biphenylene pendant group, with inherent viscosities of 0.32–0.49 dL g^?1 was prepared by the diphenylchlorophosphate‐activated direct polyesterification of the preformed imide‐ring‐containing diacid, 4‐p‐biphenyl‐2,6‐bis(4‐trimellitimidophenyl)pyridine (1) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. A reference diacid, 2,6‐bis(trimellitimido)pyridine (2) without a biphenylene pendant group and two phenylene rings in the backbone, was also synthesized for comparison purposes. At first, with due attention to structural similarity and to compare the characterization data, a model compound (3) was synthesized by the reaction of compound 1 with two mole equivalents of phenol. Moreover, the optimum condition of polymerization reactions was obtained via a study of the model compound synthesis. All of the resulting polymers were characterized by Fourier transform infrared and ¹H NMR spectroscopy and elemental analysis. The ultraviolet λ_max values of the poly(ester‐imide)s were also determined. All of the resulting polymers exhibited excellent solubility in common organic solvents, such as pyridine, chloroform, tetrahydrofuran, and m‐cresol, as well as in polar organic solvents, such as N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfoxide. The crystalline nature of the polymers obtained was evaluated by means of wide‐angle X‐ray diffraction. The resulting poly(ester‐imide)s showed nearly an amorphous nature, except poly(ester‐imide) derived from 4,4′‐dihydroxy biphenyl. The glass transition temperatures (T_g) of the polymers determined by differential scanning calorimetry thermograms were in the range 298–342 °C. The 10% weight loss temperatures (T_10%) from thermogravimetric analysis curves were found to be in the range 433–471 °C in nitrogen. Films of the polymers were also prepared by casting the solutions. Copyright © 2006 Society of Chemical Industry     

Synthesis and properties of hydrogen‐bonded poly(amide‐imide) hybrid films

Poly(amide‐imide), PI, hybrid films are prepared by using sol–gel techniques. First, the poly(amide amic acid) with controlled block chain length of 5000 and 10,000 g/mol and uncontrolled chain length are synthesized by condensation reaction with 4,4′‐diaminodiphenyl ether (ODA), 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA), trimellitic anhydride chloride (TMAC) and terminated with p‐aminopropyltrimethoxysilane (APrTMOS). And then the imidization reactions of poly (amide amic acid) are proceeded to obtain the poly (amide‐imide) hybrid film. Hybrid films with 5000 g/mol block chain length possess higher storage modulus, lower glass transition temperature and damping intensity comparing to films with 10,000 g/mol block chain length. The addition of TMAC to the poly(amide‐imide) hybrids is due to the increase of toughness and intermolecular hydrogen bonding, which is the average strength of intermolecular bonding and studied by the hydrogen‐bonded fraction (f_bonded), frequency difference (Δν) and shiftment. Meanwhile, PI hybrid films containing more APrTMOS and TMAC content possess higher thermal and mechanical properties. On the other hand, hybrid films with 10,000 g/mol block chain length and more TMAC content have higher gas permeabilities than other films. The degradation temperatures of 5 wt % loss of all hybrid films are all higher than 540°C and increased as the increase of TMAC content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

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 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     

Organosoluble and light‐colored fluorinated polyimides based on 1,1‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]‐1‐phenylethane and various aromatic dianhydrides

To investigate the CF₃ group affecting the coloration and solubility of polyimides (PI), a novel fluorinated diamine 1,1‐bis[4‐(4‐amino‐2‐ trifluoromethylphenoxy)phenyl]‐1‐phenylethane (2) was prepared from 1,1‐ bis(4‐hydrophenyl)‐1‐phenylethan and 2‐chloro‐5‐nitrobenzotrifluoride. A series of light‐colored and soluble PI 5 were synthesized from 2 and various aromatic dianhydrides 3a–f using a standard two‐stage process with thermal 5a– f(H) and chemical 5a–f(C) imidization of poly(amic acid). The 5 series had inherent viscosities ranging from 0.55 to 0.98 dL/g. Most of 5a–f(H) were soluble in amide‐type solvents, such as N‐methyl‐2‐pyrrolidone (NMP), N,N‐ dimethylacetamide (DMAc), and N,N‐dimethylformamide (DMF), and even soluble in less polar solvents, such as m‐Cresol, Py, Dioxane, THF, and CH₂Cl₂, and the 5(C) series was soluble in all solvents. The GPC data of the 5a–f(C) indicated that the Mn and Mw values were in the range of 5.5–8.7 × 10⁴ and 8.5–10.6 × 10⁴, respectively, and the polydispersity index (PDI) Mw /Mn values were 1.2–1.5. The PI 5 series had excellent mechanical properties. The glass transition temperatures of the 5 series were in the range of 232–276°C, and the 10% weight loss temperatures were at 505–548 °C in nitrogen and 508–532 °C in air, respectively. They left more than 56% char yield at 800°C in nitrogen. These films had cutoff wavelengths between 356.5–411.5 nm, the b* values ranged from 5.0–71.1, the dielectric constants, were 3.11–3.43 (1MHz) and the moisture absorptions were in the range of 011–0.40%. Comparing 5 containing the analogous PI 6 series based on 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐1‐ phenylethane (BAPPE), the 5 series with the CF₃ group showed lower color intensity, dielectric constants, and better solubility. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2399–2412, 2005     

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