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     

Synthesis,characterization, and thermal stability of novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s bearing pendant groups and their corresponding poly(ether-amide-1,3,4-oxadiazole)s

Four novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s containing various pendant groups on their aromatic rings were synthesized from p-aminosalicylic acid hydrazide (PASH) with an equimolar amount of either 4,4′-(1,4-phenylenedioxy)dibenzoyl chloride (1a), 4,4′-(2,5-tolylenedioxy)dibenzoyl chloride (1b), 4,4′-(2-tert-butyl-1,4-phenylenedioxy)dibenzoyl chloride (1c), or 4,4′-(2,5-biphenylenedioxy)dibenzoyl chloride (1d) via a low temperature solution polycondensation reaction. A polyamide-hydrazide without the ether and pendant groups, poly[4-(terephthaloylamino)salicylic acid hydrazide, PTASH, is also investigated for comparison. It was synthesized from PASH and terephthaloyl chloride by the same synthetic route. The polymer intrinsic viscosities ranged from 4.5 to 2.47 dlg⁻¹ in N,N-dimethyl acetamide (DMAc) at 30 °C and decreased with the introduction of the ether and pendant groups into the polymer. All the polymers were soluble in DMAc, N,N-dimethyl formamide (DMF), and N-methyl-2-pyrrolidone (NMP) and their solutions could be cast into flexible films with good mechanical strengths. Further, they exhibited a great affinity to water sorption. Their solubility and hydrophilicity increased with introduction of the ether and pendant groups into the polymer. The prepared polymers could be thermally cyclodehydrated under nitrogen atmosphere into the corresponding poly(ether-amide-1,3,4-oxadiazole)s approximately in the region of 300–450 °C. The introduction of the flexibilizing ether linkages and the pendant groups into the polymer improves the solubility of the resulting poly(ether-amide-1,3,4-oxadiazole)s compared to poly(amide-1,3,4-oxadiazole) free from these groups.     

New poly(1,3,4‐oxadiazole)s bearing pentadecyl side chains: Synthesis and characterization

The 4‐[4′‐(Hydrazinocarbonyl)phenoxy]‐2‐pentadecylbenzohydrazide was polycondensed with aromatic diacid chlorides viz., terephthalic acid chloride (TPC), isophthalic acid chloride (IPC), and a mixture of TPC : IPC (50 : 50 mol %) to obtain polyhydrazides which on subsequent cyclodehydration reaction in the presence of phosphoryl chloride yielded new poly(1,3,4‐oxadiazole)s bearing flexibilizing ether linkages and pentadecyl side chains. Inherent viscosities of polyhydrazides and poly(1,3,4‐oxadiazole)s were in the range 0.53–0.66 dL g^?1 and 0.49–0.53 dL g^?1, respectively, indicating formation of medium to reasonably high molecular weight polymers. The number average molecular weights (M_n) and polydispersities (M_w/M_n) of poly(1,3,4‐oxadiazole)s were in the range 14,660–21,370 and 2.2–2.5, respectively. Polyhydrazides and poly(1,3,4‐oxadiazole)s were soluble in polar aprotic solvents such as N,N‐dimethylacetamide, 1‐methyl‐2‐pyrrolidinone, and N,N‐dimethylformamide. Furthermore, poly(1,3,4‐oxadiazole)s were also found to be soluble in solvents such as chloroform, dichloromethane, tetrahydrofuran, pyridine, and m‐cresol. Transparent, flexible, and tough films of polyhydrazides and poly(1,3,4‐oxadiazole)s could be cast from N,N‐dimethylacetamide and chloroform solutions, respectively. Both polyhydrazides and poly(1,3,4‐oxadiazole)s were amorphous in nature and formation of layered structure was observed due to packing of pentadecyl chains. A decrease in glass transition temperature was observed both in polyhydrazides (143–166°C) and poly(1,3,4‐oxadiazole)s (90–102°C) which could be ascribed to “internal plasticization” effect of pentadecyl chains. The T₁₀ values, obtained from TG curves, for poly(1,3,4‐oxadiazole)s were in the range of 433–449°C indicating their good thermal stability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124:1281–1289, 2012     

Synthesis of novel poly(amide‐imide)s containing trimellitylimido‐DL/L‐alanine moieties via direct polycondensation

N‐Trimellitylimido‐DL and L ‐alanine ( 3 ) were prepared from the reaction of trimellitic anhydride ( 1 ) with DL and L ‐alanine ( 2 ) in N,N‐dimethyl formamide (DMF) solution at refluxing temperature. The direct polycondensation reaction of the monomers imide‐diacid ( 3 ) with 4,4′‐diaminodiphenylsulfone ( 4a ), 4,4′‐diaminodiphenylmethane ( 4b ), 1,4‐phenylenediamine ( 4c ), 1,3‐phenylenediamine ( 4d ), 2,4‐diaminotoluene ( 4e ), and 4,4′‐diaminodiphenylether ( 4f ) was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrolidone (NMP), pyridine, and calcium chloride. The resulting poly(amide‐imide)s PAIs, with inherent viscosities 0.32–0.66 dL/g, were obtained in high yield. All of the above‐mentioned compounds were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAI s are reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1312–1318, 2001     

Synthesis and luminescence properties of new blue‐light‐emitting polyconjugated poly{1,1′‐biphenyl‐4,4′‐diyl‐[1‐(4‐t‐butylphenyl)]vinylene} polymers and copolymers

Three new soluble polyconjugated polymers, all of which emitted blue light in photoluminescence and electroluminescence, were synthesized, and their luminescence properties were studied. The polymers were poly{1,1′‐biphenyl‐4,4′‐diyl‐[1‐(4‐t‐butylphenyl)]vinylene}, poly((9,9‐dioctylfluorene‐2,7‐diyl)‐alt‐{1,4‐phenylene‐[1‐(4‐t‐butylphenyl)vinylene‐1,4‐phenylene]}) [P(DOF‐PVP)], and poly([N‐(2‐ethyl) hexylcarbazole‐3,6‐diyl]‐alt‐{1,4‐phenylene‐[1‐(4‐t‐butylphenyl)]vinylene‐1,4‐phenylene}). The last two polymers had alternating sequences of the two structural units. Among the three polymers, P(DOF‐PVP) performed best in the light‐emitting diode devices of indium–tin oxide/poly(ethylenedioxythiophene) doped with poly(styrene sulfonate) (30 nm)/polymer (150 nm)/Li:Al (100 nm). This might have been correlated with the balance in and magnitude of the mobility of the charge carriers, that is, positive holes and electrons, and also the electronic structure, that is, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels, of the polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 307–317, 2006     

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 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 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     

Aromatic polyesters (polyarylates) containing arylene sulfone ether linkages

A series of soluble aromatic polyesters (polyarylates) containing arylene sulfone ether linkages and having inherent viscosities of 0.36–1.10 dl/g were prepared by the two-phase low temperature polycondensation of 4,4′-[sulfonyl-bis(p-phenyleneoxy)]dibenzoyl chloride and 3,3′-[sulfonylbis(p-phenyleneoxy)]-dibenzoyl chloride with various bisphenols in an organic solvent-aqueous alkaline solution system in the presence of a phase transfer catalyst. Bisphenols 4,4′-[sulfonylbis(p-phenyleneoxy)]diphenol and 3,3′-[sulfonylbis(p-phenyleneoxy)]-diphenol were synthesized in quantitative yields by an improved procedure. The aromatic polyesters prepared were characterized by infrared spectroscopy, elemental analysis, solution viscosity, thermogravimetric analysis, differential scanning calorimetry and X-ray diffraction. The polyesters prepared had glass transition temperatures in the range 150–230°C and initial decomposition temperatures of 397–491°C. They gave transparent, tough and flexible films by the solution casting technique.     

Microwave‐promoted rapid synthesis of new optically active poly(amide imide)s derived from N,N′‐(pyromellitoyl)‐bis‐L‐isoleucine diacid chloride and aromatic diamines

A pyromellitic dianhydride (benzene‐1,2,4,5‐tetracarboxylic dianhydride) was reacted with L ‐isoleucine in acetic acid, and the resulting imide acid [N,N′‐(pyromellitoyl)‐bis‐L ‐isoleucine] (4) was obtained in a high yield. 4 was converted into N,N′‐(pyromellitoyl)‐bis‐L ‐isoleucine diacid chloride by a reaction with thionyl chloride. The polycondensation reaction of this diacid chloride with several aromatic diamines, including 1,4‐phenylenediamine, 4,4′‐diaminodiphenyl methane, 4,4′‐diaminodiphenylsulfone (4,4′‐sulfonyldianiline), 4,4′‐diaminodiphenylether, 2,4‐diaminotoluene, and 1,3‐phenylenediamine, was developed with two methods. The first method was polymerization under microwave irradiation, and the second method was low‐temperature solution polymerization, with trimethylsilyl chloride used as an activating agent for the diamines. The polymerization reactions proceeded quickly and produced a series of optically active poly(amide imide)s with good yields and moderate inherent viscosities of 0.17–0.25 dL/g. All of the aforementioned polymers were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these optically active poly(amide imide)s are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 951–959, 2004     

Synthesis and characterization of new polyamides containing p‐phenylenediacryloyl moieties in the main chain

Six new polyamides 8a–f containing p‐phenylenediacryloyl moieties in the main chain were prepared by the direct polycondensation reaction of bis(p‐amidobenzoic acid)‐p‐phenylene diacrylic acid 6 with 1,4‐diphenylene diamine 7a , 1,3‐diamino toluene 7b , 1,5‐diamino naphthalene 7c , 4,4′‐diamino diphenyl ether 7d , 4,4′‐diamino diphenyl sulfone 7e , and 3,3′‐diamino diphenylsulfone 7f by using thionyl chloride, N‐methyl‐2‐pyrolidone, and pyridine as condensing agents. These new polymers 8a–f were obtained in high yield and inherent viscosity between 0.35–0.65 dL/g. The resulting polyamides were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility test, FTIR and UV–vis spectroscopy. Diacid acid 6 as a new monomer containing p‐phenylenediacryloyl moiety was synthesized by using a three‐step reaction. First, p‐phenylenediacrylic acid 3 was prepared by reaction of terephthal aldehyde 1 with malonic acid 2 in the presence of pyridine, then diacid 3 was converted to p‐phenylenediacryloyl chloride 4 by reaction with thionyl chloride. Finally, bis(p‐amidobenzoic acid)‐p‐phenylene diacrylic acid 6 was prepared by the condensation reaction of phenylenediacryloyl chloride 4 with p‐aminobenzoic acid 5 . © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

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     

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     

Polyaramides containing arylene sulfone ether linkages

Polyamides containing arylene sulfone ether linkages were synthesized from 4,4′[sulfonybis (p-phenyleneoxy)] dibenzoyl chloride (SPCI), 3,3′-[sulfonylbis (p-phenyleneoxy)] dibenzoyl chloride (SMCl) and various aromatic diamines (ARD), by solution and interfacial polymerization techniques. In solution polymerization, the effect of various acid acceptors such as propylene oxide (PO), lithium hydroxide (LiOH) in the presence of lithium chloride (LiCl), and triethylamine (TEA) on teh molecular weight of the olyamides was studied. The effect of structure of studied. The effect of structur of various aromatic diamine sof molecular weight and thermal properties of polyamides was also studied. The polyamides prepared were characterized by solution viscosity, elemental analysis thermo-gravimetric analysis, differential scanning calorimetry, and x-ray diffraction. Physical and thermal properties of polyamides prepared from SPcl and Ard were compared with the polyamides prepared from SMCl and ARD.     

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 of novel optically active poly(ester‐imide)s with benzophenone linkages by microwave‐assisted polycondensation

A new simple and rapid polycondensation reaction of 4,4′‐carbonyl‐bis(phthaloyl‐L ‐alanine)diacid chloride [N,N ′‐(4,4′‐carbonyldiphthaloyl)]bisalanine diacid chloride with several diphenols, such as bisphenol‐A, phenolphthalein, 1,8‐dihydroxyanthraquinone, 4,4′‐dihydroxybiphenyl, 1,5‐dihydroxynaphthalene and hydroquinone, in the presence of a small amount of a polar organic medium such as o‐cresol was performed using a domestic microwave oven. The polycondensation reaction proceeded rapidly and was almost complete within 12 min to give a series of poly(ester‐imide)s with inherent viscosities of about 0.35–0.58 dl g⁻¹. The resulting poly(ester‐imide)s were obtained in high yield and are optically active and thermally stable. All the above compounds have been fully characterized by IR spectroscopy, elemental analysis, inherent viscosity (η_inh), solubility test and specific rotation. Thermal properties of the poly(ester‐imide)s have been investigated using thermal gravimetric analysis (TGA). © 2000 Society of Chemical Industry     

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 containing arylene sulfide-sulfone groups

Polyamides containing arylene sulfide as well as arylene sulfide-sulfone linkages were prepared from bis(4-phenylthio)dibenzoyl chloride (BPCl), 4,4′-[sulfonylbis(4-phenylthio)]dibenzoyl chloride (SPCl) and aromatic diamines both by solution and interfacial polymerization techniques. In the solution polymerization the effect of two different acid acceptors, lithium chloride and triethylamine, on inherent viscosity of the polyamides was studied. The effect of aromatic sulfone ether diamines and conventional aromatic diamines on viscosity and thermal properties of polyamides was also investigated. The polyamides prepared were characterized by IR, ¹H NMR, elemental analysis, solution viscosity, thermogravi-metry, differential scanning calorimetry and X-ray diffraction. Thermal and physical properties of polyamides prepared from BPCl and SPCl were compared.     

A copolymer of poly[2,2′‐(m‐phenylene)‐5,5′‐ bibenzimidazole] and poly(2,5‐benzimidazole) for high‐temperature proton‐conducting membranes

A novel copolymer of polybenzimidazoles was prepared by copolymerization of 3,3′‐diaminobenzidine tetrahydrochloride, 3,4‐diaminobenzoic acid and isophthalic acid in polyphosphoric acid at 200 °C. The polymerization could be performed within 90–110 min with the assistance of microwave irradiation. The solubility of the copolymer obtained in N,N‐dimethylacetamide (DMAc) was improved compared with those of poly[2,2′‐(m‐phenylene)‐5,5′‐bibenzimidazole] and poly(2,5‐benzimidazole). Thus copolymer membranes could be readily prepared by dissolving the copolymer powders in DMAc with refluxing under ambient pressure. The decomposition temperature of the copolymer was about 520 °C in air according to thermogravimetric analysis data. The proton conductivity and mechanical strength of the phosphoric acid‐doped copolymer membranes were investigated at elevated temperatures. A conductivity of 0.09 S cm^?1 at 180 °C and a tensile stress at break of 5.9 MPa at 120 °C were achieved for the acid‐doped copolymer membranes by doping acids in a 75 wt% H₃PO₄ solution. Copyright © 2010 Society of Chemical Industry     

Blue‐light‐emitting poly(arylene ethynylenes) containing alternating sequences of biphenylene or fluorenediyl and p‐phenylene moieties linked through triple bonds

Two new poly(arylene ethynylenes) were synthesized by the reaction of 1,4‐diethynyl‐2.5‐dioctylbenzene either with 4,4′‐diiodo‐3,3′‐dimethyl‐1,1′‐biphenyl or 2,7‐diiodo‐9,9‐dioctylfluorene via the Sonogashira reaction, and their photoluminescence (PL) and electroluminescence (EL) properties were studied. The new poly(arylene ethynylenes) were poly[(3,3′‐dimethyl‐1,1′‐biphenyl‐4,4′‐diyl)‐1,2‐ethynediyl‐(2,5‐dioctyl‐1,4‐phenylene)‐1,2‐ethynediyl] (PPEBE) and poly[(9,9‐dioctylfluorene‐2,7‐diyl)‐1,2‐ethynediyl‐(2,5‐dioctyl‐1,4‐phenylene)‐1,2‐ethynediyl] (PPEFE), both of which were blue‐light emitters. PPEBE not only emitted better blue light than PPEFE, but it also performed better in EL than the latter when the light‐emitting diode devices were constructed with the configuration indium–tin oxide/poly(3,4‐ethylenedioxythiophene) doped with poly(styrenesulfonic acid) (50 nm)/polymer (80 nm)/Ca:Al. The device constructed with PPEBE exhibited an external quantum efficiency of 0.29 cd/A and a maximum brightness of about 560 cd/m², with its EL spectrum showing emitting light maxima at λ = 445 and 472 nm. The device with PPEFE exhibited an efficiency of 0.10 cd/A and a maximum brightness of about 270 cd/m², with its EL spectrum showing an emitting light maximum at λ = 473 nm. Hole mobility (μ_h) and electron mobility (μ_e) of the polymers were determined by the time‐of‐flight method. Both polymers showed faster μ_h values. PPEBE revealed a μ_h of 2.0 × 10^?4 cm²/V·s at an electric field of 1.9 × 10⁵ V/cm and a μ_e of 7.0 × 10^?5 cm²/V·s at an electric field of 1.9 × 10⁵ V/cm. In contrast, the mobilities of the both carriers were slower for PPEFE, and its μ_h (8.0 × 10^?6 cm²/V·s at an electric field of 1.7 × 10⁶ V/cm) was 120 times its μ_e (6.5 × 10^?8 cm²/V·s at an electric field of 8.6 × 10⁵ V/cm). The much better balance in the carriers' mobilities appeared to be the major reason for the better device performance of PPEBE than PPEFE. Their highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels were also a little different from each other. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 299–306, 2006