Highly soluble phenylethynyl terminated oligoimides derived from 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane, 4,4′-oxydianiline and mixed thioetherdiphthalic anhydride isomers

Novel highly soluble phenylethynyl-endcapped oligoimides derived from mixed thioetherdiphthalic anhydride isomers (m-TDPA) and 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane (DAPI), 4,4′-oxydianiline (4,4’-ODA) with 4-phenylethynylphthalic anhydride (PEPA) as a reactive endcapping agent were synthesized. The calculated molecular weights of all the oligoimides were 2500 g·mol^?1.The effect of the mole ratio of DAPI/4,4’-ODA on solubility and melt viscosity of oligoimides as well as the thermal and mechanical properties of cured polyimide films was investigated. Experimental results indicated that DAPI greatly improved the solubility (>30 wt.%) of the oligoimides in low boiling points solvents when the content of DAPI was more than 10 mol% per total diamine. All the oligoimides exhibited very good processability with minimum melt viscosity lower than 60 Pa·s at about 330 °C. Tough and brown films were obtained after thermally cured at 370 °C for 1 h and dynamic mechanical analysis (DMA) showed that glass transition temperatures of the cured films increased up to 340 °C with the increasing content of DAPI. However, the thermal stability and mechanical properties decreased with the increase of DAPI content. The temperature of 5% weight loss was higher than 470 °C in both air and N₂ atmosphere obtained by thermogravimetric analysis (TGA). And the tensile strengths of the cured films were about 60 MPa.     

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     

Synthesis of Diimide-Diacid Monomers and Poly(amideimide)s: Effects of Flexible Linkages and Pendant Hexafluoroisopropylidine Unit on Processability,Thermal Stability and Electrical Properties

Two diimide-diacid monomers N,N′-bis(4-carboxypheny-4-oxyphenyl)oxydiphthalimide and N,N′-bis(4-carboxyphenyl-4-oxyphenyl)4,4′-(hexafluoroisopropylidene)diphthalimide were synthesized and characterized by IR and ¹H-NMR. A series of poly(amideimide)s were prepared by direct polycondensation of diimide-diacids with aromatic diamines through phosphorylation reaction. The poly(amideimide)s were characterized by IR, XRD, TGA, DSC, solution viscosity, solubility studies and electrical properties. X-ray diffraction studies indicate that the poly(amideimide)s were amorphous. Poly(amideimide)s were soluble in common organic solvents and exhibit excellent thermal stability. The PAIs have electrical insulation character and can be used in insulation of electrical items operating at elevated temperatures.     

Synthesis and characterization of aromatic polyamides derived from various derivatives of 4,4’-oxydianiline

Three aromatic diamines, 2,2′-diiodo-4,4′-oxydianiline (DI-ODA 2), 2,2′-bis[p-(trifluoromethyl)phenyl]-4,4′-oxydianiline (BTFP-ODA 3) and 2,8-diaminodibenzofuran (DADBF 5) were synthesized by using 4,4-oxydianiline (4,4′-ODA) as the starting material. New aromatic polyamides 6, 7 and 8 were prepared from these three diamines and six commercially available aromatic diacids by direct polycondensation, respectively. Polyamides 6 and 7 contained bulky iodide and p-trifluoromethylphenyl substitutents that would hinder the chain packing and increase the free volume. They exhibited good optical transparency in visible light region and showed excellent solubility in organic solvents such as DMSO, DMAc, DMF and NMP. Polyamides 8 containing planar dibenzofuran moieties had the highest glass transition temperatures and decomposition temperatures among these polyamides. Polyamides 6 had the lowest decomposition temperatures due to the presence of weak carbon–iodine bond. All of these polyamides showed amorphous nature evidenced by wide angle X-ray diffraction. No endothermic peaks were observed from DSC thermograms up to their decomposition temperatures. High optical transparency and excellent solubility combined with good thermal stability make these polyamides attractive for potential soft electronics applications.     

Synthesis and properties of polyimides derived from diamine monomer containing bi-benzimidazole unit

A new aromatic heterocyclic diamine monomer containing bi-benzimidazole unit, 2,2-bis(4′-aminophenyl)-5,5-bi-1H-benzimidazole, was synthesized from 2,2-bis(4′-nitrophenyl)-5,5-bi-1H-benzimidazole (BNPBBI) prepared via the reaction of 3,3′,4,4′-biphenyltetramine and p-nitrobenzaldehyde with a high yield. Their compositions and chemical structures containing polybenzimidazole backbone were characterized by FTIR, ¹H NMR and elemental analysis. A series of aromatic polyimides containing the heterocyclic moiety in the main chain were prepared by the reaction of BAPBBI with various aromatic dianhydrides of 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride or pyromellitic dianhydride. The polymers possess a high glass transition temperature of >415 °C and a good thermal stability up to 566 °C with a 5 % weight loss. The combination of polybenzimidazole and polyimide via introducing BAPBBI into the main chains provides the rigid structure, and macromolecular interactions are thus enhanced, resulting in the outstanding mechanical properties. These polyimides exhibit the strong tensile strength of 201 to 327 MPa, and the ultrahigh tensile moduli of 10.7 to 15.5 GPa without post stretching.     

Flexible thin films based on poly(ester imide) materials for optoelectronic applications

A series of high-performance poly(ester imide)s bearing cycloaliphatic moieties was manufactured by a two-step procedure via solution polycondensation of an aromatic–aliphatic dianhydride containing preformed ester units and cyclohexanone ring in the main chain, with various aromatic diamines. The new dianhydride monomer, namely 2-oxocyclohexane-1,3-bis[4,4′-bis(trimellitate)benzylidene] dianhydride, was synthesized by the reaction between 2,6-bis(4-hydroxybenzylidene)cyclohexanone and trimellitic anhydride chloride. The chemical structure of the resulting dianhydride was confirmed by means of Fourier transform infrared, ¹H NMR and ¹³C NMR spectroscopies. The poly(ester imide)s from the series exhibited water uptake capacity in the range 3.45–10.09%. The onset temperatures, corresponding to the first detected thermal weight loss in the samples, ranged from 367 to 441 °C. Besides the cycloaliphatic moieties coming from the dianhydride monomer, the other aliphatic segments present in the diamine structures were responsible for improved optical performance in the resulting poly(ester imide)s, the transmittance being higher than 80% at 684 nm. © 2021 Society of Industrial Chemistry.     

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.     

Synthesis and characterization of new sulfonated copolytriazoles and their proton exchange membrane properties

This work reports the synthesis and characterization of a series of new sulfonated copolytriazoles. The polymers were prepared by CuI catalyzed 1,3-cycloaddition reaction of an equimolar amount of a dialkyne monomer, 1,3-diethynylbenzene and a mixture of two diazide monomers, namely, 4,4′-diazidodiphenyl ether and 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt. The copolymers showed high inherent viscosity indicating the formation of high molar mass product. The copolymers were characterized by Fourier transform infrared and proton nuclear magnetic resonance spectroscopic techniques. The copolymer membranes displayed moderate water uptake, high dimensional, mechanical, and thermal stability. Transmission electron microscopy micrographs displayed excellent phase-separated morphology along with very fine ionic clusters. The copolymer PTEOSH-90 (90% degree of sulfonation) showed much higher proton conductivity value which is up to 196 mS cm⁻¹ at 80 °C in completely hydrated condition compared to that of Nafion (165 mS cm⁻¹). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48514.     

Preparation and properties of melt‐processable polyimides based on fluorinated aromatic diamines and aromatic dianhydrides

Two series of melt‐processable polyimides were prepared from 4,4′‐bis(3‐amino‐5‐trifluoromethylphenoxy)biphenyl (m‐6FBAB) and 4,4′‐bis(4‐amino‐5‐trifluoromethylphenoxy) biphenyl (p‐6FBAB) with various aromatic dianhydrides. The effects of the chemical structures of the polyimides on their properties, especially the melt processability and organic solubility, were investigated. The experimental results demonstrate that some of the fluorinated aromatic polyimides showed good melt processability at elevated temperatures (250–360°C) with relatively low melt viscosities and could be melt‐molded to produce strong and tough polyimide sheets. Meanwhile, the polyimides showed excellent organic solubility in both polar aprotic solvents and common solvents to give stable polyimide solutions with high polymer concentrations and relatively low viscosities. Thus, we prepared high‐quality polyimide films by casting the polyimide solutions on glass plates followed by baking at relatively low temperatures. The polyimides derived from m‐6FBAB showed better melt processability and solubility than the p‐6FBAB based polymers. The melt‐processable polyimides showed a good combination of thermal stability and mechanical properties, with decomposition temperatures of 547–597°C, glass‐transition temperatures in the range 205–264°C, tensile strengths of 81.3–104.9 MPa, and elongations at break as high as 19.6%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Organosoluble polyimides derived from asymmetric 2‐substituted‐and 2,2′,6‐trisubstituted‐4,4′‐oxydianilines

We report a new method for the preparation of asymmetric diamines using 4,4′‐oxydianiline (4,4′‐ODA) as the starting material. By controlling the equivalents of bromination agent, N‐bromosuccinimide, we were able to attach bromide and phenyl substituents at the 2‐ or 2,2′,6‐positions of 4,4′‐ODA. Thus, four new asymmetric aromatic diamines, 2‐bromo‐4,4′‐oxydianiline (6), 2,2′,6‐tribromo‐4,4′‐oxydianiline (7), 2‐phenyl‐4,4′‐oxydianiline (8) and 2,2′,6‐triphenyl‐4,4′‐oxydianiline (9), were synthesized by this method. Their structural asymmetry was confirmed using ¹H NMR spectroscopy. Asymmetric polyimides (PI10–PI13) were prepared from these diamines and three different dianhydrides (pyromellitic dianhydride (PMDA), 3,3′,4,4′‐biphenyltetracarboxylic dianhydride and 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride) in refluxing m‐cresol. The formed polyimides, except PI10a derived from 6 and PMDA, were all soluble in m‐cresol without premature precipitation during polymerization. These polyimides with inherent viscosity of 0.41–0.96 dL g^?1, measured at a concentration of 0.5 g dL^?1 in N‐methyl‐2‐pyrrolidone at 30 °C, can form tough and flexible films. Because of the structural asymmetry, they also exhibited enhanced solubility in organic solvents. Especially, polyimides PI11a and PI13a derived from 7 and 9 with rigid PMDA were soluble in various organic solvents at room temperature. The structural asymmetry of the prepared polyimides was also evidenced from ¹H NMR spectroscopy. In the ¹H NMR spectrum of PI11a, the protons of pyromellitic moiety appeared in an area ratio of 1:2:1 at three different chemical shifts, which were assigned to head‐to‐head, head‐to‐tail and tail‐to‐tail configurations, respectively. These polyimides also exhibited good thermal stability. Their glass transition temperatures ranged from 297 to 344 °C measured using thermal mechanical analysis. © 2013 Society of Chemical Industry     

Interfacial Polymerization of Linear Aromatic Poly(ester amide)s

Linear aromatic poly(ester amide)s (PEAs) have been synthesized by interfacial polycondensation (IPC) of aromatic diamidoacid chloride: 2-{[4-({[2-(chlorocarbonyl) phenyl]amino} carbonyl) benzoyl]amino} benzoyl chloride (2CCBC), with ethylene glycol, bisphenol A, resorcinol, 4,4′-bis(4-hydroxybenzilidine)diaminobenzanilide and 4,4′-bis(4-hydroxy benzilidine)-m-phenylenediamine in chloroform/water system employing phase-transfer-catalyst. The aromatic diamidoacid chloride has been prepared by condensation of terephthaloyl chloride with anthranilic acid. These polymers were characterized by elemental analysis, FTIR, ¹H-NMR, solubility studies, intrinsic viscosity and TGA analysis. The polyester-amides so obtained show good thermal stability.     

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.     

Benzoxazine monomers based on aromatic diamines and investigation of their polymerization by rheological and thermal methods

In the present article with the aim to find new polybenzoxazines with improved thermal properties, new benzoxazine monomers based on phenol and the following aromatic diamines were synthesized: 3,4′-oxydianiline (P-3,4′oda); o-tolidine (P-ot); m-tolidine (P-mt) and 4,4′-(1,3-phenylenedioxy)dianiline (P-tper) and their comparison with the previously known benzoxazines based on 4,4′-diaminodiphenylmethane (P-ddm); 4,4′-oxydianiline (P-4,4′-oda) and 2,2-Bis[4-(4-aminophenoxy)phenyl]propane (P-bapp). The dependence of the thermal and rheological characteristics on the structure of benzoxazine monomers based on various diamines was estimated and possible methods for their processing were identified. All the polybenzoxazines obtained in this work have high char yield and reduced flammability. It was found that the structure of the diamine can have a fundamental effect on both the rheological properties and heat resistance of polybenzoxazines. The benzoxazine monomers P-ddm, P-tper and P-4,4′oda retain viscosity up to 1 Pa s. at 110°C for 2 h, the P-tper monomer with a resorcinol bridge has about five times lower viscosity compared to the P-bapp monomer with a bisphenol A bridge. Polybenzoxazines based on the monomers P-ddm, P-mt, P-bapp and P-tper show excellent thermal stability with a temperature of 10% weight loss above 400°C. In particular, T_g of P-3,4′oda and P-mt monomers is relatively high (202 and 239°C, respectively), while P-ot's is unusually low (115°C), which may be caused by the specific effect of the substituents in the aromatic ring of the amine and their position.     

Products of the reaction of 4,4′-bis(mercaptomethyl)benzophenone with halogenalkane acids and halogenalkane diols as new monomers

A few new thiodicarboxylic acids and thiodiols were obtained by condensation reaction of 4,4′-bis(mercaptomethyl)benzophenone (BMMB) with some halogen acids or halogen alcohols, respectively, in aqueous sodium hydroxide solution. By melt polycondensation of one of these acids, i.e. benzophenone-4,4′-bis-(methylthioacetic acid) (BBMTAA) with 1,5-pentanediol, a new linear polyester was obtained, and by melt polyaddition of one of these diols, i. e. benzophenone-4,4′-bis(methylthiohexanol) (BBMTH) with hexamethylene diisocyanate (HDI) a new linear polyurethane was obtained. The structures of monomers and polymers were confirmed by elemental analysis and FT-IR and ¹H NMR spectroscopy. The polymers were studied to describe their physicochemical, thermal and mechanical properties.     

Curing kinetics and thermal properties of diglycidylether of bisphenol A with various diamines

To prepare a high‐performance epoxy, we synthesized three types of diamines {N,N′‐(4,4′‐diphenylether)‐bis(4‐aminophthalimide), 4,4′‐bis(p‐aminophenoxy)dibenzalphentaerythriol, and 2,2′‐bis[4‐(p‐aminobenzoyl)phenyl]propane} as epoxy curing agents with a two‐step reaction sequence. The structures of the synthesized diamines were confirmed with Fourier transform infrared and nuclear magnetic resonance spectroscopy. The curing kinetics and thermal stability of the cured epoxy resin with diglycidylether of bisphenol A were estimated with differential scanning calorimetry and thermogravimetric analysis under a nitrogen atmosphere. The kinetics parameters were determined with the Ozawa and Kissinger equations. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 279–284, 2001     

Synthesis and properties of poly(amide–imide)s based on N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide,p‐aminobenzoic acid and various aromatic diamines

A new diimide–diacid monomer, N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide (I), was prepared by azeotropic condensation of 4,4′‐oxydiphthalic anhydride (ODPA) and p‐aminobenzoic acid (p‐ABA) at a 1:2 molar ratio in a polar solvent mixed with toluene. A series of poly(amide–imide)s (PAI, III_a–m) was synthesized from the diimide–diacid I (or I′, diacid chloride of I) and various aromatic diamines by direct polycondensation (or low temperature polycondensation) using triphenyl phosphite and pyridine as condensing agents. It was found that only III_k–m having a meta‐structure at two terminals of the diamine could afford good quality, creasable films by solution‐casting; other PAIs III using diamine with para‐linkage at terminals were insoluble and crystalline; though III_g–i contained the soluble group of the diamine moieties, their solvent‐cast films were brittle. In order to improve their to solubility and film quality, copoly(amide–imide)s (Co‐PAIs) based on I and mixtures of p‐ABA and aromatic diamines were synthesized. When on equimolar of p‐ABA (m = 1) was mixed, most of Co‐PAIs IV had improved solubility and high inherent viscosities in the range 0.9–1.5 dl g^?1; however, their films were still brittle. With m = 3, series V was obtained, and all members exhibited high toughness. The solubility, film‐forming ability, crystallinity, and thermal properties of the resultant poly(amide–imide)s were investigated. © 2002 Society of Chemical Industry     

Chain‐extended polyurethanes—Synthesis and characterization

Chain‐extended polyurethanes (PUs) were prepared using castor oil and different diisocyanates such as toluene‐2,4‐diisocyanate and 4,4′‐methylene bis(phenylisocyanate) as a crosslinker and different aromatic diamines like 4,4′‐diaminodiphenyl methane and 4,4′‐diaminodiphenyl sulphone as chain extenders. The effect of aromatic diamines on the swelling and thermal degradation behavior of PU have been discussed. A thermogravimetric analyzer (TGA) curve shows that all the chain‐extended PUs are stable up to 194°C and that maximum weight loss occurs at 490°C. The TGA thermograms show that the thermal degradation of the PUs was found to proceed in two steps. The average molecular weight between crosslinks (M?_c) was determined by swelling studies. The properties imparted by the aromatic chain extenders are explained on the basis of groups present in the diamines. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 359–369, 2002; DOI 10.1002/app.10347     

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 Novel Polycyanurates Derived from 2-(N-piperidino)-4,6-bis (naphthoxy-2-carbonyl chloride)-s-triazine

Various polyamides containing s-triazine rings in the main chain were synthesized by high temperature polycondensation of 2-(N-piperidino)-4,6-bis(naphthoxy-2-carbonyl chloride)-s-triazine [PNCCT] with various aromatic diamines such as 4,4′-diaminodiphenyl [DADP], 4,4′-diaminodiphenylamide [DADPA], 4,4′-diaminodiphenylsulphone [DADPS], 4,4′-diaminodiphenylsulphonamide [DADPSA], 4,4′-diaminodiphenyl methane [DADPM], 2,4-diamino toluene [DAT] and p-phenylene diamine [PPDA]. All the polyamides were characterized by viscosity measurements, IR spectra, NMR spectra, and thermogravimetric analysis.     

Synthesis and characterization of new thermally stable aromatic copoly(ester–amide)s from diester‐dicarboxylic acids

Two new aromatic diester‐dicarboxylic acids containing furan rings, namely, benzofuro[2,3‐b]benzofuran‐2,9‐dicarboxyl‐bis‐pyridyl ester‐4,4′‐dicarboxylic acid and benzofuro[2,3‐b]benzofuran‐2,9‐dicarboxyl‐bis‐phenyl ester‐4,4′‐dicarboxylic acid were synthesized by the reaction of benzofuro[2,3‐b]benzofuran‐2,9‐dicarbonyl chloride with 6‐hydroxynicotinic acid and 4‐hydroxybenzoic acid, respectively. These monomers were converted to aromatic copoly(ester–amide)s by reaction with various aromatic diamines via direct polycondensation. Polymers were characterized by FTIR and ¹H NMR spectroscopy, thermogravimetry, viscosity and solubility tests. The inherent viscosity of the polymers was in the range 0.23–0.46 dl g^?1 in dimethyl sulfoxide at 30 °C. They dissolved readily in polar solvents at room temperature. They possess a glass‐transition temperature in the range 210–260 °C and exhibit excellent thermal stability. Copyright © 2004 Society of Chemical Industry