Preparation and properties of new aromatic polyamides from bis(4-aminophenyl) phenylphosphine and aromatic dicarboxylic acids

A new triphenylphosphine-type monomer, bis(4-aminophenyl) phenylphosphine, was synthesized starting from p-bromoaniline and dichlorophenylphosphine. The aromatic polyamides (aramids) containing triphenyphosphine unit in the polymer backbone was prepared by the polycondensation of this diamine with various aromatic diacid chlorides using a low-temperature solution method in N,N-dimethylacetamide (DMAc). The aramids having inherent viscosities of 0.4–0.7 dL/g were obtained in quantitative yields. The polymers were amorphous and soluble in various organic solvents such as DMAc, N-methylpyrrolidone, dimethyl sulfoxide, pyridine, and m-cresol. Transparent, tough, and flexible films were obtained by casting from the DMAc solutions. The glass transition temperatures of the aramids were in the range of 265–310°C, and the 10% weight loss temperatures were above 400°C in air. © 1993 John Wiley & Sons, Inc.     

Synthesis and properties of polyamides of p-phenylenedioxydiacetic acid

Several polyamides of p-phenylenedioxydiacetic acid (PDDA) were synthesized by the low-temperature solution polycondensation techniques. Six different diamines were condensed independently with p-phenylenedioxydiacetyl chloride (PDC) in a mixture of N-methyl pyrolidone (NMP) and hexamethyl phosphoramide (HMPA). The polymers were obtained in 80–95% yield and possessed inherent viscosities in the range 0.32–0.81 dL/g. The polymers were characterized by infrared (IR) and H¹-NMR spectra. The solubility, density, crystallinity, and thermal stability of the polyamides were also determined. A model diamide (MDA-1) was also synthesized from aniline and PDC to confirm the formation of polyamides from diamines.     

Aromatic polyisophthalamides with N-benzylidene pendant groups

A new series of modified polyisophthalamides bearing N-benzylidene pendant groups was prepared by reacting various aromatic diamines with 5-(N-benzylidene) isophthalic acid. The latter was synthesized from the reaction of 5-aminoisophthalic acid with benzaldehyde and characterized by IR and ¹H-NMR spectroscopy. Triphenyl phosphite and pyridine was used as condensing agents for preparing polyamides. In addition, the corresponding unsubstituted polyisophthalamides were prepared under identical experimental conditions for comparative purposes. Characterization of modified polyamides was accomplished by IR as well as inherent viscosity measurements. They showed a slightly lower solubility in various media than the corresponding unsubstituted polyamides. The cured modified polyamides displayed significantly higher thermal stability than the cured unsubstituted polyamides. They were stable up to 355–308°C in N₂ or air and afforded anaerobic char yield of 66–61% at 800°C. © 1992 John Wiley & Sons, Inc.     

Optically high transparency and light color of organosoluble polyamides containing trifluoromethyl and kink diphenylmethylene linkage

New polyamides were prepared directly from a diamine, bis[4‐(2‐trifluoromethyl 4‐aminophenoxy)phenyl] diphenylmethane, containing an electron‐withdrawing trifluoromethyl group and a kink diphenylmethylene linkage with various aromatic dicarboxylic acids having inherent viscosities ranging from 0.66 to 0.83 dL g^?1. All the polyamides showed outstanding solubility and could be easily dissolved in amide‐type polar aprotic solvents (e.g., N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, and N,N‐dimethylformamide) and even dissolved in less polar solvents (e.g., pyridine, cyclohexanone, and tetrahydrofuran). The dielectric constants of the polyamide films were 3.37–3.87 (100 KHz) and decreased with an increase in the frequency, which ranged from 1 Hz to 100 KHz. A low coefficient of thermal expansion for the polyamides was observed in the range of 54–78 ppm/°C (by thermomechanical analysis). These polyamides showed excellent thermal stability, and the 10% weight loss temperatures were in the range of 484–507 °C in an atmosphere of nitrogen. The polymers had an initial modulus of 1.8–2.2 GPa. The polyamides with kink and electron‐withdrawing trifluoromethyl units afforded light‐color polymer films with high transmittance in the visible region (400–700 nm), and their cutoff wavelength was lower than 362 nm. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4559–4569, 2005     

Synthesis and characterization of new soluble polyamides containing phthalimide pendent group

A dicarboxylic acid monomer, 5-phthalimidoisophthalic acid, containing a phthalimide pendent group was prepared by the condensation of 5-aminoisophthalic acid and phthalic anhydride in glacial acetic anhydride. The monomer was reacted with various aromatic diamines to produce polyamides using triphenyl phosphite and pyridine as condensing agents. These polyamides were produced with inherent viscosities of 0.64–1.14 dL · g⁻¹. All the polymers, characterized by wide-angle X-ray diffraction, revealed an amorphous nature resulting from the presence of the bulky pendent group. These polyamides exhibited excellent solubility in a variety of solvents such as N- methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, dimethyl sulfoxide, pyridine, and cyclohexanone. These polyamides showed glass-transition temperatures (T_g's) between 247 and 273 °C (by DSC) and 248 and 337 °C (by a dynamic mechanical analyzer). The thermogravimetric analytic measurement revealed the decomposition temperature at 10% weight-loss temperatures (Td₁₀) ranging from 442 to 530 °C in nitrogen. The polyamides containing phthalimide groups exhibited higher T_g and Td₁₀ values than those having no phthalimide groups. Transparent, tough, and flexible films of these polyamides could be cast from the DMAc solutions. These casting films had tensile strengths ranging from 81 to 126 MPa, elongations at break ranging from 7 to 13%, and tensile moduli ranging from 2.0 to 2.9 GPa. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1557–1563, 2001     

Synthesis and properties of new polyamides derived from 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene and aromatic dicarboxylic acids

The diamine 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene, containing symmetric, bulky di-tert-butyl substituents and a flexible ether unit, was synthesized and used to prepare a series of polyamides by the direct polycondensation with various aromatic dicarboxylic acids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. All the polymers were obtained in quantitative yields with inherent viscosities of 0.32–1.27 dL g⁻¹. Most of these polyamides, except II _a , II _d , and II _e , showed an amorphous nature and dissolved in polar solvents and less polar solvents. Polyamides derived from 4,4′-sulfonyldibenzoic acid, 4,4′-(hexafluoro-isopropylidene)dibenzoic acid, and 5-nitroisophthalic acid were even soluble in a common organic solvent such as THF. Most polyamide films could be obtained by casting from their N,N-dimethylacetamide (DMAc) solutions. The polyamide films had a tensile strength range of 49–78 MPa, an elongation range at break of 3–5%, and a tensile modulus range of 1.57–2.01 GPa. These polyamides had glass transition temperatures ranging between 253 and 276°C, and 10% mass loss temperatures were recorded in the range 402–466°C in nitrogen atmosphere. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1069–1074, 1998     

Synthesis and properties of new soluble N-phenyl–substituted aromatic-aliphatic and all aromatic polyamides derived from 4,4′-dianilinobiphenyl

New N-phenylated aromatic-aliphatic and all aromatic polyamides were prepared by the high-temperature solution polycondensation of 4,4′-dianilinobiphenyl with both aliphatic (methylene chain lengths of 6–11) and aromatic dicarboxylic acid chlorides. All of the aromatic-aliphatic polyamides and the wholly aromatic polyamides exhibited an amorphous nature and good solubility in amide-type and chlorinated hydrocarbon solvents, except for those aromatic polyamides containing p-oriented phenylene or biphenylylene linkages in the backbone; the latter were crystalline and insoluble in organic solvents except m-cresol. The N-phenylated aromatic-aliphatic polyamides and aromatic polyamides had glass transition temperatures in the range of 79–116°C and 207–255°C, respectively, and all the polymers were thermally stable with decomposition temperatures above 400°C in air. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2193–2200, 1998     

High Glass Transition and Optical Transparency of Novel Organosoluble Polyamides Containing 4‐tert‐‐Butyltoluene Moiety

A series of novel polyamides 3a – 3d containing 4‐tert‐butyltoluene moiety, were prepared using the phosphorylation polycondensation technique. FT‐IR and ¹H NMR techniques were used to investigate the chemical structures of 3a–3d . The results confirmed that they agreed with the proposed structures for 3a – 3d completely. The 3a – 3d had inherent viscosities ranging from 0.71 to 1.67 dL·g⁻¹. All the polyamides showed excellent solubility, with the dissolvability at a concentration of 10 wt% in most amide polar solvents. Flexible and tough polyamide films could be prepared by casting from DMAc (N,N‐dimethylacetamide) solvent. Their films were nearly colorless and exhibited high optical transparency, with the UV cutoff wavelength in the range of 346–363 nm and transmittance higher than 80% at 450 nm. They also exhibited high glass transition temperatures in the range of 310–343°C and the onset decomposition temperatures in the range of 435–462°C in nitrogen atmosphere. Meanwhile, these polyamide films possess good mechanical properties with tensile strengths of 76.4–86.1 MPa and elongations at break of 11.2%–27.3%. Due to those properties, these polyamides could be considered as photoelectric and microelectronic materials.     

Synthesis and characterization of new soluble polyamides derived from 3,3′,5,5′-tetramethyl-2,2-bis[4-(4-carboxyphenoxy)phenyl]propane

A series of new soluble polyamides having isopropylidene and methyl-substituted arylene ether moieties in the polymer chain were prepared by the direct polycondensation of 3,3′,5,5′-tetramethyl-2,2-bis[4-(4-carboxyphenoxy)phenyl]propane and various diamines in N-methyl-2-pyrrolidinone (NMP) containing CaCl₂ using triphenyl phosphite and pyridine as condensing agents. Polymers were produced with moderate to high inherent viscosities of 0.85–1.47 dL g⁻¹ while the weight-average molecular weight and number-average molecular weight were in the range of 86,700–259,000 and 43,300–119,000, respectively. All the polymers were readily dissolved in polar aprotic solvents such as NMP, N,N-dimethylacetamide, and N,N-dimethylformamide, as well as less polar solvents such as m-cresol and pyridine, and even soluble in tetrahydrofuran. These polymers were solution-cast into transparent, flexible and tough films. All of the polymers were amorphous and the polyamide films had a tensile strength range of 82–122 MPa, an elongation at break range of 6–18%, and a tensile modulus range of 2.0–2.8 GPa. These polyamides had glass transition temperatures between 233–260°C and 10% weight loss temperatures in the range of 450–489 and 459–493°C in nitrogen and air atmosphere, respectively. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1997–2003, 1999     

Synthesis and characterization of novel aromatic polyamides from 3,4-bis(4-aminophenyl)-2,5-diphenylfuran and aromatic diacid chlorides

A new highly phenylated heterocyclic diamine, 3,4-bis(4-aminophenyl)-2,5-diphenylfuran, was synthesized in three steps from 4–-nitrodeoxybenzoin. The low temperature solution polycondensation of the diamine with various aromatic diacid chlorides afforded tetraphenylfuran-containing aromatic polyamides with inherent viscosities of 0.2–0.8 dL/g. Copolyterephthalamides were obtained from the diamine and 4,4′-oxydianiline. The polyamides were generally soluble in a wide range of solvents that included N,N-dimethylacetamide, N-methyl-2-pyrrolidone, pyridine, and m-cresol. Glass transition temperatures of the polyamides and copolyamides ranged from 302–342°C, and 10% weight loss was observed above 480°C in nitrogen.     

Synthesis and characterization of new soluble aromatic polyamides from diaminotetraphenylimidazolin-2-one and various aromatic dicarboxylic acid chlorides

Novel aromatic polyamides, having inherent viscosities of 0.76-2.31 dL/g, were synthesized by the low temperature solution polycondensation of a new highly phenylated diamine monomer having an imidazolinone group, 1,3-bis(4-aminophenyl)-4,5-diphenylimidazoline-2-one (TPIDA), with various aromatic diacid chlorides. All the polymers were amorphous, and most of the polyamides were readily soluble in organic solvents such as N-methyl–2-pyrrolidone, N,N-dimethylacetamide (DMAc), and m-cresol. Flexible and tough films could be prepared from the DMAc solutions of these soluble aromatic polyamides. The glass transition temperatures and 10% weight loss temperatures under nitrogen of the polyamides were in the range of 275–315°C and 430–505°C, respectively. © 1995 John Wiley & Sons, Inc.     

Synthesis and characterization of new polyamides derived from 1,6-bis[4-(4-aminophenoxy)phenyl]diamantane

A series of new polyamides 3 were synthesized by direct polycondensation of the 1,6-bis[4-(4-aminophenoxy)phenyl]diamantane (1) with various dicarboxylic acids. The polyamides had inherent viscosities of 0.45–1.90 dL/g and number-average molecular weights (M_n) of 24,000–110,000. Dynamic mechanical analysis (DMA) reveals that polymers 3 have two relaxations on the temperature scale between −100 and 400°C. Their α relaxations occurred at high temperatures, ranging from 338 to 389°C. Moreover, these polymers remained quite stable at high temperatures and maintained good mechanical properties (G′ = ca. 10⁸ Pa) up to temperatures close to the main transition markedly exceeding 350°C. Due to the bulky diamantane elements and the flexible ether segments, the polymers 3 were amorphous and soluble in a number of organic solvents such as pyridine, N-methyl-2-pyrrolidone (NMP), and N,N-dimethylacetamide (DMAc). The polyamides 3 have tensile strengths of 56.7–90.2 MPa, elongation to breakage values of 7.5–27.7%, and initial moduli of 1.8–2.1 GPa. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2185–2192, 1998     

Synthesis and characterization of tough polycyclic polyamides containing 4,9-Diamantyl moieties in the main chain

A series of new polyamides were synthesized by direct polycondensation of the 4,9-diamantane dicarboxylic acid ( I ) with various aromatic diamines in N-methyl-2-pyrrolidone (NMP) containing lithium chloride. The polyamides had inherent viscosities of 0.56–1.85 dL/g. Dynamic mechanical analysis revealed the polymers IIIa–IIId to have main melting transitions at 403, 431, 423, and 452°C, respectively. Moreover, these polymers were quite stable at high temperatures and maintained good mechanical properties (G′ = ca. 10⁸ Pa) up to temperatures close to the main transition well above 400°C. Although the polyamides contained rigid 4,9-diamantyl moieties in the main chain, the tensile properties of the polyamides showed toughness. Elongations of polyamides IIIa and IIIb reached 38.3 and 31.7%, respectively, before breaking. A glass transition was not observed. However, polyamide IIIc shows a melting transition with a sharp endothermic peak at 423°C by DSC measurement. Additionally, the introduction of 4,9-diamantyl units into the polyamide backbone resulted in polyamides with high thermal stability and good mechanical properties. © 1996 John Wiley & Sons, Inc.     

Synthesis of polyamides by a new direct polycondensation reaction using triphenyl phosphite and lithium chloride

Metal salts such as lithium chloride were found to facilitate significantly the reaction of carboxylic acids and amines promoted by triphenyl phosphite, and the reaction was applied successfully to the direct polycondensation reaction of dicarboxylic acids and diamines and of p-aminobenzoic acid. Among metal salts tested, lithium chloride was most effective to the reaction; the chloride was involved catalytically in the reaction, its addition of about twice equivalent to triphenyl phosphite giving the most favorable results. Triphenyl phosphite was most effective, whereas diphenyl phosphite was less effective, and alkyl esters gave no polymers. The reaction was also markedly affected by solvents, the most favorable results being given in N-methylpyrrolidone (NMP). Various polyamides of high molecular weight were obtained in quantitative yield.     

Synthesis and characterization of new polyamides containing adamantyl and diamantyl moieties in the main chain

This work synthesized a series of new polyamides by direct polycondensation of 1,3-bis[4-(4-carboxyphenoxy)phenyl]adamantane ( I ) with various diamines. The diacid I was synthesized from 1,3-bis(4-hydroxyphenyl)adamantane in two steps. Polyamides III were soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), and pyridine. The polyamides had medium inherent viscosities of 0.30–0.55 dL/g and number-average molecular weights (M_n) of 22,000–36,000. The polyamides III _a and III _b had tensile strengths of 59.8 and 77.5 MPa, elongation to breakage values of 5.8 and 7.6%, and initial moduli of 1.9 and 1.8 GPa, respectively. Their glass transition temperatures were found to be 219–295°C by means of differential scanning calorimetry (DSC). Dynamic mechanical analysis (DMA) reveals that the incorporation of rigid and bulky diamantane into polyamides III _a and III _b leads to high glass transition temperatures (T_gs), at 299 and 286°C, respectively. The decomposition temperatures of polyamides III at a 5% weight loss ranged from 388 to 416°C in air and from 408 to 435°C in N₂ atmosphere. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 785–792, 1998     

High α transitions of new polyamides based on diamantane

A series of new polyamides were synthesized by direct polycondensation of the 1,6-bis(4-aminophenyl)diamantane with various dicarboxylic acids. The soluble polyamides had high inherent viscosities, ranging from 0.73 to 1.21 dL/g. Polyamides derived from 5-tert-butylisophthalic acid and (±)-1,3-cyclohexanedicarboxylic acid were soluble in N-methyl-2-pyrrolidone (NMP) and pyridine. When NMP and N-dimethylacetamide (DMAc) were added with 3% (w/v) LiCl, the solubilities of polyamides derived from 4,4′-oxybis(benzoic acid) and cis-1,4-cyclohexanedicarboxylic acid were markedly enhanced. Polyamides had tensile strengths of up to 87.8 MPa, elongation to breakage values of up to 19.3%, and initial moduli of up to 2.1 GPa. Dynamic mechanical analysis (DMA) reveals that the polyamides have three relaxations. Their α relaxations occurred at high temperatures, ranging from 380 to 462°C. Three of polyamides exhibited good retention of storage modulus (above 10⁸ Pa) at a temperature exceeding 410°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1257–1263, 1998     

Dechlorination of N-chloro poly(hexamethylene adipamide) and N-chloro poly(ε-caprolactam) products to the corresponding polyamides

A rapid dechlorination method of N-chloro poly(hexamethylene adipamide) and N-chloro poly(ε-caprolactam) to the corresponding polyamides was studied. This method can be used for molecular weight determinations of N-chloro polyamides by viscosimetric measurements. The dechlorination was achieved in formic acid solution by the reaction of N-chloro polyamides with trialkyl phosphites. The reaction was exothermic and vigorous and was applied to a series of products of various degrees of N-chlorination covering the range of 0–100%. No N—Cl was detected by iodimetric titration of the dechlorination products. The dechlorination of N-chloro polyamides was demonstrated by infrared (IR) spectroscopy. No significant molecular weight reduction except that taking place in the N-chlorination reaction of poly(hexamethylene adipamide) was observed.     

Synthesis and characterization of N-phenylated aromatic polyamides from N-silylated dianilino compounds and aromatic diacid chlorides

N-Phenylated aromatic polyamides of high molecular weights were synthesized by the hightemperature solution polycondensation of N,N′ -di(trimethylsilyl)-substituted dianilino compounds derived from p-dianilinobenzene, bis(4-anllinophenyl) ether, and α,α′-dianilino-p-xylene, with isophthaloyl and terephthaloyl chloride. Almost all of the N-phenylated polyamides were amorphous, and soluble in a variety of organic solvents including dimethylformamide, m-cresol, and chloroform. Transparent and flexible films of these polymers could be cast from the dimethylformamide solutions. Four wholly aromatic polyamides had glass transition temperatures in the range of 195–255°C, and began to lose weight around 400°C in air.     

Poly(methylene sebacate): Synthesis and characterization

The synthesis of poly(methylene sebacate) was carried out via the reaction of cesium sebacate with bromochloromethane in N-methylpyrrolidone over a range of temperatures (55–130°C). A number of polymers having limiting viscosity numbers in the range of 0.29–0.94 dL g^?1 (CHCl₃; 25°C) were characterized by elemental analyses, ¹H- and ¹³C-NMR, DSC, and GPC techniques. The polymerization was found to be very rapid at 100°C, being complete in ca. 15 min. and was relatively insensitive to the stoichiometric ratio of the monomers. As high molecular weight polymers were produced without the quantitative conversion of the reactants, the polymerization is considered to be occurring by an interfacial mechanism.     

Preparation and properties of polyamides and polyimides derived from 1,3-diaminoadamantane

1,3-Diaminoadamantane (I) was used as a monomer with various aromatic dicarboxylic acyl chlorides and dianhydrides to synthesize polyamides and polyimides, respectively. Polyamides having inherent viscosities of 0.10–0.27 dL/g were prepared by low-temperature solution polycondensation. The polyamides were soluble in a variety of solvents such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), pyridine, dioxane, and nitrobenzene. These polyamides had glass transition temperatures in the 179–187°C range and 5% weight loss temperatures occurred at up to 354°C. Polyimides based on diamine I and various aromatic dianhydrides were synthesized by the two-stage procedure that included ring-opening to form polyamic acids, followed by thermal conversion to polyimides. The polyamic acids had inherent viscosities of 0.14–0.38 dL/g. The glass transition temperature of these polyimides were in the 245–303°C range and showed almost no weight loss up to 350°C under air and nitrogen atmosphere. © 1996 John Wiley & Sons, Inc.