Polyisophthalamides with benzoyl pendent groups: Synthesis,characterization, and evaluation of properties

Polyisophthalamides containing benzoyl pendent groups were prepared from 5-benzoylisophthaloyl chloride and seven aromatic diamines, and their properties were compared with those of unsubstituted polyisophthalamides. The incorporation of one pendent benzoyl group per repeat unit brought about a decrease in the glass transition temperature of 10–30°C, relative to the unmodified polymers, while the thermal resistance (programmed TGA) remained unchanged or went down slightly. Other properties investigated were mechanical properties, solubility, and water absorption. © 1993 John Wiley & Sons, Inc.     

Synthesis and properties of aromatic polyamides with oligobenzamide pendent groups. I. Poly-5-(4-benzoylamino-1-benzoylamino)isophthalamides

A series of polyisophthalamides having pendent oligomeric benzamide groups were prepared by the Yamazaki reaction from common aromatic diamines and 5-(4-benzoylamino-1-benzoylamino)isophthalic acid. The latter was synthesized from 5-aminoisophthalic acid in a three-step synthesis by successive incorporation of benzamido groups. The new polymers were characterized by NMR, DSC, TGA, and WAXD and the properties were compared to those of corresponding unsubstituted polyisophthalamides. All of the polymers were essentially amorphous and their T_gs were about 20°C higher than the reference polymers. Initial thermal decomposition temperatures ranged from 375 to 420°C. All of the polymers were soluble in aprotic polar solvents without added salts. Properties of particular note were: the water uptake, which was particularly high, ranging from 7.5 to 18.2%, and the temporary insolubilization in concentrated sulfuric acid of films of the polymers heated for a short time to ≥ 200°C. © 1995 John Wiley & Sons, Inc.     

Aromatic polyisophthalamides with iminobenzoyl pendant groups

Polyisophthalamides were prepared from aromatic diamines and 5-iminobenzoylisophthalic acid by the Yamazaki method of direct polyamidation catalyzed by triphenylphosphite. The properties of the polymers were measured and compared with the analogous unsubstituted polyisophthalamides. The incorporation of one iminobenzoyl pendant group per repeating unit gave rise to better solubility in strongly polar solvents. Higher content of amide groups per repeating unit allowed the modified polymers to absorb moisture to a greater extent than the parent polyisophthalamides. The glass transition temperatures were raised 20–30 by the presence of the pendant groups and they ranged from 290 to 317°. On the contrary, the substituted polymers showed lower initial decomposition temperatures, as measured by TGA, all of them beginning to decompose at about 410°. The mechanical properties of polymer films seemed not to be greatly affected by the pendant groups and only small differences were observed between substituted and unsubstituted polymers.     

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.     

Polyisophthalamides with phenylthio pendent groups

A series of polyisophthalamides containing pendent phenylthio groups was prepared from seven aromatic diamines and 5-phenylthioisophthalic acid by the phosphorylation polycondensation method. The properties of these polymers were compared with those of the analogous unmodified ones. The modified polymers exhibited better solubility in organic solvents than their unmodified counterparts. They also showed glass transition temperatures that were lower by approximately 30°C. However, the presence of the side groups did not bring about any substantial lowering of the thermal stability as measured by TGA. Other properties investigated were mechanical strength and water sorption.     

Polyisophthalamides with phenylsulfonyl pendent groups

A series of polyisophthalamides containing phenylsulfonyl groups was prepared from seven aromatic diamines and 5-phenylsulfonylisophthalic acid by the phosphorylation condensation method, and from 5-phenylsulfonylisophthaloyl chloride by the solution polycondensation method at low temperature. When compared to the analogous unmodified polyisophthalamides, the modified ones were found to be essentially amorphous, and they showed better solubility in organic solvents, and slightly higher glass transition temperatures. Thermogravimetric analysis showed that the polyisophthalamides containing pendent phenylsulfonyl groups have thermal stabilities similar to the unmodified ones. Mechanical strength of films and water sorption were also investigated. © 1993 John Wiley & Sons, Inc.     

Effect of pendent oxyethylene moieties on the properties of aromatic polyisophthalamides

Twelve novel polyisophthalamides containing short sequences of oxyethylene as pendent substituents were synthesized by the reaction of three aromatic diamine monomers and four novel diacid monomers containing pendent oxyethylene units. Two of the diacid monomers were derived from 5‐hydroxyisophthalic acid and the other two diacid monomers were derived from 5‐aminoisophthalic acid. The polymers were prepared in high yield and high molecular weight by the phosphorylation method of polycondensation. All of the polymers were soluble in organic aprotic solvents at room temperature and gave creasable films by casting from solution. The mechanical properties of the films were reasonably good, with tensile strengths in the range of 70–100 MPa and moduli around 2.5 GPa. However, the presence of the oxyethylene side sequences greatly diminished the thermal resistance and the glass transition temperatures of the present polymers compared with wholly aromatic polyisophthalamides. A study was also made on the effect of the chemical composition on water uptake. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45:4671–4683, 2007     

Synthesis and characterization of new aromatic polyamides bearing crown ethers or their dipodal counterparts in the pendant structure. II. Benzo‐15‐crown‐5 and ortho‐bis[2‐(2‐ethoxyethoxy)ethoxy]benzene

This article describes the synthesis and characterization of two diacid monomers, each containing a benzo‐15‐crown‐5 subunit or its dipodal counterpart. Both novel monomers were reacted with technical aromatic diamines with Yamazaki's direct polyamidation method to render modified polyisophthalamides with high molecular weights containing side moieties of cyclic and acyclic ethylene oxide sequences. All the polymers were soluble in aprotic polar solvents and showed high glass‐transition temperatures in the range of 190–345 °C. The polymers with side crown ethers showed much higher glass‐transition temperatures than those with acyclic linear side ethylene oxide arms. The chemical composition, particularly with respect to the diamine and the open or closed character of the pendent ethylene oxide sequence, also affected other general properties such as the mechanical resistance, mechanical modulus, or water absorption. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4063–4075, 2006     

Synthesis and properties of new aromatic polyisophthalamides with adamantylamide pendent groups

A new diacid monomer containing a pendent adamantyl ring was reacted with various aromatic diamines to prepare novel aromatic polyisophthalamides (PIPAs). The polymers were obtained in high yield and high molecular weight by the Yamazaki‐Higashi phosphorylation method of polycondensation. Inherent viscosities ranged from 0.40 to 0.82 dL/g, which corresponds to weight‐average and number‐average molecular weights (GPC) in the range 21,000–63,000 g/mol and 9000–31,000 g/mol, respectively. The polymers were essentially amorphous and soluble in a variety of polar aprotic solvents, and they afforded transparent, creasable films by the solution‐casting method. The great size of the polyhedral adamantyl moiety brought about a significant restriction of segmental mobility, which translated into a strong increase of T_g, so that very high glass transition temperatures were observed, in the range 335–370 °C (DSC), which are 70–90 °C above the glass transition temperatures of homologous PIPAs without pendent groups. Thus, it can be stated that these adamantyl containing polyamides are among the soluble aromatic PIPAs with highest T_g ever described. Conversely, the initial decomposition temperature, as measured by thermogravimetric analysis, was about 400 °C, which is lower by 40–70° than that of unsubstituted counterparts. Polymer films exhibited good mechanical properties, with tensile strengths over 65 MPa and tensile moduli between 2.0 and 2.6 GPa. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1743–1751, 2010     

Synthesis of novel polyaryl(ether–ketones) with tert-butyl pendent groups

Linear polyaryl(ether ketones) containing tert-butyl pendent groups were prepared from aromatic hydrocarbons and aromatic diacid chlorides, both classes of monomers containing tert-butyl pendent groups. The polymers were prepared in high yield and high molecular weight by low-temperature precipitation polycondensation in 1,2-dichloroethane. The presence of meta-oriented moieties and bulky pendent groups played a beneficial role with regard to solubility, while the thermal transitions and thermal resistance were not greatly impaired relative to conventional all para-oriented polyaryl(ether–ketones). The current polyaryl(ether–ketones) showed glass transition temperatures in the range 170–240°C and decomposition temperatures, as measured by TGA, of about 500°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1251–1256, 1998     

Aromatic Polyamides Containing Pendent Acetoxybenzamide Groups

Polycondensation reaction of 5-(4-acetoxy-benzamide) isophthaloylchloride with different aromatic diamines gave a series of polyisophthalamides with good solubility in organic solvents. These polymers showed good thermal stability with initial decomposition temperature above 300 °C and glass transition temperature in the range of 220–335 °C. Thin, flexible, transparent films were cast from solutions, having good electroinsulating properties.     

Synthesis and characterization of aromatic polyamides containing alkylphthalimido pendent groups

A series of polyisophthalamides containing pendent phthalimido groups and flexible side spacers were prepared from four novel diacids and three commercial aromatic diamines. These polyamides were prepared in high yields and with high molecular weights by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 70,000–137,000 and 47,000–86,000 g/mol, respectively. The novel polyamides were amorphous and readily soluble and showed glass‐transition temperatures of 150–240 °C, as measured by differential scanning calorimetry. Thermogravimetric analysis showed that the 10% weight‐loss temperatures in nitrogen were 355–430 °C, a significant improvement in thermal stability having been observed with the increase in the side‐chain length. A theoretical quantum mechanical study was successfully carried out to explain these results. Flexible and tough films, cast from polymer solutions, showed tensile strengths of 50–125 MPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3711–3724, 2002     

New organosoluble and thermally stable poly(amide‐imide)s with benzoxazole or benzothiazole pendent groups: synthesis and characterization

Two new benzoxazole or benzothiazole‐containing diimide‐dicarboxylic acid monomers, such as 2‐[3,5‐bis(N‐trimellitimidoyl)phenyl]benzoxazole ( 2 _o ) or 2‐[3,5‐bis(N‐trimellitimidoyl)phenyl]benzothiazole ( 2 _s ) were synthesized from the condensation reaction between 3,5‐diaminobenzoic acid and 2‐aminophenol or 2‐aminothiophenol in polyphosphoric acid (PPA) with subsequent reaction of trimellitic anhydride in the presence of glacial acetic acid, respectively, and two new series of modified aromatic poly(amide‐imide)s were prepared. This preparation was done with pendent benzoxazole or benzothiazole units from the newly synthesized diimide‐dicarboxylic acid and various aromatic diamines by triphenyl phosphite‐activated polycondensation. In addition, the corresponding unsubstituted poly(amide‐imide)s were prepared under identical experimental conditions for comparative purposes. Characterization of polymers was accomplished by inherent viscosity measurements, FT‐IR, UV–visible, ¹H‐NMR spectroscopy and thermogravimetry. The polymers were obtained in quantitative yields with inherent viscosities between 0.39 and 0.81 dl g^?1. The solubilities of modified poly(amide‐imide)s in common organic solvents as well as their thermal stability were enhanced compared to those of the corresponding unmodified poly(amide‐imide)s. The glass transition temperature, 10% weight loss temperature, and char yields at 800°C were, respectively, 7–26°C, 17–46°C and 2–5% higher than those of the unmodified polymers. Copyright © 2010 John Wiley & Sons, Ltd.     

Poly(1,3,4-oxadiazole-amide)s containing pendent imide groups

A series of new poly(1,3,4-oxadiazole-amide)s containing pendent imide groups has been synthesized by solution polycondensation of aromatic diamines containing preformed 1,3,4-oxadiazole rings with two diacid chlorides containing imide rings. These polymers were also prepared by the reaction of the same diacid chlorides with p-aminobenzhydrazide which were subsequently cyclodehydrated in solid state. The polymers were soluble in polar amidic solvents and some of them gave transparent flexible films by casting from solutions. They showed high thermal stability with decomposition temperatures above 400°C and glass transition temperatures in the range of 245–327°C. They had low dielectric constants, in the range of 3.32–3.94, and good tensile properties.     

Polyisophthalamides with heteroaromatic pendent rings: Synthesis,physical properties,and water uptake

A set of novel aromatic polyamides containing pyridine pendent groups was prepared from aromatic diamines and new monomers that are 5‐substituted derivatives of isophthalic acid bearing nicotinamide, isonicotinamide, or picolinamide groups. The polymers were obtained in high yield and high molecular weight by the phosphorylation method of polycondensation. They were characterized by spectroscopic and chromatographic methods and several of their properties were investigated. All of the polymers were soluble in polar aprotic solvents and gave films of good mechanical properties. Glass transition temperatures were higher than that of the reference polymer, poly(m‐phenyleneisophthalamide) (IP‐MPD), while the thermal resistance, defined by the initial decomposition temperature observed by thermogravimetry, was in the range 370–420 °C, lower by 30–70 °C than that of IP‐MPD. The presence of a pendent pyridine group and an additional amide side group per repeat unit made the polymers essentially amorphous and greatly improved their abilities to absorb water in comparison with nonsubstituted polyamides. Water uptake values up to 15% were observed at 65% relative humidity. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5300–5311, 2005     

Synthesis and characterization of halogen‐containing poly(ether ketone ketone)s

A series of novel poly(ether ketone ketone)s (PEKKs) were synthesized from diphenyl ether and isophthaloyl chloride derivatives such as 5‐halo‐ and 5‐tert‐butyl‐isophthaloyl chloride. The aromatic electrophilic substitution route to polyketones was a convenient route for the preparation of the polymers in high yields via precipitation polycondensation at a low temperature with aluminum trichloride as a catalyst. High molecular weight PEKKs were achieved with number‐average molecular weights of 15,000–100,000 g/mol for polymers that showed good solubility in organic solvents. The presence of substituents greatly modified the spectroscopic features in comparison with those of unsubstituted isophthaloyl poly(ether ketone ketone)s, particularly for the series containing halogens, for which significant variations of the chemical shifts in both ¹H and ¹³C NMR spectra were observed; these shifts could be related to the nature of the halogen. Thermal properties were also affected by the presence of pendent substituents, with clear enhancements of the glass‐transition temperatures, which could be ascribed to the nature and bulkiness of the substituents. Thermogravimetric analyses showed that the new polymers had good thermal resistance, although an important drop in thermal resistance was observed for polymers bearing large halogen atoms, such as bromine and iodine. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2601–2608, 2002     

New high temperature polymers. I. Wholly aromatic ordered copolyamides

Wholly aromatic ordered copolyamides of unusually high thermal stability were prepared by the condensation of aromatic diacid chlorides with symmetrical diamines containing preformed aromatic amide units in an ordered arrangement. The preservation of order in the condensation step was assured by using interfacial or solution polymerization techniques at temperatures below 50°C. Each polymer contains units derived from aminobenzoic acids, arylene diamines, and arylene diacids. By use of para- and meta- phenylene units, eight different polymers are possible; all were prepared. Differential thermal analyses and thermogravimetric analyses showed these polymers to have melting points or decomposition temperatures in a range from 410°C. for the all-meta polymer to 555°C. for the all-para one. Substitution of the internal N-hydrogens of the diamines with methyl groups or phenyl groups leads to additional ordered copolymers. Several were prepared, but their melting points were much lower than those of the parent polymers limiting their usefulness in high temperature applications. Tough pliable films were prepared from all eight unsubstituted polymers, and crystalline fibers with tenacities of ca. 6 g./den. were prepared from three of the polymers. The properties of the fibers were retained to a high degree even when determined at temperatures up to 400°C. Fibers aged at 300°C. for extended periods of time showed remarkable retention of fiber properties.     

Modified polyisophthalamides bearing pendent benzoylamino and/or (phenylamino)carbonyl groups

A series of modified polyisophthalamides were prepared from 5-(phenylamino)carbonyl-1,3-phenylenediamine and 5-benzoylamino-isophthalic acid. The polymers were characterized by FT-IR, ¹H-NMR, inherent viscosity, water absorption measurements, x-ray, DTA, TGA, and isothermal gravimetric analysis. The modified polyamides were amorphous and softened at 210–245°C. They showed higher hydrophilicity and better solubility in certain solvents such as DMF, DMSO, CCl₃COOH, cyclohexanone, and m-cresol than the corresponding unmodified polyamide. They started to lose weight at 329–344°C in N₂ or air, whereas the degradation of unmodified polyamide started at 320°C in N₂ and 308°C in air. © 1996 John Wiley & Sons, Inc.     

Linear polyisophthalamides from the trifunctional monomer 5-hydroxyisophthalic acid. A convenient approach towards functionalized aromatic polymers

Wholly aromatic polyisophthalamides (PIPAs) containing free hydroxylic groups were prepared from 5-hydroxyisophthalic acid and sulfonyldianiline by the condensation phosphorylation method, using triphenylphosphite as a condensing agent, in the presence of pyridine. Linear polymers were attained in high yield and high molecular weight, and the properties of the polymers were investigated in comparison with homologous polyisophthalamides without OH groups. The presence of OH groups did not much modified the solubility of hydroxyl-containing polyisophthalamides as they behaved against common solvents in a similar manner as that of reference polyisophthalamides. However, hydroxyl side groups greatly enhanced the water affinity of polyisophthalamides, which showed up to 16% water uptake in 98% relative humidity, and contact angles about 10° smaller than those of classical PIPAs. The presence of free OH groups slightly diminished the thermal resistance, as evaluated by TGA, but the glass transition temperatures were higher by 20–30 °C, with a maximum of 345 °C. The mechanical properties of hydroxyl-containing polyisophthalamides were reasonably acceptable, with modulus around 2000 MPa and tensile strength up to 60 MPa.     

Polypyrazoles from aromatic dipropynones and aromatic dihydrazines

Two types of polypyrazoles, unsubstituted and phenylated, were prepared by a novel synthetic route involving the cyclopolycondensation of aromatic dihydrazines and aromatic dipropynones. The polymers had inherent viscosities as high as 1.05 dL/g and were soluble in N, N-dimethylacetamide, chloroform (phenylated polypyrazoles only), and sulfuric acid. The polymers exhibited glass transition temperatures ranging from 202 to 266°C and polymer decomposition temperatures (10% weight loss) as measured by thermogravimetric analysis of 400–500°C in air and 465–512°C in nitrogen. The synthesis and characterization of several polypyrazoles are discussed.