Synthesis Of Aromatic Poly Research Articles

Liquid phase synthesis of aromatic poly(azomethine)s, their physicochemical properties, and measurement of ex situ electrical conductivity of pelletized powdered samples

Aromatic bis-aldehydes have been used as building blocks in the synthesis of polyazomethines (a class of conjugated Schiff bases) and their physicochemical properties have been studied. Six dialdehydes have been synthesized, 3a-3f, via etherification reaction between aromatic diols (2a-2f) and 4-fluorobenzaldehyde (1) (see Scheme 1), and then polymerized with 1,4-phenylenediamine (4a) and 4,4′-oxydianiline (4b) (see Scheme 2). The chemical structures of the bis-aldehydes were elucidated by FTIR, 1H NMR and 13C NMR spectroscopic studies, elemental analysis and single crystal whereas the polymers were studied by FTIR and NMR spectroscopy. Their physicochemical properties were examined by their inherent viscosity, organosolubility, differential scanning calorimetry, X-ray powder diffraction, thermogravimetric analysis, solvatochromism, and photoluminescence. We report the electrical conductivity of each polymer measured by the four probe method. The results indicate that the electrical conductivity of polymers lies in range 0.019–0.051 mScm−1 which is reasonably higher than any reported value.

Controlled variation of monomer sequence distribution in the synthesis of aromatic poly(ether ketone)s

The effects of varying the alkali metal cation in the high-temperature nucleophilic synthesis of a semi-crystalline, aromatic poly(ether ketone) have been systematically investigated, and striking variations in the sequence distributions and thermal characteristics of the resulting polymers were found. Polycondensation of 4,4′-dihydroxybenzophenone with 1,3-bis(4-fluorobenzoyl)benzene in diphenylsulphone as solvent, in the presence of an alkali metal carbonate M2CO3 ( M = Li, Na, K, or Rb) as base, affords a range of different polymers that vary in the distribution pattern of two-ring and three-ring monomer units along the chain. Lithium carbonate gives an essentially alternating and highly crystalline polymer, but the degree of sequence randomization increases progressively as the alkali metal series is descended, with rubidium carbonate giving a fully random and non-thermally crystallizable polymer. Randomization during polycondensation is shown to result from reversible cleavage of the ether linkages in the polymer by fluoride ions, and an isolated sample of alternating sequence polymer is thus converted to a fully randomized material on heating with rubidium fluoride.

Novel high Tg, organosoluble poly(ether imide)s containing 4,5-diazafluorene unit: Synthesis and characterization

The synthesis of aromatic poly(ether imide)s containing 4,5-diazafluorene units in the polymer backbone is described. 9,9-di[4-(4-Aminophenoxy)phenylene]-4,5-diazafluorene (3), which was used as a new monomer, was synthesized with 4,5-diazafluoren-9-one as the starting material. This diamine monomer was employed in reactions with a variety of aromatic dianhydrides to furnish poly(ether imide)s. These 4,5-diazafluorene-based polymers showed solubility in polar amidic solvents such as NMP, DMAc and DMF, good optical transparency, and high thermal stability. The glass transition temperatures (Tg) of these poly(ether imide)s were recorded between 325 and 356°C with the help of differential scanning calorimetry (DSC), and the Tg determined by dynamic mechanical thermal analyses (DMA) stayed in the range of 329–363°C, and the 10% weight-loss temperatures all occurred above 560°C in both nitrogen and air atmospheres. In addition, the flexible polyimide films possessed tensile strengths in the range of 64–101MPa, tensile modulus of 1.8–2.1GPa, and elongations at break of 6–13%.

Synthesis of aromatic poly(pyridinium salt)s and their electrochromic properties

Synthesis of a series of new conjugated electrochromic polymeric pyridinium salts containing main-chain triphenylamine and their electrochromic properties were demonstrated. All polymers exhibit intense UV absorptions at 336–338 nm in DMF and 340–343 nm in thin film form and fluorescence centered at 410–438 nm in DMF and 460–461 nm in thin film form. The electrochromic properties of the films were investigated by electrochemical and spectroelectrochemical methods. Reversible redox signals with stable electrochromic characteristics were obtained via cyclic voltammetry. The electrochromic properties of the polymers remain highly stable after 50 cycles between 0 and 1.2 V.

Synthesis of aromatic poly(ether ketone)s bearing optically active macrocycles through Suzuki coupling polymerization

Palladium (Pd)-catalyzed Suzuki coupling polymerization of macrocycle-bearing monomers, obtained through two-step nucleophilic aromatic substitution reactions with three types of diboric acid pinacol esters, produced aromatic poly(ether ketone)s that have optically active macrocycles composed of two 2,2′-dioxy-1,1′-binaphthyl-6,6′-diyl units and two aromatic ether ketone linkers. The macrocycle-bearing aromatic poly(ether ketone)s have excellent thermal and optical properties, that is, high glass-transition temperatures (Tg: 220–257 °C) and large molar rotations ([Φ]D25: +1906–1976 deg). In addition, polyketones have excellent solubility in typical solvents such as CHCl3 and N,N-dimethylformamide (DMF). Pd-catalyzed Suzuki coupling polymerization of macrocycle-containing monomer with diboric acid pinacol esters afforded aromatic poly(ether ketone)s with optically active macrocycles. The resulting aromatic poly(ether ketone)s have high glass transition temperatures (Tg: 220–257°C), large molar rotations ([Φ]D25: +1906–1976 deg) and excellent solubility to typical solvents such as CHCl3 and DMF.

Synthesis of aromatic poly(ether amide amide ether ketone ketone)s by electrophilic Friedel–Crafts solution polycondensation

AbstractA new monomer, N,N′‐bis(4‐phenoxybenzoyl)‐p‐phenylenediamine (BPBPPD), was prepared by the condensation of p‐phenylenediamine with 4‐phenoxybenzoyl chloride in N,N‐dimethylacetamide (DMAc). Novel aromatic poly(ether amide amide ether ketone ketone)s (PEAAEKKs) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of BPBPPD with a mixture of terephthaloyl chloride (TPC) and isophthaloyl chloride (IPC), over a wide range of TPC/IPC molar ratios, in the presence of anhydrous aluminum chloride and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The influences of reaction conditions on the preparation of polymers were examined. The polymers obtained were characterized by different physico–chemical techniques such as FT‐IR, Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), and wide angle X‐ray diffraction (WAXD). The polymers with 70–100 mol% IPC are semicrystalline and have remarkably increased Tgs over commercially available poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK) due to the incorporation of amide groups in the main chain. The polymers with 70–80 mol% IPC had not only high Tgs of 209–213°C, but also moderate Tms of 339–348°C, which are suitable for melt processing. The polymers with 70–80 mol% IPC had tensile strengths of 107.5–109.8 MPa, Young's moduli of 2.53–2.69 GPa, and elongations at break of 9–11% and exhibited high thermal stability and good resistance to organic solvents. Copyright © 2009 John Wiley & Sons, Ltd.

Synthesis of aromatic poly(amide-imide)s from novel diimide-diacid (DIDA) containing sulphone and bulky pendant groups by direct polycondensation with various diamines

A novel diimide-diacid (DIDA) monomer, 4-{4-[(4-methyl phenyl) sulphonyl]}-1,3-bis-trimellitoimido benzene containing sulphone and bulky pendant groups was successfully synthesized and used to synthesize a series of wholly aromatic poly(amide-imide)s (PAIs) by direct polycondensation method. The direct polycondensation of newly synthesized DIDA with different diamines was carried out via Yamazaki’s phosphorylation method using triphenyl phosphite and pyridine system. The resulting poly(amide-imide)s were obtained in quantitative yields with inherent viscosities 0.36–0.47 dl/g in DMAc at 30 ± 0.1 °C. The poly(amide-imide)s were amorphous and were readily soluble in various solvents such as N-methyl-2-pyrrolidinone (NMP), N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), and pyridine. Tough and flexible films were obtained by casting their DMAc solution. According to thermogravimetric analysis, the polymers were fairly stable up to temperature around 396 °C, and 10% weight losses in the temperature range of 476–511 °C that showed good thermal stabilities of these polymers.

“One‐pot” synthesis of aromatic poly(1,3,4‐oxadiazole)s in novel solvents—ionic liquids

AbstractThe new convenient method for the synthesis of high molecular weight aromatic poly(1,3,4‐oxadiazole)s (PODs) has been proposed. These polymers were prepared by “one‐pot” procedure from dicarboxylic acid and hydrazine's salt (sulfate, phosphate) or dicarboxylic acid dihydrazides. The mixture of ionic liquid and triphenyl phosphite was used both as a solvent and condensing agent. The polycyclization occurred at a sufficiently low temperature of 210 °C for 2–5 h and resulted in obtaining film‐forming PODs having inherent viscosities up to 0.9 dL/g and good thermal stability. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 380–394, 2006

Control of molecular weight distribution in polycondensation polymers 2. Poly(ether ketone) synthesis

Synthesis of aromatic poly(ether ketone) ( 3) with a narrow molecular weight distribution ( M w/ M n) was investigated via polycondensation. M ns of 3 could be controlled varying the feed ratio of monomer ( 1) and initiator ( 2) maintaining relatively narrow M w/ M ns (<1.3). The kinetics of polycondensation obeyed a first-order relationship between polycondensation time and –(1/[ 2] 0) ln([ 1]/[ 1] 0), and the rate of polycondensation was estimated as 2.57 mol −1 L h −1. MALDI-TOF mass analysis of 3 indicated that polycondensation should proceed via chain growth manner to give 3 having an initiator unit in each chain end.

Synthesis of aromatic poly(ether ketone)s having adhesion property to steel surface

Aromatic copoly(ether ketone)s composed of 5′-(2′-methoxyphenylen)oxy-4-phenylenecarbonyl and 4″-phenylenoxy-4′-phenylenoxy-4-phenylenecarbonyl units were successfully synthesized via P 2O 5-MsOH-mediated direct polycondensation of the corresponding carboxylic acids, i.e., 4-(2-methoxyphenoxy)benzoic acid and 4-(4-phenoxyphenoxy)benzoic acid. The aromatic copoly(ether ketone)s bearing methoxy groups thus obtained have prominent adhesion property to steel surface with good thermal stability and high glass transition temperature.

Synthesis of aromatic poly(urea-imide) with hetero-cyclic side chain structure

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

Synthesis and characterization of soluble polyimides derived from 2,2′‐Bis(3,4‐dicarboxyphenoxy)‐9,9′‐spirobifluorene dianhydride

AbstractThe synthesis of aromatic poly(ether imide)s containing spirobifluorene units in the polymer backbone is described. 2,2′‐Bis(3,4‐dicarboxyphenoxy)‐9,9′‐spirobifluorene dianhydride, which was used as a new monomer, was synthesized with 2,2′‐dihydroxy‐9,9′‐spirobifluorene as the starting material. In the spiro‐segment, the rings of the connected bifluorene were orthogonally arranged. This bis(ether anhydride) monomer was employed in reactions with a variety of aromatic diamines to furnish poly(ether imide)s, involving an initial ring‐opening polycondensation and subsequent chemically induced cyclodehydration. Excellent solubility in common organic solvents at room temperature, good optical transparency, and high thermal stability are the prominent characteristic features of these new polymers, which can be attributed to the presence of spiro‐fused orthogonal bifluorene segments along the polymer chain. The glass‐transition temperatures of the polyimides were 240–293 °C, and the 5% weight‐loss temperatures were greater than 500 °C. © 2001 John Wiley &amp; Sons, Inc. J Polym Sci Part A: Polym Chem 40: 262–268, 2002

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

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

Synthesis of aromatic poly(ether ketone)s with ferrocene units in the main chain

AbstractAromatic poly(ether ketone)s with ferrocene units in the main chain were prepared by direct polycondensation of 1,1′‐ferrocenedicarboxylic acid with diphenyl ether or 1,4‐diphenoxybenzene using various catalysts such as trifluoromethanesulfonic acid (triflic acid), a combination of methanesulfonic acid/P2O5 (Eaton's reagent) or a combination of triflic acid/P2O5. Polycondensations at room temperature for 24 h gave poly(arylene ether ketone)s with inherent viscosities up to 40 mL g−1. Monoacylation of diphenyl ether with ferrocenecarboxylic acid was studied in detail in order to show the efficiency of polymer formation employing Eaton's reagent as catalyst and solvent.

Synthesis of aromatic poly(ether ketone)s containing C36 aliphatic unsaturated groups in the main chain

Synthesis of aromatic poly(ether ketone)s containing C36 aliphatic unsaturated groups in the main chain

Synthesis of aromatic poly(ether ketone)s containing C36 aliphatic unsaturated groups in the main chain

Aromatic poly(ether ketone)s (PEKs) were modified with various amount of C36 dimer acid Pripol 1017 obtained from polymerization of unsaturated C18 fatty acids. To obtain modified PEKs, polycondensation was carried out using various dicarboxylic acids with diphenylether at 75°C in phosphorus pentoxide/methanesulfonic acid as condensing agent and solvent. The reduced viscosities of polymers are relatively low, up to 0.13 dL/g. PEK with a structure (molar ratio of aliphatic to aromatic segment: 0.33) is soluble in organic polar solvents and can be cast from a tetrahydrofuran solution with cobalt naphthenate air dryer in order to obtain crosslinked film at room temperature. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1275–1278, 1997

Synthesis and 1H NMR study of aromatic poly(amide‐thioether)s

AbstractThe synthesis of aromatic poly(amide‐thioether)s by reaction between 4,4′‐thiodianiline, 4,4′‐thiodibenzoic acid and 4‐(4‐aminophenylthio)benzoic acid is studied. Depending on the initial monomer ratio, polymers with head‐to‐head, head‐to‐tail or statistical distribution of amido groups along the polymer chains were obtained. Corresponding triads effects were observed in the 1H NMR spectra and assigned. The synthesis of the same aromatic poly(amidethioether)s by reaction between dichlorobenzanilides and Na2S is also studied. Only the Cl substituents in para position to a carbonyl groups are reactive and a head‐to‐head poly(amidethioether) was obtained by reaction of N,N′‐thiobis(1,4‐phenylene)‐di‐4‐chlorobenzamide (2f) with Na2S.

Synthesis of Aromatic Poly(ether sulfone)s by Nickel-Catalyzed Coupling Polymerization of Aromatic Dichlorides

Aromatic poly(ether sulfone)s were prepared by the nickel-catalyzed coupling polymerization of aromatic dichlorides containing ether sulfone structures. Polymerizations were carried out in N,N-dimethylacetamide (DMAc) in the presence of nickel chloride, zinc, triphenylphosphine, and bipyridine and produced aromatic poly(ether sulfone)s with inherent viscosities up to 0.38 dl g−1 under mild conditions. The effects of various factors, such as amount of catalyst, ligand, zinc and solvent, reaction temperature, and sonication, were studied. The thermogravimetry of the aromatic poly(ether sulfone)s showed 10% weight loss in air and in nitrogen at 525–565 and 530–570°C, respectively.

Synthesis of aromatic poly(ether ketone)s by nickel-catalyzed coupling polymerization of aromatic dichlorides

Le couplage de l'oxy-4,4' bis-(chlorobenzophenone) et de la p-phenylenedioxy-4,4' bis-(Chlorobenzophenone) en presence de NiCl 2 , PPh 3 , Zn et de bipyridine donne des poly(ethercetone) de viscosite jusqu'a 0,87 dl/g. Influence des conditions operatoires sur la masse moleculaire des polymeres. Les polymeres ont une perte de masse de 10% a 510-570 o C sous air et azote

Synthesis of poly(1,3,4‐oxadiazole)s by direct polycondensation of dicarboxylic acids with hydrazine sulfate using phosphorus pentoxide/methanesulfonic acid as condensing agent and solvent

AbstractA convenient method for the synthesis of poly(1,3,4‐oxadiazole)s of high molecular weights has been developed. These polymers were prepared readily by the direct polycondensation of dicarboxylic acids with hydrazine sulfate (1) using phosphorus pentoxide/methanesulfonic acid (PPMA) as both a condensing agent and solvent. Polycondensation of aliphatic dicarboxylic acids with 1 proceeded even at room temperature and produced poly(1,3,4‐oxadiazole)s with inherent viscosities up to 1.4 dL/g. The synthesis of aromatic poly(1,3,4‐oxadiazole)s from aromatic dicarboxylic acids containing phenyl ether structures was carried out by a one‐pot procedure because the preactivation of dicarboxylic acids was required. The synthesis of 2,5‐disubstituted‐1,3,4‐oxadiazoles by the reaction of carboxylic acids with 1 in PPMA was studied to demonstrate the feasibility of the reaction for polymer formation. The thermogravimetry of the aromatic poly(1,3,4‐oxadiazole)s showed 10% weight loss both in air and in nitrogen at 440–490°C.