Synthesis and characterization of wholly aromatic polyesters derived from 1-phenyl-2,6-naphthalene-dicarboxylic acid and aromatic diols

A series of new wholly aromatic polyesters was synthesized by melt polycondensation of 1-phenyl-2,6-naphthalenedicarboxylic acid (PNDA) and diacetates of various aromatic diols. The aromatic diols studied are hydroquinone (HQ), methylhydroquinone (MHQ), phenylhydroquinone (PHQ), (α-phenylisopropyl)hydroquinone (PIHQ), 2,6-naphthalenediol (2,6-ND), 1,4-naphthalenediol (1,4-ND), and 4,4′-biphenol (BP). These polyesters were characterized for their crystallinity, glass transition temperature (T_g), melting temperature (T_m), liquid crystallinity, and thermal stability. In general, crystallinity of the polyesters are very low and the T_g values of the polyesters range from 150 to 172°C depending on the structure of aromatic diols. All of the polymers formed nematic phases above their T_m or T_g. The polyesters derived from PHQ and PIHQ are soluble in chlorinated hydrocarbon solvents. The initial decomposition temperatures of the polyesters are above 400°C under N₂ atmosphere. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of aromatic polyesters with dicyanovinyl substituents

The synthesis, characterization, and structure—property relations of aromatic polyesters with dicyanovinyl substituents is presented. Two comparable series of polyesters based on 3,4-dihydroxybenzylidenemalononitrile and 3,4-dihydroxy-5-methoxybenzylidenemalononitrile were prepared. As aromatic diacid components, terephthalic acid, phenylterephthalic acid, isophthalic acid, and 2-phenylisophthalic acid were used. The polyesters were prepared by solution polycondensation. GPC investigations revealed the existence of substantial amounts of defined cyclic products. These cycles could be isolated by preparative GPC. The polyesters are soluble in common low boiling organic solvents, particularly the phenyl-substituted ones. The polyesters are amorphous and have glass transition temperatures between 140 and 170°C. The absorption maxima are in the 306–322 nm range. The cut-off wavelength is between 400 and 428 nm. The polyesters with methoxy substitutent have generally the absorptions at longer wavelength. The refractive index of thin films of these polyesters were between 1.61 and 1.63 at 632.8 nm. © 1993 John Wiley & Sons, Inc.     

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 properties of soluble,fluorescent polyesters and polyethers with substituted m‐terphenyl segments in the main chain

A new series of rigid polyesters and semiflexible polyethers were synthesized from 4,4″‐dihydroxy‐5′‐phenyl or anthracenyl‐m‐terphenyl. The polymers were characterized by viscometry, Fourier transform infrared, NMR, X‐ray, differential scanning calorimetry, thermomechanical analysis, thermogravimetric analysis, ultraviolet–visible, and luminescence spectroscopy. The polyesters were amorphous, whereas some of the polyethers showed a low degree of crystallinity. All the polymers displayed an enhanced solubility even in 1,1,2,2‐tetrachloroethane and tetrahydrofuran. The glass‐transition temperatures were 123–146 °C for the polyesters and 45–117 °C for the polyethers. The polymers were stable up to 213–340 °C and afforded anaerobic char yields of 36–62% at 800 °C. Their optical properties were investigated both in solution and in the solid state. They showed ultraviolet fluorescence, violet‐blue fluorescence, or both with emission maxima at 333–487 nm. The polymers with anthracenyl pendent groups exhibited higher fluorescence quantum yields and emission maxima redshifted compared with the corresponding polymers with phenyl pendent groups. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2381–2391, 2000     

Synthesis and characterization of new soluble aromatic polyimides from diaminotetraphenylimidazolinone and aromatic tetracarboxylic dianhydrides

A series of new soluble aromatic polyimides with inherent viscosities of 0.65–1.12 dL/g were synthesized from 1,3-bis(4-aminophenyl)-4,5-diphenylimidazolin-2-one and various aromatic tetracarboxylic dianhydrides by the conventional two-step procedure that included ring-opening polyaddition and subsequent thermal cyclodehydration. These polyimides could also be prepared by the one-pot procedure in homogeneous m-cresol solution. Most of the tetraphenyl-pendant polyimides were soluble in organic solvents such as N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidone, and m-cresol. Some polyimides gave transparent, flexible, and tough films with good tensile properties. The glass transition temperatures and 10% weight loss temperatures under nitrogen of the polyimides were in the range of 287–326 and 520–580°C, respectively. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1767–1772, 1998     

Thermotropic copolyesters of a series of aromatic diols with phenylterephthalic acid and 4,4′-oxybisbenzoic acid

Wholly aromatic, liquid crystalline, main chain copolyesters derived from various linearly substituted aromatic diols with mixtures of 2-phenylterephthalic acid and a nonlinear aromatic dicarboxylic acid, 4,4′-oxybisbenzoic acid, were prepared by acidolysis condensation polymerization reactions and characterized for their liquid crystalline properties. The formation of a liquid crystalline phase at elevated temperatures was not prevented by the introduction of up to 50 mol % of the nonlinear diacid in the copolymers, and all of those copolyesters exhibited nematic liquid crystalline phases. Furthermore, the inclusion of a nonlinear monomer was not as effective as was the presence of a phenyl substituent in decreasing the melting transition of these copolymers. All of the copolymers had high glass transition temperatures and high thermal stabilities. © 1993 John Wiley & Sons, Inc.     

Synthesis and characterization of new soluble aromatic polyimides from 3,4-bis(4-aminophenyl)-2,5-diphenylpyrrole and aromatic tetracarboxylic dianhydrides

Novel aromatic polyimides containing tetraphenylpyrrole unit were synthesized from 3,4-bis(4-aminophenyl)-2,5-diphenylpyrrole and various aromatic tetracarboxylic dianhydrides by the usual two-step procedure that included ring-opening polyaddition and subsequent thermal cyclodehydration. These polymers had inherent viscosities in the 0.20–0.65 dL/g range and were practically amorphous as shown by the X-ray diffraction studies. All the polyimides except for polypyromellitimide were easily soluble in a wide range of organic solvents such as o-chlorophenol, pyridine, 1,3-dimethyl-2-imidazolidone, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone at room temperature. These polyimides had high glass transition temperatures of 302–359°C and exhibited 10% weight loss at temperatures above 510°C in nitrogen.     

New thermally stable polyesters based on 2,5-pyridinedicarbonyl dichloride and aromatic diols:Synthesis and characterization

Six new thermally stable polyesters(4a-f) were synthesized through the solution polycondensation reaction of 2,5-pyridine dicarbonyldichloride(2) with six aromatic diols in N,N'-dimethyl acetamide(DMAc) solution and in the presence of pyridine as a base.The polycondensation reactions produce a series of new polyesters(4a-f) in high yields,and inherent viscosity between 0.30 and 0.55 dL/g.The resulting polyesters were characterized by elemental analysis,viscosity measurements,thermal gravimetric analysis(...     

Synthesis and characterization of polyesters derived from polychlorinated aromatic diacids

New, thermally stable polyesters with varying chlorine content were prepared by solution and interfacial polycondensation between chlorinated aromatic dichlorides (perchloroterephthaloyl dichloride, 2,5-dichloroterephthaloyl dichloride, and perchloro-4,4′-dichloroformyl biphenyl with different aliphatic and aromatic diols). The polymers were characterized by infrared spectroscopy, elemental analysis, differential scanning calorimetry, and thermogravimetric analysis. Their solubilities and molecular weights were also determined. The influence of chlorine content on the thermal properties of the polymers is discussed.     

Soluble aromatic polyamide and polyimides derived from di(aminophenyl) acetylenediurea

New aromatic polyamide and polyimides were prepared from di(aminophenyl)acetylenediurea. In addition, model compounds were synthesized and their IR spectra were in agreement with those of the corresponding polymers. The polymers were amorphous and readily soluble in polar aprotic solvents (DMF, NMP, DMSO) and certain acids (H₂SO₄, CCl₃COOH). The hydrophilicity of polyamide was estimated by measuring the isothermal water absorption. The polyamide softened at 260°C but no softening was observed for polyimides. The glass transition temperatures of polymers were determined by the TMA method and they were in the range of 235–310°C. The polymers were stable up to 359–404°C in N₂ or air and afforded char yields of 53–65% at 800°C in N₂. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of polyesters derived from aromatic 1,4-dimethoxylated diacids

Polyesters were synthesized from the dichlorides of 2,5-dimethoxyterephthalic and 2,5-dimethoxy-1,4-benzenediacetic with dialcohols. The polymers were characterized by elemental analysis and infrared (IR) spectroscopy. Their intrinsic viscosity, glass transition temperature, and thermal decomposition were determined.     

Synthesis and characterization of aromatic polythiazole-amides from new aromatic diamines containing phenyl-pendant thiazole units

New aromatic diamines containing phenyl-pendant thiazole units were synthesized in three steps starting from p-nitrobenzyl phenyl ketone. Novel aromatic polyamides containing phenyl-pendant thiazole units were prepared by the low-temperature solution polyconden-sation of 1,4- (or 1.3-) bis[5-(p-aminophenyl)-4-phenyl-2-thiazolyl] benzene with various aromatic dicarboxylic acid chlorides in N,N-dimethylacetamide. High molecular weight polyamides having inherent viscosities of 0.5–3.0 dL/g were obtained quantitatively. The polythiazole-amides with m-phenylene, 4,4′-oxydiphenylene, and 4,4′-sulfonyldiphenylene units were soluble in N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and pyridine, and gave transparent flexible films by casting from the solutions. These organic solvent-soluble polyamides displayed prominent glass transition temperatures (T_g) between 257 and 325°C. On the other hand, the polythiazole-amides with p-phenylene and 4,4′-biphenylene units were insoluble in most organic solvents, and had no observed T_g. All the polythiazole-amides started to decompose at about 400°C with 10% weight loss being recorded at 450–525°C in air. © 1995 John Wiley & Sons, Inc.     

Preparation and properties of novel soluble aromatic polyimides from 4,4′-diaminotriphenylamine and aromatic tetracarboxylic dianhydrides

New aromatic polyimides containing triphenylamine unit were prepared by two different methods, i.e., a conventional two-step method starting from 4,4′-diaminotriphenylamine and aromatic tetracarboxylic dianhydrides and the one-step thioanhydride method starting from the aromatic diamine and aromatic tetracarboxylic dithioanhydrides. Both procedures yielded high-molecular-weight polyimides with inherent viscosities of 0.47–1.17 dL/g. Some of these polymers were soluble in organic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, m-cresol, and pyridine. All the polyimides afforded transparent, flexible, and tough films, and the color varied from pale yellow to dark red, depending markedly on the tetracarboxylic acid components. The glass transition temperatures (T_gs) of these polyimides were in the range of 287–331°C and the 10% weight loss temperatures were above 520°C in air. The polyimides prepared by the one-step method exhibited better solubility in organic solvents and had somewhat lower T_gs than the polymers prepared by a conventional two-step method.     

Synthesis of aromatic polyesters and polyamides by alternating copolymerizations of 1,4-dicarbonyl-1,4-dihydronaphthalene with bezoquinones and benzoquinone diimines

1,4-Dicarbonyl-1,4-dihydronaphthalene ( 1 ) was synthesized by the dehydrochlorination reaction of 1,4-dihydronaphthalene-1,4-dicarbonyl chloride with triethylamine and obtained as its very dilute solution, but it easily polymerized in the concentration as high as 0.1 mol/L to give its polymer. 1 generated in situ by the dehydrochlorination reaction of 1,4-dihydronaphthalene-1,4-dicarbonyl chloride in a deoxygenated toluene polymerized alternatingly with benzoquinones such as 2-dodecylthio-p-benzoquinone, 2,5-di(tert-butyl)-p-benzoquinone, p-benzoquinone, and 2,3-dichloro-5,6-dicyano-p-benzoquinone, and with benzoquinone diimines such as N,N′-diethoxycarbonyl-p-benzoquinone diimine, N,N′-dibenzoyl-p-benzoquinone diimine, and N,N′-diphenyl-p-benzoquinone diimine to give aromatic polyesters and polyamides, respectively. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1929–1936, 1998     

Synthesis and characterization of water‐soluble hyperbranched poly(ester amine)s from diacrylates and diamines

Various water‐soluble hyperbranched poly(ester amine)s were synthesized by the direct polyaddition of diamines to diacrylates in the absence of a catalyst. Each diamine contained a secondary amino group and a primary amino group such as 1‐(2‐aminoethyl)piperazine, N‐methyl‐1,3‐propanediamine, or N‐ethylethylenediamine. When the ratio of diacrylate to diamine was 1/1, no gelation was observed throughout the polymerization. When the ratio of diacrylate to diamine was 3/2, no crosslinking occurred in the diluted solution, whereas an insoluble network formed in the concentrated solution. Fourier transform infrared and mass spectrometry were used to investigate the reaction procedure. The secondary amino group of diamine reacted faster with the vinyl group of diacrylate; this resulted in the formation of the intermediate with an acrylate group and two active hydrogen atoms attached to a nitrogen atom. Further self‐polyaddition of the intermediate, a kind of AB₂‐type monomer, gave the hyperbranched poly(ester amine). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2340–2349, 2002     

Synthesis and characterization of aromatic cyclolinear phosphazene polyetherketones containing bis‐Spiro‐substituted cyclotriphosphazene unit

A novel monomer, 2,2‐bis‐(4′‐fluorobenzoylphenoxy)‐4,4,6,6‐bis[spiro‐(2′,2″‐dioxy‐1′, 1′‐biphenylyl)] cyclotriphosphazene, was synthesized and polymerized with 4,4′‐difluorobenzophenone as a comonomer and 4,4′‐isopropylidenediphenol or 4,4′‐(hexafluoroisopropylidene) diphenol in N,N‐dimethylacetamide at 162 °C for 4 h to give two series of aromatic cyclolinear phosphazene polyetherketones containing bis‐spiro‐substituted cyclotriphosphazene groups. The structure of the monomer was confirmed by ¹H, ¹³C, and ³¹P NMR. The effect of the incorporation of the bis‐spiro‐substituted cyclotriphosphazene group on the thermal properties of these polymers was investigated by DSC and thermogravimetric analysis. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2993–2997, 2001     

Synthesis and characterization of novel aromatic polyamides containing 3-trifluoromethyl-substituted triphenylamine

A new 3-trifluoromethyl-substituted triphenylamine-containing aromatic diacid monomer, N,N-bis(4-carboxyphenyl)-3-trifluoromethylaniline, was prepared by the substitution reaction of 3-trifluoromethylaniline with 4-fluorobenzonitrile, followed by alkaline hydrolysis of the dinitrile intermediate. Novel aromatic polyamides with 3-trifluoromethyl-substituted triphenylamine moieties were prepared from the diacid and various aromatic diamines via the direct phosphorylation polycondensation. All the polyamides were amorphous and readily soluble in many polar organic solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone, and could be solution-cast into transparent, tough, and flexible films with good mechanical properties. They exhibited good thermal stability with relatively high glass-transition temperatures (258–327°C), 10% weight-loss temperatures above 500°C, and char yields higher than 60% at 800°C in nitrogen. These polymers had low dielectric constants of 3.22–3.70 (100 Hz), low moisture absorption in the range of 1.75–2.58%, and high transparency with an ultraviolet–visible absorption cut-off wavelength in the 375–395 nm range. Cyclic voltammograms of the polyamide films cast onto an indium tin oxide coated glass substrate exhibited a reversible oxidation redox couple with oxidation half-wave potentials (E_1/2) of 0.95–1.00 V vs. Ag/AgCl in an acetonitrile solution.     

Synthesis and characterization of chiral liquid‐crystalline polyesters containing sugar‐based diols via melt polymerization

Liquid‐crystalline (LC) polyesters based on hexanediol or butanediol, dimethyl 4,4′‐biphenyldicarboxylate, and a sugar‐based diol, isosorbide or isomanide, were prepared with conventional melt polymerization. ¹H NMR spectroscopy confirmed that 50 mol % of the charged sugar diol was successfully incorporated into various copolyesters. Modest molecular weights were obtained, although they were typically lower than those of polyester analogues that did not contain sugar‐based diols. Thermogravimetric analysis demonstrated that the incorporation of isosorbide or isomanide units did not reduce the thermal stability in a nitrogen atmosphere. Melting points that ranged from 190 to 270 °C were achieved as a function of the copolyester composition. The lined focal conic fan textures, typical indications of a chiral smectic C LC phase, were observed upon the shearing of the LC melt under polarized light microscopy. Atomic force microscopy revealed that the twisted molecular orientation in the chiral LC phase induced periodically soft lamellar structures. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2512–2520, 2003     

Synthesis and characterization of new polyesters based on 2,5-bis[(4-chloro carboxyanilino) carbonyl] pyridine and aromatic diols

<正>Six new polyesters 7a-f were synthesized through the solution polycondensation reaction of diacid chloride 5 with six aromatic diols 6a-f in N,N-dimethyl acetamide(DMAc) as solvent in the presence of pyridine as base.The polycondensation reaction produced a series of novel polyester containing pyridyl moiety in the main chain in high yields with inherent viscosities between 0.35 and 0.54 dL/g.The resulted polymers were fully characterized by means of FT-IR spectroscopy,elemental analyses,inherent viscosity and solubility tests.Thermal properties of these polymers were investigated by using thermal gravimetric analysis(TGA) and differentional thermal gravimetric(DTG).The glass-transition temperatures of these polyesters were recorded between 130 and 170℃by differential scanning calorimetry(DSC) and the 10%weight loss temperatures were ranging from 390 to 450℃under nitrogen.     

Synthesis and characterization of novel polyesters derived from 4-aryl-2,6-bis(4-chlorocarbonyl phenyl) pyridines and various aromatic diols

A new class of aromatic polyesters containing pyridine heterocyclic rings (PE_1-15) was prepared via reactions of 4-aryl-2,6-bis(4-chlorocarbonyl phenyl) pyridines (DAC_1-3) and commercial diols by high temperature solution polymerization method in o-dichlorobenzene and catalytic amount of triethylamine hydrochloride. The optimum condition of polymerization was obtained via study of a model compound prepared from reaction of 4-phenyl-2,6-bis(4-chlorocarbonylphenyl) pyridine (DAC₁) and phenol. All polymers were characterized by FTIR and ¹H-NMR spectroscopies, and their physical properties including solution viscosity, solubility properties, thermal stability and thermal behavior were studied. The prepared polyesters showed excellent thermal stability and good solubility in polar aprotic solvents.