Polymers with quinoxaline units. IV. Polymers with quinoxaline and oxazine units

Six ladder or partly ladder polymers have been prepared by the condensation of diaminodiphenols with tetrachloro- or terahydroxyquinoxaline derivatives with the use of poly (phosphoric acid), pyridine, and naphthalene as reaction media. The polymers thus obtained are highly colored powdery materials which are slightly soluble in concentrated sulfuric acid and methanesulfonic acid. These polymers show good thermal stability.     

Polymers containing anthraquinone units: Polymers from 1,5-diaminoanthraquinone and aralkyldiketones

Schiff's-base polymers have been formed by the condensation of 1,5-diaminoanthraquinone with 1,4- and 1,3-diacetylbenzene and 2,6-diacetylpyridine. These polymers were soluble in methanesulfonic and concentrated sulfuric acids (1,4-diacetylbenzene polymer) or N,N-dimethylacetamide. The polymer formed from 1,4-diacetylbenzene was ring-closed in polyphosphoric acid to yield a thermally stable polymer soluble in concentrated sulfuric acid which lost only 10% of its weight at 900°C in a TGA test.     

Polymers with quinoxaline units. V. Polymers with quinoxaline and dioxin units

Ladder or partly ladder polymers have been prepared by condensation of tetraphenols with tetrachloroquinoxaline compounds in melt, or in pyridine, naphthalene, and nitrobenzene reaction media. The polymers are dark-colored, powdery materials with good thermal stability. Some of the samples are slightly soluble in sulfuric acid, while others are completely insoluble. No other solvents were found.     

Preparation of some new polybenzimidazoquinazolines

Several new types of polybenzimidazoquinazolines with a different recurring unit have been prepared by solution polycondensation in polyphosphoric acid followed by heating at elevated temperature under reduced pressure. The polymers thus obtained were light yellow to brown powdery materials hardly soluble in common organic solvents and soluble in concentrated sulfuric acid. The inherent viscosity of the polymers ranged from 0.1 to 0.58 and showed good thermal stability.     

SYNTHESIS OF NOVEL SOLUBLE AROMATIC POLYPYROMELLITIMIDE CONTAINING ORDERED 1,2,4-TRIAZINE IN THE MAIN CHAIN

A new heat-resistant, soluble polymer, poly(phenyl-1,2,4-triazine imide), has been prepared via a two-step methodof polycondensation of N,N'-bis(4-benzil)pyromellitimide and terephthalamidrazone in cresol, followed by curing at highertemperature. The rigid 1,2,4-triazine group increases the solubility of the polyimide so that the polymer is soluble in cresol,N-methyl-2-pyrrolidone (NMP), trifluoroacetic acid and concentrated sulfuric acid, etc. Thermogravimetric analysis (TGA)indicates that this novel polyimide has good thermal stability with a high decomposition temperature of 447℃ in air and of423℃ in N_2. It has a tensile strength of 107.4 MPa with an elongation at break of around 7.6%.     

Polymers with quinoxaline units. III. Polymers with quinoxaline and thiazine recurring units

Six ladder or partly ladder polymers have been prepared by the condensation reactions of combinations of two diaminodithiophenols, 4,6-diamino-1,3-dithiophenol and 3,3′-dimercaptobenzidine, with three tetrachloroquinoxaline derivatives, 2,3,7,8-tetrachloro-1,4,6,9-tetraazaanthracene, 2,2′,3,3′-tetrachloro-6,6′-bisquinoxaline, and 2,2′,3,3′-tetrachloro-6,6′-diquinoxalyl ether, with the use of dimethylacetamide, hexamethylphos phoramide, and polyphosphoric acid as reaction media. The polymers thus obtained are highly colored, powedery materials which are slightly soluble in methanesulfonic acid and concentrated sulfuric acid. These polymers (η_inh > 1) show good thermal stability.     

Electrochemical polymerization of thianaphthene

Thianaphthene has been electrochemically polymerized in pure boron trifluoride diethyl etherate (BFEE) solution or in a mixed electrolyte of BFEE and concentrated sulfuric acid (SA). The addition of a certain amount of sulfuric acid into BFEE accelerated the polymerization and also increased the current efficiency of the electrosynthesis. Poly(thianaphthene) (PTN) in the dedoped state is soluble in usual strong polar organic solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF) and N-methyl pyrrolidinone (NMP). Its structure has been examined by infrared, H¹-NMR and UV spectra. Fluorescent spectral studies indicate that the polymer is a strong blue light emitter.     

Self-condensation reaction of aromatic tetraamines in polyphosphoric acid

Ladder and partial ladder polymers have been obtained by self-condensation reactions of 1,2,4,5-tetraaminobenzene, 3,3′,4,4′-tetraaminodiphenyl ether, 3,3′-diaminobenzidine and 3,3′,4,4′-tetraaminodiphenyl sulfone in polyphosphoric acid. The products thus obtained are highly colored compounds with good thermal stability. They seem to be made up of polyquinoxaline or dihydrophenazine or a mixture of these two recurring units. They are slightly soluble in methanesulfonic acid and concentrated sulfuric acid and have inherent viscosities in the 0.2 to 0.4 range.     

Preparation of soluble and fusible poly(2,5-dimethoxy-1,4-phenylene)

Poly(2,5-dimethoxy-1,4-phenylene) was prepared by oxidative polymerization of p-dimethoxybenzene with aluminum chloride and copper(II) chloride in nitrobenzene under reduced pressure. The polymers obtained were soluble in sulfuric acid and fusible at 320°C. The intrinsic viscosity of the polymer was ca. 0.07 in sulfuric acid. Demethylation of methoxy groups did not occur during the polymerization.     

聚甲基丙烯酸-2,2,3,3-四氟丙酯的立构规整性

本文报道了由60℃自由基引发聚合得到的聚甲基丙烯酸-2,3,3-四氟丙酯,经浓硫酸水解而生成聚甲基丙烯酸。后者以重氮甲烷酯化,转化成聚甲基丙烯酸甲酯,并且分别作红外光谱、核磁共振波谱分析。根据分析结果推断聚甲基丙烯酸-2,2,3,3-四氟丙酯为无规立构聚合物,并与聚甲基丙烯酸正丙酯衍生而来的相应产物作比较。     

Heat-resistant polymers containing thianthrene analogs units. I. Polyimides

Polyimides that contained thianthrene and dibenzo-p-dioxins units were synthesized. The tricyclic fused rings were successfully incorporated by polymerizing the diamines of the units with aromatic tetracarboxylic dianhydrides. The resulting polyamic acids were converted to polyimides by thermal cyclodehydration. The influence of the tricyclic units on the properties of the polyimides has been investigated. Polyimides that contained dibenzo-p-dioxins (ODP) exhibited sufficient thermal stability but were insoluble even in concentrated sulfuric acid. The introduction of a methyl group did not produce an appreciable increase in solubility. Thianthrene polyimides were considerably less stable than the equivalent polymers derived from open-chain diamine, 4,4′-diaminodiphenyl sulfide but were partly soluble in acid solvents. The results are discussed in terms of packing the polymer molecules.     

Polytetrazoles and polyaminotetrazoles

Polyaminotetrazoles were obtained by the action of hydrazoic acid on solutions of polycarbodimides prepared from methylenebis(4-phenyl isocyanate), toluene 2,4-diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, mesitylene diisocyanate, and hexamethylene diisocyanate. The polyaminotetrazoles, which were soluble only in concentrated sulfuric acid, had inherent viscosities of 0.12–0.78. Polymerization of the disodium salts of bistetrazoles with α,ω-dihalides gave polytetrazoles without the secondary amine linkage in the chain. The bistetrazoles, used were methylenebis(5-tetrazole) and 5,5′-p-phenylenebistetrazole, and the dihalides were α,α′-dichloro-p-xylene, 1,2-dibromoethane, and 1,4-dibromobutane. The polytetrazoles were soluble in concentrated sulfuric acid and had low inherent viscosities, 0.08–0.17. Thermogravimetric analyses showed that marked degradation of both classes of polymers occured at 250–300°C.     

New thermally stable polymer with a graphite-type structure

A new thermally stable polymer with a structure resembling that of graphite has been synthesized by the condensation of 1,4,5,8-tetraaminoanthraquinone and 1,3,6,8-tetraketo-1,2,3,6,7,8-hexahydropyrene (naphthalene-1,8,4,5-diindandione). Prepolymers, with an open structure, were soluble to some extent in concentrated sulfuric acid but were more completely solubilized by methanesulfonic acid. The final polymer with a closed-ring structure, which was obtained by heating the prepolymer having an inherent viscosity of 0.4, was completely insoluble in these acids. Elemental analysis indicated that a high degree of cyclization was achieved, and the final polymer showed good thermal stability. Prepolymers with inherent viscosities in the range 0.11–1.58 have been obtained but, usually, a high viscosity was accompanied by a low acid solubility. Prepolymers with an inherent viscosity of 0.4, which were very soluble (>90%) in strong acids, were solubilized to a high degree by reduction with sodium dithionite in alkaline, aqueous dimethylacetamide. The highest molecular weight prepolymer (inherent viscosity of 1.30–1.58) was solubilized to a greater extent in this base mixture than in methanesulfonic acid. However, it was not completely soluble, under the conditions employed. The propolymers of higher molecular weight showed some fiber- and film-forming properties.     

Synthesis and Characterization of Heat-Resistant Polyamides from Thiadiazacycloheptatriene Dicarboxylic Acid

Novel polyamides containing 2,3,6,7-dibenzo-1-thia-4,5-diazacy-clohepta-2,4,6-triene-4′,4″-dicarboxy-l, l-dioxide (VII) are reported. The acid VII was prepared in several steps from p-chlorobenzoic acid and characterized by spectral data and elemental analysis. Prior to polymer synthesis, a model diamide (MDA) was prepared from VII and p-toluidine. The model diamide and several polyamides were obtained in an overall yield of (75-90%) by direct polycondensation of acid VII with certain diamines through a phosphorylation reaction at 100-110°C employing a solvent mixture of NMP-pyridine. The resulting polyamides and MDA were characterized by spectral, analytical, and thermal methods. The solubility, density, viscosity, and morphology (X-ray) were also studied for the polyamides. These polymers were moderately soluble in conventional polymer solvents, and the inherent viscosities were measured in concentrated sulfuric acid. Integral procedural decomposition temperatures (ipdt) were calculated from their primary thermogram in the temperature range 100-650°C in order to have quantitative data regarding their relative thermal stabilities. The polymers exhibit a 10% weight loss at 500°C in static air.     

Novel hydrophilic membrane materials: sulfonated polyethersulfone Cardo

Sulfonated polyethersulfone Cardo was prepared by solvent-free reaction of concentrated sulfuric acid on the polymer. The polymer can be sulfonated to different degrees by control of the reaction temperature and time. The degradation of it main chain was shown to occur at high reaction temperature or at very long time. Higher sulfonation obtained at longer reaction times led to soluble polyelectrolytes. Polymers with an ion exchange capacity lower than 1.75 equiv. kg⁻¹ are not soluble in water while being hydrophilic. Asymmetric membranes can be prepared from the latter polymers by the wet phase-inversion method with water as the precipitation medium. They can be used as hydrophilic membranes for ultrafiltration or nanofiltration.     

Partial ladder polymers with anthraquinone units. Reaction of 1,2,5,6-tetraaminoanthraquinone with p-benzoquinone derivatives

1,2,5,6-Tetraaminoanthraquinone has been condensed with 2,5-diaminobenzoquinone, 2,5-diaminobenzoquinone diimide, and 2,5-diaminohydroquinone to give partial ladder polymers which are only slightly soluble in sulfuric acid and do not produce soluble products on reduction with sodium dithionite in alkaline media.     

Thermally stable polymers from 1,4,5-naphthalene–tricarboxylic acid and aromatic tetramines

New thermally stable polymers that contained benzimidazole and benzimidazobenzoisoquinoline fragments in polymer chains were synthesized by one-stage cyclopolycondensation of aromatic tetramines (3,3′, 4,4′-tetraminodiphenyl ether, 3,3′,4,4′-tetraminodiphenyl methane, 3,3′,4,4′-tetraminodiphenyl sylfone, and 3,3′-diaminobenzidine) with 1,4,5-naphthalene tricarboxylic acid 4:5–anhydride in polyphosphoric acid and with 1,4,5-naphthalene tricarboxylic acid 4:5–anhydride 1-phenyl ester. All polymers obtained were soluble in concentrated sulfuric acid, 85% phosphoric acid, polyphosphoric acid, methane sylfonic acid. Some were soluble in formic acid. Thermogravimetric analyses indicated that these polymers were stable up to 450–500°C in air. The polymers had good hydrolytic stability.     

Polymers containing anthraquinone and quinoxaline units: Polypyrrolones

Four ladder or partial ladder polypyrrolones containing anthraquinone recurring units have been synthesized by condensing the dianhydride of 1,2,5,6-bis(α,β-dicarboxyl-pyrazino)anthraquinone with four different tetraamines, 1,2,4,5-tetraaminobenzene tetrahydrochloride, 3,3′,4,4′-tetraaminodiphenyl, 3,3′,4,4′-tetraaminodiphenyl ether, and 1,2,5,6-tetraaminoanthraquinone in dimethylacetamide and tetramethylene sulfone as reaction media. A prepolymer with an open structure was first formed which on further heating gave a closed-ring structure. These polymers which were highly colored, powdery materials, were insoluble in common organic solvents and slightly soluble only in concentrated H₂SO₄. They could, however, be solubilized in alkali by reduction with sodium dithionite. These polymers with an inherent viscosity in the range of 0.2–0.5, showed good thermal stability.     

Synthesis and characterization of sulfonated poly(phthalazinone ether ketone) for proton exchange membrane materials

As a novel class of proton exchange membrane materials for use in fuel cells, sulfonated poly(phthalazinone ether ketone)s (SPPEKs) were prepared by the modification of poly(phthalazinone ether ketone). Sulfonation reactions were conducted at room temperature with mixtures of 95–98% concentrated sulfuric acid and 27–33% fuming sulfuric acid with different acid ratios, and SPPEK was obtained with a degree of sulfonation (DS) in the desired range of 0.6–1.2. The presence of sulfonic acid groups in SPPEK was confirmed by Fourier transform infrared analysis, and the DS and structures were characterized by NMR. The introduction of sulfonic groups into the polymer chains increased the glass‐transition temperature above the decomposition temperature and also led to an overall decrease in the decomposition temperature. Membrane films were cast from SPPEK solutions in N,N‐dimethylacetamide. Water uptakes and swelling ratios of SPPEK membrane films increased with DS, and SPPEKs with DS > 1.23 were water‐soluble at 80 °C. Proton conductivity increased with DS and temperature up to 95 °C, reaching 10^?2S/cm. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 497–507, 2003     

Synthesis and characterization of phenylated pyrazino-benzimidazophenanthroline polymers

Novel phenylated quinoxaline tetraamines have been prepared and polymerized with 1,4,5,8-naphthalenetetracarboxylic acid in polyphosphoric acid solution. The resulting BBB-type polymers with pendant phenyl groups along the polymer backbone are soluble in m-cresol. The polymers, with inherent viscosities ranging from 0.3 to 0.6 dl/g in sulfuric acid, exhibited thermal stabilities near 500°C under nitrogen and near 400°C in air.