Aromatic Tetraamines Research Articles

Synthesis and investigation of polyheteroarylenes with benzimidazole cycles

AbstractPoly(benzimidazoles) and poly(amidobenzimidazoles) containing sulfur heteroatoms or sulfon groups in the macromolecular chain were synthesized and investigated. Sulfur‐containing aromatic tetramines, diamines and dicarboxylic acids were used as the initial monomers. The produced polymers have sufficiently high molecular weights and are well soluble in usual organic solvents.

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

AbstractNew 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.

Thermal and dynamic mechanical investigations on poly[bis(benzimidazobenzisoquinolinones)

A series of new semi-ladder poly[bis(benzimidazobenzisoquinolinones)], obtained by the polycondensation of dinaphthalene dianhydrides and aromatic tetraamines was investigated by TG, DSC and DMA methods. The influence of polymer structure on the thermal behaviour of the poly[bis(benzimidazobenzisoquinolinones)] was examined. The polymers were found to be thermally stable with T d > 723 K in air and T g ranging from 585 to 701 K. A good agreement was obtained in T g values measured by DSC and DMA methods. It was found that some cross-linking processes occurred at temperatures above T g. Some of the isothermal ageing curves were used to find the activation energies of isothermal cross-linking and decomposition.

Preparation and properties of polybenzimidazoles containing cardo groups

AbstractSeveral polybenzimidazoles containing cardo groups were prepared: A cardodicarboxylic acid, 9,9‐bis(4‐carboxyphenyl)fluorene, and two cardotetramines, 9,9‐bis(3,4‐diaminophenyl)fluorene and 9,9‐bis(3,4‐diaminophenyl)10‐anthrone. The cardodicarboxylic acid was condensed with aromatic tetramines and the cardotetramines were condensed with aromatic dicarboxylic acids. Prior to polymer synthesis two model compounds, 9,9‐bis[4,(2‐benzimidazolyl)phenyl]fluorene and 2,2′‐diphenyl‐5,5′‐(9,9‐fluorenediyl)‐bibenzimidazole were prepared and characterized by spectral methods. The polymers were obtained in 60–70% yield and showed reduced viscosity in the range of 0.7–1.1 dL/g. They were soluble in dimethyl formamide (DMF) and chlorinated solvents like tetrachlorethane. The thermal stabilities of these cardopolymers were superior to noncardopoly‐benzimidazoles.

Aromatic spiro polymers

AbstractAromatic spiro polymers, polyoxoindoline‐spiro‐benzimidazolines 9a–c, were prepared by the solution polycondensation reaction of biisatyls with aromatic tetramines in polar organic solvents. The spiro polymers were found to exhibit good solubility in polar organic solvents, such as N,N‐dimethylacetamide and hexamethylphosphoramide, in contrast to the insolubility of the corresponding polyindoloquinoxalines in these solvents. The improvement of the solubility was discussed mainly in terms of the hydrogen bonding and packing in polymer molecules. The spiro polymers slowly rearranged at high temperatures to give polyindoloquinoxalines with high thermal stability.

Bisorthoesters as Polymer Intermediates. IV. Polybenzoxazole Oligomers

Abstract Polybenzoxazoles of relatively low molecular weight have been prepared from hexa-n-propylorthoisophthalate in DMSO at 100°C. Unlike the preparation of polybenzimidazoles via the same route which gave high molecular weight linear polybenzimidazoles, condensation of dihydroxy-diaminobiphenyl with bisorthoesters gave only polymers of low molecular weight. It has not been established but it is most likely that the formation of only low molecular weight polymers was caused by the low basicity of the aromatic amino groups. Benzimidazoles of low molecular weight had also been observed when aromatic tetramines of low basicity were used for the condensation with bisorthoesters.

Synthesis and investigation of poly(benzimidazole imides) based on new di-imidodicarboxylic acids

Members of a new class of compounds, di-imidodicarboxylic acids, containing six-membered imide rings, have been synthesized by reacting 4-carboxynaphthalic anhydride with aromatic diamines. Polycondensation of these acids with aromatic tetramines in polyphosphoric acid produced poly(benzimidazole imides), notable for their high resistance to acids and bases. Some properties of these polymers were investigated.

Bisorthoesters as polymer intermediates. II. A facile method for the preparation of polybenzimidazoles

AbstractAromatic bisorthoesters were found to be good polymer intermediates and could be condensed with aromatic tetramines under mild conditions, in DMSO at 100°C in a relatively short reaction time to give polybenzimidazoles. The hexapropyl orthoesters of terephthalic and isophthalic acid were the preferred aromatic orthoesters because they were relatively easily purified by vacuum distillation to polymer grade intermediates, since they are liquids. Higher orthoesters distill even under good vacuum near or above the decomposition temperature of the orthoester group. Hexaethyl orthooxalate was also used and is a very useful and stable derivative of oxalic acid, which can be used for condensation reactions. These three orthoesters were used for condensations with 3,3′,4,4′‐tetraaminobiphenyl, 1,2,3,4‐tetraaminobenzene, 3,3′,4,4′‐tetraaminobiphenyl ether, and 3,3′,4,4′‐tetraaminobenzophenone. All polybenzimidazoles were obtained in high to quantitative yields and with varying molecular weights (ηinh = 0.1−0.8 dl/g), which in some cases were in the fiber forming range.

Synthesis of polybenzimidazoles with sulfonic acid groups

Abstract2‐Sulfoterephthalic acid (STA) and disulfoisophthalic acid (DSIA) were synthesized through the sulfonation and the oxidation of m‐ and p‐xylene. The polycondensation reactions of STA and DSIA with aromatic tetraamines gave polybenzimidazoles which contained one or two sulfonic acid groups for each repeating unit. The polymer obtained was soluble in sulfuric acid, some organic solvents, and aqueous strong alkaline solution. The polymers were stable up to 400°C, but they gave polybenzimidazoles above 400°C by eliminating sulfonic acid groups, instead of ring closure.

Phosphorus-containing polybenzimidazoles prepared by reaction of bis( p-carboxyphenoxymethyl)methylphosphine oxide with aromatic tetramines

Two types of polybenzimidazoles (phosphorus- and phosphorus and chlorine containing) are synthesized from bis( p-carboxyphenoxymethyl)methylphosphine oxide or its chlorine-containing analogue and aromatic tetramines in polyphosphoric acid. The structures of the new polybenzimidazoles are determined with the aid of model compounds and i.r. and u.v. spectroscopy. The polymers possess comparatively high thermal stability and resistance to ignition.

Study of the chemical structure of p-carborane containing polyamino amide macromolecules

A study has been made of relationships between some properties of polyamino-amides based on p-carboranedicarboxylic acid and aromatic tetramines and the chemical structure of their macromolecules. It was found that the elemental composition and solubility of the polymers, as well as their ability to undergo chemical conversions, depend on the conditions under which the polycondensation reaction is carried out.

Polyimidophenylquinoxalines

A method has been developed for the synthesis of bis-(α-diketones) with structures containing imide rings. These products are obtained by reacting 4-aminobenzyl with dianhydrides of aromatic tetracarboxylic acids in the presence of benzoic acid as catalyst. The products were obtained in 90–95% yields. Polyimidophenylquinoxalines were prepared by reacting the foregoing products with aromatic tetramines. It was found that a 25 to 50% content of naphthylimide fragments in the polyphenylquinoxalines results in goed thermal stability and high heat resistance of the polymers along with good processing properties. In addition the polymers possess good deformation-strength properties, so that serviceability at temperatures above 300° may be envisaged.

Synthesis and study of polybenzimidazoles containing p-carborane

Polybenzimidazoles containing p-carborane were obtained by a single stage method in melt formed of diphenyl ester of p-carborane dicarboxylic acid and aromatic tetramines and a two stage method from p-carborane dicarboxylic acid dichloride and aromatic tetramines in THF solution in the presence of trioctylamine with the separation of linear polyaminoamides and subsequent cyclodehydration to polybenzimidazoles. The properties of both polyaminoamides and polybenzimidazoles were examined and it was shown that these properties are not only influenced by the isomerism of the carborane nucleus, but also conditions of synthesis.

Polymers containing the benzimidazole and the quinazolinedione unit in the main chain

AbstractAromatic diphenyl esters containing the quinazolinedione unit (7a,b and 8a,b) were synthesized from phenyl N‐(phenoxycarbonylphenyl)carbamates (3 and 5) and aromatic bis(o‐amino) esters (6a,b). The corresponding dicarboxylic acids (7c,d and 8c,d) were obtained by hydrolyzing the diphenyl esters. The condensation of either the diphenyl esters 7a,b and 8a,b or the dicarboxylic acids 7c,d and 8c,d with aromatic tetraamines (11a‐c) gave polymers 12 and 13 containing benzimidazole and quinazolinedione units. These polymers exhibited highly thermal stability.

Methods of investigations evaluating the branching of polyaminoamides containing m-carboran by high resolution NMR

It was found possible to determine branching of polyaminoamides containing, m-carboran, prepared by non-equilibrium polycondensation of aromatic tetramines with m-carboran dicarbosylic acid dichloride using high resolution NMR for these polymers and compounds, which simulate the structure of the polymer unit.

Polyphenylquinoxalines with high glass transition temperatures via highly fused aromatic tetraamines

AbstractA series of polyphenylquinoxalines has been synthesized by the reaction of p,p′‐oxydibenzil with aromatic tetraamines containing varying numbers of fused rings. It was found that the glass transition temperatures of the resultant polymers increased as the the number of adjacent fused rings in the polymers was increased. This provided the basis for achieving glass transition temperatures for the polymers in excess of 400°C, substantially higher than the state‐of‐the art polyphenylquinoxalines. All of the polymers displayed both the good thermal stability and the solubility in m‐cresol characteristic of the polyphenylquinoxaline family of polymers.

Synthesis and study of polymers prepared from dianhydrides of 3,4,9,10-perylene-1,4,5,8-naphthalene tetracarboxylic acids and aromatic tetra-amines

Low molecular weight products of the condensation of dianhydride of perylene tetracarboxylic acid (DAPTA) with tetra-aminodiphenyl ester (TADPE) and high molecular weight soluble polyaminoamido acids containing alternating naphthalene and perylene units, were obtained in an aprotonic solvent-inorganic salt system. The effect of various factors (LiCl concentration, concentrations of initial components, reaction temperature and dianhydride ratio) on the rate of polycondensation and the molecular weight of polyaminoamido acids was examined. Conditions of cyclization were determined for copolymers. Poly-(aroylene-bis-benzimidazoles) containing alternating perylene and naphthalene units were prepared by high temperature polycondensation in polyphosphoric acid.

The reaction of m-carboranedicarboxylic acid chloride with aromatic tetramines

Soluble polymers of linear and branched structure have been prepared by non-equilibrium, low temperature polycondensation of aromatic tetramines with m-carboranedicarboxylic acid chloride, the products have been characterized and some correlations involved in their formation are studied. It is shown that polycondensation of this acid chloride with tetramines in solution in tetrahydrofuran in the presence of pyridine produces branched polymers, but in N-methylpyrrolidone polyaminoamides of linear or branched structure are formed, depending on the reaction conditions.

New heat-resistant polymers from 4-carbophenoxynaphthalic anhydride and aromatic tetramines

Heat-resistant polymers have been prepared from 4-phenyl naphthalenetricarboxylic acid anhydride and aromatic tetramines by polycondensation in the melt. Some relationships of the reaction have been studied and the optimal conditions of preparation have been found. These polymers are soluble and are highly resistant to thermal-oxidative degradation. Dynamic thermogravimetric analysis showed that the temperature of decomposition in air is above 400°.

Synthesis and study of poly(benzimidazolenaphthoyl-enebenzimidazoles) based on 1,4,5-naphthalene tricarboxylic acid and aromatic tetramines

Synthesis and study of poly(benzimidazolenaphthoyl-enebenzimidazoles) based on 1,4,5-naphthalene tricarboxylic acid and aromatic tetramines