WO2012088190A1

WO2012088190A1 - 2,4,5-triaminothiophenols and related compounds

Info

Publication number: WO2012088190A1
Application number: PCT/US2011/066310
Authority: WO
Inventors: Rajiv Dhawan; Joachim C. Ritter
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 2010-12-20
Filing date: 2011-12-20
Publication date: 2012-06-28
Anticipated expiration: 2013-06-20

Abstract

New triaminothiophenol compositions and related compounds are disclosed, as are processes for their preparation and for the preparation of novel salts, diacid complexes, and polymers from such compounds. Polymers prepared from these compositions can be made into high strength fiber, film, and tape and are useful in applications such as protective apparel, aircraft, automotive components, personal electronics, and sports equipment.

Description

2, 4, 5-TRIAMINOTHIOPHENOLS AND RELATED COMPOUNDS

FIELD OF DISCLOSURE The disclosure relates to new compositions based on 2 , 4 , 5-triaminothiophenols , which are then used in the manufacture of high-performance heterocyclic aromatic polymers.

BACKGROUND Aromatic amines and phenols are useful as monomers for high performance polymers such as aramid polymers and polybenzarenazoles . The structure of the specific monomer used greatly impacts polymer

properties such as tenacity, solubility, and also the rheological behavior of the polymer during processing such as spinning. It is thought that replacing highly symmetric monomers that are currently used (e.g., 2, 3, 5, 6-tetraaminopyridine) with asymmetric monomers would increase the solubility of the corresponding polymers and the ease with which they are processed. It is also thought that the polymers would exhibit improved properties, including increased tenacity and strength, and reduce water ingression into the crystal structure of the fiber. However, such monomers are often difficult to synthesize or are unknown. These materials are unknown and have not been synthesized.

There is a need for asymmetric monomers that can be readily synthesized and used in the production of high performance polymers such as aramid polymers and heterocyclic aromatic polymers. DESCRIPTION

The following description is exemplary and explanatory only and is not restrictive of the

invention, as defined in the appended claims.

The disclosures herein include new

triaminothiophenols and related compounds, processes for the preparation of such triaminothiophenols and related compounds, processes for the preparation of products into which such triaminothiophenols and related compounds can be converted, and the products obtained and obtainable by such processes.

In the context of this disclosure, a number of terms shall be utilized.

As used herein, the term "free base," as applied to a triaminothiophenol , is used to denote a triaminothiophenol compound per se, for example, Formula (I)

to distinguish it from the acid salt of a

triaminothiophenol or a complex of the

triaminothiophenol with a diacid.

As used herein, the term "triaminothiophenol salt" or "[specific triaminothiophenol name or formula reference] salt," e.g., "Formula (II) salt" or "TATHIO salt" where TATHIO means 2 , 4 , 5-triaminothiophenol , denotes a compound formed by reaction of a

triaminothiophenol with "n" equivalents of an acid ("A") such as HC1, acetic acid, H₂S0₄, or H₃P0₄. One example of a triaminothiophenol salt is TATHIO- 2HC1

(n=2, A=HC1) . The salt may also be a hydrate; one such example is TATHIO · 3HC1 · x¾0. The acid name may also be incorporated into the name of the salt, so that, e.g., TATHIO · nHCl can be referred to as "2,4,5- triaminothiophenol hydrochloride salt" or "TATHIO hydrochloride." Where n is known, it can be

incorporated as well; for example, TATHIO- 3HC1 can also be referred to as "2 , 4 , 5-triaminothiophenol

trihydrochloride salt" or "TATHIO trihydrochloride . "

As used herein, the term "triaminothiophenol complex" or "[specific triaminothiophenol name] [diacid source name] complex denotes a compound formed by reaction of a triaminothiophenol with a diacid source. Where the complex is to be used as a monomer in a polymerization, it can also be referred to as a

"monomer complex." One example of a triaminothiophenol complex is TATHIO- TA, wherein "TATHIO" is 2,4,5- triaminothiophenol and "TA" is terephthalic acid.

As used herein the term "diacid source" refers to the diacid HOOC-Q-COOH itself, a disodium salt of HOOC-Q-COOH, a dipotassium salt of HOOC-Q-COOH, or mixtures thereof, wherein Q is a Ci to C2₀

substituted or unsubstituted monocyclic or polycyclic aromatic nucleus.

As used herein, an acid (A) useful in the practice of the present invention can be an acid or a diacid as described above, or a mixture of diacids with other acids .

As used herein, the term "XYTA" denotes 2-X- 5-Y-terephthalic acid, where X and Y are each

independently selected from the group consisting of H, OH, SH, S0₃H, methyl, ethyl, F, CI, and Br. One example is 2 , 5-dihydroxyterephthalic acid ("DHTA") , in which X=Y=OH. The disodium or dipotassium salt of the XYTA diacid can be represented by the term "M₂XYTA" where M is Na or K.

As used herein, the term "oleum" denotes fuming sulfuric acid, which is anhydrous and is formed by dissolving excess sulfur trioxide (SO₃) into

sulfuric acid.

As used herein, the term "weak base" denotes a base having a base dissociation constant (also referred to as "ionization constant") K_b that is less than 1 at 25°C. Some examples are acetate ion CHsCOO-, ammonia, and bicarbonate ion, HC03^~.

As used herein, the term "net yield" of P denotes the actual, in-hand yield, i.e., the

theoretical maximum yield minus losses incurred in the course of activities such as isolating, handling, drying, and the like.

As used herein, the term "purity" denotes what percentage of an in-hand, isolated sample is actually the specified substance.

As used herein, the term "alkyl" is used to denote a univalent group derived from an alkane by removing a hydrogen atom from any carbon atom: -C_nH_2n+i where n ≥ 1 ; as used herein, the term "alkyl" includes both substituted and unsubstituted groups.

As used herein, the term "aryl" is used to denote a univalent group whose free bonding site is to a carbon atom of an aromatic ring; as used herein, the term "aryl" includes both substituted and unsubstituted groups. An example is the "phenyl" group, i.e., the C₆H₅ radical shown below:.

As used herein, the term "aralkyl" denotes an alkyl group which bears an aryl group; as used herein, the term "aralkyl" includes both substituted and unsubstituted groups. One such example is the benzyl group, i.e., the C₇H₇ radical shown below,

As used herein, the term "alkaryl" denotes an aryl group which bears an alkyl group; as used herein, the term "alkaryl" includes both substituted and unsubstituted groups. One example of an alkaryl group is the 4-methylphenyl radical, C₇H_7i shown below:

As used herein, the "acetyl" is used to denote the univalent radical CH₃CO-, i.e.,

0

H₃C C

In various embodiments of this invention, new compositions represented by the structures of Formulas (I) through (V) below are provided.

V

Also provided are novel polymer compositions comprising repeat units represented by Formula (VI) .

In Formulas (I) through (VI),

R¹ and R² are each independently H, alkyl, aryl, alkaryl, or aralkyl;

R³ and R⁴ are each independently H, alkyl, aryl, alkaryl, or aralkyl; or may be joined to form an aliphatic ring structure; R⁵ and R⁶ are each independently H, alkyl, aryl, alkaryl, or aralkyl; or may be joined to form an aliphatic ring structure;

R⁷ and R⁸ are each independently H, alkyl, aryl, alkaryl, or aralkyl; or may be joined to form an aliphatic ring structure;

R⁹ is H or acetyl;

n is 1 to 10;

A is an acid, e.g., HC1, acetic acid, H₂S0₄, or H₃P0₄; and

Q is a Ci to C20 substituted or unsubstituted monocyclic or polycyclic aromatic nucleus.

In one embodiment of the composition

represented by Formula (I), R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸ are each H. This compound (Formula (VII)) is 2, 4, 5-triaminothiophenol ( "TATHIO" ) .

VII

In another embodiment of the composition represented by Formula (I), R¹ and R² are each

independently H, alkyl, aryl, alkaryl, or aralkyl, R³ is H, R⁴ is alkyl or H, and, of the four groups R⁵, R⁶, R⁷, and R⁸, any three are H and the fourth is H, alkyl, aryl, alkaryl, or aralkyl. An example of this

embodiment is shown below (Formula (VIII)) :

VIII

In another embodiment, a process is provided for preparing compositions of Formula (I) wherein each R³, R⁴, R⁵, and R⁶ is H, represented by Formula (IX)

IX

In one embodiment, R¹, R², R⁷, and R⁸ are each

independently H or a C1-C4 alkyl group (substituted or unsubstituted) . In one embodiment, the composition represented by Formula (IX) is made by

(a) monoaminating a composition of Formula (X) ,

X

wherein each Z is independently CI or Br, by heating a suspension of the composition of Formula (X) in solvent to a temperature in the range of about 60 °C to about 140°C and contacting it with an aqueous solution of at least 2.0 equivalents HNR R to produce a composition of Formula (XI)

XI

(b) reacting the composition of Formula (XI) ' SH^~ or S^~2 to produce the composition represented by Formula (IV); and

IV

(c) contacting the composition represented by Formula (IV) produced in (b) with a reducing agent, thereby producing the composition of Formula (IX) .

The composition represented by Formula (X) may be prepared by nitration of the corresponding dihalobenzene according to the method described in copending U.S. Patent Application 12/335,959, which is hereby incorporated by reference in its entirety for all purposes; by admixing a dihalobenzene represented by the structure of Formula (XII)

XII

wherein each Z is independently CI or Br, with nitric acid, sulfuric acid, and oleum or SO₃, to form a reaction mixture that is characterized by (i) a

concentration of nitric acid therein that is in the range of about 2.0 to about 2.3 moles per mole of dihalobenzene ; (ii) a concentration of SO₃ therein that is in the range of about 1 to about 3 moles per mole of dihalobenzene; (iii) a concentration of dihalobenzene therein that is in the range of about 12 to about 24 weight percent; and (iv) a temperature of up to about 120°C; and stirring the reaction mixture at a

temperature in the range of about -10°C to about 70°C to form a dihalodinitrobenzene product represented by the structure of Formula (X) . In an embodiment, each Z is CI and R¹ and R² are each H; i.e., the compound of Formula (X) is 1 , 3-dichloro-4 , 6-dinitrobenzene and the Formula (XII) dihalobenzene is 1 , 3-dichlorobenzene, which is commercially available.

The monoamination of the dihalodinitrobenzene can be carried out as described in copending U.S.

Patent Application 61/288,436, which is hereby

incorporated by reference in its entirety for all purposes. A suspension of the composition of Formula (X) in solvent is heated to a temperature in the range of about 60°C to about 140°C, preferably about 100°C to about 135°C, and more preferably about 130°C, to dissolve the composition of Formula (X) in a solvent. A suitable solvent is an organic solvent inert to the reaction such as an aliphatic dihydric alcohol, such as ethylene glycol ("glycol") . The resulting solution is contacted at that temperature with an aqueous solution of HNR⁷R⁸ for approximately two to four hours close to ambient pressure; the HNR⁷R⁸ solution is fed as it is consumed, as indicated by any convenient analytical technique (e.g., pH monitoring or measuring the flow rate of HNR⁷R⁸ in the gas phase above the reaction mixture) . In one embodiment, the compound represented by Formula (XI) is l-amino-3-chloro-4 , 6-dinitrobenzene (i.e., R¹, R², R⁷, and R⁸ are each H and Z is CI) . At least 2.00, preferably about 2.03 to about 2.07, equivalents of HNR⁷R⁸ are required. At reaction completion, the composition of Formula (XI) thereby produced can be directly isolated from the reaction mixture since it is only sparingly soluble in suitable solvents such as glycol at temperatures below 50°C;

impurities remain in solution, and net yields of 85% have been found at greater than 98% purity for 1-amino- 3-chloro-4, 6-dinitrobenzene specifically.

The composition of Formula (XI) is filtered, typically at about 60°C, and washed with solvent. It can then be thiolated (step (b) ) . In one embodiment, the composition of Formula (XI) is slurried in ethanol and reacted in step (b) with aqueous SH^~ (for example, from NaSH) under mild conditions (e.g., at about 10°C to 50°C) in a molar ratio of at least 1.0 mole SH^~ per mole Formula (XI) composition, to form the disulfide represented by Formula (IV) .

IV

When R¹, R², R⁷, and R⁸ are each H, the disulfide is bis (3, 4-diamino-6-dinitrophenyl) disulfide ("DANDS") , represented by Formula (XIII) .

XIII

In another embodiment, the composition of Formula (XI) is contacted in step (b) with sulfide ion, S^~2 (e.g., from an aqueous solution of a₂S) to produce the disulfide represented by Formula (IV) .

In either of these embodiments, the disulfide represented by Formula (IV) can be isolated and

contacted with a reducing agent (e.g., Zn, in acetic acid; or Sn⁺²) to form the triaminothiophenol

represented by Formula (I) . The isolation step results in higher purity product. Alternatively, the disulfide is not isolated but simply heated with NaSH in an ethanol/water mixture at about 80°C to about 90°C to form the triaminothiophenol represented by Formula (I) .

In another embodiment, the composition of Formula (XI) is prepared as described above (step (a)) and then is contacted in step (b) with thioacetate ion (for example, from sodium thioacetate, prepared by reacting thiolacetic acid with aqueous NaOH in an oxygen-free environment) , typically under ambient conditions, in an ethanol/water mixture in a molar ratio of at least 1.0 mole thioacetate per mole Formula

(XI) composition, to form the composition represented by Formula (XIV) , which is the same as Formula (V) wherein R⁹ is acetyl.

The thioacetate

hydrolyzed.

Procedures for hydrolyzing thioacetates are well known in the art and are described in, for example, P. N. Rylander and D. S. Tarbel, Journal of the American

Chemical Society, 72 (1950) 3021-3025; B. K. Morse and D. S. Tarbell, Journal of the American Chemical

Society, 74 (1952) 416-419; and S. Iimura et al . , Organic Letters, 5(2) (2003) 101-103. In general, hydrolysis of thioacetates can occur via base or acid catalysis. For example, the thioacetate (Formula XIV) can be hydrolyzed by heating in an aqueous or alcoholic solution of 1 equivalent NaOH (e.g., at about 50°C for about 1 h) to form the sodium salt of the

dinitroaminothiophenol below, after which the sodium salt is neutralized to liberate the free dinitroaminothiophenol represented by Formula (XV) , which is the same as Formula (V) wherein R⁹ is H. In acid-catalyzed hydrolysis, the thioacetate represented by Formula (XIV) is instead heated in an aqueous acid solution, e.g., aqueous HC1; one embodiment of acid- catalyzed hydrolysis is presented in Example 5, in which concentrated HC1 is added to a thioacetate solution until the solution is slightly acidic. Excess acid is not added to avoid the formation of the

hydrochloride of Formula (XV) , which is partially soluble .

XV

The dinitroaminothiophenol can be isolated and subsequently contacted with a reducing agent (e.g., Zn in acetic acid, Sn⁺², or SH^~) or it can be directly reduced without isolation to form triaminothiophenol represented by Formula (I) . Including the isolation step results in higher purity product.

In another embodiment, a process is provided for the efficient production of novel, high-purity salts represented by Formula (II) ("Formula (II) salt")

II wherein n is 1 to 10 and A is an acid, e.g., HC1, acetic acid, H₂SO₄, or H₃PO₄. The Formula (II) salt can be converted to the free base or to a novel aromatic diacid complex of the free base with a diacid source, the complex represented by Formula (III),

III

of high enough purity for use in making a high

molecular weight polymer material for producing high- performance fibers. The salt may also be a hydrate; one such example is 2 , 4 , 5-triaminothiophenol · 3HC1 · x¾0 ("TATHIO- 3HC1 · χΗ₂0") . In one embodiment, A in Formula (II) is HC1 and n is 2 to 4. In one embodiment, to prepare the Formula (II) salt, the composition of

Formula (IX) having R⁸=H is prepared as described above, slurried in water, and contacted with an acid to form and precipitate the Formula (II) salt. The mixture containing the precipitated Formula (II) salt is then cooled to about 5°C to about 15°C, stirred, and filtered. The Formula (II) salt is then washed. It may be washed with deaerated aqueous acid, such as HC1 (33%) , and then optionally with deaerated ethanol or methanol to produce a wet cake material.

Whether aqueous acid or cold water is used as a wash, it may be possible to eliminate the ethanol or methanol wash and dry directly from aqueous wet cake or simply use the wet cake in subsequent processing. It is likely that in a commercial process one would only wash with HCl_aq and, if desired, dry directly.

The resulting wet cake material (Formula (II) salt) can be used in subsequent processing without drying or can be dried, for example at a pressure less than 400 Torr and a temperature of about 30 °C to about 50°C, under a stream of N₂. The dried product is preferably kept under nitrogen.

In another embodiment, a process is provided for preparing novel complexes of Formula (III),

III

wherein Q is a Ci to C2₀ substituted or unsubstituted monocyclic or polycyclic aromatic nucleus.

Examples of Q include without limitation:

1, 4-phenylene (C6¾

2, 5-dihydroxy-l , 4-phenylene

1, 4-naphthylene (CioH₆) ,

1 , 5-naphthylene (CioH₆)

2, 6-naphthylene (CioH₆) ,

4 , 4 ' -biphenyl diradical (C^Hg) ,

4 , 4 ' -biphenyl ether diradical (OCi₂H₈0) , and

1, 5-dihydroxy-2 , 6-naphthylene (CioH₆0₂)

One or more heteroatoms (such as N, 0, S) may be present in the ring(s) of Q, for example, as shown below :

2, 5-pyridylene (C₅H₃N)

In one embodiment, Q is represented by the structure of Formula (XVI)

XVI wherein X and Y are each independently selected from the group consisting of H, OH, SH, SO₃H, methyl, ethyl, F, CI, and Br. Preferably, X=Y=OH (i.e., the diacid is 2 , 5-dihydroxyterephthalic acid) or X=Y=H (i.e., the diacid is terephthalic acid) . When X=Y=H, the diacid is referred to as "XYTA" .

In one embodiment ("Option A") , the Formula

(II) salt is precipitated and washed as described above, then slurried with water. Base (e.g., NaHCOs) , sufficient to neutralize the reaction mixture, and a diacid source are then added to the slurry to form and precipitate the complex, Formula (III) . As used herein the term "diacid source" refers to the diacid HOOC-Q- COOH itself, a disodium salt of HOOC-Q-COOH, a

dipotassium salt of HOOC-Q-COOH, or mixtures thereof.

Alternatively ("Option B") , the reaction mixture containing the composition of Formula (IX) (with R⁸=H) can be combined directly with the base and the diacid source to form and precipitate the complex of Formula (III) . In another alternative ("Option C") , filtered free base (Formula (IX) with R⁸=H) can be dissolved in about 1-2 equivalents of acid (e.g., HC1) and the solution so produced contacted with the base and the diacid source to form the complex of Formula (III) .

In the complex described by Formula (III), it is important that the ratio of the free base to the diacid source be 1:1. This allows the production of high molecular weight polymer from the complex and high strength fiber from the polymer. In some instances, including, but not limited to, complexes wherein the free base is 2 , 4 , 5-triaminothiophenol ("TATHIO") , i.e., the desired complex is represented by Formula (XVII),

XVII the use of a strong base such as aqueous sodium

hydroxide or aqueous potassium hydroxide in the Option A, B, or C process can cause the free base to diacid ratio in the complexes so produced to deviate from 1:1. In such cases, a preferred process is to dissolve the Formula (II) salt, e.g., TATHIO · 3HC1 , in water and contact that solution with the diacid source in an aqueous solution of a weak base such as aHC03 or KHCO3. This process can be performed under mild conditions, e.g., from ambient temperatures to about 50°C. The ratio of equivalents of the Formula (II) salt to equivalents of diacid source is between and optionally including any two of the following ratios: 1.00:1.00, 1.025:1.00, 1.05:1.00, 1.075:1.00, 1.10:1.00;

1.20:1:00, 1.30:1.00, 1.40:1.00, and 1.50:1.00. In one embodiment, the ratio is from 1.025:1.00 to 1.10:1.00.

Various designs are possible for combining the Formula (II) salt with the diacid source and aqueous base to produce the complex. For example, the base and the diacid source are most conveniently added as a single solution. In other embodiments, the Formula (II) salt in an acid solution could be introduced into a vessel containing a basic diacid source solution, or the diacid source stream could be fed into the vessel containing the Formula (II) salt in an acid solution. Which design is best for a specific situation will be evident to one of skill in the art.

The Formula (III) complex is recovered from the reaction mixture by filtration at a temperature in of the range of about 5°C to about 50°C, preferably about 10°C to about 15°C, and washed with water and methanol, typically at a temperature in the range of about 15°C to about 40°C, and then dried. The washed and dried Formula (III) complex is kept under nitrogen to protect it from oxygen. It is of high enough quality and purity to produce heterocyclic aromatic polymer of high enough molecular weight to make high performance fibers .

The Option A embodiment discussed above can produce higher purity Formula (III) complex than

Options B or C. On the other hand, Options B and C have fewer steps, generate less waste and also require less acid (e.g., HC1) and base (e.g., NaHCOs) , thus lessening raw material and handling costs. All

disclosed embodiments produce polymer grade material suitable for the manufacture of high-performance fibers .

Oxygen is excluded throughout all steps of the processes of making the free base, the Formula (II) salt, and the Formula (III) complex. Deaerated water and deaerated acid are used. A small amount of a reducing agent (e.g., about 0.5% tin powder) is

optionally added to one or more of aqueous suspensions or aqueous solutions containing the triaminothiophenol free base, the Formula (II) salt, or the Formula (III) complex during the process to reduce impurities caused by oxidation and to prevent further impurity formation by that route .

In another embodiment, novel polymer compositions are provided comprising a composition of Formula (I) as a monomer. Articles comprising these polymers are also provided. Examples of such articles include without limitation fiber, film, and tape. In one embodiment, novel polymer compositions are provided comprising repeat units represented by Formula (VI) .

VI

wherein R¹, R², and R⁷ are each independently H, alkyl, aryl, alkaryl, or aralkyl; and Q is a Ci to C2₀

substituted or unsubstituted monocyclic or polycyclic aromatic nucleus as defined above.

Polymers comprising repeat units represented by Formula (VI) can be prepared at high molecular weight from a mixture of a triaminothiophenol salt represented by Formula (II) (e.g., TATHIO · 3HC1 ) with HOOC-Q-COOH in polyphosphoric acid, or from a complex represented by Formula (III) at temperatures from about 100°C to about 180°C.

In one embodiment, represented by Formula (XVIII), R¹, R², and R⁷ are each H and Q is 1,4- phenylene .

XVIII The polymer represented by Formula (XVIII) can be made by polymerizing the 1:1 monomer complex of 2,4,5- triaminothiophenol with terephthalic acid ("TATHIO- T complex") ; or by polymerizing a mixture of a TATHIO salt (e.g., TATHIO · 3HC1 ) and terephthalic acid.

In another embodiment, represented by Formula (XIX), R¹, R², and R⁷ are each H and Q is 2 , 5-dihydroxy- 1 , 4 -phenylene .

XIX

The polymer represented by Formula (XIX) can be made by polymerizing the 1:1 monomer complex of 2,4,5- triaminothiophenol with 2 , 5-dihydroxyterephthalic acid ("TATHIO · DHTA complex"); or by polymerizing a mixture of a TATHIO salt (e.g., TATHIO · 3HC1 ) and 2,5- dihydroxyterephthalic acid.

The polymerization of the monomer complex is typically carried out in a reactor suitably equipped with connections for purging with inert gas, applying a vacuum, heating and stirring. Monomer complex, P₂O₅, polyphosphoric acid ("PPA") and powdered metal (for example, tin or iron metal) are typically added to the reactor. The reactor is typically purged, heated and mixed to effect polymerization. In a preferred

embodiment, about 20 parts by weight of monomer

complex, about 10 parts of P₂O₅, 100 parts of PPA, and about 0.1 parts tin or iron metal are added to a suitable reactor. The contents of the reactor are stirred at about 60 rpm and heated to about 100°C for about one hour under vacuum with a slight nitrogen purge. The temperature is typically raised to at least 110°C, preferably at least about 120°C, and preferably not more than 140°C for a few more hours, preferably about four hours. The temperature is then raised and held at a higher temperature, at least about 130°C, more typically at least about 140°C, and preferably at about 150 °C for about an hour, more preferably about three hours. The temperature is subsequently then raised and held at a higher temperature, at least about 150°C, more typically at least about 170°C, and

preferably at about 180°C for about an hour, more preferably about three hours. The reactor is typically flushed with nitrogen and a sample of the polymer solution is taken for viscosity determination.

In certain embodiments, the polymers so produced from monomer complexes are polybenzarenazoles that are characterized as providing a polymer solution having an inherent viscosity of at least about 8 dL/g at 30°C at a polymer concentration of 0.05 g/dL in methanesulfonic acid. In certain embodiments, the metal powder is present in an amount of about 0.1 to about 0.5 weight percent based on monomer complex.

In certain embodiments, the reaction mixture includes polyphosphoric acid having an equivalent P₂O₅ content of at least about 81 percent after

polymerization, and more preferably at least about 86 percent after polymerization. In certain embodiments, the reaction mixture includes polyphosphoric acid having an equivalent P₂O₅ content of at least about 81 percent after contacting, in polyphosphoric acid, the monomer complex with metal powder, the metal powder added in an amount of from about 0.05 to about 0.9 weight percent, based on the total monomer weight and polymerizing the monomers in polyphosphoric acid to form the polymer solution. In certain of these

embodiments, the ratio of equivalents of the

triaminothiophenol to the diacid source is at least about 1.00:1.00, at least 1.025:1.00, at least

1.05:1.00, at least 1.075:1.00, at least 1.10:1.00, at least 1.125:1.00, or at least about 1.15 to 1.

A solution of such polymers at about 10 to about 30 wt% in polyphosphoric acid can be used to prepare high strength fiber, films, and tapes, which can be used, for example, as reinforcement materials for thermoplastic and thermoset matrices. Fibers may also be cut and used as staple fiber or, when

fibrillated, as pulp. Useful articles comprising the polybenzarenazole polymers described herein include without limitation: protective apparel (e.g., body armor, industrial gloves, flame retardant apparel) ; aircraft applications (e.g., components of aircraft cabin, flooring and interiors, landing gear doors;

rotor blades; space craft; maritime vessels; automotive components (e.g., tires, friction and sealing

applications, brake pads, belts, gaskets, hoses, composites, vehicular armor) ; sports equipment; and personal electronics.

All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly

understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control .

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

Unless stated otherwise, all percentages, parts, ratios, etc., are by weight.

When an amount, concentration, or other value or parameter is given as either a range, preferred range or a list of upper preferable values and lower preferable values, this is to be understood as

specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values recited when defining a range.

When the term "about" is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end- point referred to.

As used herein, the terms "comprises,"

"comprising," "includes," "including," "containing," "characterized by," "has," "having" or any other variation thereof, are intended to cover a non^¬ exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or

apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present) , A is false (or not present) and B is true (or present) , and both A and B are true (or present) .

Use of "a" or "an" are employed to describe elements and components of the invention. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

The materials, methods, and examples herein are illustrative only and, except as specifically stated, are not intended to be limiting.

EXAMPLES

The present invention is further defined in the following examples. It should be understood that these examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these examples, one skilled in the art can ascertain the essential characteristics of this invention, and without

departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various uses and conditions. All water used was deaerated and de-ionized water .

The Examples were carried out under exclusion of oxygen.

The meaning of abbreviations is as follows:

"ACDNB" means l-chloro-3-amino-4 , 6-dinitrobenzene, "cm" means centimeter ( s ) , "d" means density, "DADNB" means 1 , 3-diamino-4 , 6-dinitrobenzene, "DANDS" means bis (3,4- diamino- 6-dinitrophenyl ) disulfide, "DCDNB" means 1,3- dichloro-4 , 6-dinitrobenzene, "DHTA" means 2,5- dihydroxyterephthalic acid, "dL" means deciliter ( s ) , "DMAC" means dimethylacetamide, "equiv" means

equivalent ( s ) , "g" means gram(s), "GC" means gas chromatography, "h" means hour(s), ^{λ 1}Η NMR" means proton nuclear magnetic resonance spectroscopy, "h" means hour(s), "K₂DHTA" means the potassium salt of 2 , 5-dihydroxyterephthalic acid, "kg" means kilogram (s), "L" means liter (s), "mL" means milliliter ( s ) , "min" means minutes, "mmol" means millimole ( s ) , "mol" means mole(s), "PPA" means polyphosphoric acid, "rpm" means revolutions per minute, "TATHIO" means 2,4,5- triaminothiophenol , and "ηι_η¾" means inherent viscosity.

Example 1. Preparation of DCDNB

To a 1 L 3-neck round bottom flask equipped with external ice cooling, mechanical stirrer, addition funnel, 2 inlet, and thermometer was added 126 g (2 mol) fuming nitric acid (d=1.54 g/cm³), followed by 208 g sulfuric acid and 508 g 30% oleum (2.2 molar equiv SO3) , maintaining a temperature between 10 and 40°C. Subsequently, 140 g (0.95 mol) 1 , 3-dichlorobenzene (Toray Ltd., Tokyo, Japan, >99% purity) were added over a time period of 90 min while maintaining a temperature of about 5°C. The ice bath was removed, and the reaction mixture was allowed to warm up to room

temperature. It was then heated from room temperature to 100°C over a time period of 45 min. At that point, a small sample of crude product was taken from the reaction vessel and poured into ice water. The crude product was extracted with methylene chloride. Analysis by GC and ¹R NMR indicated a reaction selectivity for 1 , 3-dichloro-4 , 6-dinitrobenzene of 92%. After 15 min at 100°C, the reaction mixture was allowed to cool to room temperature over 2 h and then cooled to 5°C over 30 min, after which it was filtered through a glass fritted funnel and washed with 300 mL water followed by 200 mL 10% aqueous N¾ solution. Analysis indicated a net content of about 184 g of >98% pure product (-80% net yield) and the dry mass content of the wet cake was about 90%.

Example 2. Preparation of ACDNB from DCDNB

A degassed solution of wet 1 , 3-dichloro-4 , 6- dinitrobenzene (329 g, 24% water) in ethylene glycol under nitrogen (1 kg) was heated to 130°C. Ammonium hydroxide (28% aqueous N¾, 2.32 mol) was added over a period of approximately 2 h such that the desired product was exclusively formed. After addition was complete, the reaction was allowed to cool to room temperature and the precipitate was collected via suction filtration. The filter cake was washed

sparingly with water and was used as is for the next step. The final yield was 233 g, of which 6% was water leaving a dry weight of 219 g (95% yield) . The purity was >91% with the main impurity (8.6%) being DADNB . ¹R NMR (d6 DMSO) : 8.79 ppm (s, 1H) ; 8.27 ppm (b, 2H) ; 7.22 (s, 1H)

Example 3. Preparation of DANDS from ACDNB via

Thiolation with NaSH

A degassed solution of 1 equiv NaSH (25.79 g) in water (75 mL) was added dropwise to a slurry of ACDNB (100 g) in ethanol (250 g) , under N₂, over a period of one hour. A very slight exotherm was observed and the reaction mixture was stirred at room temperature overnight. The solution was then heated to 40°C, and the remaining NaSH (51.77 g) in water (150 mL) was added dropwise, resulting in a exotherm that increased the temperature approx. 30 °C over the addition period of 2 hours. Stirring was continued under N2 at 40°C overnight, and the heat was removed the next morning. After cooling to room temperature, the suspension was filtered under a nitrogen atmosphere and washed with water, followed by a minimal amount of ethanol. The crude brown solid was then purified by dissolving in

DMAC (5% by wt) and subsequently precipitating back out with water to give copper colored crystals. The net yield after purification was 44% and the purity was >98%. ^XH NMR (d6 DMSO) : 7.50 ppm (s, 2H) ; 6.74 ppm (s, 2H) ; 6.38 (b, 4H) ; 5.12 ppm (b, 4H) .

Example 4. Preparation of TATHIO · 3HC1 from DANDS

To a solution of DANDS in HC1 (0.75 g) was slowly added a solution of SnCl₂-2H₂0 (1.53 g) in HC1 (1 g) . After heating at 40°C for 1.5 h the slurry was filtered and the brown solid was washed with cold HC1. The crude solid was then dissolved in aqueous NaOH to form a solution having pH=13, and any insolubles were removed via filtration. The filtrate was then brought to a neutral pH with 34% HC1 and the free base was collected via filtration. The solid was then added to HC1, stirred and filtered to give the tri-hydrochloride as a grey solid. The net yield W3.S 58 "6 and the purity was >85%. ^XH NMR (D₂0, NaOD) : 6.92 ppm (s, 1H) ; 6.44 ppm (s, 1H) .

Example 5. Preparation of 3-amino-4 , 6-dinitrothiophenol from ACDNB via Thiolation with Sodium Thioacetate

In an oxygen-free atmosphere, ACDNB (100 g) was added to 250 mL water to form a yellow slurry. In a separate reaction vessel, thioacetic acid (38.49 g) was slowly added to a cooled solution of NaOH (47.84) in 250 mL of water. The resultant thioacetate salt was then slowly added to the ACDNB slurry. After stirring for

approximately 15 minutes, the temperature was slowly increased to 80°C and the reaction was stirred

overnight. The solution was then carefully acidified with concentrated HC1 until the pH was slightly acidic. The crude product was collected by vacuum filtration, washed with water and then sparingly washed with cold methanol to yield the crude product as an orange solid. The net yield was 92% and the purity was >90%. ¹E NMR (d6 DMSO) : 8.96 ppm (s, 1H) ; 8.29 ppm (b, 2H) ; 7.24 (s, 1H)

Example 6. Preparation of TATHIO-3HC1 by Reduction of 3-amino-4, 6-dinitrothiophenol hydrochloride

To a solution of 3-amino-4 , 6-dinitrothiophenol

hydrochloride in HC1 (2.5 g) was slowly added a

solution of SnCl₂-2H₂0 (5.24 g) in HC1 (3 g) . After heating at 60 °C for 1.5 h the slurry was filtered and the yellow solid was washed with cold HC1. The crude solid was then dissolved in aqueous NaOH to form a solution having pH=13, and any insolubles were removed via filtration. The filtrate was then brought to a neutral pH with 34% HC1 and the free base was collected via filtration. The solid was then added to HC1, stirred and filtered to give the tri-hydrochloride as a yellow solid. The net yield was 55% and the purity was >96%. ^XH NMR (D₂0, NaOD) : 6.87 ppm (s, 1H) ; 6.39 ppm (s, 1H)

Example 7. Preparation of TATHIO · DHTA from TATHIO · 3HC1 and K₂DHTA 11.41 g of 2 , 5-dihydroxyterephthalic acid (41.58 mmol) along with 5.50 g of sodium bicarbonate (65.489 mmol) was added to a reaction vessel. This was

followed by the addition of 126 g of deaerated water and heating to 75°C. About 12.03 g of TATHIO- 3HC1

(45.74 mmol) was dissolved in deaerated and deionized water (90 g) . The solution of the TATHIO · 3HC1 was added to the hot solution of the dipotassium salt of 2,5- dihydroxyterephthalic acid (K₂DHTA) and the mixture was cooled down slowly over 1 hour, while stirring. The mixture was allowed to stand for 30 minutes and then subsequently filtered and washed with ethanol (50 mL) . The solid yellow product (14.51 g, 99%) was allowed to dry for 18 hours under vacuum. ^XH NMR analysis

revealed the TATHIO to DHTA ratio was 1.00:1.02.

Example 8. Preparation of TATHIO -T from TATHIO -3HC1

solution 1.842 g of terephthalic acid (11.09 mmol) along with 3.07 g of sodium bicarbonate (36.59 mmol) was added to a 100 mL reaction vessel. This was followed by the addition of 32 g of deaerated/de-ionized water and heating to 72°C (internal temperature) to effect dissolution over a period of 45 minutes. About 3.21 g of 2 , 4 , 5-triaminothiophenol trihydrochloride

(TATHIO- 3HC1) (12.197 mmol) was dissolved in deaerated and de-ionized water (90 g) and stirred at room

temperature. The solution of the terephthalic

acid/sodium bicarbonate solution was added to the

TATHIO_3HCl solution over a period of 3 minutes. The mixture was allowed to stir over 1 hour while cooling to room temperature. The reaction vessel was

subsequently allowed to stand for 30 minutes and the solid filtered through a medium glass frit and washed with methanol (50 mL) . The solid beige product (3.10 g, 87%) was allowed to dry for 18 hours under vacuum. ^XH NMR analysis revealed the TATHIO to T ratio was 1.00:1.01.

Example 9. Polymerization of TATHIO- DHTA Complex in

Polyphosphoric Acid

Into a clean dry 200 mL glass tubular reactor having an inside diameter of 4.8 cm, equipped with the necessary connections for purging nitrogen and applying a vacuum, and around which a heating jacket was arranged and which further contained double helix shaped basket stirrer, was charged 17.6 g of

TATHIO- DHTA monomer complex, 3.9 g of P₂0₅, 78.51 g of PPA with a % P₂0₅ equivalent to 85.4%, and 0.05 g Sn powder. The stirrer was turned on at 100 rpm and the contents were heated to 100°C for one hour under vacuum. The temperature was raised and held at 135°C for 20 hours. The temperature was raised and held at 180°C for 3 hours. The reactor was flushed with nitrogen gas ("N₂") and a sample of the polymer

solution was diluted with methane sulfonic acid to 0.05% concentration. The n_inh was 22.59 dL/g.

It is to be appreciated that certain features of the invention which are, for clarity, described above and below in the context of separate embodiments, may also be provided in combination in a single

embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further,

reference to values stated in ranges include each and every value within that range.

Claims

CLAIMS What is claimed is:

1. A composition represented by the structure

Formula (I)

I

wherein

R¹ and R² are each independently H, alkyl, aryl, alkaryl, or aralkyl; R³, and R⁴ are each independently H, alkyl, aryl, alkaryl, or aralkyl; or may be joined to form an aliphatic ring structure;

R⁵ and R⁶' are each independently H, alkyl, aryl, alkaryl, or aralkyl; or may be joined to form an aliphatic ring structure; and

R⁷ and R⁸ are each independently H, alkyl, aryl, alkaryl, or aralkyl; or may be joined to form an aliphatic ring structure.

2. The composition of claim 1 wherein R¹ is methyl and R², R³, R⁴' R⁵' R⁶' R⁷, and R⁸ are each H.

3. The composition of claim 1 wherein R¹, R², R³, R⁴' R⁵' R⁶' R⁷, and R⁸ are each H.

4. The composition of Claim 1, further comprising an acid A, wherein the composition is a salt represented by the structure of Formula (II)

II

whereinj_ R¹, R², and R⁷ are each independently H, alkyl, aryl, alkaryl, or aralkyl;

n is a number from 1 to 10; and

A is an acid selected from the group consisting of HCl, H₂S0₄, H₃PO₄, and acetic acid.

5. The composition of claim 4 wherein R¹, R², and R⁷ are each H, A is HCl, and n is 2 to 4.

6. The composition of Claim 1 further comprising a diacid, wherein the composition is represented by the structure of Formula (III)

III

wherein R¹, R², and R⁷ are each independently H, alkyl, aryl, alkaryl, or aralkyl; and Q is a C₆ to C₂o

substituted or unsubstituted monocyclic or polycyclic aromatic nucleus.

7. A polymer composition obtained by polymerization of the composition of Claim 6 comprising repeat units represented by Formula (VI) .

VI

8. The polymer composition of claim 7 wherein R , R , and R⁷ are each H.

9. The polymer composition of claim 7 wherein Q is selected from the group consisting of:

1, 4-phenylene (C6¾

2, 5-dihydroxy-l , 4-phenylene

1, 4-naphthylene (CioH₆) ,

2, 6-naphthylene (CioH₆) ,

10 4, 4' -biphenyl diradical (Οι₂Η_ε

4 , 4 ' -biphenyl ether diradical (OCi₂H₈0) ,

1, 5-dihydroxy-2 , 6-naphthylene (CioH₆0₂) , and

2, 5-pyridylene (C₅H₃N)

10. The polymer composition of claim 7 wherein

represented by the structure of Formula (XVI)

XVI

wherein X and Y are each independently selected from the group consisting of H, OH, SH, SO₃H, methyl, ethyl, F, CI, and Br.

11. The polymer composition of claim 10 wherein X=Y=H or X=Y=OH.

12. The polymer composition of claim 11 wherein R¹, R², and R⁷ are each H.

13. A process comprising the steps:

a) preparing a mixture of

(i) either a monomer complex of Claim 6 or a salt of either of Claims 4 or 5;

(ii)a diacid source selected from the group consisting of HOOC-Q-COOH, a disodium salt of HOOC-Q- COOH, a dipotassium salt of HOOC-Q-COOH, or mixtures thereof;

(iii)P₂05 and polyphosphoric acid; and

(iv) tin metal powder or iron metal powder; and b) stirring the mixture and heating the reactor, under vacuum with a slight nitrogen purge, at a first temperature of about 100°C for about one hour; at a second temperature between about 110°C and about 140°C for about 2.5 to about 4.5 hours; at a third

temperature between about 130°C and about 150°C, with the proviso that the third temperature is higher than the second temperature, for about one hour to about three hours; and at a fourth temperature between about 150°C, with the proviso that the fourth temperature is higher than the third temperature, for about one hour to about four hours .

13. The process of claim 12 wherein the mixture

contains about 20 parts by weight of monomer complex, about 10 parts of P₂O₅, about 100 parts of

polyphosphoric acid.

14. The process of claim 12 wherein the tin metal powder or iron metal powder is present in an amount of about 0.1 to about 0.5 weight percent based on monomer complex.

15. The process of claim 12 wherein the ratio of equivalents of the triaminophenol to the diacid is from about 1:1 to about 1.15:1.

16. The process of claim 12 wherein R¹, R², and R⁷ are each H, and Q is either 1 , 4-phenylene or 2 , 5-dihydtoxy-

1 , 4-phenylene .

17. An article of manufacture comprising the polymer composition of claim 7.

18. A process comprising the steps:

(a) monoaminating a composition of Formula (X) ,

wherein

each Z is independently CI or Br and

R¹ and R² are each independently H, alkyl, aryl, alkaryl, or aralkyl;

by heating a suspension of the composition of Formula (X) in solvent to a temperature in the range of about 60°C to about 140°C and contacting it with an aqueous solution of at least 2.0 equivalents HNR⁷R⁸, wherein R⁷ and R⁸ are each independently H, alkyl, aryl, alkaryl, or aralkyl, or may be joined to form an aliphatic ring structure ;

to produce a composition of Formula (XI)

XI (b) slurrying in ethanol the composition of Formula (XI) produced in step (a);

(c) contacting the slurry produced in (b) with with aqueous thioacetate ion in a molar ratio of at least one mole thioacetate ion per mole of the

composition of Formula (XI), to produce the composition represented by Formula (XIV)

XIV

(d) hydrolyzing the composition represented by Formula (XIV) , thereby producing the compound

represented by Formula (XV)

XV

and

(e) contacting the composition represented by

Formula (XIV) produced in (d) with a reducing agent, thereby producing the composition of Formula (IX) .

19. A process for producing the composition of Claim 1, wherein R³, R⁴, R⁵, and R⁶ are each H, comprising the steps :

(a) monoaminating a composition of Formula (X) ,

X

wherein

each Z is independently CI or Br and

R¹ and R² are each independently H, alkyl, aryl, alkaryl, or aralkyl;

by heating a suspension of the composition of Formula (X) in solvent to a temperature in the range of about 60°C to about 140°C and contacting it with an aqueous solution of at least 2.0 equivalents HNR⁷R⁸, R⁷ and R⁸ are each independently H, alkyl, aryl, alkaryl, or aralkyl, or may be joined to form an aliphatic ring structure;

to produce a composition of Formula (XI)

20. A process for preparing the composition of Claim 6 comprising the steps:

(a) providing an aqueous solution of a

composition represented by Formula (II)

II

wherein R¹, R², and R⁷ are each independently H, alkyl, aryl, alkaryl, or aralkyl; n is a number from 1 to 10; and A is an acid selected from the group consisting of HCL, H₂S0₄, H₃PO₄, and acetic acid;

(b) contacting the solution with a diacid source and an aqueous solution of a base having a pKa in water at 25°C between about 6 and about 11, thereby forming and precipitating the complex represented by Formula (III)

1¹¹

wherein the diacid source is HOOC-Q-COOH, the salt a disodium salt of HOOC-Q-COOH, a dipotassium salt of HOOC-Q-COOH, or mixtures thereof; and wherein Q is a Ci to C2₀ substituted or unsubstituted monocyclic or polycyclic aromatic nucleus.

21. A composition represented by the structure of Formula (IV)

IV

wherein R , R , R , and R are each independently H, alkyl, aryl, alkaryl, or aralkyl.

22. A composition represented by the structure of

Formula (V)

wherein

R¹ and R² are each independently H, alkyl, aryl, alkaryl, or aralkyl;

R⁷ and R⁸ are each independently H, alkyl, aryl, alkaryl, or aralkyl; or may be joined to form an aliphatic ring structure; and

R⁹ is H or acetyl.

23. The composition of either claim 1 or claim 2 wherein R¹, R², R⁷, and R⁸ are each H.

24. The composition of either claim 1 or claim 2 wherein R¹, R², R⁷, and R⁸ are each independently a substituted or unsubstituted C1-C4 alkyl group.