Thermal processes for increasing polyareneazole inherent viscosities

1. A process for making polyareneazole comprising the steps of:

contacting a complex comprising aromatic or heteroaromatic tetraamine and aromatic or heteroaromatic diacid in a dehydrating solvent;

wherein each amine group of said tetraamine is positioned on the aromatic or heteroaromatic ring moiety adjacent to at least one of the remaining amine groups of said tetraamine, and

wherein the acid groups of said diacid are bonded to non-adjacent aromatic or heteroaromatic ring carbon atoms of said diacid; and

a) heating with agitation to a temperature of about 90 to about 110° C. for a period of about 30 to about 100 minutes;

b) heating the product of step a) with agitation to a temperature of about 130 to about 145° C. for a period of about 75 to about 300 minutes;

c) heating the product of step b) with agitation to a temperature of about 175 to about 185° C. for a period of about 40 to about 90 minutes; and

d) heating the product of step c) with agitation to a temperature of about 186 to about 220° C. for a period of about 15 to about 90 minutes to provide said polyareneazole.

2. The process of claim 1 , wherein the dehydrating solvent is polyphosphoric acid.

3. The process of claim 1 , wherein the aromatic or heteroaromatic tetraamine comprises a compound of formula Ia, Ib, Ic, Id, or Ie:

or any combination thereof,

wherein:

each Q is independently CR or N; and

each R is independently H, alkyl, aryl, heteroaryl, or alkoxy.

4. The process of claim 3 , wherein the aromatic or heteroaromatic tetraamine comprises a compound of formula Ia, Ib, Ic, or Id:

or any combination thereof,

wherein:

each Q is independently CR or N; and

each R is independently H, alkyl, aryl, heteroaryl, or alkoxy.

5. The process of claim 3 , wherein each R is independently H, alkyl, aryl, or heteroaryl.

6. The process of claim 3 , wherein aromatic or heteroaromatic tetraamine comprises a compound selected from the group consisting of 2,3,5,6-tetraaminopyridine, 1,2,4,5-tetraaminobenzene, 3,3′-diaminobenzidine, 1,2,5,6-tetraaminonaphthalene, 2,3,6,7-tetraaminonaphthalene, 1,4,5,8-tetraaminonaphthalene, and any combination thereof.

7. The process of claim 6 , wherein aromatic or heteroaromatic tetraamine comprises a compound selected from the group consisting of 2,3,5,6-tetraaminopyridine, 1,2,4,5-tetraaminobenzene, 3,3′-diaminobenzidine, 1,2,5,6-tetraaminonaphthalene, 2,3,6,7-tetraaminonaphthalene, and any combination thereof.

8. The process of claim 1 , wherein the aromatic or heteroaromatic diacid comprises a compound of formula IIa, IIb, IIc, or IId:

or any combination thereof,

wherein:

each Q 1 and Q 2 is independently CR 1 or N provided that in any compound of formula IIb, IIc, or IId, not more than one of Q 2 is N; and

each R 1 is independently H, OH, alkyl, aryl, heteroaryl, or alkoxy.

9. The process of claim 1 , wherein aromatic diacid comprises a compound selected from the group consisting of terephthalic acid, 2,5-dihydroxyterephthalic acid, 4,4′-bibenzoic acid, 2,6-naphthalenedicarboxylic acid, and any combination thereof.

10. The process of claim 1 , wherein the process is carried out in the presence of an inert atmosphere.

11. The process of claim 1 , wherein inert atmosphere comprises greater than 99 percent by weight nitrogen.

12. The process of claim 1 , further comprising metal powder.

13. The process of claim 12 , wherein the metal powder is iron powder, tin powder, or any combination thereof.

14. The process of claim 13 , wherein metal powder is present in an amount of from about 0.1 to about 0.5 weight percent.

15. The process of claim 7 , wherein the tetraamine comprises 2,3,5,6-tetraaminopyridine.

16. The process of claim 15 , wherein the tetraamine comprises greater than about 50 mole percent 2,3,5,6-tetraaminopyridine.

17. The process of claim 9 , wherein the diacid comprises 2,5-dihydroxyterephthalic acid.

18. The process of claim 17 , wherein the diacid comprises greater than about 50 mole percent 2,5-dihydroxyterephthalic acid.

19. The process of claim 1 , wherein the complex comprises 2,3,5,6-tetraaminopyridine and terephthalic acid.

20. A process for making polyareneazole comprising the steps of:

contacting aromatic or heteroaromatic tetraamine and aromatic or heteroaromatic diacid in a dehydrating solvent;

wherein each amine group of said tetraamine is positioned on the aromatic or heteroaromatic ring moiety adjacent to at least one of the remaining amine groups of said tetraamine, and

wherein the acid groups of said diacid are bonded to non-adjacent aromatic or heteroaromatic ring carbon atoms of said diacid; and

a) heating with agitation to a temperature of about 90 to about 110° C. for a period of about 30 to about 100 minutes;

b) heating the product of step a) with agitation to a temperature of about 130 to about 145° C. for a period of about 75 to about 300 minutes;

c) heating the product of step b) with agitation to a temperature of about 175 to about 185° C. for a period of about 40 to about 90 minutes; and

d) heating the product of step c) with agitation to a temperature of about 186 to about 220° C. for a period of about 15 to about 90 minutes to provide said polyareneazole.