f" NASA CASE h 

PRINT FIG. NIA 

NOTlCE 

The invention disclosed in this document resulted from research in aeronautical and 

space activities performed under programs of the National Aeronautics and Space 

Administration. The invention is owned by NASA and is, therefore, available for licensing 

in accordance with the NASA Patent Licensing Regulation (14 Code of Federal 

Regulations 1245.2). 

To encourage commercial utilization of NASA-owned inventions, it is NASA policy to grant 

licenses to commercial concerns. Although NASA encourages nonexclusive licensing to 

promote competition and achieve the widest possible utilization, NASA will provide the 

necessary incentive to the licensee to achieve early practical application of the invention. 

Address inquiries and all applications for license for this invention to NASA Patent 

Counsel, Langley Research Center, Code 143, Hampton, Virginia 23665-5225. 

Serial No. : 071790,730 

10-31 -91 LaRC 

(NASA-Case-kAR-14643-11 PCLYBENLPHIDAZOLES 

VIA AROMATIC NUCLEOPHILIC DISPLACEMENT 

Patent Application <NASA1 22 p 
AWARDS ABSTRACT 

POLYBIENZIMIDAZOLES VIA AROMATIC NUCLEOPHILIC DISPLACEMENT 

NASA Case No. 14643-1 -CU 

Polybenzimidazoles (PBls) are heterocyclic macromolecules commonly 

prepared by the condensation reaction of an aromatic bis(o-diamine) with an 

aromatic diacid or derivative thereof. These polymers possess high thermal, 

thermooxidative, and chemical stability; good mechanical properties; and excellent 

flame resistance, making them high-performancelhigh-temperature materials which 

are attractive for use in harsh environments. However, despite these properties, 

the processing of these polymers is somewhat difficult. 

'/ 

In the present invention, several di(hydroxyphenyl)benzimidazole monomers 

were prepared from the reaction of phenyl-4-hydroxybenzoate with aromatic bisQdiamine)~. Soluble PBls were then prepared by the nucleophilic displacement 

reaction of these di(hydroxyphenyl)benzimidazole monomers with activated 

aromatic dihalide or dinitro compounds in the presence of an alkali metal base. 

These polymers had glass transition tem eratures (T s) of 264O-352"C, much 

lower than their commercial counterparts w t: ich exhibite l Tgs of 400°C. The lower 

Tg allows for better compression moldability than other PBls. These polymers 

were soluble in cold dimethyl-acetamide (DMAc), as opposed to requiring hot 

DMAc and pressure to solubilize. The use of the benzimidazole monomers to 

make PBls proved to be more economical and easier to process than commercial 

PBls. 

The novelty of this invention lies in the polybenzimidazole polymers. These 

new compositions of matter exhibited lower Tgs and increased solubility which 

allows for easier processing. 

Inventors: John W. Conneli 

Address: 204 Henry Lee Lane 

Yorktown, VA 23690 

Employer: 

SS: 

NASA 

- 

LaRC 

Paul M. Hergenrother 

304 Old Dominion Rd. 

Yorktown, VA 23692 

SS: m 

NASA LaRC 
Inventor: Joe G. Smith 

Address: 2658 N. Armistead Ave., Apt. W4 

Hampton, VA 23666 

SS: 

U. of Akron 

Initial Evaluator: Terry L. St. Clair 

Serial No.: 07/790,730 

Filed: 10-31-91 
"::7/7f 7sc.'

+I

/ O- 3z'-

LAR 14643-1-CU -1- PATENT APPLICATION

POLYBENZIMIDAZOLES VIA AROMATIC NUCLEOPHILIC

DISPLACEMENT

5

10

Ori.qin of the Invention

The invention described herein was jointly made by employees of the

United States Government and a contract employee in the performance of

work under NASA Grant No. NAG1-448 and is subject to the provisions of

Public Law 96-517 (35 USC 202) in which the contractor has elected not to

retain title.

Back.qround of the Invention

15

20

o Field of the Invention

The present invention relates generally to polybenzimidazoles. In

particular, it relates to polybenzimidazoles prepared by the aromatic

nucleophilic displacement reaction of di(hydroxyphenyl)benzimidazole

monomers with activated aromatic dihalides or activated dinitro compounds.

i

. Description of the Related Art

25

30

Polybenzimidazoles (PBIs) are heterocyclic macromolecules

commonly prepared by the condensation reaction of an aromatic bis(_odiamine) with an aromatic diacid or derivative thereof. These polymers

possess high thermal, thermooxidative, and chemical stability; good

mechanical properties; and excellent flame resistance, making them highperformance/high-temperature materials which are attractive for use in harsh

environments. However, despite these properties, the processing of these

polymers is somewhat difficult.
LAR 14643-1-CU -2- PATENT APPLICATION

Buckley et al (Encyclopedia of Polymer Science and T,echnolo.qy,

Volume 11, 2nd Ed., 1988, p.572) review polybenzimidazoles. They

specifically review poly[2,2'-(_.m_-phenylene)-5,5'-bibenzimidazole], which is

commercially available primarily from Hoechst-Celanese Corporation. The

5 processing of this material involves two steps: the formation of a foam

which must be ground into a powder and reheating of the PBI powder. This

polymer is mainly used in the formation of fibers because it is not very

soluble in solvent. For example, in order to dissolve the PBI in dimethylacetamide (DMAc), both the solvent and the polymer had to be heated

10 under pressure. The glass transition temperatures (Tg) of this polymer is

435°C. Because of this high Tg, the polymer is difficult to compression and

injection mold.

Several methods have been used to prepare PBIs. Brinker and

Robinson (U.S. 2,895,948) synthesized PBIs by reacting aliphatic

15 dicarboxylic acids with aromatic bis_-diamine)s. Vogel and Marvel (Journal

of Polymer Science, 50, 511 (1961)) formed PBIs from the melt

condensation of aromatic bis(.o-diamine)s with aromatic diacids or derivatives

thereof. Iwakura et al (Journal of Polymer Science, PAPA, 2_,2605, (1964))

prepared PBIs in polyphosphoric acid. Hedberg and Marvel (Journal of

20 Polymer Science, Polymer Chemistry, 1_._22, 1823 (1974)) foi'med PBIs in

sulfolane or diphenylsulfone from aromatic bis(_0_-diamine)s and aromatic

diacids or derivatives thereof. Another preparative route by Higgins and

Marvel (Journal of Polymer Science, Part A-l, 8, 171 (1970)) involves the

reaction of aromatic bis(.o.-diamine)s with the bis(bisulfite adduct)s of

25 dialdehydes. Packham et al (Polymer, 10 (12), 923 (1969)) formed PBIs

from the alkoxide catalyzed reaction of aromatic bis_-diamine)s with

dinitriles. None of these methods teach the preparation of PBIs by the

reaction of di(hydroxyphenyl)benzimidazole monomers with activated

aromatic dihalide or dinitro compounds in the presence of an alkali metal

30 base.
LAR 14643-1-CU

Summary of the Invention

-3- PATENT APPLICATION

5

Several di(hydroxyphenyl)benzimidazole monomers were prepared

from the reaction of phenyl-4-hydroxybenzoate with aromatic bis_-

diamine)s. These monomers have the following structural formulas:

10

a) 5,5'-Bis[2-(4-hydroxyphenyl)benzimidazole

15

b) 5,5'-Carbonyl-bis[2-(4-hydroxyphenyl)benzimidazole

0 14

20

c) 5,5'-Oxy-bis[2-(4-hydroxyphenyl)benzimidazole

tt

25

Soluble polybenzimidazoles (PBIs) were then prepared by the

nucleophilic displacement reaction of these di(hydroxyphenyl)benzimidazole

monomers with activated aromatic dihalide or dinitro compounds in the

presence of an alkali metal base. The resulting PBIs had the following

general structural repeat units:

3O
5

LAR 14643-1-CU -4-

a)

H

I

/, ,_N, A ..-. .N,.

PATENT APPLICATION

q

"o ©

!

10

b)

O H

15

c)

H

N I

2O

D

where x is

25

30
5

10

15

LAR 14643-1-CU -5- PATENT APPLICATION

These polymers had glass transition temperatures (Tg) ranging from

264 ° to 352°C, much lower than their commercial counterparts which

exhibited Tgs of 400°C. As a result of the lower Tgs, these polymers

exhibited much better compression moldabUity than other PBIs. These

polymers were found to be soluble in cold DMAc, as opposed to requiring

hot DMAc and pressure to solubilize. The use of benzimidazole monomers

to make PBIs proved to be more economical and easier to process than

commercial PBIs without showing a loss in their physical and mechanical

properties.

An object of the present invention is to prepare di(hydroxyphenyl)-

benzimidazole monomers.

Another object of the present invention is to prepare soluble

polybenzimidazoles.

Another object of the present invention is to develop a new process

for preparing soluble polybenzimidazoles.

Another object of the present invention is to prepare films from the

soluble polybenzimidazoles.

20 Descril_tion of the Preferred Embodiments

25

30

The synthesis of soluble PBIs involved the use of di(hydroxyphenyl)-

benzimidazole monomers. These monomers were prepared by reacting

phenyl-4-hydroxybenzoate with various aromatic bis(o-diamine)s. These

monomers have the following general structural formula:

It
LAR 14643-1-CU -6-

where z is either nil, -CH2-, -O-, -S-,

,o, , mSOt-- )

PATENT APPLICATION

t

5

; and

the catenation of the hydroxy groups may be meta-meta, para-para, or parameta.

10

15

These benzimidazole monomers undergo a nucleophilic displacement

reaction with activated aromatic dihalide or dinitro compounds in the

presence of an alkali metal base such as: potassium carbonate, sodium

carbonate, potassium hydroxide, and sodium hydroxide. The resulting PBIs

are soluble in DMAc and have the following general structural repeat unit:

2O

H

I

//I \Ar X

/ \ O

25

where:

the catenation of oxygen is either meta-meta, para-para, or parameta;

Ar is any one of the following:

0
LAR 14643-1-CU -7- PATENT APPLICATION

5

0 O

II II

10

15

20

25

30

and

; and

x is any one of the following:

O o

o 0 o ' 0

P

, 0

I!

--_ _ Ctt z

p P

The solubility of these polymers allows for film formation, something

which was difficult to achieve in previous PBI systems. These polymers also

exhibited lower Tgs which makes compression and injection molding much

easier.

The following examples are illustrative of the invention.
LAR 14643-1 -CU -8-

Example 1

PATENT APPLICATION

Preparation of the di(hydroxyphenyl)benzimidazole monomers

5 5,5'-Bis[2-(4-hydroxyphenyl)benzimidazole]

A mixture of 3,3',4,4'-tetraaminobiphenyl (commercially available from

Hoechst-Celanese Corporation) (25.80 g, 0.120 mol), phenyl-4-

hydroxybenzoate (commercially available from K and K Laboratories) (52.62

10 g, 0.246 mol), diphenylsulfone (95.30 g), and toluene (100 ml) was heated

under a nitrogen atmosphere for 2.5 hours at 150°C. The toluene was

removed and the temperature increased to 250°C and maintained for 0.75

hour. The reaction mixture solidified to a yellow mass. A vacuum was

subsequently applied and the temperature increased to 280°C and

15 maintained for 1.25 hours. The cooled brown reaction mixture was washed

successively in hot acetone and toluene and subsequently dried at 110°C to

afford 48.90 g (97% crude yield) of a brown powder. The melting

endothermic peak as determined by differential thermal analysis (DTA) at a

heating rate of 10°C/min was 404°C (sharp). The solid was recrystallized

!

20 twice from N,N-dimethylacetamide (DMAc) using charcoal to afford a tan

powder (28.37 g, 56% yield). The compound exhibited a broad endothermic

peak by DTA with a minimum at 398°C. Analysis calcd, for C26H18N402: C,

74.63%; H, 4.34%; N, 13.39%. Found: C, 73.31%; H, 4.32%; N, 13.26%.

The resulting monomer had the following structural formula:

25

tt

HO N OH

30
LAR 14643-1-CU -9- PATENT APPLICATION

5,5'-Carbonyl-bis[2-(4-hydroxyphenyl)benzimidazole]

5

10

15

2O

A mixture of 3,3',4,4'-tetraaminobenzophenone (commercially

available from Burdick and Jackson) (22.61 g, 0.093 mol), phenyl-4-

hydroxybenzoate (40.01 g, 0.187 mol), diphenylsulfone (110.45 g), and

toluene (135 ml) was heated under a nitrogen atmosphere for 3 hours at

150°C. The toluene was removed and the temperature increased to 250°C

and maintained for 1.25 hours. A vacuum was subsequently applied and the

temperature increased to 270°C and maintained for 1 hour. The cooled

yellow reaction mixture was washed successively in hot toluene and water

and subsequently dried at 110°C to afford 39.83 g (96% crude yield) of a

yellow powder. The endothermic peak as determined by DTA was 387°C

(broad). The yellow solid was dissolved in DMAc, treated with activated

charcoal, filtered, and poured into water to afford a yellow precipitate. The

solid was dried under vacuum at 245°C to afford 31.52 g (76% yield) of a

brown powder. The endothermic peak as determined by DTA was 346°C

(broad). Analysis calcd, for C27HlEN403: C, 72.64%; H, 4.06%; N, 12.55%.

Found: C, 71.96%; H, 4.20%; N, 12.42%. The resulting monomer had the

following structural formula:

I

O It

25

5,5'-Oxy-bis[2-(4-hydroxyphenyl)benzimidazole]

Oxydianaline was acetylated, nitrated, and the acetylated group

hydrolyzed to give 3,3'-dinitro-4,4'-diaminodiphenyl ether. The 3,3'-dinitro-
LAR 14643-1-CU -10- PATENT APPLICATION

4,4'-diaminodiphenyl ether was then reduced with stannous chloride and

hydrochloric acid to give bis(3,4-diaminophenyl)ether.

A mixture of bis(3,4-diaminophenyl)ether (22.00 g, 0.096 mol), phenyl4-hydroxybenzoate (41.00 g, 0.194 mol), diphenylsulfone (110.17 g), and

5 toluene (135 ml) was heated under a nitrogen atmosphere for 3.5 hours at

150°C. The toluene was removed and the temperature increased to 250°C

and maintained for 1.5 hours. A vacuum was subsequently applied and the

temperature increased to 280°C and maintained for 1.25 hours. The cooled

dark reaction mixture was washed in hot toluene and dried at 110°C to

10 afford 20.59 g (50% crude yield) of a dark purple powder. The dark solid

was extracted with acetone to afford 12.39 g (30% yield) of a tan solid. The

endothermic peak as determined by DTA was 317°C (broad). Analysis

calcd, for C26H18N403: C, 71.88%; H, 4.18%; N, 12.90%. Found: C,

71.91%; H, 4.22%; N, 13.06%. The resulting monomer had the following

15 structural formula:

It

I

20 Example 2

25

30

Into a 100 ml three necked round bottom flask equipped with nitrogen

inlet, thermometer, mechanical stirrer, and Dean Stark trap was placed 5,5'-

bis[2-(4-hydroxyphenyl)benzimidazole] (2.7835 g, 6.7 mmol), 4,4'-difluorobenzophenone (which is commercially available) (1.4515 g, 6.7 mmol),

pulverized anhydrous potassium carbonate (2.4509 g, 17.7 mmol), dry DMAc

(22 ml, 18% solids w/w), and toluene (50 ml). The mixture was heated to

140°-150°C for 3.5 hours and then heated to 155°-160°C. After 2.5 hours

the viscous reaction mixture was diluted with 25 ml DMAc (6.3% solids w/w)

after 1.25 hours. Stirring was continued for 10 minutes at 160°C and then
5

10

15

LAR 14643-1-CU -11- PATENT APPLICATION

the reaction mixture cooled. The viscous solution was precipitated in a

water/acetic acid (10/1) mixture, washed successively in hot water and

methanol and dried at 110°C to provide a light brown polymer (3.60 g, 91%

yield) with a Tg of 307°C. The inherent viscosity of a 0.5% solution in DMAc

at 25°C was 1.11 dL/g. Unoriented thin films cast from a DMAc solution

gave tensile strength, tensile modulus, and elongation at 23°C of 22.8 ksi,

647 ksi, and 11.6%, respectively. Although the activated aromatic dihalide

compound contained the halogen fluorine, a chlorine-containing compound

may be substituted as is known to those skilled in the are. The resulting

polymer had the following structural repeat unit:

H

I

oco

20 Example 3

25

3O

Into a 100 ml three necked round bottom flask equipped with nitrogen

inlet, thermometer, mechanical stirrer, and Dean Stark trap was placed 5,5'-

bis[2-(4-hydroxyphenyl)benzimidazole] (2.0392 g, 4.9 mmol), 1,3-bis(4-

fluorobenzoyl)benzene (commercially available from Kennedy and Klin)

(1.5707 g, 4.9 mmol), potassium carbonate (1.7379 g, 12.6 mmol), dry

DMAc (18 ml, 18% solids w/w), and toluene (50 ml). The mixture was

heated to 140°-150°C for 3.5 hours and then heated to 155°-160°C. After

approximately 2 hours, the viscous reaction mixture was diluted with 21 ml

DMAc (9.0% solids w/w) and stirring continued at 155°-160°C. The viscous
5

10

LAR 14643-1-CU -12- PATENT APPLICATION

reaction mixture was diluted with 25 ml DMAc (5.7% solids w/w) after

approximately 0.75 hour. The viscous solution was precipitated in a

water/acetic acid (10/1) mixture, washed successively in hot water and

methanol and dried at 110°C to provide a light brown polymer (2.48 g, 73%

yield) with a Tg of 276°C. The inherent viscosity of a 0.5% solution in DMAc

at 25°C was 1.99 dL/g. Unoriented thin films cast from a DMAc solution

gave tensile strength, tensile modulus, and elongation at 23°C of 19.4 ksi,

598 ksi, and 13.1% respectively. The resulting polymer had the following

structural repeat unit:

Ft

15 Example 4

2O

25

30

Into a 100 ml three necked round bottom flask equipped with nitrogen

inlet, thermometer, mechanical stirrer, and Dean Stark trap was placed 5,5'-

carbonyl-bis[2-(4-hydroxyphenyl)benzimidazole] (2.5651 g, 5.7 mmol), 4,4'-

difluordbenzophenone (1.2537 g, 5.7 mmol), pulverized anhydrous

potassium carbonate (2.0686 g, 15.0 mmol), dry DMAc (18.5 ml, 18% solids

w/w) and toluene (45 ml). The mixture was heated to 140°-150°C for 3.5

hours and then heated to 155°-160°C. After 1.75 hours the viscous reaction

mixture was diluted with 18 ml DMAc (10% solids w/w) and stirring continued

at 155°-160°C. The viscous reaction mixture was diluted with 20 ml DMAc

(6.7% solids w/w) after 0.25 hour. Stirring was continued for 0.5 hour at

160°C and the reaction mixture was cooled. The viscous solution was

precipitated in a water/acetic acid (10/1) mixture, washed successively in hot

water and methanol and dried at 110°C to provide a pale yellow polymer

(3.03 g, 84% yield) with no observable Tg by differential scanning
5

LAR 14643-1-CU -13- PATENT APPLICATION

calorimetry. The inherent viscosity of a 0.5% solution in DMAc at 25°C was

0.93 dL/g. The polymer had the following structural repeat unit:

H

O I O

10

Example 5

Into a 100 ml three necked round bottom flask equipped with nitrogen

inlet, thermometer, mechanical stirrer, and Dean Stark trap was placed 5,5'-

carbonyl-bis[2-(4-hydroxyphenyl)benzimidazole] (2.5712 g, 5.8 mmol), 1,3-

bis(4-fluorobenzoyl)benzene (1.8562 g, 5.8 mmol), pulverized anhydrous

15 potassium carbonate (2.200 g, 15.9 mmol), dry DMAc (22 ml, 18% solids

w/w), and toluene (50 ml). The mixture was heated to 140°-150°C for 3.5

hours and then heated to 155°-160°C. After approximately 1.1 hours the

viscous reaction mixture was diluted with 20 ml DMAc (10% solids w/w) and

stirring continued at 155°-160°C. The viscous reaction mixture was diluted

20 with 2d ml DMAc (7.0% solids w/w) after approximately 0.15 hour. The

viscous solution was precipitated in a water/acetic acid (10/1) mixture,

washed successively in hot water and methanol and dried at 110°C to

provide a pale yellow polymer (3.13 g, 75% yield) with a Tg of 264°C. The

inherent viscosity of a 0.5% solution in DMAc at 25°C was 1.43 dL/g.

25 Unoriented thin films cast from a DMAc solution gave tensile strength,

tensile modulus, and elongation at 23°C of 19.6 ksi, 612 ksi, and 5.6%

respectively. The polymer had the following structural repeat unit:

9 Y

N _ N 0

oG
LAR 14643-1 -CU -14-

Example 6

PATENT APPLICATION

10

15

2O

25

Into a 100 ml three necked round bottom flask equipped with nitrogen

inlet, thermometer, mechanical stirrer, and Dean Stark trap was placed 5,5'-

oxy-bis[2-(4-hydroxyphenyl)benzimidazole] (2.9733 g, 6.8 mmol),

4,4'-difluorobenzophenone (1.4933 g, 6.8 mmol), pulverized anhydrous

potassium carbonate (2.4468 g, 17.7 mmol), dry DMAc (21.5 m1,18% solids

w/w), and toluene (45 ml). The mixture was heated to 140°-150°C for 3.5

hours and then heated to 155°-160°C. After approximately 3 hours the

viscous reaction mixture was diluted with 20 ml DMAc (10% solids w/w) and

stirring continued at 155°-160°C. The viscous reaction mixture was diluted

with 25 ml DMAc (6.7% solids w/w) after approximately 1.5 hours. Stirring

was continued for 0.25 hour at 160°C and the reaction mixture was cooled.

The viscous solution was precipitated in a water/acetic acid (10/1) mixture,

washed successively in hot water and methanol and dried at 110°C to

provide a white polymer (3.60 g, 84% yield) with a Tg of 294°C. The

inherent viscosity of a 0.5% solution in DMAc at 25°C was 1.34 dL/g.

Unoriented thin films cast from a DMAc solution gave tensile strength,

tensile modulus, and elongation at 23°C of 19.7 ksi, 576 ksi, and 7.0%,

respectively. The resulting polymer had the following structural repeat unit:

H

I

30
LAR 14643-1-CU -15-

Example 7

PATENT APPLICATION

Into a 100 ml three necked round bottom flask equipped with nitrogen

inlet, thermometer mechanical stirrer, and Dean Stark trap was placed 5,5'-

5 oxy-bis[2-(4-hydroxyphenyl)benzimidazole] (2.3330 g, 5.4 mmol),

1,3-bis(4-fluorobenzoyl)benzene (1.7308 g, 5.4 mmol), pulverized anhydrous

potassium carbonate (1.9948 g, 14.1 mmol), dry DMAc (19.5 ml, 18% solids

w/w), and toluene (45 ml). The mixture was heated to 140°-150°C for 3.5

hours and then heated to 155°-160°C. After approximately 1 hour the

10 viscous reaction mixture was diluted with 20 ml DMAc (9.9% solids w/w) and

stirring continued at 155°-160°C. The viscous reaction mixture was diluted

with 20 ml DMAc (6.8% solids w/w) after approximately 0.3 hour. Stirring

was continued for 5 minutes and the reaction mixture was cooled. The

viscous solution was precipitated in a water/acetic acid (10/1) mixture,

15 washed successively in hot water and methanol and dried at 110°C to

provide a white polymer (3.13 g, 75% yield) with a Tg of 269°C. The

inherent viscosity of a 0.5% solution in DMAc at 25°C was 1.79 dL/g.

Unoriented thin films cast from a DMAc solution gave tensile strength,

tensile modulus, and elongation at 23°C of 18.4 ksi, 591 ksi, and 6.1%,

20 respectively. The resulting polymer had the following structural repeat unit:

H

I O O

o

25

Although these polymers were made using DMAc as the solvent,

other solvents known to those skilled in the art, such as N-methylpyrrolidinone, diphenylsulfone, and sulfolane may also be used.
LAR 14643--1-CU -16- PATENT APPLICATION

In addition to the polymers made in the foregoing examples,

additional polymers were made arId their propgwtiesare tabulated in Tables 1

and 2.
LAR 14643-1-CU -17- PATENT APPLICATION

TABLE 1: POLYMER CttARACTERIZATION

tt

!

Y X qlnh, I [g,2 _D,__

dL/_g °c 5% wt.Iosa._,_

El2

nil 1.07 352 441 456

gO2 O 1.42 322 435 451

CO 0.93 ND. 4 422 433

nil O 1.11 1.34 307 294 466 442 502 48g

CO 0.g3 N.D.4 433 4Sf

____ illl O 1.19 295 46g 520 1.23 282 46g 490

CO 0.7g 276 444 478

illl 1.99 276 476 5 ! 5

O 1.79 269 454 499

CO 1.43 264 467 48g

I. lift!erredvlgcostlymeagufod In DMA¢ on 05 % (w/vJeofufloneol 25_C .

I. OIsIl_lIrmnelllon!emper_ure deletmh_d by DgC Id I hoallng.lie of 20"Clmln

S. TO^ meesmedon powderedlamplee'N I _NDatllla roleof 2.6_7,hnl. IRe, preheal e_rn_leIo 180"Cnnd

hold_g for O.Bh befme imalyeld

4. Not de!ecled
PATENT APPLICATION 

LAR 1 4643- 1 -CU 

TABLE 2: UNORIENTED THIN FILM 

TENSILE PROPERTIES AT 23°C 

Y X rl Inh, Sttenclth. Modulus. EhMA 

dLla ksl bsl kmkab 

SO2 nil 1 -87 22.5 652 9.3 

0 1.42 18.8 569 7.6 

nil 1.11 22.8 647 

0 1.34 19.7 576 

nil 1.19 20.2 605 

0 1 23 17.6 .539 

0 rm8 nit o1.799 19.48 

CO 1.43 19.6 

Films dried at 100.200, and - 50°C above their respective Tg in an sir oven 
LAR 1 4643-1 -CU 

What is claimed is: 

PATENT APPLICATION 

, , 
LAR 1 4643- 1 -CU 

90 

-26- PATENT APPLICATION 

POLYBENZIMIDAZOLES VIA AROMATIC NUCLEOPHILIC 

DISPLACEMENT 

Abstract : 

Di(hydroxyphenyl)benzimidazole monomers were prepared from 

phenyl-4-hydroxybenzoate and aromatic bisk-diamine)~. These monomers 

were used in the synthesis of soluble polybenzimidazoles. The reaction 

involved the aromatic nucleophilic displacement of various di(hydroxypheny1)- 

benzimidazole monomers with activated aromatic dihalides or activated 

10 aromatic dinitro compounds in the presence of an alkali metal base. These 

polymers exhibited lower glass transition temperatures, improved solubility, 

and better compression moldability over their commercial counterparts.