Diamines have shown their utility in the formation of many polymers. Examples of these polymers include polyimides, polyamides, and epoxies. The properties of these polymers are often dependent on the diamine which is used to make the polymer. By the present invention, a process was developed to make a diamine containing pentafluorosulfanylbenzene moiety. This process involves two steps: the preparation of a dinitro precursor and the reduction of the dinitro compound to form the diamine. This diamine was then reacted with various dianhydrides, diacidchlorides, and epoxy resins to yield the corresponding polyimide, polyamide, and epoxy polymers. These polymers were then used to make films, a wire coating enamel, and a semi-permeable membrane. The novelty of this invention resides in the process to make the diamine. Traditionally, dinitro compounds are reduced with hydrazine or a catalyst such as palladium on charcoal. The catalyst which is used in this invention is platinum oxide. When this catalyst is used, it makes it possible to form a polymer-grade diamine

St.clair, Anne K.

St.clair, Terry L.

Thrasher, Joseph S.

English

NASA Technical Reports Server

NASA CASE NO. LAR 1 4 7 7 3 - c u
PRINT FIG. N/A
NOTICE
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.: 07/755,207
Filed: September 5, 1991 LaRC
V
wHO-S-PENTAFtUOROSULFAH
POLYMERS THEREFROM Patent Appl .cat.on^ ^^<SJ/27 0050974
(NASA) 18 P _ . .. • - -
https://ntrs.nasa.gov/search.jsp?R=19920000887 2020-03-17T14:49:17+00:00Z
AWARDS ABSTRACT
A PROCESS FOR PREPARING
1.3-DIAMINO-5-PENTAFLUOROSULFANYLBENZENE
AND POLYMERS THEREFROM
NASA Case No. LAR 14773-1-CU
Diamines have shown their utility in the formation of many polymers. Examples of these
polymers include polyimides, polyamides, and epoxies. The properties of these polymers
are often dependent on the diamine which is used to make the polymer.
By the present invention, a process was developed to make a diamine containing a
pentafluorosulfanylbenzene moiety. This process involves two steps: the preparation of
a dinitro precursor and the reduction of the dinitro compound to form the diamine. This
diamine was then reacted with various dianhydrides, diacidchlorides, and epoxy resins
to yield the corresponding polyimide, polyamide, and epoxy polymers. These polymers
were then used to make films, a wire coating enamel, and a semi-permeable membrane.
The novelty of this invention resides in the process to make the diamine. Traditionally,
dinitro compounds are reduced with hydrazine or a catalyst such as palladium on
charcoal. The catalyst which is used in this invention is platinum oxide. When this
catalyst is used, it makes it possible to form a polymer-grade diamine.
Inventors: Anne K. St. Clair Terry L St.Clair
Address: 17 Roberts Landing Dr. 17 Roberts Landing Dr.
Poquoson, VA 23662 Poquoson, VA 23662
SS:  SS: 
Employer: NASA LaRC NASA LaRC
Joseph S. Thrasher
6211 37th Ct. N.E.
Tuscaloosa, AL 35406
SS: 
University of Alabama
Initial Evaluator: Darrel R. Tenney
Serial No.: 07/755,20?
Filed: September 5, 1991
OLAR 14773-1-CU -1- PATENT APPLICATION
A PROCESS FOR PREPARING
1.3-DIAMINO-5-PENTAFLUOROSULFANYLBENZENE
AND POLYMERS THEREFROM
5 Origin 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. NAG1-1069 and is subject to the provisions of
10 Public Law 96-517 (35 DSC 202) in which the contractor has elected not to
retain title.
Background of the Invention
15 1. Field of the Invention
The present invention relates to a process for preparing a diamine. It
specifically relates to a process for preparing a diamine which contains a
pentafluorosulfanylbenzene moiety.
20
2. Description of Related Art
Diamines have shown their utility in the formation of many polymers.
Examples of these polymers include polyimides, polyamides, and epoxies.
25 The properties of these polymers are often dependent on the diamine which
is used to make the polymer. By the present invention, a process was
developed to make a diamine containing a pentafluorosulfanylbenzene
moiety.
30
LAP 14773-1-CU -2- PATENT APPLICATION
Summary of the Invention
The diamine, 1,3-diamino-5-pentafluorosulfanylbenzene (DASP), was
prepared and has the structural formula:
5
H2N
10
A new process was developed in order to prepare this diamine. This
process involves two steps: the preparation of a dinitro precursor and the
reduction of the dinitro compound to form the diamine.
15 The dinitro compound was prepared by reacting silver fluoride with
bis(3,5-dinitrophenyl)disulfide. The mixture was evacuated and a chlorinated
fluorocarbon was added. The reaction was gradually heated to 130°C and
this temperature was maintained for two hours. The reactor was cooled to
room temperature and the chlorinated fluorocarbon was removed under
20 vacuum. The product was extracted and distilled under vacuum. The
resulting yellow oil was further purified by high pressure liquid
chromatography (HPLC) and the dinitro product precipitated. The product,
1,3-dinitro-5-pentafluorosulfanylbenzene, was filtered and dried.
The 1,3-dinitro-5-pentafluorosulfanylbenzene was mixed with absolute
25 ethanol, chloroform, concentrated hydrochloric acid, and a catalyst. The
reaction mixture was pressurized with hydrogen gas, filtered and distilled to
form a crude amine hydrochloride. The amine hydrochloride was neutralized
and a non-water soluble organic solvent was added to form a separate
phase containing the diamine. This phase was separated and dried, forming
30 a solid. The solid was recrystallized to give the diamine, DASP.
LAR 14773-1-CD -3- PATENT APPLICATION
This diamine monomer (DASP) was combined with the following
dianhydrides to form the corresponding polyimide polymers.
10
6FDA
ODPA o oPMDA
BTDA
BPDA
15
HQDEA BFDA
20
IRAN BDSDA
DASP was also reacted with the following diacidchloride to form the
25 corresponding polyamide.
TPC
30
LAP 14773-1-CD -4- PATENT APPLICATION
A crosslinked epoxy polymer was formed by reacting DASP with the
liquid epoxy resin, MY-720®, available commercially from Ciba-Giegy and
having the structure:
CH2—CH-
CH2—CH-
O
'\
CH2—CH CH2
10
15
20
Several articles were prepared from these polymers. These articles
include: semi-permeable membranes, wire coatings, and films.
An object of the present invention is to develop a process to make
1,3-diamino-5-pentafluorosulfanylbenzene.
Another object of the present invention is to make polymers with the
diamine, 1,3-diamino-5-pentafluorosulfanylbenzene.
Another object of the present invention is to make articles from the
polymers.
Description of the Preferred Embodiments
Example 1
25 A 1000 ml capacity stainless steel reactor, tested at 60 p.s.i. pressure
and pre-treated with fluorine, was charged with 165 g of silver fluoride
(AgF2), 30 g of bis(3,5-dinitrophenyl)disulfide, ten copper sheets (0.1 x 15 x
60 mm), and then an additional 150 g of AgF2. The reactor was evacuated
on a vacuum line, and 200 ml of 1,1,2-trichlorotrifluoroethane was added
30 while maintaining the reactor at -80°C. The reactor was shaken for 5
LAR 14773-1 -CD -5- PATENT APPLICATION
minutes, warmed to room temperature, and then placed in an oil bath and
heated to 60°C.
After two hours at 60°C, the temperature of the oil bath was gradually
increased over 30 minutes to 130°C. During a two hour period at 130°C, the
5 reactor was shaken at 30 minute intervals for 5 minutes. The reactor was
then cooled to room temperature, and the 1,1,2-trichlorotrifluoroethane was
removed under vacuum. The product was extracted from the reaction
mixture three times with 150 ml portions of carbon tetrachloride (CCI4) and
two times with 150 ml portions of trichloromethane (CHCI3).
10 The extracts were combined and the CCI4 and CHCI3 were distilled off
under vacuum. The resulting residue, a yellow oil (25.6 g), was further
purified by HPLC using Lichroprep RP-18® packing, which is commercially
available, and a water-methanol (1:1) mixture as eluent. The volume of the
fractions containing 1,3-dinitro-5-pentafluorosulfanylbenzene was reduced in
15 half whereupon the product precipitated. The solid product (3.1 g, 7.0%
yield) was filtered and dried. The structure of the compound was confirmed
by 1H, 19F, and 13C NMR spectroscopy, mass spectrometry, and elemental
analysis.
1,3-(NO2)2-5-SF5-C6H3: mp 73-75°C; 1H NMR 8 9.25 (t,J =1.7 Hz,
20 1 H), 8.96 (d,J = 1.7 Hz, 2 H); 19F NMR (ab4 pattern) 8a 77.6 (m), ^ 62.7
(d of m) (JAB=152.4 Hz); 13C NMR 5 C-1 = C-3 148.5, C-2 121.7, C-4 = C-6
126.7 (quintet, JSF4.C = 4.8 Hz), C-5 154.6 (quintet, JSF4.C = 21.5 Hz). Mass
Spectrum (70 eV) m/e (rel. intensity) 294 M+ (100.0), 275 [M-F]+ (20.9), 248
[M-NO2]+ (28.4), 218 [M-N2O3]+ (34.3), 202 [M-N2O4]+ (13.9), 201 (94.5), 167
25 [M-SFgJ* (10.7), 127 SF5+ (3.8).
Anal. - Calcd. for C6H3F5N2O4S (294.2): C, 24.50; H.1.03; N, 9.52;
S, 10.90.
Found: C, 24.75; H, 1.05; N, 9.53; S, 10.64.
30 The 1,3-Dinitro-5-pentafluorosulfanylbenzene (4.43 g, 15.1 mmol) was
LAR 14773-1-CU -6- PATENT APPLICATION
combined with 100 ml absolute ethanol, 10 ml chloroform, 2.65 g of 41.59%
hydrochloric acid (HCI) in ethanol, and 2.65 g platinum oxide (Pt2O) and
were placed in a 500 ml pressure bottle for use on a Parr hydrogenation
apparatus. The system was flushed, pressurized to 100 p.s.i. with hydrogen,
5 and shaken.
Within 1 hour the theoretical amount of hydrogen was absorbed.
After filtration through Celite®, which is commercially available from Johns-
Manville Products Corporation, on a Buchner funnel, the volatile materials
were distilled off at room temperature. The resulting solid (crude amine
10 hydrochloride, 5.43 g) was then neutralized in a 500 ml separately funnel
with 60 ml of a 10% sodium carbonate (NagCOg) solution which was covered
with 20 ml of diethyl ether. After neutralization, the ether phase was
separated and the water phase was extracted .three times with 20 ml
aliquots of ether. The combined ether extracts were dried over magnesium
15 sulfate (MgSO4), and the ether was evaporated. The resulting solid (3.3 g)
was recrystallized from an ether-hexane mixture to give the desired product
as a pale yellow solid (2.95 g, 12.6 mmol) in 83.4% yield. The structure of
the compound, 1,3-diamino-5-pentafluorosulfanylbenzene (DASP), was
confirmed by 1H, 19F, and 13C NMR spectroscopy, mass spectrometry, and
20 elemental analysis.
1,3-(NH2)2-5-SF5-C6H3: mp 153 -154°C; 1H NMR 8 6.46 (d, J =
1.7 Hz, 2 H), 6.07 (t, J = 1.7 Hz, 1 H); 19F NMR (ab4 pattern) 6a 85.2 (m), ^
61.6 (d of m) (JAB = 149.8 Hz); 13C NMR 5 C-1 = C-3 147.4, C-2 103.5, C-4=
C-6 103.3 (quintet, JSF4.C = 4.8 Hz), C-5 155.9 (quintet JSF4^ = 20 Hz). Mass
25 spectrum (70 eV) m/e (rel. intensity) 234 M+ (100.0), 206 (3.9), 126 (6.8),
107[M-SF5]+(63.5).
Anal. - Calcd. for C6H7F5N2S (234.2): C, 30.77; H, 3.01; N, 11.96;
S, 13.69.
Found: C, 30.73; H, 3.04; N, 11.79; S, 13.56.
30
LAR 14773-1-CU -7- PATENT APPLICATION
Although 1,1,2-trichlortrifluoroethane was used in this reaction other
chlorinated fluorocarbons known to those skilled in the art can also be used.
Although platinum oxide was the catalyst used in this reaction,
palladium on charcoal (Pd/C) may also be used.
Although diethyl ether was the solvent used to separate the diamine,
any non-water soluble organic solvent known to those skilled in the art may
be used.
10
15
20
Example 2
A polyimide polymer was prepared by dissolving 0.1405 g (0.6
mmole) of DASP into 1.6282 g of N.N-dimethylacetamide (DMAc) in a 1/4
02. snap-cap jar. Next was added 0.2719 g (0.6 mmole) of 6FDA and the
mixture was allowed to stir/react over a 23 hour period. The resulting yellow
solution had an inherent viscosity (at 0.5% concentration in DMAc at 35°C)
of 0.35 dL/g indicating a high degree of polymerization. A thin film was cast
from the solution and was cured to 300°C. The resulting polyimide polymer
had the following structural formula:
25
where n = 10 - 100.
30
LAP 14773-1-CU -8-
Example 3
PATENT APPLICATION
10
A polyimide polymer was prepared by dissolving 0.1124 g (0.48
mmole) DASP into 1.6563 g of DMAc in a 1/4 oz. snap-cap jar. Next,
0.3017 g (0.48 mmole) of BFDA was added and the solution was allowed to
stir for approximately 2 hours. An additional 0.0030 g of BFDA (1 molar
percent excess) was added and the solution was stirred overnight. A pale
yellow solution resulted which had an inherent viscosity of 0.44 dL/g
indicating a high degree of polymerization. A thin film was cast from the
solution and was cured to 300°C. The resulting polymer had the following
structural formula:
15
20
where n = 10 - 100.
25 Example 4
30
A polyimide polymer was prepared by dissolving 0.1850 g (0.79
mmole) DASP into 1.6698 g of DMAc in a 1/4 oz. snap-cap jar. Next,
0.2348 g (0.80 mmole) of BPDA was added and the mixture was allowed to
stir for approximately 24 hours. A yellow solution resulted which was found
10
LAR 14773-1-CU -9- PATENT APPLICATION
to have an inherent viscosity of 0.44 dL/g. A thin film was cast from the
solution and was cured to 300°C. The resulting polymer had the following
structural formula:
where n = 10 - 100.
15
20
25
Example 5
A polyimide polymer was prepared by dissolving 0.1756 g (0.75
mmole) DASP into 1.6332 g of DMAc in a 1/4 oz. snap-cap jar. Next,
0.2350 g (0.76 mmole) of ODPA was added and the mixture was allowed to
stir overnight. Another one mole percent of ODPA was added and stirring
continued for approximately 4 hours. The resulting solution had an inherent
viscosity of 0.48 dL/g. A thin film of this solution was cast and was cured to
300°C. The resulting polymer had the following structural formula:
n
30 where n = 10 - 100.
LAR 14773-1-CU -10-
Example 6
PATENT APPLICATION
10
15
A polyimide polymer was prepared by dissolving 0.2108 g (0.9
mmole) of DASP into 1.6283 g of DMAc in a 1/4 oz. snap-cap jar. Once the
solution was attained, 0.1983 g (0.909 mmole) of PMDA was added and
stirring was continued overnight. The resulting solution had a pale yellow
color and an inherent viscosity of 0.36 dL/g. A thin film of this solution was
cast and was cured to 300°C. The resulting polymer had the following
structural formula:
where n = 10 - 100.
20 Example 7
A polyimide polymer was prepared by dissolving 0.1710 g (0.73
mmole) of DASP into 1.6658 g of DMAc in a 1/4 oz. snap-cap jar. Next,
0.2480 g (0.737 mmole) of IPAN was added and the mixture was allowed to
25 stir. After approximately 18 hours, the viscosity appeared to be low so
0.0025 g of IPAN was added to total 0.7446 mmoles of IPAN. After stirring
for approximately 4 additional hours, the polymer solution was found to have
an inherent viscosity of 0.38 dL/g. A thin film of this solution was cast and
was cured to 300°C. The resulting polymer had the following structural
30 formula:
LAR 14773-1-CU -11- PATENT APPLICATION
SFS n
10
where n = 10 - 100.
Example 8
A polyimide polymer was prepared by dissolving 0.1733 g (0.74
mmole) of DASP into 1.647 g of DMAc in a 1/4 oz. snap-cap jar. Next,
15 0.2408 g (0.747 mmole) of BTDA was added and the mixture was stirred
overnight. The resulting solution had an inherent viscosity of 0.40 dl_/g. A
thin film was cast from this solution and was cured to 300°C. The resulting
polymer had the following structural formula:
20
25
30 where n = 10 - 100.
LAR 14773-1-CD -12-
Example 9
PATENT APPLICATION
10
15
A polyimide polymer was prepared by dissolving 0.1499 g (0.64
mmole) of DASP into 1.6295 g of DMAc in a 1/4 oz. snap-cap jar. Next,
0.2601 g (0.646 mmole) of HQDEA was added and the mixture was stirred
for approximately 20 hours. The resulting pale yellow solution had an
inherent viscosity of 0.40 dL/g. A thin film of this solution was cast and was
cured to 300°C. The resulting polymer had the following structural formula:
where n = 10 - 100.
Example 10
20 A polyimide polymer was prepared by dissolving 0.1288 g (0.55
mmole) of DASP into 1.6383 g of DMAc in a 1/4 oz. snap-cap jar. Next,
0:2836 g (0.5555 mmole) of BDSDA was added and the mixture was
allowed to stir overnight. This solution had an inherent viscosity of 0.45
dL/g. A thin film of this solution was cast and was cured to 300°C. The
25 resulting polymer had the following structural formula:
30
LAR 14773-1-CD -13- PATENT APPLICATION
10
where n = 10 - 100.
Example 11
15
20
25
A polyamide polymer was prepared by mixing equimolar amounts (0.5
mmole) of DASP and terephthaloylchloride in 2 ml of DMAc and allowing the
solution to stir overnight. A yellow solution resulted which had an inherent
viscosity of 0.58 dL/g. A thin film of this solution was cast and was cured to
200°C. The polyamide film was clear, colorless and flexible and had a
dielectric constant of 3.44 at 10 GHz. The resulting polyamide had the
following structural formula:
30 where n = 10 - 100.
LAR 14773-1-CU -14-
Example 12
PATENT APPLICATION
An epoxy resin was cured with DASP by mixing equimolar amounts
(0.5 mmole) of DASP with the tetraglycidylmethylenedianiline (tetrafunotional
epoxide, MY-720® available from Ciba-Giegy). The mixture was warmed to
>125°C on a hot plate and a cured or crosslinked epoxy resin resulted. The
resulting crosslinked resin had the following structure:
10 OH Y
15 Where Y= -
CH.-CH-CH,—
OH
20
25
30
LAR 14773-1-CU -15- PATENT APPLICATION
Example 13
A semi-permeable membrane was formed from the polymer solution
of Example 3. The solution was coated onto a piece of plate glass. Next,
5 the DMAc was allowed to evaporate at room temperature for 1/2 hour. The
remainder of the DMAc was leached from the film by immersing it in
methanol to form a membrane which was subsequently thermally treated to
200°C to form a stable polyimide semi-permeable membrane. Although the
polyimide solution of Example 3 was used to make the membrane, the
10 polyamide and epoxy polymers could also be used.
Example 14
A wire coating was prepared by immersing a piece of copper wire in
15 the polymer solution from Example 3. Upon removal from the solution, the
coating was allowed to air dry for approximately 1/2 hour. After drying, the
wire was placed in an air oven at 200°C for one hour to cure the polyimide
coating. The coating on the copper wire was flexible and resisted abrading.
Although the polyimide solution of Example 3 was used to make the
20 membrane, the polyamide and epoxy polymers could also be used.
What is claimed as new and desired to be secured by Letters Patent
of the United States is:
LAR 14773-1-CU -24=- PATENT APPLICATION
A PROCESS FOR PREPARING
1.3-DIAMINO-5-PENTAFLUOROSULFANYLBENZENE
AND POLYMERS THEREFROM
5 Abstract
A process was developed to prepare 1,3-diamino-5-pentafluoro-
sulfanylbenzene. This process involved two steps: preparing the dinitro
compound, 1,3-dinitro-5-pentafluorosulfanylbenzene, and reducing this
10 compound to form the corresponding diamine. This diamine was reacted
with various dianhydrides, diacidchlorides, and epoxy resins to form
polyimides, polyamides, and crosslinked epoxies. These polymers were
used to prepare semi-permeable membranes, wire coatings, and films.


A Process for Preparing 1,3-Diamino-5-Pentafluorosulfanylbenzene and Polymers Therefrom

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