DE1570886C3 - Process for the production of nitrogen-containing polymers - Google Patents

Description

The invention relates to a process for the production of nitrogen-containing polymers by reacting essentially equimolar proportions of amines with aromatic or aliphatic ones Dicarboxylic acids or their esters or anhydrides or phenyliminochlorides.

Linear condensation polymers, such as polyamides, have been in the form of fibers, films, or molded Objects found widely used for textiles and other technical purposes, where high tensile strength and high abrasion resistance are required.

It is known to produce nitrogen-containing polymers by having equimolar proportions of monomers containing at least one preformed heterocyclic Bond and contain at least two reactive functional groups, with monomers, which contain at least two reactive functional groups, converts (see. Macromolecular chemistry [1961], Vol. 44 to 46, pp. 388 to 397).

It is also known heterocyclic compounds that are substituted by two alkyl esters or anhydride radicals are to be reacted with aromatic tetramines (cf. French patent 1 303 849). According to In this known procedure, the polymerization takes place in the melt under reduced pressure the respondent executed. However, the products thus obtained are not yet satisfactory Fiber-forming properties.

Various heterocyclic polymers are on the lookout for polymers with improved heat resistance Polymers such as polyxadiazoles, polybenzimidazoles and polymides have been produced. These polymers however, they are obtained with great difficulty and are difficult to use Objects to process. Polybenzimidazoles are made from tetramines, which are not easy to break are clean. These tetramines are easily oxidized and therefore likely to contribute to the dark color of polybenzimidazoles. A substantial amount of the polymer produced is also networked. Since polyoxadiazoles are insoluble in known solvents, the oxadiazole bond is formed after a fiber or a film is formed from a polyhydrazide. The transformation a large number of hydrazide linkages in place in a spun fiber to form oxadiazole linkages however, greatly affects the fine structure of the fiber, presumably as a result of incomplete Conversion of hydrazide bonds into oxadiazole bonds or side reactions. Such Fibers have poor physical properties, e.g. B. low tensile strength, compared with the Polyhydrazide Precursors of Polyoxadiazoles ^

The object of the invention is therefore the preparation of polymers containing heterocyclic groups, which are well suited for use as fibers, threads and films or other shaped articles and their physical properties by appropriate combinations of two or more different ones heterocyclic bonds can be adjusted according to the intended use. The solution to this problem is now a process for the production of nitrogen-containing polymers by reacting essentially equimolar proportions of amines with aromatic or aliphatic ones Dicarboxylic acids or their esters or anhydrides or phenyliminochlorides, which thereby is characterized in that the amines are heterocyclic compounds with more than three ring members that are used as Heteroatoms contain at least one oxygen, nitrogen or sulfur atom and by at least two aminophenyl or phenylhydrazide radicals are substituted.

According to the process according to the invention, heat-resistant polymers can be obtained which two or more heterocyclic bonds in regular succession with aromatic or aromatic bonds and aliphatic bonds.

One or more heterocyclic bonds are preformed in a monomer, and one or more heterocyclic bonds are formed during the course of the polymerization.
The aromatic or aliphatic-aromatic bond

dung can z. B. consist of the following units:

where R '=

—O— —S -

. CH ₃

—C—

CH ₃

or

Il ·

C.

Il ο

- (CH ₂ J ₂ -

—C-

Il
ο

where «= 1 to 10.

The aliphatic bond can be made from
- (CH ₂ ) _n -

C)

IO

- - Units

consist, where η - 1 to 10. is

The hydrocarbon bond can also consist of a hydrocarbon ring fused with the heterocyclic chunks.

The polyvalent heterocyclic bonds contain at least one O, N and S and can be selected from three 20 or more heterocyclic ring members exist. Examples of divalent heterocycles containing Leftovers are:

--C
Il ^c '■ - -C \ N C -
H Il
CH N CH R. Il
α CM
! N
j | -C-
H C. ! I
C- O Il
N
/ s' N N I.
-C
\ N \ \
N /. //

- C

O
/ \ \
r ^
Il /
- C
H S. \
C.
I. C.
H / Il
-N Il
N- I.
-N Il
N-

R.
I. I.
N
/ \ C.
π Il
N- \
C.
Il Ii
-N

N-

-N
R.

-C
CH

C-

/ \
-CC

Il Il

CH N

C C -

I! Ii

CH CH

/ O
• \ /
C.
H Il
CH / R. /
C. N
■ \ CH \
/ - * -CH \
Π Il
-CH

CH

35

40

45

CH
H N N
π N -C \
H C- Il
-C
\ 1
R. Il
C -
/ CU
\ Il
CH
/ CH \ CH
Λ / \

CH

where R = H or lower alkyl.

Examples of hydrocarbon rings fused with heterocyclic units are benzimidazole from imidazole or benzothiazole from thiazole. Radicals containing divalent heterocycles with fused-on Hydrocarbon rings are e.g. B.

55

60 s ~ \

570 886

, Ν ■ j

C ¹ I

- ■ N ¹ Xs

I.
1

-c -

I!

CH

N, -

!
R.

1, --- C

--Ν

! I

Ν—

I S

20th

C)

Ii

C)

O

O O

! I / ^ Il

-c A .JC-

- N

N--

whereby
- S - -, - H or lower
SO,-. Al
( kyl and R '= until 10. .._. ς— -
| i - ( I!
C) CH, or - (CH ,)., -. where / ι = = 1

■■ -

Typical polymers which are obtained according to the invention are

O —C

Il Il

N N

II H

cV 'VN _n , n-

C- (CIU) ₈ -C

-N ' ⁷ "N-

rf

N N

..- Ni

C-

--C

N N

Il II

-C C

N I. / \ N \ N
I. C. \ J \ / r ~ "C \ k \ /
N
I. J f ν- A. -N
M. \ / II
c -
/ -N
π I!
C- I. J

(4)

The polymers, prepared according to the invention, can by the reaction of amines with aromatic or aliphatic dicarboxylic acids.

As amines used according to the invention come for example in question: 2,5-bis- (p-aminophenyl) -l, 3, 4 - oxadiazole, 2,5 - bis - (m - aminophenyl) -1,3,4 - oxadiazole, 2,5-bis- (3,4-diaminophenyl) - 1,3,4-oxadiazole, 3,5 - bis - (m - aminophenyl) - 4 - phenyl -1,2,4 - triazole, m - bis - (4 - ρ - aminophenylthiazol - 2 - yl) benzene or 2,5-bis (m-benzoylhydrazide) -1,3,4-oxadiazole.

Examples of aromatic or aliphatic dicarboxylic acids are: oxalic acid, adipic acid, succinic acid, Glutaric acid, suberic acid, azelaic acid, sebacic acid, isophthalic acid, terephthalic acid, dibenzoic acid and naphthalenedicarboxylic acid, esters of these acids, e.g. B. Ethyl oxalate, ethyl adipate, diethyl isophthalate, Dimethyl isophthalate, diphenyl isophthalate, dianhydrides, e.g. B. pyromellitic dianhydride, naphthalenic dianhydride, Bis (phenyldicarboxylic acid anhydride), isophthaloyl chloride, terephthaloyl chloride or Ν, Ν'-diphenylisophthalimidoyl chloride.

The preparation of the polymers according to the invention can be carried out by solution polymerization or interfacial polymerization or by a solid state process. The solution polymerization is generally carried out in the following conventional manner: A heterocyclic monomer is dissolved in a suitable solvent which is inert to the polymerization reaction. Examples for such solvents are dimethylacetamide, dimethylformamide, l-methyl-2-pyrrolidone, 1,5-dimethyl-2-pyrrolidone or hexamethylphosphoramide. In many cases, these solvents can be given greater effectiveness by you with a small amount (up to 10%) of an alkali or alkaline earth salt, z. B. lithium chloride, Lithium bromide, magnesium chloride, magnesium bromide, beryllium chloride or calcium chloride, mixes. The preferred solvents for solution polymerization are dimethylacetamide or dimethylacetamide with a content of 5% dissolved lithium chloride. The solution containing the monomer becomes preferably cooled to 20 to -30 ° C, and the second monomer is either as a solid or in the form added to a solution in one of the solvents indicated above. The mixture is then stirred for a period of time until the polymerization is essentially complete and has a high viscosity is preserved.

This highly viscous solution can be used directly for the production of fibers, threads or films, or the polymer can be isolated by pouring the mixture into a non-solvent, then washing and drying the polymer and then one in the production of fibers Solution to be used, threads or films. For certain polymers, a heat treatment or a chemical treatment is necessary in order to convert the shaped object (fiber, thread or film) into a regularly arranged series of two or more heterocyclic-containing polymer.
For polymerizations in the solid state, essentially equimolar amounts of monomers can be used. Temperatures from 100 to 400 ° C and pressures from 0.01 mm to pressures above atmospheric pressure can be used.

The polymers produced according to the invention have many desirable properties. In particular they are easy to handle and pliable and can immediately become fibers, Threads, films or other shaped objects. In contrast, they had to known masses are formed as a treatable intermediate material, since these are in their final or finished form of fiber, thread or film form are untreatable. Those involved in making these heterocyclic Intermediates used in copolymers are opposed to oxidation and various side reactions more stable than those used in the production of other polymers known in the art Applied intermediate substances. Those obtained from the polymers according to the invention Products are easily processed into usable products. The one about the heterocyclizations leading reactions are direct and easy to carry out. The thermal stability of the according to the invention obtained products is superior to that of many heterocyclic polymers, which only a heterocyclic bond instead of the regular combination of several different types of heterocyclic bonds according to the invention. Polymers with different heterocyclic Bindings can be made according to various working methods.

Due to the resistance to high temperatures and the low dielectric constant the polymers prepared according to the invention are useful and suitable for such applications, such as electrical insulation, technical filters, conveyor belts, tire cord or heat-resistant parachutes.

The invention is explained in more detail below by means of examples, in which, if nothing otherwise stated, all parts and percentages are based on weight.

309 525/503

example 1

10

(2) pyridine / acetic anhydride

In a conical bottle or flask was placed 2.52 g (0.01 mol) of 2,5-bis- (p-aminophenyl) -1,3,4-oxadiazole introduced into 18 ml of dry dimethylacetamide (DMAC), the resulting solution cooled and treated with 2.02 g (0.011 mol) of pyromellitic dianhydride (PMDA) mixed. The solution was stirred at 0 ° C. for 1 hour, then to room temperature allowed to warm up. The mixture was stirred for 60 hours to complete the Ensure reaction, using a nitrogen atmosphere during the course of the polymerization would. After the completion of the polymerization, a solution of the polymer in DMAC was made with a solids content of 15%, from which to characterize the polymer obtained Films approximately 370μ (15 mils) thick poured and heated to 110 to 120 ° C. This films composed of a polyamide-oxadiazole acid were cut into strips, in a mixture of pyridine and acetic anhydride in proportion of 3: 1 soaked in dioxane for 24 hours each

rinsed and dried ^{at 110 ° C.} This treatment converted the polyamide-oxadiazole acid into the polyimide-oxadiazole. Stretching at 270 ^° C. resulted in a non-fragile film; when stretched again at 400 to 425 ° C became cloudy

Films obtained which were very crystalline and oriented as determined by X-ray diffraction. The films were strong and stable in air up to 475 ° C. Strips stretched at 400 to 425 ° C Films were used to test a thermogravimetric

see analysis (TGA) subject. Up to 500 ^° C., a weight loss of only 4% was observed. The maximum weight loss per minute at a heating rate of 4.2 ⁰ C per minute occurred at 585 ° C.

Example 2

H ₇ N-

According to the procedure described in Example 1, a polymerization between 2.20 g of 2,5-bis (m-aminophenyl) -1, 3,4-oxadiazole (m.p. = 249 to 252 ° C) and 1.96 g of PMDA carried out in 15 ml of dry DMAC. The films were converted into an imide oxadiazole copolymer with regularly arranged order of RinHnnpen and peeeniiher Temneraturen proved stable above 400 ^0C.

Example 3

A polymerization was carried out according to the procedure of Example 1, with 0.49 g of 3,5-bis- (m-aminophenyl) -4-phenyl-1,2,4-triazole and 0.33 g of PMDA (pyromellitic dianhydride) in 3.2 ml of dry dimethylacetamide were used. A film was cast from the resulting solution, and the film was converted into an imide-4-phenyl-triazole copolymer convicted.

Preparation of 2,5-bis (3,4-diaminophenyl) -1,3,4-oxadiazole

NO

COOH

COCl

+ SOCl ₂

H ₇ SQ ₁

NO,

35

55

NO ₂

+ POCl ₃ NO ₂

NO ₂ NO ₂

NO
NO-

HCl NH;

NH

NO,

NO ₂

-NH ₇

NH,

+ SnCl ₂

A. A 50 g portion of 3,4-dinitrobenzoic acid was mixed with 100 ml of thionyl chloride for 4 hours heated to reflux. The thionyl chloride was removed and the product at 182-184 ° C at a Distilled pressure of 4 mm, giving 32 g of a product with a melting point of 51 to 52 ° C became.

B. The 3,4-dinitrobenzyl chloride obtained was dissolved in 30 ml of tetrahydrofuran and with vigorous stirring a solution of 8.5 g of hydrazine sulfate, dissolved in 200 g of ice and water. Then 25 g of sodium bicarbonate were added and the Mixture stirred for about 10 minutes. The product, N, N'-bis (3,4-dinitrobenzyl) hydrazine, possessed after filtration and crystallization a melting point of 278 to 280 ° C.

Analysis:
Calculated:

C 39.99, H 1.92, N 19.99%;
found:

C 39.87, 40.12, H 2.20, N 19.63, 19.40%.

C. The dinitrohydrazide was then converted to an oxadiazole by adding a 25.3 portion to 250 ml Phosphorus oxychloride was refluxed for 3 hours, excess phosphorus oxychloride was then removed and the product was then washed, dried and reprecipitated. The pure 2,5-bis- (3,4-dinitrophenyl) -1, 3,4-oxadiazole was found in a yield of 19.0 g with a melting point from 230 to 232 ° C.

Analysis:
Calculated:

C 41.76, H 1.50, N 20.90%;
found:

C 41.75, 41.98, H 2.05, 2.31, N 20.38, 20.43%.

D. The nitro groups were converted into amino groups by reduction with stannous chloride (tin (II) chloride) reduced. A 4.02 g portion of 2,5-bis- (3,4-dinitrophenyl) -1, 3,4-oxadiazole was with a solution prepared from 50 ml of ethanol, 50 ml of concentrated hydrochloric acid in 30 g of tin (II) chloride dihydrate Heated to reflux. The mixture was cooled and a precipitate collected, washed and filtered. The white precipitate gave 2 g of tetramine with a melting point of 267 to 271 ° C.

Analysis:
Calculated :

C 49.54, H 5.00, N 29.99%;
found:

C 59.63, 59.55, H 5.31, 5.15, N 29.82, 29.62%.

Example 4
Production of an oxdiazole-benzimidazole copolymer by polymerization in the solid state

In a reaction flask was added 1.4 g (0.01 mol) of 2,5-bis (3,4-diaminophenyl) -1,3,4-oxadiazole (M.p. = 267 to 271 ° C) and 1.59 g (0.01 mol) of diphenyl isophthalate (M.p. = 134 to 135 ° C) were introduced. the Reaction was carried out in a nitrogen atmosphere at 220 ° C for about 10 minutes and at 265 ° C carried out for about 30 minutes. Phenol and water distilled at the latter temperature away.

The polymer obtained was in concentrated sulfuric acid, formic acid and dimethylacetamide soluble with a content of 5% dissolved lithium chloride.

A polymer of higher molecular weight was obtained by heating 1 g of the polymer at 400 ° C under a pressure of 0.1 mm for 3 hours. The heat or heat stability of this Oxadiazole - benzimidazole copolymer, determined by thermographic analysis, was excellent, The following weight losses were found at different temperatures: none up to 480 ° C, up to 500 ° C 7% and up to 580 ° C only 14%.

example

NH ₂
NH

-c

N-

C-

-N

NH ₂
NH,

+ HOOC- (CH ₂ J ₈ -COOH

C- (CH ₂ J ₈ -C

, N-

The tetramine described in Example 4 was in a proportion of 0.564 g (0.002 mol) with 0.404 g (0.002 mol) Sebacic acid reacted for 2 hours and 20 minutes at 255 ° C under a nitrogen atmosphere. Out threads could be drawn from the polymer melt, which had a melting point of 343 ° C. The Polymer was also soluble in m-cresol.

Example 6

NH ₂ +

The procedure of Example 1 was carried out using 4.30 g (0.01 mol) of m-bis (4-p-amino-20 phenylthiazol-2-yl-benzene) in 20 ml of dry dimethylacetamide and 2.18 g ( 0.01 mol) PMDA (pyromellitic dianhydride) repeated. An additional 10 ml amount of dimethylacetamide was added to the solution prior to casting films. Films with a thickness of about 508 μ were cast, ^{dried at 110 °} C. for 3 hours and introduced into a mixture of 3 parts of pyridine and 2 parts of acetic anhydride. After 16 hours, the films were soaked in dioxane for 2 hours and dried. When strips of this film were stretched over a heated ceramic pin, they showed excellent thermal stability to temperatures above 425 ° C.

Preparation of the starting products for Example 7 O O

Il ^ _x Il

CH ₃ CH ₂ -OC - [^ V-CO-CH ₂ CH ₃ KOH

CH ₃ CH ₂ -OH

SOCl,

CH ₃ CH ₂ -OC

O COH

X O O

NH, -NH,

- "CH ₃ -CH ₂ -OC-r ^ V-CNHNH - C- f ' ^ -COCH ₂ -CH ₃

ΝΗ, ΝΗ

I ₂₁ XIl ₂

Il ^ v Il Il s \ I '

-> NH ₂ - NHC-rr ^ V "CNH - NHC-f V-CNH-NH ₂

POCl ₃

ΝΗ, ΝΗ

2 » ⁿ 2

ο ο

Il ys. / \

- CH ₃ CH ₂ -OC ^ YC C

^ N N

O O

NH ₇ NH-CZ ^ -C

Il

COCH ₂ CH ₃

CNHNH ₂

(H)

(III)

IN (IV) 309 525/503

A. A 203 g portion (1.0 mole) of isophthaloyl chloride and 250 ml of ethanol were stirred together until the initial exothermic reaction ceased. The solution refluxed for 30 minutes held, and excess ethanol was distilled off. The product, diethyl isophthalate, was in a Yield of 206 g (bp = 175 to 178 ° C./17 mm) obtained.

B. A solution of 55 g of this diethyl isophthalate in 140 ml of ethanol was obtained by adding 15 g of potassium hydroxide saponified in 15 ml of water. The resulting gel was refluxed for 30 minutes, cooled and extracted with ether to remove unreacted diester. The water layer was acidified and the crude acid products were precipitated. Ethyl hydrogen isophthalate with a melting point from 131 to 132 ° C. was obtained in a yield of 16.5 g after recrystallization from benzene.

C. The ethyl hydrogen isophthalate was then stirred over by thionyl chloride in m-carbethoxybenzoyl chloride, Bp = 134 to 135 ° C / 5.6mm.

D. A solution of 9 g of the acid chloride in 20 ml of tetrahydrofuran was added to 2.6 g of hydrazine sulfate in Add 100 g of water and ice. Then 8 g of sodium bicarbonate was added to the mixture, which was mixed for 10 minutes. The product,

NH,

N, N'-bis (m-carbethoxybenzoyl) hydrazide (I) was filtered, washed and dried, a yield of 7.7 g was obtained, m.p. = 185 to 187 ° C.

Analysis:

Calculated ... C 62.47, H 5.25, N 7.29%;
found .... C 62.81, H 5.42, N 7.15, 7.33%.

E. The hydrazide (I) was converted into an oxadiazole by reaction with refluxing phosphorus oxychloride transferred, excess oxychloride was stripped off and the residue from ethanol recrystallized. 19.2 g of hydrazide (I) were converted into 17.8 g of 2,5-bis (m-carboethoxyphenol) -1,3,4-oxadiazole (III) obtained with a melting point of 133 to 134 ° C.

Analysis:
Calculated:

C 65.55, H 4.96, N 7.65%;
found:

C 65.76, 65.60, H 4.72, 5.05, N 7.54, 7.69%.

F. The 2,5-bis (m-carboethoxyphenyl) -1,3,4-oxadiazole (III) was converted into a dihydrazide (IV) by adding a solution of 8 g of the compound (III) and 300 ml of methanol was refluxed with 9 g of 95% hydrazine for 3 hours. When cooling down 2.8 g of product with a melting point of 230 to 235 ° C. were precipitated from the solution.

SOCl,

Dimethylformamide CatalystF

(V)

G. A from isophthaloyl chloride and aniline was distilled off and the residue from isooctane,

The part of Ν, Ν'-diphenylisophthalamide that was dried with calcium hydride was

crystallized with a large excess of less than 45 thionyl chloride. The product, Ν, Ν'-diphenylisophthal-

Use a few drops of dimethylformamide imidoyl chloride with a melting point of 146 to

kept under reflux as a catalyst until a temperature of 150 ° C, was produced in almost quantitative yield

Solution was achieved. excess thionyl chloride provided.

ΝΗ, ΝΗ

Example 7

CNH-NH ₂ +

-N = C — f \ —C = N-

Cl

Cl

(V)

(VI)

1.41 g (0.004 mol) of Ν, Ν'-diphenylisophthalimidoyl chloride (V) with a melting point were added to a suspension of 1.35 g (0.004 Mo!) Of the dihydrazide (IV) in 10 ml of dimethylacetamide with a content of 5% dissolved lithium chloride from 146 to 150 ⁰ C given. The mixture was stirred for 30 minutes at 0 ^° C., then to room temperature

let come and stir overnight. The mixture was then ^{heated at 130 °} C. for one hour and precipitated in water. The melting point of the dried polymer was 190 ° C. A film was cast from a solution of the polymer in dimethylacetamide containing 7% lithium chloride.

Claims (1)

Claim: Process for the preparation of nitrogen-containing polymers by reacting essentially equimolar proportions of amines with aromatic or aliphatic dicarboxylic acids or their esters or anhydrides or phenyliminochlorides, characterized in that as amines are heterocyclic compounds with more than three ring members, as heteroatoms contain at least one oxygen, nitrogen or sulfur atom and at least two Aminophenyl or phenylhydrazide are substituted, is used.