[1]United States Patetit Office 137 12 9, 3,376,269 POLYANUDES CONTAE'IING ADJACENT HETEROCYCLE LINKAGES Jack Preston, Raleigh, N.C., assignor to Monsanto Company, a corporation of Delaware 5 No Drawina. Filed Feb. 26, 1964, Ser. No. 347,385 11 CUms. (Cl. 260-78) This invention relates to new high temperature resistant linear condensation polymers. More - particularly, the invention relates to polymers with regularly recurring 10 structural units containing amide linkages and bis-heterocyclic linkages. Synthetic linear condensation polymers such as polyamides in the form of fibers, filaments, films and other shaped articles have found wide application in textile and 15 other industrial end uses requiring high tensile strength, a,brasion resistance, and resistance to thermal and other degradative conditions. Subsequent searching for polymers of improved thermal resistance has produced various heterocycle polymers such as polyoxadiazoles, poly20 benzimidazoles, and polyimides. Typical of such polymers are t@hose in U.S. Patents Z,895,948, 2,904,537 and 3,044,994. Such heterocycle polymers have certain characteristics, including heat resistance and resistance to acids and other degradative conditions, which are supe- 25 rior to those of polya@mides in (,Yencral. Wholly aromatic polyamides such as those of U.S. 3,006,899 and 3,049,518 1 0 0 F 11 11 Patented Apr. 2, 1968 2 from t-he description of the invention which follows hereinafter. This invention is concerned with the provision and preparation of "sym-metrical" amideheterocycle polymers having the formula r 0 LHN-Y-NH@8- wherein Y and Y' are selected from Ar and Ar-X-X-Ar where Ar is an aromatic divalent radical which may have a single, multiple or fused structure, and X represents a divalent 5 or 6 ring mem-bor heterocyclic linkage which contains from one to three hetero elements such as N, S, P, As, 0 and Se. In the general formula Y and Y' may be - the same or different provided that there is at least one Ar-X-X-Ar linkage in each repeating unit. All occurrences of X in the polymer repeating unit must be the same. In each Ar-X-X-Ar linkage the two heterocyclic radicals are joined to each other by a single common carbon to carbon valence bond. The use of the ter-m "symmetrical" herein is intended to relate to a characterist-ic of the polymers of this inven@ tion which may be describedby the fact that there is at least one p6int in each repeating unit of the polymers through which a plane of symmetry can be drawn. F6r example, repeating units may be shown as follows: N N 101 0 C,-HN-<7>-C 'C-'-(, c c NH-C H C s S-C 1 0 1 c plane of symmetry mirror Image half mirror iinage half and 0 0 0 0 -HN11 / / \ C---/ k@-0 C-:-C C--/ -N 10, HN-N N-N plane of symmetry mirror Image half have also been found to be highly resistant to high temperatures. This invention presents polymers which combine the desirable qualities and characteristics of both aromatic polyamides and heterocycle polymers. 56 Accordingly, it is an object of this invention to provide new composit-ions of mat@ter and a process for th6ir preparation. Another object of this invention is the provision of novel amideheterocycle polymers which are character55 ized by the fact that they have amide and two adjacent ,heterocyclic linkages in each repeating un-it which appear in a perfectly regular sequence along the polymer chain, each amide and each pair of adjacent heterocyclic linkages being separated by an aromatic radical, the 60 poly,mers further being characterized by the fact that there is at least one point in each repeating unit of thb polymer through which a plane of symmetry can be &awn. It is a further object to provide polymers which pos- 65 sess unusual therinal stability. An additional object of the invention is the - provision of fibers, filaments, films and other shaped articles prepared from the amide bis-heterocycle polymers of this 70 invention. Other objects and advantages will become apparent mirror Image half wherein a plane of symmetry as indicated by the dotted line shows that the repeating unit consists of two halves vhich are -mirror images of each other. The heterocyclic linkages are exemplified by N N N N -C C-C 0- -0 CC cR SI SI ICI R' SI [Cl ICI lb I i R R 0 0 s 9 -C c-c C- - C C-0 c11 11 11 11 I 11 11 11 it N-N N-N N-N N-N R n R R I I I I N N N N -C C-C c_r C-C C11-11 11 [I- , . 11 11 11 if R-C N N-C R N-N N-N R R N \ N u -C C-C C- - 0 0-0 cll_ll 8 1 and 11 I I I 0 C -o N-N N-@ 1 1 1 1 -K R R R w-here R=H, lower alkyl or phenyl.
[2]313765269 3 4 Suitable aromatic linkages include 101 0 O' 0 0 10 where R' is -0-, -S@, --SO, and the like. As examples @ of the polymers of this invention the following may be cited: (1) N N [NH-<:@@%C/ C 0 c NH-CO CoU-S S-CH (2) N N FNEI- -C c-c C ^ NFL-CO- CO] II -S S-0,11 (3) 0 0 [NH-^-C/ \C-C/ NII=CO---Ill @-co N-N N(4) FN 0 / 0 \ C-C / 0 \ c NII CO --^-CC@l N N N N-- N N c CO -CO C C r N-N N-N (6) Nil-<D>-C c-b C-</ H-CO CO @l- IN I (7) @T N 0 F Zlt :@-I \ 8 HN-e \\@>-C/ c-c c- NH11 I I 11 0 IEIC-S s CH (8) N N 0 ol r HN-<:@>C/ Z@@c-C@@ :@"C-e iic s s CH (9) F N \ 0 -HN c c-0 C,--- -C s s
[3]3)376)269 (10) N :@-I N 0 ol -HN 0 C-C C---@ NII- ICI li_l 1-8 c 8 s N N 0 11 / @@ @:-, \ c- c C-C C-<@D-cl@-NH11 I I if C-S S-CH (12) 0 N 'N 0 c- -N @-c C-C 0 HC s s -8H HI The polymers of this invention may be prepared by reacting togetber two monomers, each containing functional groups whigh react with the functional groups of the other to produce a polymer containing amide and two or four heterocyclic linkages in each repeating unit which appear in a perfectly regular sequence along the polymer chain. Thus, the polymers may be prepared via -the reaction of an aromatic diacid cbloride witb an aromatic diamine containing two heterocyclic linkages separated by an aromatic linkage or from the reaction of an aromatic diacid chloride containing two heterocyclic linkages separated by an aromatic linka.-C with an aromatic diamine. An alternate route to the polymers of this invention employs the reaction of a rinonomer containing preforined amide linkages and functional groiips which, when reacted with the functional groiips of a second monomer, produce heterocyclic linkages, The polymerization of the reactants is a condensation reaction which may be conveniently conducted by interfacial or solution polymerization methc)ds, by heating of stoichiometric amounts of reactants.and th,like. The following equations are exemplary of how the polymers of the invention can be prepared: N N NH2- 0 C-C O-e CH S S-@CH rH] N N 0 c-c 0 -U C-S S-C 0 0 NH2 c C-C c- \\,)-NH2 11 N 25 0 0 NH2 c C-C c 2 11 11 A-4 N-N 30 The methods of preparation of the diamines of this invention i-i general are described by P. Karrer et al., 35 Helv. 28, 820 (1945), and R. StoII6, J. ftir praktische chem., 68, 139 (1903). Conveniently, it involves the preparation of dinitro interinediate which is then reduced to the dia compound containing heterocyclic linkages. The dinitro intermediate may be prepared by any of 40 several well kiiown methods. A 1,3,4-oxadiazole linkage may be formed from a hydrazide linkage which may be formed i@i solution or via a Schotten-Baumann reaction. The Schotten-Baumann or iiiterfacial type reaction in)-NH3 + cico coci N N FNH-<D_C/ \C- NHC 0 co] CH-S S-Cil I 0 0 0 0 s s C NII-I -ICICH2-Br + NH2--C;-C-NH2 - ----- @ I Br-CH2-ii-e/ -NI-1-8 c Of the several routes to the preparation of the polymers 65 of this invention, the polyrneiization of an aromatic diamine containing two adjacent heterocyclic linkages, i.e., a bis-heterocyclic linkage, is typical. As examples of the diamines which may be used in the practice of this invention, the following are typical and 7o illustrative. N N Nil c C-C c NH2 1 1 If-S S-Cu 75 volves the use of a nitroaromatic acid chloride either alone or in a suitable solvent which will dissolve the acid chloride and which will at the same time not adversely affect the other component which is dissolved or. dispersed in water. Suitable solvents include chloroform, tetrahydrofuran, benzene, benzonitrile, acetophenone, acetontrile, dimethylacetamide, and other solvents-tetrahydrofuran being preferred. The reaction mixture is then stirred rapidly until the reaction is completed and the dinitro compound is Mtered from the reaction mixture. The choice of intermediate reactants will, of course, depend
[4]3,376,269 7 upon the type of heterocyclic linkage desired. For example, the reaction of m-nitrobenzoyl chloride plus oxalic dihydrazide in a basic reaction media will produce a nitro-m-benzoylhydrazide intermediate which may then be converted by a dehydrating agent, such as - phosphor- 5 ous pentoxide, to a dinitro intermediate compound containing a bis-1,3,4-oxadiazole link-age. The hydrazide intermediate may also be produced in a solvent, such as diinethylacetamide. The dintro compound containing the bis-oxadiazole linkage may then be reduced to the di- 16 amino comp6und. It is also possible to prepare the dinitro hetero-containing intermediate in a one-step synthesis. Other bis-heterocyclic linkages may be preformed readily in the compositions of this invention. Such heterocyclic linkages in- 15 clude: bis - 1,3,4 - thiodiazole, bis-3,5-4-N -phenyl-1,2,4- triazole, bis-pyrazole, bis-oximidazole, etc. The reduction of the dinitro intermediate to the diamine may be effected by use of catalytic reducing methods such as those involving the use of a palladium on charcoal 20 catalyst typically employing 5 percent palladiuni on cbarcoal, a Parr hydro,-enation unit or other unit. The reduction may also employ Raney nickel, cobalt and other similar heavy metal catalysts, these catalyst systems usually being effected in an alcohol or in solution in - dimethyl- 25 formamide or similar compoiinds. Reduction may also be accomplished using chemical reduction methods, such as stannous chloride and hydrochloric acid, iron and sulfuric acid, polysulfide solutions and the like. Suitable dicarboxylic acids or diacid derivatives ivhich 30 may be used in the practice of the inventioi include all diacid compounds where the carbonyl radicals are joined by aromatic or bis-heterocyclic-aromatic linkages, for example, aromatic diacid halides, such as isophthaloyl halide and substituted isophthaloyl chlorides such as alkyl, aryl, 35 alkoxy, nitro and other similar isophthaloyl chlorides and isophthaloyl bromides. Examples of such compounds include 4,6-dimethyl-5-propyl isophtbaloyl chloride, 2,5- dimethyl isophthaloyl chloride, 2 5-dimethoxy isophthaloyl chloride, 4,6-dimethoxy iso;@thaloyl chloride, 2, 5_ 40 diethoxy isophthaloyl chloride, 5-propoxy isophthaloyl chloride, 5-phenyl isophthaloyl chloride, 2-methyl-5- phenyl isophthaloyl chloride, 2,5-dinitro isophthaloyl chloride, 5-nitro isophthaloyl chloride and the like. Terephthaloyl chloride or terephthaloyl bromide may also 45 be used and may be substituted 'm the manner - described above for isophthaloyl chloride. Examples of terephthaloyl chlorides include 2,6-dimethyl terephthaloyl - chloride, tetramethyl terepththaloyl chloride, 2-methoxy terephthaloyl chloride, 2-nitro terephthaloyl chloride and the 50 like. These diacid morlomers may be prepared by any of the will known prior art methods used to prepare aromatic diacid compounds. For example, oxidation of xyle-ne--s. The polymers of the invention may be obtained by 55 any of the well known condensation polymerization tec,@ iinique,s such as solid state, melt, interfacial or solution polymerization techniques. The solution polymerization method generally involves 60 dissolving the diamine in a suitable solvent wblich is inert to the polymerization reaction. Among such solvents there may be mentioned dimethylacetamide, 1-methyl-2- pyrrolidone, 1,5-dimethy.1-2-pyrrolidone and the like. These solvents are rendered more effective in many instances by mixing them with a small amount, up to 10 65 percent, of an alkali or alkaline earth salt such as lithium chloride, lithium bromide, magnesium bromide, magnesium chloride, beryllium chloride, or calcium chloride., ture may be then stirred for a period of time untu polymerization is substantially complete and high yiscosity is attained. This hi-hly viscous solution may be spun per se, neutralized with caustic, or the polymer may be isolated by pouring the mixture in a non-solvent, washing and drying the polymer and then preparing the spinning solution. The interfacial polymerization reaction is conducted b3r mixing water, an emulsifier and the diamine wbich may be in the form of its dihydrochloride. A proton acceptor is then added and the mixture is then stirred rapidly. During this rapid stirring a solution of the dicarbonyl monomer in an inert organic solvent is added, the mixture is stirred until polymerization is complete, the polymer is then isolated by filtration and is washed and dried, The dicarbonyl monomer solvent may be any convenient solvent such as a cyclic non-aromatic oxygenated or.-anic solvent such as a cyclic tetramethylene sulfone, 2,4- dimethyl cyclic tetramethylene sulfone, tetrahydrofuran, propylene oxide and cyclohexanone. Other suitable dicarbonyl monomer solvents include chlorinated bydrocarbons such as methylene chloride, cbloroform andchlorobenzene, benzene, acetone, nitrobenzene, benzonitrile, acetophenone, acetonitrile, toluene and mixtures of the above solvents such as tetrahydrofuran and benzonitrile, tetrahydrofuran and acetophenone or benzene and acetone and the lil-,e. The amounts of the various reactants which may be employed will, of course, vary according to the type of polymer desired. However, in most instances, substantially eqliimolar quantities or a slight excess of diamine to dicarbonyl may be used. For interfacial polymerization reactions, sufficient proton acceptor to keep the acidic byproducts neutralizde may be added, the exact amount easily determined by one skilled in the art. Sui,able emulsifying agents for interfacial polymerization include anionic and nonionic compounds such as sodium lauryl sulfate, nonyl phen oxy(ethylencoxy) ethane, the sodium or.potassium salt of atiy suitable condensed sulfonic acid a@nd the like. A proton acceptor as the term is employed herein indicates a compound -which acts as an acid scavenger to neutralize HCI, formed during the reaction, and which aids to carry the reaction to completion. Suitable proton acceptors include sodium carbonate, magnesium carbonate, calcium carbonate, tertiary amines, such as triethyl amine, trimethyl amine, tripropyl amine, ethyl dimethyl amine, tributyl amine and similar compounds which react as desired. The products of this invention are useful in a wide range of applications. In the form of fibers, Maments and fflms the polymers of this invention are thermally resistant as well as being resistant to acids and other types of chemicaldegradation. The invention is further illustrated by the following examples in which all parts and percents are b3i weight unless otherwise indicated. Heat resistant properties of the polymers of the invention were tested by differential thernial analysis (DTA) and thermogravimetric analysis (TGA). Inherent vihcosity values are determined at 30' C. in dimethylacetamide containing 6 percent dissolved lithium chloride, using a concentration of 0.5 of polymer per 100 ml. of solvcnt. Fibers were characterized in general by baving good strength reteiation above 300' C. EXAMPLEI Preparation of 4,4'-bis(p-aminophenyl)-2,2'-bithiazole The diamine used for polymerization (4,4@-bis (p-aminoThe preferred solvent for soltition polymerization is di70 phenyl)-2,2'-bithiazole, diamine A) was prepraed in the methylacetamide or dimethylacetamide containing a small following manner: amount of dissolved lithium chloride. The diamine solution may be cooled to between 20 and -30' C. and the s s dicarbonyl inonomer may be added either as a solid or in 3NO2--e"'@-CO-CI12Br + NH2-ici-ici-NH2 a solution of one of the aforementioned solvents. The mix- 75
[5]31376;269 9 10 N N hydroA nalysis.-Cale'd: C, 61.67; H, 4.02; N, 15.95. Found: genati oii C, 61.24; 61.55; H, 4.07; 4.09; N, 15,82; 15.92. N cl 2-e -C/ C-0 c N02 8H- I I E XAMPLE 11 s S-81, N N 5 Polymers of 4,4'-bis(paininophenyl)-2,2'-bithiazole NH2-e -C/ Ce \\\>-NH2 Polymers prepared from diamine A may be illustrated CH-S S8H b y the following structures: N ' N F / z@"\ -NH-- S-C C-C c --l@-NH-0 0 c 0 -e S'-811 N N C-C c-C H-CO co B un-S S-CH N, N @coi_ c 0 - [NH-,e @-0 C-C C-e -NH-C L 8n-s S-CH --- / N N NH@e >- c C0 C-e---'@-NH-C Oe D L CH-S S-CH N N FNH-el c CC c-s, ' '@ H L 8H S-C A. To a solutidn of 48.8 g. (0.2 mole) of 2-bromo-4'- nitroacetophenone in 200 ml. dirnethylacetamide 35 (DMAC) was added 12.0 g. (0.01 mole) dithioxamide (rubeanic acid). After 30 minutes, a product began to precipitate from solution. The reaction n-.dxttire was stirred overnight, then filtered. The crude product was washed in ethanol and dried to yield 30 g. of material, M.P. 324- 40 326' C. The procedure was repeated' 5 times and the total product of the six runs combined to yield 142.1 g. of bluish-green material. The crude product was recrystallized twice from 900 ml. portions of DMAC, then recrystallized a third time from 1.5 liters DMAE to yield 121.9 g. of pure product in the form of long yellow - needles, 45 M.P. 325-327' C. Alaternately, the reaction may be run usin'g heat and the product recrystallizes from the re- 1 action mixture. B. Reduction was effected on the product prepared 50 according@to the method in section A above. Thus, 30 g. of 4,4'-bis(p-nitrophenyl)-2,2'-bithiazole, 300 ml. DMAE, and 3 g. Raney nickel were placed in a bom-b!and pressured to 2700 p.s.i. at 30' C. The bomb was repressured to 3700 p.s.i. at 50o C.; after five hours at 120' C. the 55 pressure was 3100 p.s.i. The bomb was cooled, vented and the contents of the bomb filtered. The filtrate was poured into 2 liters water at 50' C. and the product collected, washed in 500 rnl. water, filtered Dff and dried 16 hours at 50' C. in vacuum oven. Thus, 23 g. or product, M.P. 275-278'C. was collected. The process above 60 was repeated three times to yield 71 g. of crude - diamine. C. The crude diarnine of section B above was purified by dissolving 23 g. of the diamine in I liter of water at 90' C. containing 25 ml. concentrated hydrochloric acid, 65 heating the solution to the boil, filtering, and making the filtrate basic with 4,N sodium hydroxide solution. T'he mixture was cooled 30 minutes, then the diamine was collected, washed with 100 ml. water, dried 16 hours at 50' C. in a vacuum oven. Two more batches of crude 70 diamine were purified in the above manner to yield a total of 68 g. of product, which was reefystallized from 500 ml. DMAC, washed with 50 ml. methanol, dried in a vacuum oven at 50' C. for 16 hours to yield 53.5 gm. of pure diamine, M.P. 280-283' C. 75 s NH@-CO-e Or- >-coi E j A. A solution of 10.5 g. (0.03 mole) diamine A in 100 ml. DMAC containing 6 percent dissolved lithium chloride was cooled to -30' C. and 6.09 g. (0.03 rnole) isophthaloyl chloride was added with stirring. After 15 minutes the solution was allowed to warm to 01 C. and after an additional 15 minutes the soltition was allowed to warm to room tempera@ture. The solution became so viscous that it became necessary to add another 50 ml. solvent. After 3 hours, the solution was neutralized by addition of a slurry of 1.5 g. lithium hydroxide in 25 ml. DMAE. Two additional runs of the same size were made in the above manner. Polymer from each run was isolated by addition of water to a drute solution of polymer. After washing and drying, a total of 40.1 g. polymer was collected having an inherent viscosity of 2.4. Fiber spun frorn the polymer above and drawn at 300' C. was found to have the following physical properties: Denier per filament -------------------------- 4.9 Tension ----------------------------- g.p.d.-- 7.75 Elongation ------------------------- percent-- 6.6 Initial modulus ------------------------ g.p.d.-- 168 Grams per denier 200 ----------------------------------- 4.51 300 ------------------------------------- 3.08 350 ------------------------------------ 2.43 400 ------------------------------------ 2.34 450 ------------------------------------- 2.08 500 ------------------------------------ 0.36 Other pertinent fiber data were: round cross-section, high order as indicated by X-ray, a melting point of 550' C. in nitro.-en for undranvn fiber according to DTA, less than 15 percent weight loss in air to 500' C. (TGA), less than , 20 percent weight loss in nitrogen to 550' C. (TGA). B A solution of 1.75 g. (0.005 mole) diamine A in 15 mi ' . DMAE containing 5 percent dissolved lithium chloride was cooled to'-30' C. and 1.02 g. (0.005 niole) terephthaloyl chloride was added. The solution was stirred 15 minutes at -30' C., and 15 minutes at O' C. before the addition of an6ther 5 ml. DMAC containing 6 percent dissolved lithium chloride. After 1 h6urs af room temTension at, ' C.:
[6]3@3761269 perature, the mixture was neutralized with 0.25 g. lithium hydroxide slurried with 10 ml. DMAE containing 6 percent dissolved lithium hydroxide. The paste of polymer did not dissolve upon addition of 0.5 g. lithium chloride and heating of the paste to 80' C. Precipitation of the 5 polymer in water, followed by washing and drying of . the polymer gave a yield of 2.0 g. of very thermally stable material. Film showed little or no effect upon bein,- heated to 435' C. in air; unoriented films heated to 525' C for 3 minutes in air began to char but were still@ 10 flexible' C. A solution of 1.75 g. (0.005 mole) d@lamine A in 20 ml. DMAC containing 5 percent dissolved lithium chloride was cooled to -30' C. and 1.26 g. (0.005 mole) 2,6-naphthalenedicarbonyl chloride was added. The solu- 15 tion was stirred at -30' C. for 15 minutes, then at O' C. for 30 minutes. After 2 hours, the paste of polymer and solvent was neutralized with 0.24 g. lithium hydroxide slurried with 5 ml. DMAC containing 5 percent dissolved lithium chloride. The polymer was isolated by pouring 20 the above mixture into water, washing and drying the resulting precipitate. D. The procedure of section C was repeated using 1.39 g. of 4,4'-bibenzoyl chloride instead of 2,6-naphthalenedicarbonyl chloride. 25 E. A solution of 1.05 g. (0.003 mole) diamine A in 9 ml. DMAE containin.- 6 percent dissolved lithium chloride was cooled to -30' C. and 1.03 g. (0.003 mole) 4,4'-sulfonebibenzoyl chloride was added. A very viscous, clear solution was obtained even when the solution was 30 allowed to warm to room temperature. Film prepared from this polymer was thermaily stable. EXAMPLEIH This example shows the preparation of 5',5'-di,(3- 35 aminophenyl)-2,2' bis(1,3,4- oxadiazolyl), diamine B, used to prepare the polymers illustrated in Example IV. NH [NH-( N.H NO--///\\--COCI + NII2-NH-COCO-NH-NH: 60 CONH-NHCOCO-N 02 P20s NO- -/// - HNH-CO-(: v I IF 250' C. VI 0 0 65 \ / \ N 0 -C C 01 reduction 02-]@ IN@ - CN N 0 0 70 NHr- CC C -NHI 11 II III i-N Nbis(m-nitrobenzoyl)oxalylhydrazide 75 12 A. A slurry of 5.9 g. of oxalic dihydrazide in 150 ml. water was stirred rapidly in a blender jar and 19 g. mnitrobenzoyl chloride in 25 rnl. tetrahydrofuran was added. Next, 11 g. of sodium carbonate was added and the mixture was stirred rapidly for 10 minutes. The slurry was acidified with dilute hydrochloric acid, filtered and the product washed with 700 ml. hot water. The dried material weighed 16.9 g., M.P. 306-310' C. A pure material, M.P. 312-314' C. was obtained upon r ecrystallization from DMAC. 5,5'-di(3-nitrophenyl)-2,2',bis(1,3,4-oxadiazolyl) B. Treatment of 9 g. of the product of section A above with an equal portion of phosphorous pentoxide at 250' C. for 2 hours followed by water, gave 6@7 g. of material, M.P. 235-25@g' C. Recrystallization of this crude product from 60 ml. dimetbylformamide (DMF) gave 4.5 g. pure material, M@P. 275-278' C. Analysis.-Calc'd: C, 50.58; H, 2.10; N, 22.11. Found: C, 50.47, 50.59; H, 2.22, 2.25; N, 22.16, 22@ 17. 5,5'-di(3-aminophenyl)-2,2'-bis(1,3,4-oxadiazoyl) C . A r e d u c t i o n o f t h e d i n i t r o c o m p o u n d o f s e c t i o n 1 3 above was performed by placing 4.5 g. of dinitro compound in a solution of 15 g. stannous chloride dihydrate in 18 ml. concentrated hydrochloric acid and 30 @ml. ethanol. After a 45 minute reflux period, the swollen solids were wasbed in ethanol, slurried with aqueous sodium hydroxide solution, washed in water and dried. The resulting crude diamine B had a M.P. of 330-333' C.; pure diarnine B., M.P. 339-341' C., was obtained upon recrystallization from ethylene glycol monomethyl ether@ Analysis.-Caled: C, 60.00; H, 3.77; N, 26.23. Found: C, 59.06, 59.27; H, 3.58i 3.74; N, 25.69, 25.76. EXAMPLE IV, Polymers prepared according to this example have the following structure: 0 0 C/ \C-C/ C co 11 ii II N-N N N coi A 0 0 co] C HC -C co N-N N-N co 0 0 C C-C C H-Co-N,N-N C A. A solution of 0.16 g. (0.0005 mole) diamine B in 2 ml. DMAC containing 6 percent dissolved lithium chloride was cooled to -30' C@ and 0.102 g. (0.0005 mole) isophthaloyl chloride was added@ The viscous solution obtained was stirred at -30' C. for 5 minutes, then at O' C ' for 15 minutes, and at room temperature for 2 hours. The solution was neutralized with lithium hydroxide and cast into film. After the dissolved salts were removed from the film and the film was dried, a tough gray fflm -was obtained. The film readily increased in length when drawn at elevated temperatures and do not soften until heated to temperatures in excess of 300' C. B. A solution of 0.48 .-. (0.0015 mole) diamine B in 8 ml. DMAC containing 6 percent dissolved lithium chloride was colled to -30' C., and 0.305 g. (0.0015 mole) terephthaloyl chloride was added. The Yiscous solution was stirred 15 minutes at -30' C., then 15 minutes at O' C., and finally ovemight at room temperature. Next, 0.072 g. of lithium hydroxide, was added to neutralize the solu-
[7]3)376,269 13 tion, which was then c@st 6nt6 a glass plate. A film obtained by evdporation of solvent, soaking out dissolved salts followed by air drying, was tough and clear; the film did not soften until heated in excess of 300' C. C. A solutibn of 0.64 g. (0.002 mole) diamine B in 4 5 ml. DM.AC containing 6 percent dissolved li.thium chloride was cooled to -30' C. and 0.505 g. (0.002 mole) 2,6- naphthalenedicarbonyl chloride was added. A paste of solids was obtained; @ddition of another 4 ml. of solvent gave a dope which was spread to a film. 1( EXAMPLE V This example illustrates the preparation of intermediates. used to prepare the polymers of Example VI. 2NO,-<F---,@-COCI + NHr-NHCO-CO-NH-NI12 i4 Preparation of diamine D A mixture of 21 9. L 1 g. of Raney nickel, and 300 ml. DMAC was placed in an Aminco hydrogenation apparatus; the system.was pressurized with hydrogen to 2000 p.s.i. The temperature was raised to 120' C. and the tressure maintained at 2600 p.s.i. for 5 hours. The bomb was cooled to 70' C., vented, and the contents of the bomb filtered. The filtrate was poured into I liter of benzene and the diamine D collected; the melting point of the crude diamine D was 276-280' C. Diamine D recrystallized from ethylene glycol monomethyl ether had a M.P. of 280-28 I' C. CO-NH-NH-COCO-NH-NHNole CO-e -NO2 0 0 P205 e -NOi I No,-<, -C C-.C C240' C. \---/ 11 A 11 11 N- N-N 0 0 H2 C=C c-e R."y <@@,c, 1111 11 N-N N-N Diamirle C Hs I --------------- NH2-<@@-@CONH-NH-CO-CO-NH-NH-Co-e Raney nickel Diamine D Preparation of I EXAMPLE VI @A solution of 95 g. (0.51 mole) mole p-nitrobenzyl 35 Polymers prepared according to this exaniple have the chloride@ in 125 ml. tetrahydrofuran was added to 29.5 g. following str-ticture: 0 0 r / \ / \ CO ] NII- C CC -NH- CO - N N A 0 0 0 0 H-C 0 COT ICI-NH-NH-8-ICI-NH-NH icl-e -N B (0-.25 mole) ovalic dihydrazide slurried in 750 ml. icewat6'r and the mixture, @tirred raljidly while, 55@ g. of sodi- 50 iirp carbonate was added. Aft@i 15 minutes therhixtu@e w@s made acid, filtered, and washed with hot water. The dried product, 1, weighed 96.0 g. (92.3 percent yield); t.he melting point was 312-314' C. 55 Preparation of II A 23.4 portion of I was heated to 240' C. with an excess Of P205 for 4, hours (with occasional shaking), then w@ter and ice was added to the cooled mixture. The troduct Nvas filtered and dried to yield 11.7 g. of crude prod- 60 uct; a recrystallizatio'n'ir@iii-876 'ml. DMAC gave 9.7 g. of pure II, -M.,P. 358-360' C. A repeat experiment using 20 g.., of I gave 15 g. of IL M.P.,3 59-3 61 ' C. Repeat runs gave comparable@ results. Analysis.-@@Calc'd: C@, 50.58; H, 210; N 22 11- 65 Found: C, 50.58,.50.75;,H, 2.26, 2.29; N, 22.1@, 22.'30, Preparation of diamine C A mixture of 38 g. II, 2 g. Raney nickel, and 300 ml. DMAC was placed in an Aminco hydrogenation apparatus. The system was pressurized to 2000 p.s.i. with -hy70 drogen and heated to 120' C. for a period of four hours, with shaking. The bomb Nvas cooled, the contents of the flask were heated to the boil, and the slurry filtered. The filtrate was poured into hot water, the diamine C collected 75 and dried (M.P. 400' C., dec.). A. A slurry of 1.60 g. (0.005 mole) diamine C in 10 ml. DMAE containing 5 percent dissolv-ed lithium chloride.was cooled to O' C. and 1.01 g. (0.005 mole) isori phthaloyl chloride added Nvith stir 'ng. The solution obtained was viscous but polymer shortly began to precipitate. The slurry was diluted by the addition of 13 ml. DMAC containing 5 percent dissolved lithium chloride and was heated to 60' C. The polymer was precipitated; ini a water, collected nd dried. B. A solution of 0.89 g. (0.0025 mole) diamine D in @3.6 r@l. DMAC containing 5 percent dissolved lithium chloride was cooled to -30' C. and 0.51 g. (0.0025 raole) isophythaloyl @hloride added with stirring. The solution was allowed to warm I to O' C., then to room temperature, and finally was heated to 50' C. before it was spread on a glass plate. The film obtained was brittle. Removal'of water from 'polymer B (Example VI) by chemical treatment or heating above 3006 C. converted it into polymer A (Example VI). The fore.-oing detailed description has been given for cleamess of understanding only, and unnecessary limitations are not to be construed therefrom. The invention is n . ot to be limited to the exact details shown and described since obvious modifications will occur to those skilled in the art, and any departure from the description herein that conforms to the present invention is intended to be included within the scope of the claims.
