Aromatic polyamide resins having repeating units, each containing at least one m-ethynyl amido subunit: ##STR1## These resins can be thermally treated to undergo intra-molecular cyclization, without evolution of volatiles, into polyimidines containing the following subunit. ##STR2##

BACKGROUND OF THE INVENTION 
This invention relates to novel polymeric compounds and to a method for 
their synthesis. In particular, this invention relates to novel 
ethynyl-substituted aromatic polyamides. 
Interest in laminates and laminating processes for use in a wide variety of 
industrial applications has increased considerably in the past few years. 
Glass fiber laminates, for example, find wide use as structural materials 
because of their lightweight, high relative strength, and high resistance 
to corrosion and other damaging effects encountered in an environment 
subject to extreme fluctuations in temperature and weather. Consequently, 
a concentrated research effort has evolved in an attempt to develop 
polymeric materials suitable for use as laminating resins. Such resins 
must possess a high degree of thermal stability and strength after curing 
coupled with good solubility characteristics before curing, if they are to 
be useful for impregnating and bonding the wide variety of laminate 
materials presently in use. 
The research effort referred to above has culminated in the development of 
several resinous materials that have been found suitable from a stability 
and strength standpoint. Unfortunately, however, problems have arisen when 
using such materials due to the evolution of gas during the curing step 
which occurs after the laminate sheets are impregnated. The curing process 
which liberates gaseous side products has the deleterious effects of 
producing voids in the cured laminates which, in turn, substantially 
weakens the final laminated product. 
It is an object of the present invention to provide novel aromatic 
polyamide resins which can be cured without evolving volatile side 
products. 
Other objects, aspects and advantages of the invention will be readily 
apparent to those skilled in the art from the following detailed 
disclosure of the invention. 
SUMMARY OF THE INVENTION 
In accordance with the present invention there is provided a novel aromatic 
polyamide resin having repeating units, each containing at least one 
o-ethynyl amido subunit: 
##STR3## 
The resins of this invention which contain the above subunit can be 
thermally treated to undergo intramolecular cyclization, without evolution 
of volatiles, into polyimidines containing the following subunit: 
##STR4## 
More specifically, in accordance with with the present invention there is 
provided a first aromatic polyamide resin of the general formula: 
##STR5## 
wherein n is an integer and Ar is a divalent aromatic radical having the 
general formula: 
##STR6## 
wherein Z is selected from the following: --CH.sub.2 --, --CO--, --S--, 
--O--, and --SO.sub.2 --. 
There is also provided a second aromatic polyamide resin represented by 
either of the following formulas: 
##STR7## 
wherein n and Ar are as described above and Ar' is a monovalent aromatic 
radical selected from the group consisting of phenyl and C1- to 
C3-substituted phenyl, such as, for example, p-tolyl, p-cumenyl, 
p-ethylphenyl, and p-propylphenyl. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The polymer represented by Formula III is prepared by the polycondensation 
of tolane-2,4'-dicarbonyl chloride with a diamino compound. The reaction 
may be represented by the following equation: 
##STR8## 
The polymer represented by Formula IV is prepared by the polycondensation 
of a 2,5-bis(arylethynyl)terephthaloyl chloride with a diamino compound. 
The reaction may be represented by the following equation: 
##STR9## 
The polymer represented by Formula V is prepared by the polycondensation of 
a 2,4-bis(arylethynyl)isophthaloyl chloride with a diamino compound. The 
reaction may be represented by the following equation: 
##STR10## 
As shown by the above equations, substantially equimolar amounts of 
reactants are utilized. The reaction is carried out in the presence of a 
suitable solvent, one which is inert to the reactants and the resulting 
polymer, and one in which at least one of the monomers is soluble. 
Examples of suitable solvents include N-methyl-2-pyrrolidone, 
N,N-dimethylacetamide, N,N-diethyl-acetamide, N,N-dimethylformamide, 
tetramethyl urea, sulfolane, and the like. 
The polycondensation reaction is carried out at low temperature, i.e. about 
0.degree. to 5.degree. C. for about 0.5 to 5 hours. Following the initial 
reaction period, the reaction mixture may be allowed to warm to room 
temperature. The mixture is preferably stirred at room temperature for an 
additional period of about 5 to 72 hours. At the end of the reaction 
period, the polymer is recovered by a general procedure that is 
conventionally followed in solution polymerization processes. For example, 
the reaction mixture is poured into a non-solvent for the polymer, e.g., 
an alcohol such as methanol, thereby causing the polymer to precipitate 
from solution. The precipitated polymer is then separated from the liquid 
by any suitable means, such as by filtration or decantation. The 
precipitated polymer may be thereafter washed with the so-called 
non-solvent. If desired, the polymer can be dissolved in a suitable 
solvent and again precipitated from solution by pouring the solution into 
a non-solvent. This procedure can be repeated as necessary to further 
purify the product. 
The products of this invention can be heat cured to provide thermoset 
resins. When heated to temperatures on the order of 150.degree. C., the 
products of the invention undergo intermolecular cyclization to 
polyphthalimidines without evolution of volatiles. 
When used as a coating material, the products of the invention should be 
laid down on the substrate and heat cured at temperatures of 175.degree. 
C. or higher. To prepare laminates, the fabric may be impregnated with a 
solvent solution of the polymer, e.g., methane sulfonic acid, then rinsed 
with a non-solvent for the polymer, e.g., methanol, to precipitate the 
polymer in the interstices of the fabric and to remove the solvent. The 
fabric is then dried to remove the non-solvent. The dried fabric can then 
be laid up and heated to cross-link the resin solids. Modest pressures on 
the order of 15-200 psig are sufficient, if employed. Curing temperatures 
on the order of 150.degree.-250.degree. C., preferably about 
170.degree.-220.degree. C. are employed for curing times on the order of 
about 1 to 12 hours. The laminates may be post cured for 10 to 50 hours at 
temperatures of about 200.degree.-300.degree. C. Alternatively, the 
laminate fabric may be dusted with dry resin powder, instead of the 
solvent procedure described above. 
The acid chloride monomers employed in the preparation of the polymers of 
this invention can be prepared by reacting the corresponding carboxylic 
acid with thionyl chloride by a general procedure that is conventionally 
followed. 
The following examples illustrate the invention:

EXAMPLE I 
Tolane-2,4'-dicarbonyl Chloride 
2,4'-Tolanedicarboxylic acid (2.40 g, 0.009 moles) was stirred at room 
temperature for 48 hours in 35 ml of thionyl chloride (redistilled from 
boiled linseed oil). This suspension was then refluxed for eight hours to 
give a clear, light red solution. The excess thionyl chloride was then 
stripped off to give a grey solid, mp 79.degree.-85.degree. C. 
Recrystallization from hexane afforded 1.38 g (51% yield) of 
tolane-2,4'-dicarbonylchloride as a waxy, off-white solid which after 
drying at 58.degree. C./0.10 mm Hg exhibited mp 
184.5.degree.-185.5.degree. C. 
Anal. Calc'd for C.sub.16 H.sub.8 Cl.sub.2 O.sub.2 : C, 63.39; H, 2.66; Cl, 
23.39; MW, 266. Found: C, 63.42; H, 2.12; Cl, 23.21; MW, 266 (mass 
spectrum). 
EXAMPLE II 
4,6-Bis(phenylethynyl)isophthaloyl Chloride 
Bromine (395.5 g, 2.472 mole) (dried over concentrated sulfuric acid) was 
added dropwise to stirred 4,6-dibromo-1,3-xylene (150 g, 0.568 mole) in an 
ultraviolet irradiation apparatus. Approximately 90 ml of bromine was 
added over 2.5 hour with the temperature being maintained at 
120.degree.-130.degree. C. An additional 20 ml was added over two hours at 
130.degree.-150.degree. C. and the final 17 ml was added over two hours at 
150.degree.-160.degree. C. After the bromine was completely taken up, the 
yellow reaction mixture was distilled in portions to give a 
1,3-bis(dibromomethyl)-4,6-dibromobenzene as a white solid bp 
178.degree.-182.degree. C./0.02 mm Hg. Recrystallization from absolute 
ethanol yielded a total of 259 g (79% yield) of white crystals, mp 
115.degree.-118.degree. C. 
Anal. Calc'd for C.sub.8 H.sub.4 Br.sub.6 : C, 16.58; H, 0.69: MW, 580. 
Found: C, 16.49; H, 0.67; MW, 580 (mass spectrum). 
An aqueous solution of silver nitrate (71.0 g, 0.418 mole) in 544 ml of 
water added dropwise over three hours to a stirred solution of 
1,3-bis(dibromomethyl)-4,6-dibromobenzene (40.0 g, 0.069 mole) in 300 ml 
cellosolve at 80.degree.-85.degree. C. The green reaction mixture was 
stirred at temperature for an additional 3.5 hours and filtered while hot. 
The collected precipitate was washed thoroughly with water and suction 
dried on the frit. Water added to the filtrate produced a white product 
that was recrystallized from cyclohexane to yield 6.1 g of white crystals. 
The dried green precipitate was extracted with hot benzene and the 
resulting material recrystallized from cyclohexane to yield 7.1 g of white 
crystals. Combined yield of 4,6-dibromoisophthalaldehyde was 13.6 g (66% 
yield), mp 188.degree.-191.degree. C. 
Anal. Calc'd for C.sub.8 H.sub.4 Br.sub.2 O.sub.2 : C, 32.91; H, 1.38; MW, 
292. Found: C, 32.83; H, 1.46; MW, 292 (Mass spectrum). 
The 4,6-dibromoisophthaladehyde (16.4 g, 0.056 mole) was dissolved in a 
solution of triethylamine (280 ml) and pyridine (315 ml) under a nitrogen 
atmosphere. To the desired solution palladium acetate (0.28 g, 0.0013 
mole) and triphenyl phosphine (0.70 g, 0.0027 mole) were added. 
Phenylacetylene (14.3 g, 0.140 mole) was added dropwise over the course of 
an hour to the red reaction mixture at 45.degree.-50.degree. C. The 
reaction was continued an additional 3.5 hours. It was then cooled and 
poured into a sulfuric acid-ice mixture. The resultant yellow precipitate 
was collected by filtration, thoroughly washed with water, and suction 
dried on the frit. Recrystallization of the material from heptane yielded 
12.0 g (64% yielded) of 4,6-bis(phenylethynyl)isophthalaldehyde, mp 
170.degree.-172.degree. C. 
Anal. Calc'd for C.sub.24 H.sub.14 O.sub.2 : C, 86.21; H, 4.22; MW, 334. 
Found: C, 85.56; H, 4.40; MW, 334 (Mass spectrum). 
4,6-Bis(phenylethynyl)isophthalaldehyde (7.8 g, 0.023 mole) was dissolved 
in acetone (distilled from solid potassium permanganate) and the solution 
was chilled to 0.degree. C. A chromium trioxide-sulfuric acid solution was 
prepared by slurrying 26.7 g of chromium trioxide in 23 ml of concentrated 
sulfuric acid and 40 ml of distilled water. This solution was diluted in 
the cold with distilled water to 110 ml. A portion of this solution (16.9 
ml) was added dropwise over 1.5 hours to the stirred yellow acetone 
solution. During this period the color of the reaction mixture changed 
from yellow to brown and finally to green. After an additional 20 hours of 
reaction, the mixture was warmed to room temperature and poured into a 
vessel containing ice and water. The yellow precipitate was collected by 
filtration and washed thoroughly with water. Suction drying on the frit 
yielded 7.3 g (85.5% yield) of the light yellow 
4,6-bis(phenylethynyl)isophthalic acid. 
Anal. Calc'd for C.sub.24 H.sub.14 O.sub.4 : C, 78.68; H, 3.85; MW, 366. 
Found: C, 78.08; H, 3.95; MW, 366 (mass spectrum). 
4,6-Bis(phenylethynyl)isophthalic acid (4.0 g, 0.0109 mole) was slurried in 
170 ml of thionyl chloride (freshly distilled from boiled linseed oil) for 
30 minutes. To the reaction mixture, a few drops of N,N-dimethylformamide 
was added to effect solution. The reaction mixture was stirred between 
35.degree.-40.degree. C. for 16 hours. Removal of the excess thionyl 
chloride under reduced pressure yielded an orange-yellow solid. 
Recrystallization from hexane gave 16 g (36.4% yield) of 
4,6-bis(phenylethynyl)iophthaloyl chloride as light yellow crystals, mp 
157.degree.-160.degree. C. 
Anal. Calc'd for C.sub.24 H.sub.12 Cl.sub.2 O.sub.2 : C, 71.48; H, 3.00; 
MW, 402. Found: C, 70.95; H, 3.32; MW, 402 (mass spectrum). 
EXAMPLE III 
2,5-Bis(phenylethynyl)terephthaloyl Chloride (Method 1) 
2,5-Dibromo-1,4-xylene (43.0 g, 0.163 mole) was dissolved in 550 ml of 
glacial acetic acid and 550 ml of acetic anhydride. To the vigorously 
stirred solution at 0.degree.-5.degree. C. was cautiously added 90 ml of 
concentrated sulfuric acid. With the temperature being maintained at 
-5.degree. C., chromium trioxide (93.0 g, 0.930 mole) was gradually added 
over a period of 1.5 hours, care being taken to keep the reaction 
temperature below 5.degree. C. The red solution mixture gradually became 
very viscous and took on a deep green coloration. After being stirred for 
four more hours, it was then brought to room temperature and poured with 
stirring into five liters of cold water. The white precipitate was 
isolated by filtration and washed on the frit with water until no green 
color appeared in the washings. The white solid was stirred in two liters 
of 2% sodium solution for one hour, isolated by filtration, and washed 
well on the frit with water. Air drying overnight afforded 45.5 g (56% 
yield) of unpurified 
2,5-dibromo-.alpha.,.alpha.,.alpha.',.alpha.'-tetraacetoxy-1,4-xylene, mp 
200.degree.-210.degree. C. Recrystallization of an analytical sample from 
isopropanol gave mp 219.degree.-221.degree. C. 
Anal. Calc'd for C.sub.16 H.sub.16 O.sub.8 Br.sub.2 : C, 38.73; H, 3.25; 
Br, 32.22. Found: C, 39.01; H, 3.08; Br, 32.11. 
Unpurified 
2,5-dibromo-.alpha.,.alpha.,.alpha.',.alpha.'-tetraacetoxy-1,4-xylene 
(60.5 g, 0.122 mole) was dissolved with stirring in three liters of hot 
ethanol. Then 450 ml of water was added followed by 75 ml of concentrated 
sulfuric acid which was added very slowly. After being allowed to reflux 
for an hour, the reaction mixture was diluted with 900 ml of hot water. 
Cooling overnight at -10.degree. C. resulted in the recrystallization of 
30.9 g (87% yield) of 2,5-dibromoterephthalaldehyde, mp 
184.degree.-189.degree. C. (lit 189.degree.-190.5.degree. C.) which was 
isolated of filtration. 
Anal. Calc'd for C.sub.8 H.sub.4 O.sub.2 Br.sub.2 : C, 32.91; H, 1.38; Br, 
54.75; MW, 292. Found: C, 32.68; H, 0.90; Br, 54.60; MW, 292 (mass 
spectrum). 
A solution of diphenyl(.alpha.-chlorobenzyl)phosphonate (28.70 g, 0.080 
mole) in 150 ml of dry dimethylsulfoxide was cooled to 0.degree.-5.degree. 
C. Sodium hydride (3.84 g, 0.160 mole) (as a 50% suspension in mineral 
oil) was added to the rapidly stirred solution. With the temperature being 
maintained at 0.degree.-5.degree. C., 2,5-dibromoterephthalaldehyde (11.64 
g, 0.04 mole) slurried in 50 ml of dry dimethylsulfoxide was added over a 
five minute period. Considerable foaming took place during the addition. 
After being allowed to continue at room temperature overnight, the 
reaction mixture was added to 250 ml of ice water. The resultant beige 
precipitant was isolated by filtration and washed on the frit with water. 
Drying at 60.degree. C./1.0 min Hg for two hours yielded 16.63 g of beige 
product, mp 130.degree.-235.degree. C. The crude product was extracted 
with 400 ml of heptane for two hours in an extraction apparatus. The 
heptane solution upon cooling gave 8.45 g (48% yield) of 
1,4-bis(phenylethynyl)-2,5-dibromobenzene as light yellow crystals, mp 
155.degree.-158.degree. C. An additional 3.5 g of slightly lower melting 
material was recovered from the mother liquor. 
Anal. Calc'd for C.sub.22 H.sub.14 Br.sub.2 : C, 60.58; H, 2.77; Br, 36.65; 
MW, 436. Found: C, 60.85; H, 2.52; Br, 36.41; MW, 436 (mass spectrum). 
n-Butyl lithium (2.11 g, 0.033 mole) (14.25 ml of a 2.32 M solution in 
hexane) was added over five minutes to a vigorously stirred solution of 
1,4-bis(phenylethynyl)2,5-dibromobenzene (6.54 g, 0.015 mole) in 500 ml of 
ether at 0.degree. C. The initial yellow slurry took on a brown color for 
several minutes before a dull yellow precipitate was formed. After being 
allowed to stir for three hours at 0.degree. C. under a nitrogen blanket, 
the reaction mixture was added to a slurry of dry ice in 300 ml of ether. 
This slurry was stirred for five hours and the excess dry ice was then 
allowed to evaporate. The ether solution was then extracted with 500 ml of 
a very dilute aqueous potassium hydroxide solution which was in turn 
extracted with 50 ml of ether. The cooled aqueous layer was acidified with 
dilute sulfuric acid to give a yellow precipitate which was isolated by 
filtration. Drying for three hours at 60.degree. C./1.0 mm Hg yielded 
5.10 g of crude product, mp&gt;360.degree. C. with prior shriveling at 
190.degree.-200.degree. C. Recrystallization from isopropanol afforded 
2.90 g (53% yield) of 2,5-bis(phenylethynyl)terephthalic acid as a powdery 
yellow solid, mp&gt;360.degree. C. with shrinking at 270.degree.-275.degree. 
C. 
Anal. Calc'd for C.sub.24 H.sub.14 O.sub.4 : C, 78.68; H, 3.85; MW, 366. 
Found: C, 78.72; H, 3.65; MW, 366 (mass spectrum). 
A mixture of 2,5-bis(phenylethynyl)terephthalic acid (2.20 g, 0.006 mole) 
suspended in 40 ml of thionyl chloride (redistilled from boiled linseed 
oil) was stirred at refux overnight to give a deep yellow solution. The 
excess thionyl chloride was stripped off to give a deep yellow solid which 
was recrystallized from 150 ml of heptane. 
2,5-Bis(phenylethylyl)terephthaloyl chloride (1.35 g, 56% yield) was 
obtained as a deep yellow crystals, mp 179.degree.-181.degree. C. with 
prior shrinking at 176.degree. C. 
Anal. Calc'd for C.sub.24 H.sub.12 O.sub.2 Cl.sub.2 : C, 71.48; H, 3.00; 
MW, 403. Found: C, 71.30; H, 2.91; MW, 403 (mass spectrum). 
EXAMPLE IV 
2,5-Bis(phenylethynyl)terephthaloyl Chloride (Method 2) 
2,5-Dibromoterephthalaldehyde (29.2 g, 0.100 mole) and phenylacetylene 
(25.5 g, 0.250 mole) were dissolved at 80.degree. C. under nitrogen in a 
mixture of freshly distilled triethylamine (200 ml) and pyridine (200 ml). 
Palladium acetate (0.54 g, 0.0024 mole) and triphenylphosphine (1.26 g, 
0.0048 mole) were added to the vigorously stirred red solution. The 
resultant exotherm did not subside for fifteen minutes and a voluminous 
white precipitate was formed. After an additional hour at reflux, the red 
slurry was added with vigorous stirring to a sulfuric acid ice mixture. 
The slightly gummy brown precipitate was washed several times with water 
in a blender and isolated by filtration. It was dried overnight over 
phosphorus pentoxide at 80.degree. C./1.0 mm Hg to yield 39.5 g of light 
brown solid, mp 145.degree.-162.degree. C. The crude product was 
recrystallized from toluene to give 17.5 g of golden crystals, mp 
174.degree.-179.degree. C. Subsequent recrystallization from ethyl acetate 
gave 14.6 g (44% yield) of 2,5-bis(phenylethynyl)terephthalaldehyde, mp 
179.degree.-181.degree. C. 
Anal. Calc'd for C.sub.24 H.sub.14 O.sub.2 : C, 86.21; H, 4.22; MW, 334. 
Found: C, 86.42; H, 4.42; MW 334 (mass spectrum). 
2,5-Bis(phenylethynyl)terephthalaldehyde (5.01 g, 0.015 mole) was stirred 
under nitrogen in 300 ml of redistilled acetone at 0.degree. C. Then a 
chromium trioxide/sulfuric acid solution (11.25 ml containing 3.0 g, 0.030 
mole of chromium trioxide) was pipetted into the yellow slurry which was 
then stirred for four hours at 0.degree. C. An additional 1.88 ml of 
chromium trioxide/sulfuric acid solution was then added and the reaction 
was allowed to proceed at 0.degree. C. for an additional two hours. The 
resultant slurry was poured into 600 ml of ice water and the yellow 
precipitate was isolated by filtration. After being washed well on the 
frit with water, the yellow solid was allowed to dry on the frit. Drying 
for one hour at 50.degree. C./1.0 mm Hg over phosphorus pentoxide afforded 
5.40 g (98% yield) of 2,5-bis(phenylethynyl)terephthalic acid, 
mp&gt;360.degree. C. with slight shrinking at 260.degree.-270.degree. C. 
2,5-Bis(phenylethynyl)terephthalic acid (5.40 g, 0.015 mole) was stirred at 
room temperature in 320 ml of thionyl chloride (distilled from boiled 
linseed oil). Several drops of N,N-dimethylformamide were added to the 
yellow slurry which was stirred overnight at room temperature. The small 
amount of insolubles which remained then went into solution after ten 
minutes at reflux. The excess thionyl chloride was stripped off at reflux 
to give an orange solid which was recrystallized from heptane to give 2.4 
g (40% yield) of 2,5-bis(phenylethynyl)terephthaloyl chloride, mp 
174.degree.-180.degree. C. 
EXAMPLE V 
Polycondensation of Tolane-2,4'-dicarbonyl Chloride with 
4,4'-(m-Phenylenedioxy)dianiline) 
4,4'-(m-Phenylenedioxy)dianiline (0.6724 g, 0.0023 mole) was dissolved in 5 
ml of N-methyl-2-pyrolidone (distilled from calcium hydride) and the 
resultant water-white solution was cooled to 0.degree. C. 
Tolane-2,4'-dicarbonyl chloride (0.6972 g, 0.0023 mole) followed by eight 
ml of N-methyl-2-pyrolidone was added to the vigorously stirred solution. 
The resultant pale green solution was stirred at 0.degree. C. for an hour 
and at room temperature for 36 hours. The polymer was precipitated from 
methanol and was washed several times with methanol in a continuous 
extraction appartus for 36 hours. Drying at 58.degree. C./0.10 mm Hg for 
16 hours gave 1.0 g (83% yield) of cream colored polymer: .eta..sub.inh 
=0.31 dl/g (N,N-dimethylacetamide, 25.degree. C., 0.2 g/dl). 
Anal. Calc'd for (C.sub.34 H.sub.22 N.sub.2 O.sub.4).sub.n : C, 78.15; H, 
4.24; N, 5.36. Found: C, 76.87, H, 4.23; N, 5.40. 
EXAMPLE VI 
Polycondensation of 2,5-Bis(phenylethynyl)terephthaloyl Chloride with 
4,4'-(m-phenylenedioxy)dianiline) 
4,4'-(m-phenylenedioxy)dianiline (0.5847 g, 0.0020 mole) was dissolved in 
10 ml of N,N-dimethylacetamide (distilled from calcium hydride). The 
resultant water white solution was cooled under nitrogen to 0.degree. C. 
2,5-Bis(phenylethynyl)terephthaloyl chloride (0.8065 g, 0.0020 mole) was 
added as a solid to the vigorously stirred solution over a five minute 
period. Three ml of N,N-dimethylacetamide were used to wash residual 
diacid chloride into the reaction flask. The resultant yellow slurry 
gradually became a clear pale green solution over the course of thirty 
minutes. After being stirred for three hours at 0.degree. C. and sixteen 
hours at room temperature, the slightly viscous solution was a pale yellow 
color. The polymer was isolated by precipitation from methanol and washed 
several times with methanol in a blender. Drying at 58.degree. C./0.10 mm 
Hg for eight hours and at 100.degree. C./0.10 mm Hg for four hours gave 
1.20 g (96% yield) of fluffy yellow polymer: .eta..sub.inh =0.51 dl/g 
(MeSO.sub.3 H, 25.degree. C., 0.2 g/dl). 
Anal. Calc'd for (C.sub.42 H.sub.38 N.sub.2 O.sub.4).sub.n : C, 81.01; H, 
4.21; N, 4.50. Found: C, 81.07; H, 4.24; N, 4.38. 
EXAMPLE VII 
Polycondensation of 2,5-Bis(phenylethynyl)terephthaloyl Chloride with 
4,4'-Oxydianiline 
4,4'-Oxydianiline (0.2880 g, 0.0014 mole) was dissolved in 5 ml of 
N-methyl-2-pyrollidone (distilled from calcium hydride) and the resultant 
water-white solution was cooled under nitrogen to 0.degree.-5.degree. C. 
2,5-Bis(phenylethynyl)terephthaloyl chloride (0.5800 g, 0.0014 mole) was 
added to the vigorously stirred solution with four ml of solvent being 
used to wash residual monomer into the reaction flask. The reaction 
temperature was maintained at 0.degree.-5.degree. C. for several hours and 
at room temperature for several days. The resultant clear yellow solution 
was added to 100 ml of methanol and the precipitated polymer was isolated 
by filtration. It was washed with methanol in a blender and extracted for 
several days with hot methanol in an extraction apparatus. Drying at 
100.degree. C./0.10 mm Hg for six hours yielded 0.68 g (92% yield) of pale 
yellow polymer: .eta..sub.inh =0.67 dl/g (MeSO.sub.3 H, 25.degree. C., 0.2 
g/dl). 
Anal. Calc'd for (C.sub.36 H.sub.34 N.sub.2 O.sub.3).sub.n : C, 81.34; H, 
4.17; N, 5.27. Found: C, 81.27; H, 4.14; N, 5.09. 
EXAMPLE VIII 
The glass transition temperatures of several polyamides prepared generally 
by the procedures given in Examples V-VII, using the monomers given in the 
Table, are set forth in the following Table. The glass transition 
temperature (second order transition temperature) was measured using a 
Differential Scanning Calorimeter (DuPont 990 Thermal Analyzer) at range 
25.degree.-450.degree. C. with a scan speed of 10.degree. C./min. In all 
cases there is a strong exotherm (T cycl) indicative of the intramolecular 
cyclization reaction of the polyamide to polyphthalimidine structure. 
Tg-final was recorded on a re-scan after the original scan was taken to 
450.degree. C. in air. 
TABLE 
__________________________________________________________________________ 
Poly- Inh. 
mer Monomer Visc. (a) 
Tg-init 
Tcycl Tg-final 
No. Acid Chloride 
Diamine dl/g (.degree.C.) 
Onset (.degree.C.) 
Peak (.degree.C.) 
(.degree.C.) 
__________________________________________________________________________ 
I Tolane-2,4'dicarbonyl 
4,4'Oxydianiline 
0.29 (b) 170 252 270 
chloride 
II Tolane-2-4'-dicarbonyl 
4,4-'(m-phenylene- 
0.31 182 190 242 220 
dicarbonyl chloride 
dioxy) dianiline 
III 2,5-bis(phenylethynyl) 
4,4'-Oxydianiline 
0.30 (b) 200 295 (c) 
terephthaloyl chloride 
IV 2,5-bis(phenylethynyl) 
4,4'-(m-phenylene- 
0.51 189 222 250 (c) 
terephthaloyl chloride 
dioxy) dianiline 
V 4,6-bis(phenylethynyl) 
4,4'-Oxydianiline 
0.20 (b) 185 250 (c) 
isophthaloyl chloride 295 
VI 4,6-bis(phenylethynyl) 
4,4'-(m-phenylene- 
0.26 174 195 255 (c) 
isophthaloyl chloride 
dioxy) dianiline 280 
__________________________________________________________________________ 
Notes: 
(a) Methane sulfonic acid, 0.2 g/dl, 25.degree. C. 
(b) Tginit obscured by Tcycl. 
(c) No Tgfinal observed after scanning to 450.degree. C. 
EXAMPLE IX 
The polymer listed as polymer no. IV in the preceding table was heated in 
an oven under nitrogen at 255.degree. C. for 16 hours. The resulting 
polyphthalimidine had a Tg-init of 278.degree. C. Differential scanning 
calorimetry and thermomechanical analysis revealed an exotherm at 
367.degree. C., indicating incomplete cyclization. Additionally, the IR 
spectrum exhibited bands indicative of the uncyclized polyamide structure 
as well as the polyphthalimidine structure. 
Various modifications may be made in the present invention without 
departing from the spirit of the invention or the scope of the appended 
claims.