Interfacial process for preparing polyaromatic esters

New, easily processable, polyaromatic esters were prepared from 2,2'-diiododiphenyl-4,4'-dicarbonyl dichloride, isophthaloyl chloride and/or terephthaloyl chloride in combination with 4,4'-isopropylidene diphenol, 4,4'-sulfonyldiphenol, or resorcinol by interfacial condensation. In these polymers, phenylacetylenyl groups can be easily introduced into the polymer chain by replacing the iodine. This process leads to soluble and curable polymers from which films can be prepared. After curing the polymers are insoluble and show excellent thermal and chemical resistance. The curing process increases the polymers' softening temperature about 20.degree. C.

BACKGROUND OF THE INVENTION 
This invention relates to a series of novel polymeric compounds and to a 
method for their preparation. In a more particular aspect, this invention 
concerns itself with novel polyaromatic esters curable by intramolecular 
cyclization. 
Polymeric materials with cyclic structures on either the chain backbone or 
side groups usually have good thermal stability and high heat resistance. 
These factors, however, contribute to the low solubility and high melting 
temperature characteristics exhibited by these polymers thus making their 
processability a problem. 
For example, it is known that polymers, such as polyphenylquinoxalines and 
aromatic polyether-keto-sulfones, which contain 2,2'-di(phenylethynyl) 
biphenyl units show increased chemical and heat stability after thermal 
curing. The curing process has been described as two adjacent 
phenylacetylenyl groups undergoing intramolecular cyclization to form 
9-phenyl benzanthracene units. The intramolecular cyclization of 
phenylethynyl groups present in the polymer contributes considerably to 
its rigidity and thermal stability. However, the poor processability of 
such materials constitutes a problem which limits their usefulness. The 
present invention, therefore, was directed toward a solution to that 
problem and the development of easily processable novel polyaromatic 
esters with good stability before curing and with improved thermal and 
chemical resistance after curing. As a consequence, it was found that 
novel polyaromatic esters could be developed which possessed the requisite 
stability before curing and improved thermal and chemical resistance after 
curing in order to overcome the processability problems associated with 
prior art polyesters. 
SUMMARY OF THE INVENTION 
The present invention concerns itself with novel polyaromatic esters which 
possess the thermal and chemical characterisitcs necessary to overcome the 
processability problems encountered heretofore in utilizing these type of 
materials for industrial applications. The novel polymers of this 
invention are synthesized by effecting a two-phase reaction between an 
acid chloride selected from the group consisting of 2,2'-diiododiphenyl 
-4,4'-dicarbonyl dichloride, isophthaloyl chloride and terephthaloyl 
chloride; and a diphenol selected from the group consisting of 
4,4'-isopropylidenediphenol, 4,4'-sulfonyldiphenol and resorcinol. 
Polyesters containing a desirable phenylethynyl group can then be 
synthesized by reacting the novel aromatic polyester with cuprous 
phenylacetylide in accordance with conventional procedures. 
Accordingly, the primary object of this invention is to provide novel 
polyaromatic esters that are easily processable. 
Another object of this invention is to provide novel aromatic ester 
polymers that are characterized by good stability before curing and 
improved thermal and chemical characteristics after curing. 
Still another object of this invention is to provide novel aromatic ester 
polymers that are curable by intramolecular cyclization. 
The above and still other objects and advantages of the present invention 
will become more readily apparent upon consideration of the following 
detailed description thereof. 
DESCRIPTION OF THE PREFERRED EMBODIMENT 
In accordance with this invention, it has been found that the above-defined 
objects can be accomplished by effecting a reaction between a mixture of 
an acid chloride and a dihydric phenol to produce polymers of high 
molecular weight and good solubility. The polymers are the polyesters of 
2,2'-diiododiphenyl -4,4'-dicarbonyl dichloride, terephthaloyl chloride 
and isophthaloyl chloride in combination with 4,4'-isopropylidenediphenol, 
4,4'-sulfonyldiphenol and resorcinol. They were synthesized by means of a 
two-phase polycondensation reaction. 
The monomeric materials utilized in the synthesis of the polyesters of this 
invention were prepared in the following manner. The 
2,2'-diiododiphenyl-4,4'-dicarbonyl dichloride monomer (I) was 
conventionally prepared at 88% yield from dimethyl 
diphenyl-4,4'-dicarboxylate. m.p. 118.degree.-119.degree. C. (lit. 
116.degree.-117.degree. C..sup.5). The isophthaloyl chloride monomer (II) 
was recrystallized four times from n-hexane, m.p. 42.degree.-43.degree. 
C., while the terephthaloyl chloride monomer (III) was recrystallized four 
times from n-hexane. m.p. 81.degree.-82.degree. C. The 
4,4'-isopropylidenediphenol monomer (IV) was recrystallized two times from 
toluene. m.p. 159.degree.-160.degree. C. The 4,4'-sulfonyldiphenol monomer 
(V) was recrystallized from benzene-ethanol mixture. m.p. 
249.degree.-250.degree. C. and the resorcinol monomer (VI) was 
recrystallized from toluene. m.p. 110.degree.-111.degree. C. 
The polymeric materials of this invention are synthesized by effecting a 
polycondensation reaction between an acid chloride selected from the group 
consisting of 2,2'-diiododiphenyl-4,4'-dicarbonyl dichloride, 
terephthaloyl chloride and isophthaloyl chloride; and a dihydric phenol 
selected from the group consisting of 4,4'-isopropylidenediphenol, 
4,4'-sulfonyldiphenol, and resorcinol. 
The reactions referred to above are further illustrated by the following 
reaction scheme A, B and C. 
##STR1## 
In reaction schemes A, B and C, the letters X, Y and Z are integers 
representing the moles of each of the reaction constituents such that the 
moles of X+Z are equal to Y and X+Y+Z represent the moles of NaCl pulled 
out. 
The general preparation of the aromatic polyesters of this invention is 
further illustrated by the following example. Although this example is 
limited to specific reaction constituents; namely, those disclosed in 
scheme C, it should be understood that the use of the reaction 
constituents of schemes A and B can be substituted for those shown in the 
example.

EXAMPLE I 
A solution of 0.02 mole bisphenol A (or bisphenol S, or resorcinol) and 1.6 
g (0.04 mole) sodium hydroxide in 150 ml. water is prepared in a household 
blender at very low speed, stirring. The sodium hydroxide should be added 
as a standardized carbonate-free solution since this will give a more 
accurate titre of alkali than weighing out pellets. A second solution of 
0.02 mole acid chloride (2,2'-diiododiphenyl-4,4'-dicarbonyl dichloride, 
terephthaloyl chloride and/or isophthaloyl chloride) in 75 ml. chloroform 
(dry, alcohol free) is prepared in a 150 ml beaker. To the solution in the 
blender is now added 15 ml of a 10% aqueous solution of sodium lauryl 
sulfate and the blender is turned to a maximum speed. The chloroform 
solution of the acid chlorides is added immediately and as rapid as 
possible to the well-stirred aqueous solution. The emulsion so formed is 
stirred for 5 minutes and the blender is stopped. The emulsion mixture is 
poured into 1.5 l. of acetone to coagulate the polymer and extract the 
solvents. The polymer is filtered and washed once on the filter with 
acetone. The granular polymer is transferred back to the blender jar and 
washed in 500 ml of water to remove the salt and dispersing agent. The 
solid polymer is filtered again and washed on the filter with water. The 
water washing step is repeated twice more and the polymer is given a final 
wash with acetone. The polymer is dried in a vacuum oven at 100.degree. C. 
overnight. Elemental analyses of the polymer of this example as well as 
the other polymers illustrated in schemes A and B are shown in Table I. 
Table II which follows discloses the solubility and viscosity of the 
polymers of this invention. 
It can be observed that the 1,1,2,2-tetrachloroethane is the only good 
solvent. Also the polymers with the higher amount of terephthaloyl 
chloride give the higher molecular weight, and the polymers with sulfonyl 
groups result in better solubility. However, the polymer containing 
resorcinol is insoluble. 
Once polymers are made having high viscosities and good solubilities, 
further reactions can be carried out. As was stated heretofore, the 
presence of a phenylethynyl group in the polymer chain contributes 
considerably to the polymer's rigidity and thermal stability after thermal 
curing of the polymer. 
TABLE I 
__________________________________________________________________________ 
Elementary Analysis Results of Polymers Prepared from 2,2'-Diiododiphenyl- 
4,4'-Dicarbonyl Dichloride (I), Isophthaloyl Chloride (II), 
Terephthaloyl 
Chloride (III), 4,4'-Isopropylidenediphenol (IV), 4,4'-Sulfonyldiphenol 
(V), 
and Resorcinol (VI). 
Acid Chloride Diol Analysis 
(moles) (moles) Calcd. (%) 
Found (%) 
Polymer 
I II III IV V VI C H S C H S 
__________________________________________________________________________ 
P-I 0.001 
0.0095 
0.0095 
0.02 
-- -- 74.67 
4.87 74.90 
4.92 
P-II 0.001 
-- 0.019 
0.02 
-- -- 74.67 
4.87 75.36 
4.90 
P-III 
0.001 
0.019 
-- 0.02 
-- -- 74.67 
4.87 76.05 
4.91 
P-IV 0.001 
-- 0.019 
-- 0.02 
-- 61.45 
3.07 
8.08 
60.88 
3.03 
8.16 
P-V 0.001 
0.019 
-- -- 0.02 
-- 61.45 
3.07 
8.08 
61.21 
3.05 
8.15 
P-VI 0.001 
0.0095 
0.0095 
-- 0.02 
-- 61.45 
3.07 
8.08 
61.47 
3.05 
7.90 
P-VII 
0.001 
-- 0.019 
-- -- 0.02 
66.93 
3.29 68.21 
3.20 
P-VIII 
0.001 
0.019 
-- -- -- 0.02 
66.93 
3.29 68.92 
3.24 
P-IX 0.001 
0.0095 
0.0095 
-- -- 0.02 
66.93 
3.29 68.68 
3.24 
__________________________________________________________________________ 
TABLE II 
__________________________________________________________________________ 
Acid Chloride Diol inh 
(moles) (moles) at 30.degree. C. 
Polymer 
I II III IV V VI DMF.sup.a 
Pyridine 
H SO 
TCE.sup.b 
in TCE 
__________________________________________________________________________ 
P-I 0.001 
0.0095 
0.0095 
0.02 
-- -- 6.sup.c 
6 6 S.sup.d 
0.62 
PII 0.001 
-- 0.019 
0.02 
-- -- 6 6 6 S 0.79 
P-III 
0.001 
0.019 
-- 0.02 
-- -- 6 6 6 S 0.58 
P-IV 0.001 
-- 0.019 
-- 0.02 
-- SW.sup.e 
S SW S 0.63 
P-V 0.001 
0.019 
-- -- 0.02 
-- SW S SW S 0.52 
P-VI 0.001 
0.0095 
0.0095 
-- 0.02 
-- SW S SW S 0.59 
P-VII 
0.001 
-- 0.019 
-- -- 0.02 
i.sup.f 
i i i -- 
P-VIII 
0.001 
0.019 
-- -- -- 0.02 
i i i i -- 
P-IX 0.001 
0.0095 
0.0095 
-- -- 0.02 
i i i i -- 
__________________________________________________________________________ 
.sup.a DMF = N,N--dimethylformamide 
.sup.b TCE = 1,1,2,2tetrachloroethane 
.sup.c 6 = slightly soluble 
.sup.d S = soluble 
.sup.e SW = swollen 
.sup.f i = insoluble 
It is also known that phenylethynyl containing polymers, such as 
2,2'-di(phenylethynyl)biphenyl, upon heating, undergo intramolecular 
cyclization to form 9-phenyl dibenzanthracene derivatives. Unfortunately, 
considerable difficulty is encountered in attempting to introduce 
phenylethynyl groups within or on the polymeric chain in order to take 
advantage of the beneficial effects obtained by using the phenylethynyl 
group. With the present invention, however, it was found that the 
synthesis of the novel aromatic polyesters provided the means for 
introducing a phenylethynyl group to the polymer chain. This is 
accomplished by replacing the iodo groups of the polymer of this invention 
with a phenylethynyl group using copper phenyl acetylide. The resulting 
polymers, after thermal cure, show increased heat and chemical stability 
and are insoluble. 
The preparation of the polymers containing a phenylacetyleneyl group is 
illustrated by Example II. 
EXAMPLE II 
One gram of the diiodo polymer of Example I was dissolved in 100 ml of 
pyridine. A little excess of cuprous phenylacetylide was added to the 
polymer solution while the mixture was refluxing under deoxygenated 
nitrogen. The reaction mixture was refluxed in a nitrogen atmosphere for 
48 hours. After the reaction, the mixture was cooled to room temperature 
and poured into 400 ml conc. hydrochloric acid (with ice). The solid was 
filtered and washed with a large amount of water, then was dried and was 
dissolved in 20 ml of 1,1,2,2-tetrachloroethane. The polymer was 
reprecipitated by large amounts of methanol. The final product was dried 
in vacuum at 90.degree. C. overnight. 
The cuprous phenylacetylide was conventionally prepared by treating an 
ammonical solution of cuprous chloride with an alcoholic solution of 
phenylacetylene. 
A thin film was prepared from the phenylethynyl containing polymers using a 
solution of 1 g polymer in 15 ml of 1,1,2,2-tetrachloroethane. This 
solution was cast on a glass plate at 110.degree. C. to remove the 
solvent. After releasing, the brown, semi-transparent film was dried in 
vacuum. Curing was carried out by putting the phenylethynyl containing 
polymer in nitrogen atmosphere at 270.degree. C. for 30 hours. 
The polyaromatic esters of this invention were tested by heating them in an 
air circulated oven at 300.degree. C. for three days. The weight loss was 
determined by weighing the sample before and after the heat treatment and 
after cooling to room temperature in a dessicator. 
The softening temperature of the polymer was measured by Vicat-type 
apparatus under a load on the sample of 44.9 psi with a heating rate of 
1.degree. C./min. 
The polymers prepared in accordance with this invention were also studied 
for their thermal stabilities by oxidative isothermal aging. Table III 
shows the weight losses of various polyesters after isothermal aging at 
300.degree. C. for three days. 
Table III also lists softening temperatures of polymers under a load on the 
sample of 44.9 psi. Iodine-containing polymers have softening temperatures 
around 185.degree. C. with only a slight variation in polymer 
compositions. 
Polymer P-X and P-XI are polymers P-I and P-III, respectively, with iodine 
replaced by the phenylacetylene group. These polymers show a relatively 
lower softening temperature of 170.degree. C. and 160.degree. C., possibly 
because of the bulky effect of the phenylacetylenyl groups. After curing, 
the softening temperature of polymers P-X and P-XI increased to 
190.degree. C. and 181.degree. C., respectively. 
TABLE III 
______________________________________ 
THERMAL AND HEAT STABILITIES OF POLYMERS 
Weight Loss Softening point 
wt at 300.degree. for 3 days 
.degree.C. 
Before After Before After 
Polymer Curing Curing Curing Curing 
______________________________________ 
P-I 8.1 -- 190-195 
-- 
P-II 10.9 -- 195-200 
-- 
P-III 11.2 -- 192-197 
-- 
P-IV 10.1 -- 185-190 
-- 
P-V 10.6 -- 180-195 
-- 
P-VI 11.2 -- 183-188 
-- 
P-VII 7.4 -- 200-205 
-- 
P-VIII 6.5 -- 185-190 
-- 
P-IX 7.9 -- 190-195 
-- 
P-X* 5.7 2.3 170 190 
P-XI* 4.8 2.1 160 181 
______________________________________ 
*Polymers with phenylacetylenyl groups. 
It should be understood by those skilled in the art to which the present 
invention pertains that while the process and novel polymers described 
herein illustrate preferred embodiments of the invention, various 
modifications and alterations may be made without departing from the 
spirit and scope thereof, and that all such modifications as fall within 
the scope of the appended claims are intended to be included herein.