Novel copoly(arylene ether ketones) having a biphenylene-4,4'-dicarbonyl group in their backbone, comprising PA1 (A) a repeat unit ##STR1## and (B) a repeat unit selected from the group consisting of ##STR2## where R, which is the same in each of repeat units (A) and (B), is a direct bond, ##STR3## the molar ratio of repeat units (A) to repeat units (B) being between about 10:90 and about 70:30.

BACKGROUND OF THE INVENTION 
This invention relates to novel copoly(arylene ether ketone) having a 
biphenylene-4,4'-dicarbonyl group in their backbone and to methods for 
their preparation. 
Poly(arylene ether ketones) possess many desirable properties, for example, 
high temperature stability, mechanical strength, and resistance towards 
common solvents. They are thermoplastics, facilitating their melt 
fabrication into articles of diverse sizes and shapes. Many are 
crystalline and retain substantial mechanical properties up to or about 
their melting temperatures (Tm), which typically are above 300.degree. C. 
While a high Tm is desirable for this reason, too high a Tm is undesirable, 
because a crystalline poly(arylene ether ketone) must be melt processed at 
a temperature substantially above its melting point--commonly at least 
30.degree. C. above. However, poly(arylene ether ketones) begin 
decomposing more or less rapidly at about or above 400.degree. C., so that 
a poly(arylene ether ketone) having a Tm in the near 400.degree. C. would 
be difficult to melt process without decomposition. For instance, Berr, in 
U.S. Pat. No. 3,516,966, reports that the polymer from diphenyl ether and 
terephthaloyl chloride (Tm 385.degree. C.) cannot be practicably 
melt-processed because it requires an extrusion temperature of 420.degree. 
C. or higher, but decomposes at temperatures in excess of 400.degree. C. 
Further, conventional melt processing equipment is frequently not designed 
for operation at temperatures above 400.degree. C., making specially 
designed equipment necessary. In view of these considerations, it is 
desirable for a poly(arylene ether ketone) to have a Tm below about 
370.degree. C. 
The high-temperature mechanical properties of a poly(arylene ether ketone) 
are also influenced by its glass transition temperature, or Tg, There is a 
significant loss in mechanical properties at about or above the Tg, even 
though for crystalline poly(arylene ether ketones) substantial mechanical 
properties may still be retained up to the Tm. For a many applications, 
substantial retention of room temperature properties at 150.degree. C. or 
above is a requirement. Because of the phenonmenon known as densification 
embrittlement, in which a polymer densifies and embrittles at about its 
Tg, merely having a Tg at or about 150.degree. C. is insufficient. To 
avoid densification embrittlement, the Tg should be be significantly above 
150.degree. C., preferably about 165.degree. C. or above. Combining the 
above factors, a poly(arylene ether ketone) having a Tg about or above 
165.degree. C. and a Tm about or below 370.degree. C. is highly desirable. 
The characteristics of a poly(arylene ether ketone)--Tg, crystallinity, Tm, 
chemical resistance, etc.--depend on a number of parameters: the 
ether-to-ketone ratio, the sequencing of subunits, linearity, the presence 
of meta-substituted and/or non-phenylene arylene groups, and the like. 
Poly(arylene ether ketones) representing various combinations of these 
parameters are known. See, for example, Marks, in U.S. Pat. No. 3,441,538; 
Rose et al., in U.S. Pat. No. 4,320,224; Dahl, in U.S. Pat. Nos. 3,953,400 
and 4,111,908; and Dahl et al., in U.S. Pat. No. 3,956,240. This is a 
continuing search for new polymers of this class having particularly 
advantageous properties for a desired end use. 
Berr, cited supra, illustrates prior art attempts to tailor the Tm of a 
poly(arylene ether ketone) by altering its molecular composition and the 
fact that often such manipulations represent trade-offs in which a gain in 
one property is at the expense of a loss in another property. Noting that 
the poly(arylene ether ketone) 
##STR4## 
was not melt-processable because of its high Tm, he partially replaced one 
monomer (terephthaloyl chloride) with another (isophthaloyl chloride). He 
was able to obtain a melt-processable copoly(arylene ether ketone) having 
the repeat units 
##STR5## 
But the meta-phenylene group reduced the crystallinity of the copolymer, 
so that copolymers having more than 30 mole % isophthaloyl 
chloride-derived repeat units crystallized only with difficulty. These 
results illustrate the negative effects of disruptions in the regularity 
of the polymer backbone. Also, the meta-phenylene group is generally not 
as thermally and/or chemically stable as para-phenylene, so that mixed 
para-/meta-copolymers are less stable than their all-para counterparts. 
Staniland, in published European application EP No. 184,458,A2, illustrates 
another attempt to modify the Tm and/or the Tg of a poly(arylene ether 
ketone) by copolymerization. He noted that while the poly(arylene ether 
ketone) 
##STR6## 
has a Tg of 143.degree. C. and a Tm of 334.degree. C., he was able to 
lower its Tm by preparing a copolymer in which the second repeat unit 
##STR7## 
was introduced. For example, the copolymer combining these two repeat 
units exhibits a minimum in the Tm at about 20 mole % of the second repeat 
unit (309.degree. C.). Thus, the second repeat unit (whose homopolymer has 
a Tg of 167.degree. C. and a Tm of 416.degree. C.) has the effect of 
lowering the Tm. However, the Tg of Staniland's copolymers remains below 
or about 150.degree. C. and does not rise significantly above this value 
until the mole % of the second repeat unit is very high, by which time the 
Tm has also risen to an undesirably high value. 
Staniland's copolymer has an ether-to-ketone ratio of 2:1. It has generally 
been observed that poly(arylene ether ketones) having lower either to 
ketone ratios, e.g. 1.5:1 or lower, have higher Tg's and are more 
chemically resistant. Since Staniland's Tm lowering repeat unit has an 
ether-to-ketone ratio of 2:1, insertion of such a repeat unit into a 
poly(arylene ether ketone) having an ether-to-ketone ratio of 1.5:1 or 
lower, would undesirably raise the ether-to-ketone ratio and lower its Tg. 
Further, it is known that in poly(arylene ether ketones) a phenylene group 
flankes by two ether groups is chemically reactive under certain 
conditions, for example being readily sulfonated, because the electron 
denoating (activating) effect of the two ether groups is not counteracted 
by an electron withdrawing groups. Since in a biphenylene group flanked by 
two ether oxygens the same considerations apply, it is unattractive for 
incorporation into copoly(arylene ether ketones) for applications 
requiring superior chemical resistance. 
This invention provides copoly(arylene ether ketones) having an 
ether-to-ketone rato of about 1.5:1 or below and Tg's significantly above 
150.degree. C. 
SUMMARY OF THE INVENTION 
This invention provides a copoly(arylene ether ketone) comprising 
(A) a repeat unit 
##STR8## 
and (B) a repeat unit selected from the group consisting of 
##STR9## 
where R, which is the same in each of repeat units (A) and (B), is a 
direct bond, 
##STR10## 
the molar ratio of repeat units (A) to repeat units (B) being between 
about 10:90 and about 70:30. 
The molar ratio of repeat units (A) to repeat units (B) is more preferably 
between about 10:90 and about 50:50, and most preferably between about 
20:80 and about 40:60. 
This invention also provides a method of making a copoly(arylene ether 
ketone), comprising polymerizing, in the presence of a Lewis acid 
catalyst, a monomer system comprising: 
(a) a first comonomer 
##STR11## 
(b) a second comonomer selected from the group consisting of 
##STR12## 
and (c) a third comonomer selected from the group consisting of diphenyl 
ether, 4,4'-diphenoxybenzophenone, and 1,4-diphenoxybenzene; 
X being a group displaceable under Friedel-Crafts polymerization 
conditions; the combined molar amounts of the first and second comonomers 
(a) and (b) being substantially equal to the molar amount of the third 
comonomer (c); and the molar ratio of first comonomer (a) to second 
comonomer (b) being between about 10:90 and about 70:30.

DETAILED DESCRIPTION OF THE INVENTION 
This invention provides copoly(arylene ether ketones) having 
biphenylene-4,4'-dicarbonyl groups, in particular copolymers having 
biphenylene-4,4'-dicarbonyl-containing repeat units interspersed with 
repeat units having no such groups. 
While poly(arylene ether ketones) in which the arylene groups are all 
para-phenylene are crystaline, their replacement with other aromatic 
moieties, for example meta-phenylene groups or aliphatic groups, may cause 
a reduction in or loss of crystallinity. 
We have discovered that, in a preferred copolymer of our invention, wherein 
the repeat unit (A) is 
##STR13## 
and the repeat unit (B) is 
##STR14## 
(hereinafter designated copolymer I), the introduction of 
biphenylene-4,4'-dicarbonyl groups does not substantially negatively 
affect crystallinity. Rather, the copolymer is highly crystalline. 
Furthermore, the glass transition temperature Tg unexpectedly remains 
substantially constant and high over a broad compositional range and yet, 
at the same time, the crystalline melting temperature Tm, instead of 
either remaining constant or trending monotonically while composition 
varies from one extreme to the other, shows a minimum at which the Tm is 
lower than that of a homopolymer composed exclusively of either repeat 
unit (A) or (B) alone. FIG. 1 shows how the Tg and Tm of this copolymer 
vary in going from 0 to 100 mole % repeat unit (A). The Tg of the 
copolymer remains desirably at about or above 165.degree. C., while its Tm 
drops to a minimum of about 349.degree. C. at about 30 mole % repeat unit 
(A). 
Another preferred copolymer of our invention, wherein the repeat unit (A) 
is 
##STR15## 
and the repeat unit (B) is 
##STR16## 
(hereinafter designated copolymer II), also shows the desirable 
characteristics of a minimum in Tm as its repeat unit (A) content is 
varied from 0 to 100 mole % while at the same time retaining a high Tg. 
To illustrate the unexpectedness and uniqueness of copoly- or poly(arylene 
ether ketones) having these desirable features of copolymers I and II, 
Table I compares the Tg's and Tm's these two copolymers and some prior art 
poly(arylene ether ketones). The prior art poly(arylene ether ketones) 
either have a Tg below 165.degree. C. or a Tm above 370.degree. C., or 
both. In contrast, at 30 mole % repeat unit (A), copolymer I has a Tg of 
172.degree. C. and a Tm of 349.degree. C., and at 25 mole % repeat unit 
(A), copolymer II has a Tg of 167.degree. C. and a Tm of 314.degree. C. 
TABLE I 
______________________________________ 
Poly = (arylene ether ketone) 
Tg (.degree.C.) 
Tm (.degree.C.) 
______________________________________ 
--CO--Ph--O--Ph-- (1,2) 
163 361 
--CO--Ph--O--Ph--O--Ph-- (3) 
144 335 
--CO--Ph--Ph--O--Ph--O--Ph-- (3) 
167 416 
--CO--Ph--CO--Ph--O--Ph--O--Ph-- (3) 
154 358 
--CO--Ph--CO--Ph--O--Ph-- (4) 
185 385 
I (30 mole % repeat unit (A)) 
172 349 
II (25 mole % repeat unit (A)) 
167 314 
______________________________________ 
(1) Ph designates pphenylene 
(2) Marks, U.S. Pat. No. 3,441,538 (1969) 
(3) Attwood et al., Polymer 22, 1096 (1981) 
(4) Sterzel, DE 3,241,444 (1983) 
The copolymers of our invention are conveniently prepared by Friedel-Crafts 
or electrophilic polymerization, in which during the polymerization step 
an carboxylic acid halide reacts with an aromatic group having a hydrogen 
activated to Friedel-Crafts reaction to form an aryl ketone group, in the 
presence of a Lewis acid catalyst. A preferred monomer system for 
Friedel-Crafts polymerization comprises: 
(a) a first comonomer 
##STR17## 
(b) a second comonomer selected from the group consisting of 
##STR18## 
and (c) a third comonomer selected from the group consisting of diphenyl 
ether, 4,4'-diphenoxybenzophenone, and 1,4-diphenoxybenzene. 
X is a group displaceable under Friedel-Crafts polymerization conditions 
and is preferably halide, especially chloride, or OR', where R' is lower 
alkyl, for example isopropyl, ethyl, or methyl. A preferred first monomer 
is [1,1'-biphenyl]-4,4'-dicarbonyl dichloride and preferred second 
monomers are terephthaloyl chloride and isophthaloyl chloride. 
The combined molar amounts of the first and second comonomers (a) and (b) 
should be substantially equal to the molar of the third comonomer (c), to 
ensure attainment of high molecular weights. A slight stoichiometric 
imbalance in the comonomers can be employed, for the purpose of molecular 
weight control or capping, as is well known in the art and is discussed in 
more detail hereinbelow. For example, the combined amounts of comonomers 
(a) and (b) can b in slight excess over the amount of comonomer (c), or 
vice-versa. 
The molar ratio of the first comonomer (a) to the second comonomer (b) can 
vary from 10:90 to 70:30, is preferably between about 10:90 and about 
50:50, and is most preferably between about 20:80 and about 40:60. 
In addition to comonomers (a), (b), and (c), small amounts of other 
comonomers may be utilized, provided they are in amounts so as to not 
affect the essential character of the copolymers of this invention and 
stoichiometric adjustments, if necessary, are made for their presence, so 
as not to prevent high molecular weights. Examples of suitable additional 
monomers include 4,4'-diphenoxydiphenyl sulfone, 
naphthalene-1,4-dicarbonyl dichloride, naphthalene-2,6-dicarbonyl 
dichloride, naphthalene-3,6-dicarbonyl dichloride, p-phenoxybenzoyl 
chloride, and the like. 
The term "Lewis acid" is used herein to refer to a substance which can 
accept an unshared electron pair from another molecule. Lewis acids which 
may be used in the practice of this invention include, for example, 
aluminum trichloride, aluminum tribromide, antimony pentachloride, 
antimony pentafluoride, indium trichloride, gallium trichloride, boron 
trichloride, boron trifluoride, zinc chloride, ferric chloride, stannic 
chloride, titanium tetrachloride, and molybdenum pentachloride. A 
preferred Lewis acid is aluminum trichloride. 
A preferred Friedel-Crafts process for the preparation of the polymers of 
this invention comprises using hydrogen fluoride and boron trifluoride as 
the reaction medium. This process is described by Dahl in U.S. Pat. Nos. 
3,953,400 and 4,247,682 and and by Dahl et al. in U.S. Pat. No. 3,956,240, 
the disclosures of which are incorporated herein by reference. 
A most preferred Friedel-Crafts process for preparing the polymers of this 
invention is described by Jansons et al. in published PCT application No. 
WO 84/03891, the disclosure of which is incorporated herein by reference. 
This application discloses a method of moderating or controlling 
Friedel-Crafts polymerizations by the addition of a Lewis base which acts 
as a controlling agent or by using specified excesses of the Lewis acid. 
Preferred Lewis bases include diphenyl sulfone, dimethyl sulfone, 
N-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide, 
1-methyl-2-pyrrolidone, tetramethylene sulfone (also known as sulfolane), 
n-butyronitrile, dimethyl sulfide, imidazole, acetone, benzophenone, 
trimethylamine, trimethylamine hydrochloride, tetramethylammonium 
chloride, pyridine-N-oxide, 1-ethylpyridinium chloride, lithium chloride, 
lithium bromide, sodium chloride, potassium chloride potassium bromide, 
and mixtures thereof. Particularly preferred Lewis bases are lithium 
chloride, N,N-dimethylformamide, and dimethyl sulfone. 
The amount of Lewis base present should be from 0 to about 4 equivalents 
per equivalent of acid halide groups present in the monomer system. 
Amounts greater than 4 equivalents could be employed, if desired. However, 
no additional controlling effect is usually achieved by adding larger 
amounts. thus, it is preferred to use no more than about 4 equivalents and 
generally no more than about 2 equivalents. When a Lewis base is added to 
control the reaction, at least about 0.01, preferably at least about 0.05 
and most preferably at least about 0.5 equivalents of Lewis base per 
equivalent of acid halide groups present should be used. 
The temperatures at which the reaction is conducted is not critical and can 
be from about -70.degree. C. to about +150.degree. C., or even higher. It 
is preferred to start the reaction at lower temperatures, for example at 
-50.degree. to about -10.degree. C., particularly if the monomer system 
contains highly reactive monomers. After polymerization has commenced, the 
temperature can be raised if desired, for example, to increase the rate of 
reaction. It is generally preferred to carry out the reaction at 
temperatures in the range of between -30.degree. and +25.degree. C. (room 
temperature). 
The reaction may also be moderated by use of an appropriate excess of Lewis 
acid. In general, the amount of Lewis acid is used in amount of at least 
one equivalent per equivalent of carbonyl and other basic groups present 
in the reaction mixture, plus an amount effective to act as a catalyst. In 
preparing the copolymers of this invention the catalytically effective 
amount should be between about 0.003 and about 0.5 equivalent per 
equivalent of acid halide groups. 
The polymerization may be carried out in the presence of a non-protic--also 
known as aprotic--diluent. Preferred non-protic diluents include methylene 
chloride, carbon disulfide, o-dichlorobenzene, 1,2,4-trichlorobenzene, 
o-difluorobenzene, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, and the 
like. 
The polymers of this invention are preferably high molecular weight 
polymers. By "high molecular weight," it is meant a polymer having an 
inherent viscosity greater than about 0.6 dL/g. Preferably the polymer has 
an inherent viscosity in the range of about 0.6 to about 2.0 dL/g. 
Polymers having an inherent viscosity below about 0.6 are generally not 
useful because they have poor mechanical properties, such as low tensile 
strength and elongation, while polymers having an inherent viscosity above 
about 2.0 are very difficult to melt process. Throughout this application, 
inherent viscosity refers to the mean inherent viscosity determined 
according to the method of Sorenson et al., "Preparative Methods of 
Polymer Chemistry", 2nd ed. (Interscience 1968), at page 44 (0.1 g polymer 
dissolved in 100 mL of concentrated sulfuric acid at 25.degree. C.). 
If desired, the molecular weight of the polymer, the degree of branching, 
and the amount of gelation can be controlled by use of, for example, 
capping agents as described by Dahl in U.S. Pat. No. 4,247,682, the 
disclosure of which is incorporated herein by reference. The molecular 
weight of the polymer can also be controlled by employing a slight excess 
of one of the monomers. 
Capping agents, when employed, are added to the polymerization reaction 
medium to cap the polymer on at least one end of the polymer chain. This 
terminates continued growth of the chain and controls the resulting 
molecular weight of the polymer, as shown by the inherent viscosity of the 
polymer. Judicious use of the capping agents results in a polymer within a 
selected narrow molecular weight range, decreased gel formation during 
polymerization, and decreased branching of the polymer chains and 
increases melt stability. Both nucleophilic and electrophilic capping 
agents can be used to cap the polymer at each end of the chain. 
Preferred nucleophilic capping agents are 4-chlorobiphenyl, 
4-phenoxybenzophenone, 4-(p-phenoxyphenoxy)benzophenone, biphenyl, 
4-benzenesulfonylphenyl phenyl ether, and the like. 
Typical electrophilic capping agents are compounds of the formula 
EQU Ar--CO--E or Ar--SO.sub.2 --E 
wherein Ar is phenyl, 3-chlorophenyl, 4-chlorophenyl, 4-cyanophenyl, 
4-methylphenyl, naphthyl, biphenyl, or an aromatic group substituted with 
an electron withdrawing substituent and E is halogen or other leaving 
group, preferably chloride. Preferred electrophilic capping agents include 
benzoyl chloride, benzenesulfonyl chloride, and the like. 
Because of a Lewis acid is used, the resulting polymer contains Lewis acid 
complexed to its carbonyl groups. For many polymerizations, the Lewis acid 
is complexed to substantially all the carbonyl groups in the polymer. As 
is well known with polymers of this type, the catalyst residue must be 
removed, i.e., the Lewis acid must be decomplexed from the polymer and 
removed. A method for removing the catalyst residue is described by Dahl 
in U.S. Pat. No. 4,237,884, the disclosure of which is incorporated herein 
by reference. 
Decomplexation may be accomplished by treating the polymerization reaction 
mixture with a decomplexing base after completion of polymerization. The 
base may be added to the reaction medium or the reaction medium can be 
added to the base. The decomplexing base must be at least as basic towards 
the Lewis acid as the basic groups on the polymer chain. Such 
decomplexation should be effected before the isolation of the polymer from 
the reaction mixture. 
The amount of decomplexing base used should be in excess of the total 
amount of bound (complexed) and unbound Lewis acid present in the reaction 
mixture and is preferably twice the total amount of Lewis acid. Typical 
decomplexing bases which can be used include water, dilute aqueous 
hydrochloric acid, methanol, ethanol, acetone, N,N-dimethylformamide, 
N,N-dimethylacetamide, pyridine, dimethyl ether, diethyl ether, 
tetrahydrofuran, trimethylamine, trimethylamine hydrochloride, dimethyl 
sulfide, tetramethylene sulfone, benzophenone, tetramethylammonium 
chloride, isopropanol, and the like. The decomplexed polymer can then be 
recovered by conventional techniques such as separating the polymer by 
filtration; adding a nonsolvent for the polymer which is a solvent for or 
miscible with the Lewis acid/Lewis base complex and the Lewis acid; 
spraying the reaction medium into a nonsolvent for the polymer; or 
evaporating the volatiles from the reaction medium and then washing with 
an appropriate solvent to remove any remaining base/catalyst complex and 
diluent from the polymer. 
In the recovery of the polymer from the reaction mixture, the reaction 
mixture can be liquefied, if desired, by the method described by Reamey in 
U.S. Pat. No. 4,665,151, the disclosure of which is incorporated herein by 
reference. 
The copolymers of this invention may also be prepared by a nucleophilic 
polymerization process, i.e. a polymerization in which an aryl ether 
linkage is formed in the polymerization step. The nucleophilic 
polymerization techniques generally disclosed by Rose, U.S. Pat. No. 
4,320,224, and Attwood et al., Polymer 22, 1096 (1981), the disclosures of 
which are incorporated herein by reference, may be employed. 
For example, copolymer I of this invention may be prepared nucleophilically 
for polymerizing a mixture of 4,4'-bis(4-fluorobenzoyl)biphenyl and 
1,4-bis(4-fluorobenzoyl)benzene with a substantially stoichiometric amount 
of 4,4'-dihydroxybenzophenone. An alterative nucleophilic synthesis of the 
same polymer is the polymerization of a mixture of 
4,4'-bis(4-hydroxybenzoyl)biphenyl and 1,4-bis(4-hydroxybenzoyl)benzene 
with a substantially stoichiometric amount of 4,4'-difluorobenzophenone. 
Similarly, copolymer II of this invention may be prepared nucleophilically 
by the polymerization of a mixture of 4,4'-bis(fluorobenzoyl)biphenyl and 
1,4-bis(4-fluorobenzoyl)benzene with a substantially stoichiometric amount 
of hydroquinone. 
EXAMPLE 1 
A 500 mL round-bottom flask equipped with a reflux condenser, nitrogen 
inlet, and magnetic stirrer was charged with chlorobenzene (150 mL), 
thionyl chloride (44.1 mL, 0.605 mol), and N,N-dimethylformamide (1 mL). 
4,4'-Biphenyldicarboxylic (24.2 g, 0.102 mol) was added, with stirring The 
reaction mixture was heated at reflux for about 4 hrs, at the end of which 
period it was a bright orange homogeneous solution. Excess thionyl 
chloride was distilled off under reduced pressure (water aspirator). The 
warm residual solution was poured into a mixture of hexanes (300 mL), 
yielding a pale yellow precipitate. 
The product was isolated by filtration, washed with hexanes, and vacuum 
dried at 100.degree. C. overnight. Two sublimations (165.degree. C./0.05 
mm Hg) afforded polymerization grade [1,1'-biphenyl]-4,4'-dicarbonyl 
dichloride, mp 185.5.degree.-187.degree. C. 
EXAMPLE 2 
[1,1'-Biphenyl]-4,4'-dicarbonyl dichloride, terephthaloyl chloride, and 
4,4'-diphenoxybenzophenone were polymerized according to the following 
general procedure, with the exact amount of monomers and capping agent 
provided in Table II, below. 
A 100 mL resin kettle, fitted with a mechanical stirrer and a nitrogen 
inlet, was charged with methylene chloride (20 mL). The temperature was 
lowered to -30.degree. C. Aluminum trichloride (136.6 to 136.8 mmol, 
depending on the exact run) and dimethyl sulfone (37.5 mmol) was added, 
and the contents of the kettle were stirred at a moderate rate. When the 
exotherm had subsided, the [1,1'-biphenyl]-4,4'-dicarbonyl dichloride and 
terephthaloyl chloride were quantitatively transferred to the kettle, with 
a methylene chloride (8 mL) rinse to ensure quantitative transfer. The 
resulting slurry was stirred for a few minutes. Next, 
4,4'-diphenoxybenzophenone (slight stoichiometric excess) and benzoyl 
chloride were added, with a methylene chloride (4 mL) rinse. The benzoyl 
chloride, along with the stoichiometric excess of 
4,4'-diphenoxybenzophenone served to double cap the polymer. 
The reaction was allowed to warm to ambient temperature (ca. 20.degree. C.) 
where it quickly became a homogeneous orange/red solution. The solution 
was stirred for about 40 min until the viscosity increased and an orange 
gel formed. The reaction was allowed to continue, for a total reaction 
time of between 4 and 6 hrs. 
At the completion of the reaction, the orange gel was broken up by hand 
stirring and decomplexed in 0.15% aqueous hydrochloric acid (500 mL). The 
resulting white polymer was isolated by filtration and washed with tap 
water (3.times.500 mL). The polymer was then digested at reflux overnight 
in 0.15% aqueous hydrochloric acid, isolated by filtration, and washed 
with tap water (3.times.500 mL). Next, the polymer was heated at reflux 
for 1 hr in 0.15% aqueous ammonium hydroxide (500 mL), isolated by 
filtration, and washed with tap water (3.times.500 mL). Finally, the 
polymer was dried in vacuo overnight at 165.degree. C. 
The polymers thus obtained had a repeat unit (A) 
##STR19## 
and a repeat unit (B) 
##STR20## 
with the (A)/(B) ratios varying according to the monomer ratios employed. 
The inherent viscosity and glass transition (Tg) and crystalline melting 
(Tm) points of the polymers are given in Table II. 
TABLE II 
______________________________________ 
Inh. 
Monomers & capping agt. (mmol) 
Vis. Tg Tm 
Run (a) (b) (c) (d) (dL/g) 
(.degree.C.) 
(.degree.C.) 
______________________________________ 
1 3.75 21.25 25.45 0.90 0.92 171 366 
2 7.5 17.5 25.5 1.0 0.86 172 349 
3 12.5 12.5 25.45 0.90 0.90 173 376 
4 16.8 8.2 25.5 1.0 0.83 174 396 
5 25.0 0 25.5 1.0 0.82 186 426 
______________________________________ 
(a) = [1,1biphenyl4,4dicarbonyl dichloride 
(b) = terephthaloyl chloride 
(c) = 4,4diphenoxybenzophenone 
(d) = benzoyl chloride 
EXAMPLE 3 
[1,1'-Biphenyl]-4,4'-dicarbonyl dichloride, terephthaloyl chloride, and 
1,4-diphenoxybenzene were copolymerized following the general procedure of 
Example 2, except that (a) N,N-dimethylformamide (96.0 mmol) was used as 
the Lewis base instead of dimethyl sulfone, (b) the amount of aluminum 
trichloride used was 176.6 mmol, (c) the total amount of methylene 
chloride used was 44 mL (30 mL initial charge, balance to rinses) and (d) 
the amount of monomers and capping agent are as provided in Table III. 
The polymers obtained had a repeat unit (A) 
##STR21## 
and a repeat unit (B) 
##STR22## 
with the (A)/(B) ratio varying according to the monomer ratios employed. 
The inherent viscosity, Tg, and Tm of the polymers are given in Table III. 
TABLE III 
______________________________________ 
Inh. 
Monomers & capping agt. (mmol) 
Vis. Tg Tm 
Run (a) (b) (c) (d) (dL/g) 
(.degree.C.) 
(.degree.C.) 
______________________________________ 
1 8.0 24.0 32.3 0.5 1.49 167 318 
2 16.0 16.0 32.3 0.5 1.39 173 333 
3 24.0 8.0 32.3 0.5 1.38 178 373 
______________________________________ 
(a) = [1,1biphenyl4,4dicarbonyl dichloride 
(b) = terephthaloyl chloride 
(c) = 1,4diphenoxybenzene 
(d) = benzoyl chloride