An aryletherketone polymer having repeating units of the formula: ##STR1## wherein Ar is selected from the group consisting of ##STR2## wherein Q is --O--, --CH.sub.2 -- or --CO--, is useful in the dispersion of active NLO chromophores containing a basic functionality to form optically clear films.

BACKGROUND OF THE INVENTION 
The present invention relates to aryletherketone polymer compositions 
containing pendent sulfo groups for ionic interaction with second order 
NLO chromophores. 
Considerable research effort has been directed toward the use of organic 
second-order nonlinear (NLO) polymers in practical devices. The predicted 
advantages of such organic polymers for frequency conversion and 
integrated optics applications is headed by potential ease of fabrication 
and low cost. The polymer properties necessary to efficiently frequency 
double light at 800 nm in a slab waveguide device include a .chi..sup.(2) 
of 60 pm/V (.mu..beta.=350.times.10.sup.-30 esu D) and no absorption at 
400 nm. 
For a polymeric material to have successful application in an electro-optic 
(EO) device, it needs to possess a somewhat different set of properties. A 
practical EO polymer must be spin coatable, easily poled by an electric 
field or self-assembled, have optical losses below 1 dB/cm and be capable 
of producing devices with modulation bandwidths of 100 GHz. For a NLO EO 
polymer material to be commercially realistic, it must also be able to 
retain a reasonable second-order activity (&gt;30 pm/V at 830 nm) at 
temperatures experienced during routine microelectronics circuit 
fabrication (as high as 320.degree. C. for 20 min.). For military 
applications, it is further necessary that a material retain at least 95% 
of its original EO coefficient after 10 years at 125.degree. C. Finally, 
the synthesis of any polymeric material for potential commercial use must 
address the issues of low cost producibility, toxicity/carcinogenicity and 
waste disposal. 
Reinhardt et al, U.S. Pat. No. 5,594,075, issued Jan. 14, 1997, disclose an 
acetylenic thermoset monomer which, when mixed with high performance 
thermoplastic materials, can be poled and cured at elevated temperatures 
to provide composites with second-order nonlinear optical (NLO) activity, 
improved thermal stability and optical transparency at wavelengths shorter 
than 830 nm. 
Other research efforts have been directed toward the incorporation of 
highly active NLO chromophores in guest host polymers. However, guest host 
polymer systems containing 20 to 30% by weight chromophores tend to phase 
separate, causing light scattering and loss of optical clarity. 
We have prepared high molecular weight sulfo-pendent aryletherketone 
polymers which provide an ionic association mechanism for basic NLO 
chromophores. Monodispersed optically clear films are obtained via the 
ionic association of the sulfonic acid groups on the polyaryletherketone 
and the basic functionality of the NLO chromophore. 
Accordingly, it is an object of the present invention to provide high 
molecular weight sulfo-pendent aryletherketone polymers. 
It is another object of the present invention to provide optically clear 
films of the sulfo-pendent aryletherketone polymers and active NLO 
chromophores. 
Other objects and advantages of the present invention will be apparent to 
those skilled in the art. 
SUMMARY OF THE INVENTION 
In accordance with the present invention there is provided an 
aryletherketone polymer having repeating units of the formula: 
##STR3## 
wherein Ar is selected from the group consisting of 
##STR4## 
wherein Q is --O--, --CH.sub.2 --or --CO--. 
DETAILED DESCRIPTION OF THE INVENTION 
The polymer of this invention is prepared by the condensation of 
hydroquinone 2-potassium sulfonate with a difluoro aromatic ketone. 
Difluoro aromatic ketones suitable for use in the present invention have 
the formula F--Ar--F, wherein Ar is as defined previously. Examples of 
suitable difluoro aromatic ketones include 4,4'-difluorobenzophenone, 
4,4'-bis(4-fluorobenzoyl) diphenylether, 4,4'-bis(4-fluorobenzoyl) 
diphenylmethane, 4,4'-bis(4-fluorobenzoyl) diphenylketone, 
2,6-bis(4-fluorobenzoyl) naphthalene and 1,3-bis(4fluorobenzoyl)benzene. 
The condensation is conveniently carried out in N-methylpyrrolidone (NMP) 
using potassium carbonate to generate the potassium salt of the bis-diol. 
The water formed from the salt generation can be removed as an azeotrope 
with benzene or toluene. Following removal of this water, additional NMP 
is added to facilitate stirring. The temperature of the reaction mixture 
is increased step-wise over a period of about 24 to 48 hours to about 
210.degree. to 225.degree. C. 
The resulting potassium sulfonate polymer is recovered from solution by 
pouring the solution into an excess of a non-solvent for the polymer, 
e.g., methanol. The polymer is then filtered, washed and dried. 
The potassium sulfonate polymer is converted to the corresponding sulfonic 
acid polymer by refluxing the former in dilute HCl. Alternatively, the 
potassium sulfonate polymer can be dissolved in methanesulfonic acid 
(MSA), then precipicated in distilled water. 
The polymer of this invention is soluble in aprotic solvents, such as 
N,N-dimethylacetamide (DMAc); the polymer is insoluble in water and 
alcohol. 
The primary utilization of the polymer of this invention is in the 
dispersion of active NLO chromophores to form optically clear films. The 
chromophores to be dispersed must contain a basic functionality and must 
be soluble in an aprotic solvent. Suitable NLO chromophores include the 
following: 
##STR5## 
These chromophores either contain a dialkylamine or pyridine moiety which 
forms an ionic association with the pendent sulfo groups of the host 
polymer. The wt% loading of the chromophore is a function of the 
equivalent sulfo content of the polymer.

The following examples illustrate the invention. 
EXAMPLE 1 
Sulfo pendent polyarylene ether ketone derived from hydroquinone 
2-potassium sulfonate and 4,4'-difluorobenzophenone 
Hydroquinone 2-potassium sulfonate (2.5087 g, 0.011 moles), 
4,4'-difluorobenzophenone (2.398 g, 0.011 moles) and anhydrous potassium 
carbonate (3.07 g, 0.022 moles) were heated in the presence of 15 ml NMP 
and 30 ml benzene. The mixture was heated to reflux with the water from 
the formation of the bisdiol salt being removed as a benzene azeotrope by 
a Dean Stark trap. An additional 15 ml benzene was added to the reaction 
mixture as the azeotrope was drawn off. Traces of benzene were removed 
under a brisk nitrogen flush at a bath temperature of 145.degree. C. The 
deep yellow reaction mixture was cooled and 45 ml NMP was added to the 
flask. A green suspension formed on heating at 125.degree. C. overnight. 
The reaction mixture turned to a darker, homogeneous solution in the 
temperature range 150.degree.-170.degree. C. and was stirred at 
170.degree. C. overnight. The temperature of the solution was raised to 
215.degree. C. -220.degree. C. and at least 50 ml NMP was distilled off 
under a high nitrogen pressure. The dark, concentrated solution (nearly 40 
w % solid or polymer) was heated overnight at 180.degree. C. 
After cooling, the viscous polymer solution was poured into a large excess 
of MeOH. Strands of off-white fibrous polymer were obtained. They were 
broken up in a blender as a methanolic slurry. The polymer was filtered, 
washed with more methanol and dried. A total of 4.1 gms of polymer was 
obtained (91% yield) after mechanical losses during blending etc. 1.5 gms 
of the polymer were stirred in 160 ml distilled water for several hours to 
remove inorganics. This was filtered, washed with more distilled water and 
dried. Microanalytical data (for sample dried in vacuum at 100.degree. 
C.): Calculated: C, 56.14; H, 2.73; S, 7.89; K, 9.62. Found: C, 52.29; H, 
2.90; S, 6.29; K, 9.58. 
0.45 gms of the polymer potassium sulfonate was heated with a dil. HCl 
solution (5 ml Conc.HCl+15 ml deionized water) under reflux for two hours. 
The solid changed color to light brown and hardened on cooling. The 
mixture was cooled, filtered and the polymer was repeatedly washed with 
deionized water and dried at 100.degree. C. in vacuum. Microanalytical 
data: Calculated: C, 61.94; H, 3.29; S, 8.70; K, 0.00. Found: C, 58.43; H, 
3.33; S, 7.88; K, 0.05. Inherent viscosity (0.5 g/dl, DMAc, 30.degree. 
C.)=1.09 dl/g. 
EXAMPLE II 
Sulfo pendent polyarylene ether ketone derived from hydroquinone 
2-potassium sulfonate and 1,3-bis-(4-fluorobenzoyl) benzene 
Hydroquinone 2-potassium sulfonate (2.5044 g, 0.011 moles), 
1,3-bis-(4-fluorobenzoyl) benzene (3.5361 g 0.011 moles) and anhydrous 
potassium carbonate (3.0753 g, 0.0222 moles) were heated in the presence 
of 15 ml NMP and 30 ml benzene. The mixture was heated to reflux with the 
water from the formation of the bisdiol salt being removed as a benzene 
azeotrope by a Dean Stark trap. An additional 15 ml benzene was added to 
the reaction mixture as the azeotrope was drawn off. Traces of benzene 
were removed under a brisk nitrogen flush. The yellow-colored slurry was 
cooled and 45 ml NMP was added to the flask. The reaction mixture was 
heated at 140.degree. C. overnight. The reaction mixture was stirred at 
170.degree. C. for 12 hours. The temperature of the solution was raised to 
210.degree. C. and over 50 ml NMP was distilled off under a brisk nitrogen 
pressure. The dark, concentrated solution was heated overnight at 
170.degree. C. overnight. 
After cooling, the viscous polymer solution was poured into a large excess 
of MeOH. Strands of off-white fibrous polymer were obtained. They were 
broken up in a blender as a methanolic slurry. The polymer was filtered, 
washed with more methanol and dried. 4.9 gms of polymer were stirred in 
500 ml distilled water for several hours to remove inorganics. This was 
filtered, washed with more distilled water and dried. Microanalytical data 
(for sample dried in vacuum at 100.degree. C.): Calculated: C, 61.15; H, 
2.97; S, 6.28; K, 7.66. Found: C, 58.89; H, 2.99; S, 5.46; K, 8.09. 
1.5 gms of the polymer potassium sulfonate was heated with a dil. HCl 
solution (15 ml Conc.HCl+40 ml deionized water) under reflux for 3 hours. 
The solid changed color to light brown. After cooling, the acid solution 
was decanted off and another 55 ml dilute HCl was added and the mixture 
refluxed for 3 hours. The mixture was cooled, filtered and the polymer was 
repeatedly washed with deionized water and dried at 100.degree. C. in 
vacuum. Microanalytical data: Calculated: C, 66.09; H, 3.42; S, 6.79; K, 
0.00. Found: C, 65.30; H, 3.30; S, 6.03; K, 0.03. Inherent viscosity (0.5 
g/dl, DMAc, 30.degree. C.)=1.20 dl/g. 
EXAMPLE III 
NLO film containing 1-(4-pyridyl)-2-(2-thienyl)ethene (PTE) 
3 ml DMAC solution of 0.048 g of the polymer of Example I was added a 
colorless solution of the chromophore (0.022 g) in 2 ml DMAc. The yellow 
solution was stirred for an hour and filtered and a bright, transparent 
yellow film was cast after removal of the solvent in high vacuum for 72 
hours. Weight of the NLO chromophore dispersed in the polymer matrix was 
30%, close to 1:1 molecular stoichiometry for the ionic association of the 
sulfonic acid pendent of the matrix with the pyridinyl functionality of 
the NLO chromophore. 
EXAMPLE IV 
NLO film containing 1-(4-pyridyl)-2-(2-thienyl)ethene (PTE) 
To 3 ml DMAc solution of 0.031 g of the polymer of Example II was added a 
colorless solution of the chromophore (0.011 g) in 2 ml DMAc. The yellow 
solution was stirred for an hour and filtered and a bright, transparent 
yellow film was cast after removal of the solvent in high vacuum for 72 
hours. Weight of the NLO chromophore dispersed in the polymer matrix was 
26%, close to 1:1 molecular stoichiometry for the ionic association of the 
sulfonic acid pendent of the matrix with the pyridinyl functionality of 
the NLO chromophore. 
EXAMPLE V 
NLO film containing 1-(4-pyridyl)-2-(5-(2.2'-bithienyl))ethene (thienyl 
PTE) 
A DMAC solution of the sulfo-polymer of Example II (0.031 g in 3 ml) was 
mixed with a yellow solution of the NLO chromophore (0.0138 g) in 2 ml 
DMAc to obtain a bright orange solution. After stirring for a few hours, 
the filtered solution was taken in a glass casting dish and DMAc was 
evaporated off under high vacuum in a vacuum desiccator over 72 hours. The 
homogeneous, transparent orange film was isolated by addition of water to 
the casting dish and dried in air. Weight of the second-order NLO 
chromophore dispersed in the sulfo-polymer matrix was 31%, close to 1:1 
molecular stoichiometry for the ionic association of the sulfonic acid 
pendent of the matrix with the pyridinyl functionality of the NLO 
chromophore. 
EXAMPLE VI 
NLO film containing 4-(4-N,N-diethylaminostyryl)pyridine (DEASP) 
A DMAc solution of the sulfo-polymer of Example II (0.065 g in 6 ml) was 
mixed with a yellow solution of the NLO chromophore (0.032 g) in 6 ml DMAc 
to obtain an homogeneous, deep red solution. After stirring, the filtered 
solution was taken in a glass casting dish and DMAc was evaporated off 
under high vacuum for 72 hours. The deep red, optically clear NLO film was 
floated off the dish by addition of water and dried. Weight of the 
second-order NLO chromophore dispersed in the polymer matrix was 33%, 
corresponding to 1:1 molecular stoichiometry for the ionic association of 
the sulfonic acid pendent of the matrix polymer with the pyridinyl 
functionality of the chromophore. 
Various modifications may be made in the instant invention without 
departing from the spirit and scope of the appended claims.