CA1297607C - Miscible blends of poly(aryl ether sulfones) - Google Patents

Abstract

MISCIBLE BLENDS OF POLY(ARYL ETHER SULFONES) ABSTRACT OF THE DISCLOSURE
Described herein are miscible blends of select poly(aryl ether sulfones). These blends are suitable for printed wiring board substrates, flexible printed circuit boards, electrical connectors and fabricated articles requiring high heat and chemical resistance, good dimensional and hydrolytic stability.

S P E C I F I C A T I O N

Description

~ ) -"` 1297607 MISCIBLE BLENDS OF POLY~ARYL ETHER SULFONES) FIELI) OF THE INVENTION
This invention i6 directed to miscible blends of different poly(aryl ether sulfones).
These blends are suitable for printed wiring board substrates, flexible printed circuit boards, electrical connectors and other fabricated articles requiring high heat and chemical resistance, good dimensional and hydrolytic stability.
BACKGROUND OF THE INVENTION
Over the years, there has been developed a substantial body of patent and other literature directed to the formation and properties of poly(aryl ethers) (hereinafter called "PAE"). Some of the earliest work such as by Bonner, U.S.
3,065,205, involves the electrophilic aromatic 6ubstitution (viz. Friedel-Craft~ catalyzed) reaction of aromatic diacylhalides with unsubstituted aromatic compounds such as diphenyl ether. The evolution of this class to a much broader range of PAEs was achieved by Johnson et al., Journal of Polymer 8cience, A-l, vol. 5, 1967, pp. 2~15-2427, Johnson et ~1., U.~. Patent No.
~,108,837, and U.8. Patent ~o. ~,175,175. Johnson et al. show that a very broad range of PAE can be formed by the nucleophilic aromatic substitution '~
A

. .

~297607 (condensation) reaction of an activated aromatic dihalide and an aromatic diol.
Thus, PAEs are well known; they can be made from a variety of starting materials, and they can be made with different glas6 tran6ition temperatures and molecular weights. ~ominally, PAEs are transparent and tough, ~.e., exhibit high values (>50 ft-lbs/in2) in the tensile impact test (ASTM
D-1822). Their favorable properties class them with the best of the engineering polymers.
Polymer blends have been widely taught and employed in the art. As broad a6 this statement may be, the blending of polymers remains an empirical art and the selection of polymers for a blend giving 6pecial properties is, in the main, an Edi60nian-like choice. Certain attributes of polymer blends are more unique than others. The more unigue attributes when found in a blend tend to be unanticipated properties.
~ a) According to Zoller and Hoehn, Journal of Polymer Science, Polymer Plastic6 Edition, vol. 20, pp. 1385-1397 (1982):
"~lending of polymer6 i6 a useful technique to obtain properties in thermopla6tic materials not readily achieved in a single polymer. Virtually all technologically important properties can be improved in this way, 60me of the more important ones being flow properties, mechanical propertie6 (especially impact 6trength), thermal stability, and price.
*J*
. . . Ultimately, the goal of 6uch modeling and correlation studies should be the prediction of blend propert~es from the propertie6 of the pure ~297607 components alone. We are certainly very far from achieving this goal."
In the field of miscibility or compatibility of polymer blends, the art has found predicta~ility to be unattainable, even though considerable work on the matter has been done.
According to authorities:
(b~ "It i6 well known that compatible polymer blends are rare." Wang and Cooper, Journal of Polymer Science, Polymer Physics Edition, vol.
21, p. 11 (1983).
(c) "Miscibility in polymer-polymer blends is a 6ubject of widespread theoretical as well a~ practical interest currently. In the past decade or 60 the number of blend systems that are known to be mi6cible has increased considerably.
Moreover, a number of sy6tems have been found that exhibit upper or lower critical solution temperatures, i.e., complete miscibility only in limited temperature ranges. Modern thermodynamic theories have had limited succes6 to date in predicting miscibility behavior in detail.' These limitations have 6pawned a degree of pessimism regarding the li~elihood that any practical theory can be developed that can accommodate the real complexities that nature has bestowed on polymer-polymer interactions." Kambour, Bendler, Bopp, Macromolecules, 1983, 16, 753.
(d) "The vast ma~ority of polymer pair~ form two-pha6e blend~ after mixing as can be surmised from the small entropy of mixing for very large molecules. These blends are generally characterized ~y opacity, di6tinct thermal .

lZ97607 ~ i transitions, and poor mechanical properties.
However, special precautions in the preparation of two-phase blends can yield composites with superior mechanical properties. These materials play a major role in the polymer industry, in several instances commanding a larger market than either of the pure components." Olabisi, Robeson and Shaw, Polymer-Polymer Miscibility, 1979, published by Academic Press, New York, N.Y., p. 7.
(e) "It is well known that, regarding the mixing of thermoplastic polymers, incompatibility is the rule and miscibility and even partial miscibility is the exception. Since most thermoplastic polymer6 are immiscible in other thermoplastic polymers, the discovery of a homogeneous mixture or partially miscible mixture of two or more thermoplastic polymers is, indeed, inherently unpredictable with any degree of certainty, for example, ~ee P. J. ~lory, Principles of Polymer Chemistry, Cornell University Press, 1953, Chapter 13, page 555." Younes, U.S. Patent No. 4,371.672.
(f) "The study of polymer blends has assumed an ever increasing importance in recent years and the resulting research effort has led to the discovery of a number of miscible polymer combinations. Complete miscibility is an unusual property in binary polymer mixtures which normally tend to form phase-separated 6ystem6. Much of the work ha6 been of a qualitative nature, however, and variables such as molecular weight and conditions of blend preparation have often been overlooked. The criteria for establi6hing miscibility are al60 (_ !
~2976~7 varied and may not always all be applicable to particular systems." Saeki, Cowie and McEwen, Polymer, 1983, vol. 24, January, p. 60.
Miscible polymer blends are not common, and those of different PAEs are unique to most uncommon.
The criteria for determining whether or not two polymers are mi~cible i6 now well e~tabli6hed.
According to Olabisi, et al., Polymer-Polymer Miscibility, 1979, publi~hed by Academic Press, New York, N. Y., p. 120:
"The most commonly used method for establishing miscibility in polymer-polymer blends or partial phase mixing in such blends is through determination of the glass tran6ition (or transitions) in the blend versus those of the unblended con6tituents. A miscible polymer blend will exhibit a ~ingle glass transition between the Tgs of the components with a sharpness of the transition similar to that of the components. In cases of borderline miscibility, broadening of the transition will occur. With cases of limited miscibility, two separate transition6 between tho6e of the constituents may result, depicting a component 1-rich phase and a component 2-rich phase. In cases where strong specific interactions occur, the Tg may go through a maximum as a function of concentration. The basic limitation of the utility of glass transition determinations in ascertaining polymer-polymer miscibility exists with blend~ composed of componellts which have equal or similar (<20C difference) Tgs, whereby resolution by the technigues to be discussed of two Tgs is not po6~ible."

(` ~29~760~ 1 W. J. MacKnight, et al., in Polymer ~lends, D. R. Paul and S. Newman, eds., 1978, publlshed by Academic Press, New York, N. Y., state on page 188:
"Perhaps the most unambiguous criterion of polymer compatibility is the detection of a single glass transition whose temperature i8 intermediate between those corresponding to the two component polymers."
In this passage, it is clear from the omitted text that by compatibility the authQrs mean miscibility, i.e., single phase behavior. See for example the d~6cus6ion in Chapter 1 by D. R. Paul in the same work.
Although it is clear from the above passages that polymer miscibility cannot be predicted, there i6 recent evidence that once 6everal examples are found where polymers of a class I are miscible with polymers of a class 2, then the phase behavior of blends of polymers of class 1 and polymers of class 2 can be correlated with structure. The net result is that a mathematical inequality can be written which correctl~ predicts when other polymers chosen from class 1 and class 2 are miscible. ~here i8 evidence that the miscibility of two polymers composed of several different types of mer un1ts can be correlated by an equation of the type Fc > ~ >~ + ~ )B~
where Fc i8 a ~mall positive number (or zero), the ~i are related to the number of mers of type i in ~97607 polymer ~, and the Bij represent the interaction energy between mers of type i and j. For example in Paul, et al., Polymer 25, pp. 487-494 (1984), the mi~c~bility of the polyhydroxy ether of bisphenol A
i8 successfully correlated with a series of aliphatic polyesters using (eguation lo in the above reference) ~ B13~ B23~2 ~ B12~1 ~2 (2) Eguation (2) is equivalent to equation (1) if the following change of notation i6 made:
}~ D O

~2' ~2 and all other ~i ~ ' In this case the ~i are taken to be the volume fraction mer i in polymer K. The Bij were essentially taken as adjustable parameters representing the enthalpy of interaction between group i and j. Paul and coworkers considered the polymer blend system to be made up of three groups:
CH2- and o (2) -C-O- which make up the aliphatic polyesters, and ( 12976~7 (3) ~ C ~ O-CH2-CH-CH2-o_ which make up the polyhydroxy ether.
Kambour, et al., (Macromolecules, 16, pp.
753-757 ~1983) ) used a similar equation to correlate the mi~cibility of poly(styrene-co-bromostyrene) with poly(xylenyl-co-bromoxylenyl ether). In the case where polymer I contained only mers of type i and polymer 2 contained mers of type j and K the condition of mi6cibility that was arrived at was (see equation 4 on page 7S6-of the above cited work) XAB ~1 ~c)xtJ ~ ~c(Xtk) ~ Rc(l-~c)Xk~

Note the mista~e in the third term of equation 4 in Kambour, et al., which i5 corrected in equation (3) above. Equation (3) i6 ~een to be identical with equation (1) if the following change o~ notation is made:

Fc ' X~B
~c' ( l-~c) ~t ~ 1 All other ~ ~ O.
X~ B1J for D-l 4 7 o 6-1 129~607 _ g _ In this in6tance Rambour ha6 taken the ~i to be the mole fraction mer i in polymer K. Again the Bi were taken to be adju~table parameters.
There i6 a precedent, then, for correlating mi6cibility ùsing equation (1). We have 6een that the O may be interpreted as volume fractions or mole fraction6. Prausnitz, et al., in the Properties of Ga6es and Liquid6, Third Edition, published by McGraw-Hill Book Co., New York, N.Y.
(1977), recommend the use of molecular area fraction~ ~n eguation6 similar to equation (1) (~ee Chapter 8 in Prausnitz, et al.). They recommend the u6e of the group contribution method developed by A.
Bondi in the Physical Properties of Molecular Liquids, Cry6tal6 and Glas6es, Chapter 14, publi6hed by John Wiley ~nd ~ons, New York, N.Y. (1968), for the estimat~on of the 6urface are4 of mer unit6.

Summary of the Invention Thus the present invention provides in a broad aspect a miscible blend of two or more different poly(aryl ether sulfones) consisting essentially of at least one unit selected from the group consisting of:

~ O- nd ~ O-a~d at least one un~ ~ele~tod from the ~roup consi~tlng o~:

~ S02- and ~ S02-, whe~e~n lZ9'760~7 -9a-~t lea~t one o~ ~ald poly~ryl eth~r rul~one) comp~l~e6 ~t leart one member sele~ted fro~ the group conslstlng of 2 ~ o- ~nd ~ S02-, the polyl~ryl ether ~ulfone6) be~n~ dlffe~ent ~nd eAch ~omprises the ~ollowln~ s~dicalrt O- , ~) ~ S~2-, and }II ) ~=j~

DESCRIPTION OF THE INVENTION
It has now been found that 6e~eral poly(aryl ether 6ulfone~) are mi6cible with each other. The mi6cible blend compri6e6 6eparately made different poly(aryl ether 6ulfones) formed into an intimate moldable mixture, each resin comprising 1,4- arylene units separated by ether oxygen and each resin containing a l,~-arylene unit 6eparated by an SO2 radical. The 1,~ arylene units preferably being l,~-phenylene or 1,4-biphenylene units.
The miscible poly(aryl ether 6ulfones) are made up of ~oly(aryl ether sulfones)containing the following radical~ arranged in any order:

A D-1~706-1 12~`76~7 ~o-2 ~ so2 They ~re misclble lf:

~2 ' ~1~2 ~ ~2) 25.2 ~ 3 ~ ~3 ' ~ 3) 14.3 ~

t~3 ~ ~2~ 2~2) 32.8~ 1 Where Xl ~ 1'4l5X2 ~-~-9~7X3 ~ .415Y2~ .9 ~2 ~ ~ ~2.

~3 ' ~ 0 D-14,706-1 ~ .. . .

129760~

Xl is the molar fraction of ~ o-radicals in polyarylether sulfone 1 X2 is the molar fractiol~ of ~ s92 radicals in polyarylether sulfone 1 X3 i6 the molar fraction of ~
radicals in polyarylether sulfone 1 Yl is the molar fraction of ~ -radicals in polyarylether sulfone 2 Y2 is the molar fraction f ~ 02-radicals in polyarylether sulfone 2 Y3 is the molar fraction of ~
radicals in polyarylether ~ulfone 2 The mi6cible blend6 defined by the above relationship have single Tg's lying between those of the two constituent6 and are transparent with the proviso that the constituents are transpatent. The blends are totally miscible in that they have a single Tg. The utility of such blend~ are without question very broad; see for example Olabisi, et al., in Polymer-Polymer Miscibility, Chapter 7, Published by Academic Press, New York, N.Y., pp.
321-353. In particular, such blends would be useful for printed wiring board substrates, flexible printed circuit boards, e]ectrical connectors and other fabricated articles reguiring high heat and chemical resi~tance, good dimQnsional and hydrolytic ~tability.

` ~12~7607 The poly(aryl ether ~ulfones) of this inventinn contain one or more radicals of the following formulae arranged in any order:

(I) ~ o-(II) ~ S02-~III) ~

with the proviso that at least one radical of the following formula:

G~
~ 2-is present in each of the poly~aryl ether 6ulfones) which make up the blend. The poly~aryl ether 6ulfones) are different since their repeating units have different proportions of radicals (I), (II) or (III) or different arrangements thereof. In the case of copolymers, the polymers may differ in the proportions of radicsl6 (I), (II) or (III). The aryl group6 repre6ented by formula6 (I), (II), and (III), can be attached to each other as will be seen in the structural formulas in the polymers below.
THE ~
Figure 1 show6 a curve of the glass transition temperature (Tg) versus a composition of ~2~7607 ' P~E II/PAE V blends (as are hereinafter structurally depicted).
Figure 2 depicts, in the shaded area, the region specified by equation 4 when polymer 1 is PAE
and polymer 2 contain6 the radicals I, II, III.
Pigures 3, 4 and 5 depict the region specified by equation 4 when polymer 1 is PAE III, PAE III and ~AE IV, respectively.
DETAILED DESCRIPTION OF THE INVENTION
The poly(aryl ether sulfone) polymers which are used in the miscible blends are prepared by methods well known in the art.
The monomers which are utilized to prepare the poly(aryl ether sulfones) include the following:
hydroquinone, 4,4-biphenol, 4,4'-dichlorodi~henyl 6ulfone, 4-chloro-4'-hydroxydiphenyl sulfone, and 4,4'-bis(4-chlorophenyl6ulfonyl)biphenyl The poly(aryl ether sulfones) are prepared by contacting substantially equimolar amounts of hydroxy containing compounds ~uch as those listed above and halo and/or nitro containing compounds with from about 0.5 to about 1.0 mole of an alkali metal carbonate per mole of hydroxyl group in a solvent mixture comprising a solvent which forms an azeotrope with water in order to maintain the reaction medium at substantially anhydrous conditions during the polymerization.
The temperature of the reaction mixture is kept at from about 120 to about 1~0C, for about I
to about 5 hours and then rai6ed and kept at from 12~76~7 about 200 to about 2500C, preferably from about 210 ~o a~out 2300C, for about 1 to 10 hours.
The reaction is carried out in an inert atmosphere, e.g., nitrogen, at atmospheric pressure, although higher or lower pressures may also be used.
The poly(aryl ether ~ulfone) is then recovered by conventional techniques such as coagulation, solvent evaporat~on, and the like.
The solvent mixture comprises a solvent which forms an azeotrope with water and a polar aprotic solvent. The solvent which forms an azeotrope with water includes an aromatic hydrocarbon such as benzene, toluene, xylene, ethylbenzene, chlorobenzene, and the like.
The polar aprotic solvents employed in this invention are those generally known in the art for the manufacture of poly(aryl ether 6ulfones) and include sulfur containing 601vents such as those of the formula:

R~ S(O)b _ Rl in which each Rl represents a monovalent lower hydrocarbon group free of aliphatic unsaturation, which preferably contains less than about 8 carbon atoms or when connected together represents a divalent alkylene group with b being an integer from 1 to 2 inclusive. Thus, in all of these solvents all oxygen~ and two carbon atoms are bonded to the sulfur atom. Contemplated for use in this invention are Euch solvents as those having the formula:

O o R2 S R2 and ~2 S R2 where the R2 groups are independently lower alkyl, such a~ methyl, ethyl, propyl, butyl, and like groups, and aryl groups such as phenyl and alkylphenyl groups 6uch as the tolyl group, as well as those where the R6 groups are interconnected as in a divalent alkylene bridge such as:

C2H4 ~

CH2 _ C~2 8~0)b in tetrahydrothiophene oxides and dioxides.
6pecifically, these solvents include dimethylsulfoxide, dlmethylsulfone, diphenylsulfone, diethylsulfoxide, diethyl6ulfone, dii60propylsulfone, tetrahydrothiophene l,l-dioxide (commonly called tetramethylene 6ulfone or sulfolane) and tetrahydrothiophene-l monoxide.
Additionally, nitrogen containing solvents may be used. These include dimethyl acetamide, dimethyl formamide and N-methylpyrolidone.
The azeotrope forming 601vent and polar aprotic solvent are used in a weight ratio of from about 10:1 to about 1:1, preferably from about 7:1 to about 5:1.
In the reaction, the hydroxy containing compound is ~lowly converted, in 8itU, to the alkali salt thereof by reacting with the alkali metal l;~iV7 carbonate. The alkal~ metal carbonate is preferably potassium carbonate. Mixture6 of carbonates such as potassium and 60dium carbonate may al60 be used.
Water i5 continuously removed from ~he reaction mass as an azeotrope with the azeotrope forming solvent 60 that substantially anhydrous conditions are maintained during the polymerization.
It is essential that the reaction medium be maintained ~ubstantially anhydrous durin~ the polycondensation. While amounts of water up to about one percent can be tolerated, and are somewhat beneficial when employed with fluorinated dihalobenzenoid compounds, amount6 of water 6ubstantially greater than thi6 are desirably avoided as the reaction of water with the halo and/or nitro compound lead~ to formation of phenolic 6pecies and only low molecular weight products are secured. Con6equently, in order to 6ecure the high polymers, the ~y6tem ~hould be 6ubstant~ally anhydrous, and preferably contain le6s than 0.5 percent by weight water during the reaction.
Preferably, after the desired molecular weight has been attained, the polymer is treated with an activated aromatic halide or an aliphatic halide such a6 methyl chloride or benzyl chloride, and the like. 8uch treatment of the polymer convert6 the terminal hydroxyl groups lnto ether ~roup6 which ~tabilize the polymer. The polymer so treated has good melt and oxidative stability.
The poly(aryl ether ~ulfone)6 may be random or may have an ordered structure.
The poly(aryl ether sulfone)6 of this invention have a reduced visc06ity of from about 0.4 ~2~37607 to greater than about 2.5, as measured in N-methylpyrolidone, or other suitable solvent, at 25C, The preferred poly(aryl ether sulfone)s are depicted by the following formulae:

~2 ~ ~
~o~o~so2-~, 2s~~52~o.7s ~0~9D2 ~0~0~51) ~o~So2~502~

~~~52~502~.7B~o~o~so2t~. 22 ~OE~o~s~2-~so2~ . i ~O~O~S02~502~
~O~S112~0~9D2~S02~
~o~so2~S2~.7s~52~so2~so2~.2s ~0~502~.~So2~.0 r 51`
~97607 The blends of this invention are miscible in all proportions. Preferably the blend contains from about 2 to about 98, more preferably from about 15 to about 85 weight percent of each of the poly(aryl ether sulfones).
The blends of this invention are prepared by conventional mixing methods. For example, the poly(aryl ether sulfones) are mixed with each other and any other optional ingredients in powder or granular form in an extruder and the mixture is extruded into 6trands, the strands are chopped into pellets and the pellets molded into the desired article, The blends of this invention may include mineral fillers such a6 carbonates including chalk, calcite and dolomite; silicates including mica, talc, wollastonite; silicon dioxide; glass spheres;
glass powders; aluminum; clay; guartz; and the like. Also, reinforcing fibers such as fiberglass, carbon fibers, and the like may be used. The blends may also include additives such as titanium dioxide;
thermal stabilizers such as zinc oxide; ultraviolet light 6tabilizer6, plasticizers, and the like.
EXAMPLES
The following example6 serve to give specific illustrations of the practice of this invention but they are not intended in any way to limit the scope of this invention.
The structures of the various poly(aryl e~her sulfone6) (PAEs) used in this ~tudy are shown in Table I along with their reduced viscosities (RVs) and glass tran~ition temperatures (Tgs). The .

., ;

~ !
~2~7607 Tgs were determined by the modulus-resilience method described in Olabisi, et al., ibid., pp. 126-~27.
To accomplish this, each PAE was compression molded into a 4 x 4 x 0.020 inch plaque in a cavity mold using a South Bend hydraulic pres6 with electrically heated plattens. Molding temperatures were between 300 and 380C. These plaques were shear cut into 1/8" wide test specimens. All PAEs except PAE V and IX were transparent as molded. All had single glass transition temperatures as noted.

( ~97607 ` i ~~ ¦N N -- N _ -- N 0 a-- N ¦ n ~ ~ Cr` ,J N c~

¦ ~ n N ~ ~)~) N N O

0 ~

X I O O O O O O O O O O O ql X I . . U") ~0 N ~ ) 0 _ G
~ Cl ~ ~ ~. >, .~ _ ~ r ~, ~ r U~ r O r r 0 r~ O r I N S C

C V ¦ ' ' N ~

1-- ¦ N N N -- NN N N N N Z

O
.
E
~r o - ~ ~ ~ ~ ~ ~ ~ x x u 1,~.1 1~.1 ~ h~ I~J ~ W
CL CL ;~ ~. 1 1~76()7 '`

Control A
50 parts by weight PAE I was mixed with 50 parts by weight PAE II in a Brabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x 0.020 inch plaques and mea6ured for glass transition temperatures as described above. The resulting blend was opaque. The Tgs of the constituent.s were too similar to distinguish 6eparately in the blend. On this basis the blend was judged to be immiscible.
Control B
50 parts by weight PAE I was mixed with 50 parts by weight PAE III in a Brabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x 0.020 inch plaques and measured for glass transit~on temperatures as described above. The resulting blend was opaque. The Tgs of the con6tituents were too similar to distinguish ~eparately in the blend. On this ba6is the blend was ~udged to be immiscible.
"
- Example 1 50 parts by weight PAE I was mixed with 50 parts by weight PAE IV in a Brabender Plasticorder*
blender at about 350C. The blends were molded into 4 x 4 x 0.020 inch plaques and measured for glass transition temperatures as described above. The resulting blend was transparent and had a single glass transition temperature of 207C. On this basis the blend was ~udged to be miscible.
* Trademark i .. . .

12~7607 ~ !

ExamPle C
50 parts by weight PAE I was mixed with 50 parts by weight PAE V in a ~rabender Plasticorder blender at about 3s0C. The blends were molded into 4 x 4 x 0.020 inch plaques and measured for glass transition temperatures as described above. The resultinq blend was opaque and had two glass transition temperatures of 215 and 280OC. On this basis the blend was judged to be immiscible.
ExamPle 2 50 parts by weight PAE I was mixed with 50 parts by weight PAE VII in a Brabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x 0.020 inch plaques and measured for glass transition temperatures as deecribed above. The resulting blend was transparent and had a single glass transition temperature of 225C. On this basis the blend was judged to be miscible.
ExamDle 3 50 part~ by weight PAE II was mixed with 50 parts by weight PAE V in a Brabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x 0.020 inch plaques and measured for glass transition temperatures as described above. The resulting blend had a single glsss transition temperature of 245C. On this basis the blend was judged to be miscible.
Exam~le D
50 parts by weight PAE II was mixed with 50 parts by weight PAE VII in a 8rabender Plasticorder D-l 4 706--1 12~7607 -blender at. about 350C. The blend~ were molded into 4 x 4 x O.020 inch plaqueE snd measured for glass trans~tion temperatures as described above. The resulting blend was opaque and had two gla~
transition temperatures of 225 and 260OC. On this basis the blend was judged to be immi~cible.
Example 4 50 parts by weight PAE II was mixed with 50 parts by weight PAE X in a Brabender Plasticorder blender at about 3s0C. The blends were molded into 4 x 4 x 0.020 inch plaques and measured for glass transition temperatures as described above. The resulting blend was tran6parent and had a single glass transition temperature of 235C. On this basis the blend was judged to be miscible.
Ex~mPle 5 50 parts by weight PAE III wa~ mixed with 50 paxts by weight PAE IV in a Brabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x O.020 inch plaques and measured for glass transition temperatures as described above. The resulting blend was transparent and had a single gla6s transition temperature of 200C. On this basis the blend was judged to be miscible.
ExamPle 6 50 parts by weight PAE III was mixed with 50 parts by weight PAE V in a ~rabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x 0.020 ~nch plaques and measured for glass i 1~97607 transition temperatures as described above. The resulting blend was transparent and had a single glass transition temperature of 245C. On this basi6 the blend wa~ ~udged to be mi6cible.
Example 7 50 parts by weight PAE III was mixed with 50 parts by weight PAE VI in a Brabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x 0.020 inch plaques and measured for glass transition temperatures as described above. The resulting blend was transparent and had a single gla~s transition temperature of 235C. On this basis the blend was judged to be mi~cible.
Control E
50 parts by weight PAE IV was mixed with 50 parts by weight PAE V in a Brabender Plasticorder blender at about 350C. The blend~ were molded into 4 x 4 x 0.020 inch plaques and measured for glass transition temperatures of 200 and 275C. On this basi~ the blend was judged to be immiscible.
ExamPle 8 50 part6 by weight PAE IV was mixed with 50 parts by weight PAE VII in a ~rabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x 0.020 inch plagues and measured for glass transition temperatures as described above. The resulting blend wa~ transparent and had a single, broad gla88 tran6ition temperature between 230C and 245C. On this basi6 the blend was judged to be partially miscible.

~297~i07 Example 9 50 parts by weight PAE II was mixed with 50 parts by weight PAE VIII in a Brabender Plasticorder blender at about 350OC. The blends were molded into 4 x 4 x 0.020 inch plaques and measured for glass transition tem~eratures as described above. The resulting blend was transparent and had a single, broad glass transition temperature of 235C. On this basis the blend was judged to be miscible.
Control F
50 parts by weight PAE IV was mixed with 50 parts by weight PAE IX in a ~rabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x O.020 inch plaques and measured for glass transition temperatures as described above. The resulting blend was opaque and had two glass transition temperatures of 190 and 265C. On this basis the blend was ~udged to be immiscible.
ExamPle 10 2.s grams of PAE II and 2.5 grams of PAE IX
were codissolved in N,N-dimethylacetamide at room temperature to make about a 10% polymer solution.
The mixture was then poured into a petri dish and the solvent evaporated off under vacuum at 150C for 16 hours. The resulting film was then boiled in water for 4 hour~ to remove the last traces of ~olvent and then heated in a circulating air oven at 250C for 16 hours. The Tg of the film was measured by the modulus resilienc~ method. The film exhibited a singlQ glass transition temperature of 240C and was therefore judged to be miscible.

D-14706-l ( 1297607 ExamPle 11 2.5 grams of PAE III and 2.5 grams of PAE
IX were codissolved in N,N-dimethylacetamide at room temperature to make about a 10% polymer solution.
The mixture was then poured into a petri dish and the solvent evaporated off under vacuum at 150C for 16 hours. The resulting film was then boiled in water for 4 hours to remove the last traces of solvent and then heated in a circulating air oven at 250C for 16 hours. The Tg of the film was measured by the modulus resilience method. The film exhibited a ~ingle glass transition temperature of 2450C and was therefore judged to be miscible.
Control G
One gram of PAE II and one gram of PAE XI
were codissolved in N,N-dimethylacetamide at room temperature to make about a 10% polymer solution.
The mixture was then poured into a petri di6h and the 601vent evaporated off under vacuum at 150C for 16 hour~. The re6ulting film was then boiled in water for 4 hour6 to remove the last trace~ of solvent and then heated in a circulating air oven at 250C for 16 hours. The Tg of the film was measured by the modulus resilience method. The film exhibited two distinct glass transition temperatures of 225 and 290C and was therefore judged to be immiscible.
Control H
One gram of PAE III and one gram of PAE XI
were codiEsolved in ~,N-dimethylacetamide at room temperature to make about a 10% polymer solution.

1~7607 The mixture was then poured into a petri dish andthe solvent evaporated off under vacuum at 150C for 4 hours. The resulting film was then boiled in water for 4 hours to remove the last traces of solvent and then heated in a circulating air oven at 250C for 16 hours. The Tg of the film was measured using a DuPont Model 990 Thermal Analyzer equipped with a DSC pressure cell by methods well known in the art (See Olabisi, et al., ibid., pp. 133-134).
The film exhibited two distinct glass transition temperatures of 231 and 258C and was therefore judged to be immiscible.
Example 12 70 parts by weight of PAE I was mixed with 30 parts by weight of PAE X tn a Brabender Plasticorder blender at bout 350C. The blend was compression molded into a 4 x 4 x 0.010 inch plaque at about 350C. The Tg of the plaque was measured by the modulus resilience method and was 225C.
Based on the existence of a single Tg and its transparency, this blend was ~udged to be mi6cible.
Control I
50 parts by weight of PAE I was mixed with 50 parts by weight of PAE IX in a Brabender Plasticorder blender at about 350C. The blends were molded into 4 x 4 x 0.020 inch plaques and mea~ured for glass transition temperatures as described above. The resulting blend was opaque and had two glass transition temperatures of 220O and 260C. On this basis the blend was judged to be immiscible.

~2~7607 Examples 13-15 In order to demonstratQ m`scibility over the entire composition range, 25/7S, 50/50, and 75/25 parts by weight PAE II/PAE V blends were made in a Brabender Plasticorder blender at about 350C.
The blends were compression molded into 4 x 4 x 0.010 inch plaques at about 350OC and their Tgs measured by the modulus resilience method. All blends had a single Tg which varied with composition.

The findings of the Examples and Controls are summarized in Table II. It i8 clear by varying the structure of the polymers in these blend~ that miscibility can be attained in many instances.
Equation (1) will be employed in order to correlate the occurrence of miscibility with the structure of polymers 1 and 2 in the blend. The ~iK are taken to be the molecular area fraction of mer i in polymer K. The three mers optionally present in each polymer are taken to be the following:

Mer Rela_ive Surface Area (1) _~o_ (2) ~ S2 1.415 (3) ~ 0.927 12~760~

Their relative molecular surface areas were estimated as above using the 6cheme giving by D.
Bondi in the Physical Properties of Molecular Llquids, Glasses and Crystals, Chapter 14. Fc was arbitrarily chosen a6 unity and the three Bij were adju~ted such that the experimental results given in Table II were all correctly correlated. The choice of the three Bij were critical in correctly correlating all the examples given in Table II. The values of the Bi; arrived at are:
B12 - 25.2 B13 ~ 14.3 B23 ' 32.8 Substitution of the relative surface area~ of the mers and the ~ij'8 given above into equation (1) results in e~uation (~) repeated here:

t~1~2 ~ 2 ~ ~l~2 ~ ~1~2) 25.2 13 _ ~12~3) 14.3 ~ 2~23 4 ~2~3 - ~1~13 _ ~22~2) 32~8~ 1 where ' Xl ~ l.4l5X2 ~ 0-9 ~ ~1 ' Yl ~ 1.415Y2 ~ 0-~27Y3 2 ~ l~2 ~ g27X3 ~2 ' Yl ~ 1 41SY2 + 0-927Y3 ~3 ~ I~2 ~ o.g21x3 ~2, 0 9Z7Y~

Xl 1~ the molar tr~ctlon ot ~ O rodlcol~ ln poly~rylether ~ulfone 1 X2 15 the molor froctlon r ~ SD radlcals In polyorylether sul-one 1 X lo the molar froctlon ~r ~ r2adlcals In polyarylether ~ulrone 1 Y 1s the molor fractlon of ~ O radlcal~ In polyarylether ~ulfone 2 Y2 1~ the molar fractlon of ~ 50 radlcals In polyarylether sulfone 2 D - 1 4 7 0 6- 1 r3 15 the molar fractlon of ~ rodlcal~ In polyarylether ~ulfone 2 76~)7 Equation 4 was evaluated for the polymer pairs corresponding to the Examples and Controls and the results are given in Table III. In each case Equation (4) correctly predicts the phase behavior of the PAE pairs.
Another way of viewing Equation (4) is to specify the composition of polymer 1. This fixes 2' and ~3 . The region of miscibility then specified by Equation (4) can be depicted graphically. For example, if polymer 1 is specified to be PAE I, ~ 2~ and ~3 can be inserted into Equation ~4) from Table I. Upon simplification, Equation (4) becomes:

18.5~2 ~ 17.4~2 _ 25.~ ~2 _ 14.~ ~2 _ 32.~ ~2 _ 7.5~ 1 (5) Since ~12, ~2~ snd ~32 are functions of Yl, Y2, and Y3 which specify the composition of polymer 2 Yl + Y2 + Y3 ~ 1, Equation (S) may be plotted vQrsus Y2 and Y2 as shown in Figure 2. The shaded portion of Figure 2 depicts the region specified by equation (4) when polymer 1 is PAE I and polymer 2 contains groups (I), (II) and (III) and in any ratio. Likewise the shaded portions of Figures 3, 4, and 5 depict the region specified by equation (4) when polymer 1 is PAE II, III, and IV, respectively.

~2~7607 Table II

Mlsc1blll tY of Varlous PAEs PAE PAE PAE PAE PAE PAE PAE PAE PAE PAE PAE
II III IV V VI VII VIII IX X XI

PAE
I I I M I M I M

PAE M I M M M
II

PAE M M M M
III

pAF I M
IV
. . _ . _ _ . .... _ M ~ mlsc1ble I . l~mlsc1ble ~2~76C)7 (`

Table III

Le~t Hand Slde Equatlon (3) Satlsfled ExamPle of Equatlon_(3) _ (Yes or No)_ _ ]nter_retatlon t 1.42 no lmmlsclble 1.99 no immlsclble 0.72 yes mlsclble 6 0 34 yes lmmlsclble 7 0.73 yes m~sclble .t9 no lmmlsclble 0. yes m~sclble 12 00o.S755 yes mlsclble 1.61 no mlsclble 4 0 37 ynes mlsclble 16 0 39 yes lmmtsclble 18 1 69 no lmmlsclble 21 1 545 ys m1sclble 0.73 no lmmlsc1ble

Claims (15)

1. A miscible blend of two or more different poly)aryl ether sulfones) consisting essentially of at least one unit selected from the group consisting of:

and and at least one unit selected from the group consisting of:
and , wherein at least one of said poly(aryl ether sulfones) comprises at least one member selected from the group consisting of:
and , the poly(aryl ether sulfones) being different and each comprises the following radicals:

, , and , said blend containing from 2 to 98% of each of the poly(aryl ether sulfones).

2. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

3. A miscible blend containing two different poly(aryl ether sulfone polymers A and B, said polymers having the following repeating units:

(A) , and (B)

4. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

, and (B)

5. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

6. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

7. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

8. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

9. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:
(A) , and (B)

10. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

11. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

12. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

13. A miscible blend containing two different poly(aryl ether sulfone) polymers A and B, said polymers having the following repeating units:

(A) , and (B)

14. The miscible blend of poly(aryl ether sulfones) of claim 1 wherein the region of miscibility of the different poly(aryl ether sulfones) in each other is specified by the following equation:

Where X1 is the molar fraction of radicals in polyarylether sulfone 1 X2 is the molar fraction Of radicals in polyarylether sulfone X3 is the molar fraction of radicals in polyarylether sulfone 1 Y1 is the molar fraction of radicals in polyarylether sulfone 2 Y2 is the molar fraction of radicals in polyarylether sulfone .
Y3 is the molar fraction of radicals in polyarylether sulfone 2

15. A miscible blend as defined in claim 1 wherein the poly(aryl ether sulfones) are selected from a poly(aryl ether sulfone) having the following repeating unit: