POLYMERIC MATERIALS

Abstract

A polymeric material has a repeat unit of formula O-Ph-O-Ph-CO-Ph- I and a repeat unit of formula O-Ph-Ph-O-Ph-CO-Ph- II wherein Ph represents a phenylene moiety; wherein the repeat units I and II are in the relative molar properties I:II of from 65:35 to 95:5; wherein log.sub.10 (X %)>1.50-0.26 MV; wherein X % refers to the % crystallinity measured as described in Example 31 and MV refers to the melt viscosity measured as described in Example 30. A process for making the polymeric material comprises polycondensing a mixture of at least one dihydroxybenzene compound and at least one dihydroxybiphenyl compound in the molar proportions 65:35 to 95:5 with at least one dihalobenzophenone in the presence of sodium carbonate and potassium carbonate wherein: (i) the mole % of said potassium carbonate is at least 2.5 and/or (ii) the following relationship applies (formula III).

Claims

1. A polymeric material having a repeat unit of formula
O-Ph-O-Ph-CO-Ph-I and a repeat unit of formula
O-Ph-Ph-O-Ph-CO-Ph-II wherein Ph represents a phenylene moiety; wherein the repeat units I and II are in the relative molar properties I:II of from 65:35 to 95:5; wherein log.sub.10 (X %)>1.500.26 MV; wherein X % refers to the % crystallinity measured as described in Example 31 and MV refers to the melt viscosity measured as described in Example 30.

2. A material according to claim 1, wherein at least 95% of the number of phenylene moieties (Ph) in the repeat unit of formula I have 1,4-linkages to moieties to which they are bonded; and at least 95% of the number of phenylene moieties (Ph) in the repeat unit of formula II have 1,4-linkages to moieties to which they are bonded.

3. A material according to claim 1 or claim 2, wherein log.sub.10 (X %)>1.500.23 MV.

4. A polymeric material according to any preceding claim, wherein log.sub.10 (X %)>1.500.28 MV+0.06 MV.sup.2.

5. A material according to any preceding claim, which includes 68 mol % to 82 mole % of units of formula I.

6. A material according to any preceding claim, which includes 72 to 77 mole % of units of formula I.

7. A material according to any preceding claim, which includes 18 to 32 mole % of units of formula II.

8. A material according to any preceding claim, which includes 23 to 28 mole % of units of formula II.

9. A material according to any preceding claim, wherein the sum of the mole % of units of formulas I and II in said polymeric material is at least 99 mole %.

10. A material according to any preceding claim, wherein Tm is in the range 300 C. to 310C.

11. A material according to any preceding claim, wherein said polymeric material has a Tg in the range 145 C.-155 C., a Tm in the range 300 C. to 310 C. and the difference between the Tm and Tg is in the range 145 C. to 165 C.

12. A material according to any preceding claim, which has a crystallinity of at least 25%.

13. A material according to any preceding claim, which is part of a composition which includes said polymeric material and a filler means.

14. A material according to claim 13, wherein said filler means comprises one or more fillers selected from glass fibre, carbon fibre, carbon black and a fluorocarbon resin.

15. A process for the production of a polymeric material having a repeat unit of formula
O-Ph-O-Ph-CO-Ph-I and a repeat unit of formula
O-Ph-Ph-O-Ph-CO-Ph-II wherein Ph represents a phenylene moiety, said process comprising polycondensing a mixture of at least one dihydroxybenzene compound and at least one dihydroxybiphenyl compound in the molar proportions 65:35 to 95:5 with at least one dihalobenzophenone in the presence of sodium carbonate and potassium carbonate wherein: (i) the mole % of said potassium carbonate is at least 2.5 and/or (ii) the following relationship (referred to as the D50/mole % relationship) applies $\frac{\mathrm{the}.Math..Math.D_{50}.Math..Math.\mathrm{of}.Math..Math.\mathrm{said}.Math..Math.\mathrm{sodium}.Math..Math.\mathrm{carbonate}.Math..Math.\mathrm{in}.Math..Math.\mathrm{.Math.m}}{\mathrm{mole}.Math..Math.\%.Math..Math.\mathrm{of}.Math..Math.\mathrm{potassium}.Math..Math.\mathrm{carbonate}}=<46.$

16. A process according to claim 15, wherein the mole % of said potassium carbonate is at least 3 mole % and is less than 10 mole %.

17. A process according to claim 15 or claim 16, wherein the mole % of said potassium carbonate is less than 6 mole %.

18. A process according to any of claims 15 to 17, wherein the mole % of sodium carbonate used in the method is at least 90 mole %.

19. A process according to any of claims 15 to 18, wherein the sum of the mole % of sodium carbonate and potassium carbonate used in the method is at least 100 mole %.

20. A process according to any of claims 15 to 19, wherein the only carbonates used in the method are sodium carbonate and potassium carbonate.

21. A process according to any of claims 15 to 20, wherein the D50/mole % relationship is less than 30.

22. A process according to any of claims 15 to 21, wherein the D50 of said sodium carbonate is in the range 50 to 140 m.

23. A process according to any of claims 15 to 22, which comprises selecting a dihydroxybenzene compound of formula ##STR00009## and selecting a dihydroxybiphenyl compound of formula ##STR00010## wherein molar proportions of compounds V and VI are in the range 65:35 to 95:5, the process comprising polycondensing said compounds of formulas V and VI with a compound of formula ##STR00011## where X.sup.1 and X.sup.2 independently represent halogen atoms.

24. A process according to any of claims 15 to 23, wherein at least 95 wt % of monomers used in the process are made up of monomers of formulae V, VI and VII.

Description

[0067] Specific embodiments of the invention will now be described, by way of example, with reference to the figures wherein:

[0068] FIG. 1 is a graph of log.sub.10 (X %), wherein X refers to the crystallinity v. melt viscosity (MV) for various PEEK:PEDEK polymeric materials made using various processes;

[0069] FIG. 2 is a schematic describing the relationship between D.sub.50 of sodium carbonate and mole % excess of potassium carbonate.

[0070] The following are referred to herein:

[0071] PEEK 150refers to polyetheretherketone supplied by Victrex Manufacturing Limited which has a melt viscosity, measured using capillary rheometry operating at 400 C. and a shear rate of 1000 s.sup.1 using a tungsten carbide die (0.5 mm3.175 mm), of 0.15 kNsm.sup.2.

[0072] Polymers were prepared as described in Example 1 to 28. Subsequent examples include details on procedures and tests undertaken.

EXAMPLE 1PREPARATION OF 0.5 MOL POLYETHERETHERKETONE (PEEK)-POLYETHERDIPHENYLETHERKETONE (PEDEK) COPOLYMER

[0073] A 0.5 litre flanged flask fitted with a ground glass lid, stirrer/stirrer guide, nitrogen inlet and outlet was charged with 4,4-diflurobenzophenone (111.29 g, 0.510 mol), 1,4-dihydroxybenzene (41.30 g, 0.375 mol), 4,4-dihydroxydiphenyl (23.28 g, 0.125 mol) and diphenylsulphone (241.07 g) and purged with nitrogen for 1 hour. The contents were then heated under a nitrogen blanket to 160 C. to form an almost colourless solution. While maintaining a nitrogen blanket, dried sodium carbonate (53.00 g, 0.5 mol) and potassium carbonate (2.76 g, 0.02 mol), both sieved through a screen with a mesh size of 500 micrometres, were added. The temperature was raised to 185 C. at 1 C./min and held for 100 minutes. The temperature was raised to 205 C. at 1 C./min and held for 20 minutes. The temperature was raised to 315 C. at 1 C./min and held for approximately 60 minutes or until the desired MV was reached as indicated by the torque rise on the stirrer. The required torque rise was determined from a calibration graph of torque rise versus MV. The reaction mixture was then poured into a foil tray, allowed to cool, milled and washed with 2 litres of acetone and then with warm water at a temperature of 40-50 C. until the conductivity of the waste water was <2 S. The resulting polymer powder was dried in an air oven for 12 hours at 120 C.

EXAMPLES 2 TO 9PREPARATION OF POLYETHERETHERKETONE (PEEK)-POLYETHERDIPHENYLETHERKETONE (PEDEK) COPOLYMER

[0074] The procedure described in Example 1 was repeated except that the quantity of potassium carbonate and the mesh size used to sieve the sodium carbonate were varied to provide polyetheretherketone (PEEK)-polyetherdiphenyletherketone (PEDEK) copolymers of different crystallinity as shown in Table 1.

EXAMPLE 10PREPARATION OF POLYETHERETHERKETONE (PEEK)-POLYETHERDIPHENYLETHERKETONE (PEDEK) COPOLYMER BASED UPON EXAMPLE 1 OF U.S. PAT. NO. 4,717,761

[0075] A 0.5 litre flanged flask fitted with a ground glass lid, stirrer/stirrer guide, nitrogen inlet and outlet was charged with 4,4-diflurobenzophenone (112.38 g, 0.515 mol), 1,4-dihydroxybenzene (41.30 g, 0.375 mol), 4,4-dihydroxydiphenyl (23.28 g, 0.125 mol) and diphenylsulphone (243.100) and purged with nitrogen for 1 hour. The contents were then heated under a nitrogen blanket to 180%; to form an almost colourless solution. While maintaining a nitrogen blanket, dried sodium carbonate (53.00 g, 0.5 mol) and potassium carbonate (0.35 g, 0.003 mol), both sieved through a screen with a mesh of 500 micrometres, were added. The temperature was raised to 200 C. at 1 C./min and held for 60 minutes. The temperature was raised to 250 C. at 1 C./min and held for 60 minutes. The temperature was raised to 300 C. at 1 C./min and held for 60 minutes. The reaction mixture was then poured into a foil tray, allowed to cool, milled and washed with 2 litres of acetone and then with warm water at a temperature of 40-50 C. until the conductivity of the waste water was <2 S. The resulting polymer powder was dried in an air oven for 12 hours at 120 C.

EXAMPLE 11PERORATION OF POLYETHERETHERKETONE (PEEK)-POLYETHERDIPHENYLETHERKETONE (PEDEK) COPOLYMER

[0076] The procedure of Example 10 was followed except that the reagents of Example 11 were reacted until a higher torque value was achieved compared to Example 10, so the copolymer of Example 11 has a higher MV.

EXAMPLE 12PERORATION OF POLYETHERETHERKETONE (PEEK)-POLYETHERDIPHENYLETHERKETONE (PEDEK) COPOLYMER BASED UPON U.S. PAT. NO. 4,717,761

[0077] The procedure described in Example 10 was repeated except that the particle size distribution of the sodium carbonate was increased (D50 approximately 140 m) to establish its effect on polyetheretherketone (PEEK)-polyetherdiphenyletherketone (PEDEK) copolymer crystallinity as shown in Table 1. The larger particle size of sodium carbonate resulted in no polymerisation taking place, so a further 4 mol % of sodium carbonate and 1 mol % of hydroquinone had to be added to the reaction.

EXAMPLES 13 & 14PREPARATION OF POLYETHERETHERKETONE (PEEK)-POLYETHERDIPHENYLETHERKETONE (PEDEK) COPOLYMER

[0078] A 0.5 litre flanged flask fitted with a ground glass lid, stirrer/stirrer guide, nitrogen inlet and outlet was charged with 4,4-diflurobenzophenone (111.29 g, 0.515 mol), 1,4-dihydroxybenzene (41.30 g, 0.375 mole), 4,4-dihydroxydiphenyl (23.28 g, 0.125 mol) and diphenylsulphone (24.09 g) and purged with nitrogen for 1 hour. The contents were then heated under a nitrogen blanket to 200 C. to form an almost colourless solution. While maintaining a nitrogen blanket, dried sodium carbonate (53.00 g, 0.5 mol) and potassium carbonate (3.46 g, 0.025 mol), both sieved through a screen with a mesh of 500 micrometres, were added. The temperature was raised to 250 C. at 1 C./min and held for 15 minutes. The temperature was raised to 320 C. at 1 C./min and held for 60 minutes. The reaction mixture was allowed to cool and stand overnight under a nitrogen blanket. The following day the temperature of the mixture was raised to 320 C. and held for 150 minutes. The vessel was then charged with 5 g of 4,4-dichlorodiphenylsulfone and held at 320 C. for a further 30 minutes. The reaction mixture was then poured into a foil tray, allowed to cool, milled and washed with 2 litres of acetone and then with warm water at a temperature of 40-50 C. until the conductivity of the waste water was <2 S. The resulting polymer powder was dried in an air oven for 12 hours at 120 C.

EXAMPLES 15 TO 24PREPARATION OF POLYETHERETHERKETONE (PEEK)-POLYETHERDIPHENYLETHERKETONE (PEDEK) COPOLYMER ON A 200 MOL SCALE

[0079] A 300 litre vessel fitted with a lid, stirrer/stirrer guide, nitrogen inlet and outlet was charged with diphenylsulphone (125.52 kg) and heated to 150 C. Once fully melted 4,4-diflurobenzophenone (44.82 kg, 205.4 mol), 1,4-dihydroxybenzene (16.518 kg, 150 mol) and 4,4-dihydroxydiphenyl (9.311 kg, 50 mol) were charged to the vessel. The contents were then heated to 160 C. While maintaining a nitrogen blanket, dried sodium carbonate (21.368 kg, 201.6 mol) and potassium carbonate (1.106 kg, 8 mol), both sieved through a screen with a mesh of 500 micrometres, were added. The temperature was raised to 180 C. at 1 C./min and held for 100 minutes. The temperature was raised to 200 C. at 1 C./min and held for 20 minutes. The temperature was raised to 305 C. at 1 C./min and held until desired melt viscosity was reached, as determined by the torque rise of the stirrer. The required torque rise was determined from a calibration graph of torque rise versus MV. The reaction mixture was poured via a band caster into a water bath, allowed to cool, milled and washed with acetone and water. The resulting polymer powder was dried in a tumble dryer until the contents temperature measured 112 C.

EXAMPLES 25 TO 28PREPARATION OF POLYETHERETHERKETONE (PEEK)-POLYETHERDIPHENYLETHERKETONE (PEDEK) COPOLYMER ON A 200 MOL SCALE

[0080] The procedure described in Example 15 to 24 was repeated except that the quantity of DPS was 96.72 kg.

[0081] Table 1 below includes a summary of Examples 1 to 28. D50 as described herein was determined as described in Example 29.

EXAMPLE 29GENERAL PROCEDURE FOR DETERMINING D50

[0082] The D50 of sodium carbonate was determined by Malvern Laser Diffractometer, using the associated Mastersizer 3000 software. A Fraunhofer type process was used to eliminate the requirement of refractive index figures for the samples. Using the Mastersizer 300 software, the following instrument parameters were set:

TABLE-US-00001 Scattering Model Fraunhofer Background measurement duration 10.00 s Sample measurement duration 10.00 s Number of measurements 2 Obscuration low limit 1% Obscuration high limit 6% Obscuration time out 5.00 s Air Pressure 1.5 barg Feed Rate 17% Venturi type Standard venturi disperser Hopper gap 2.00 mm Analysis model General Purpose

[0083] A dried sample (<5 g) of carbonate was scooped into the hopper at the top of the machine. A background measurement was run, and then two sample measurements were taken. The feed rate was started at 17%, but was manually adjusted as the measurement was taken to ensure the obscuration measurement sat within the 1-6% limits.

[0084] In Table 1, the quantity of potassium carbonate is quoted in mole %. Unless otherwise stated herein, the mole % of potassium carbonate is defined as:

[00003]$\frac{\mathrm{the}.Math..Math.\mathrm{number}.Math..Math.\mathrm{of}.Math..Math.\mathrm{moles}.Math..Math.\mathrm{of}.Math..Math.\mathrm{potassium}.Math..Math.\mathrm{carbonate}}{\mathrm{the}.Math..Math.\mathrm{total}.Math..Math.\mathrm{moles}.Math..Math.\mathrm{of}.Math..Math.\mathrm{hydroxy}.Math..Math.\mathrm{monomer}\left(s\right).Math..Math.\mathrm{used}}100.Math.\%$

[0085] Melt viscosity (MV) referred to in Table 1 may be determined as described in Example 30.

EXAMPLE 30DETERMINATION OF MELT VISCOSITY (MV) OF POLYMER

[0086] Unless otherwise stated, this was measured using capillary rheometry operating at 340 C. at a shear rate of 1000 s.sup.1 using a tungsten carbide die, 0.5 mm3.175 mm. The MV measurement was taken 5 minutes after the polymer had fully melted, which is taken to be 5 minutes after the polymer is loaded into the barrel of the rheometer.

TABLE-US-00002 TABLE 1 Sodium Sodium Quantity Carbonate Carbonate Potassium Example Sieve Size D.sub.50 Carbonate MV (@ No. (m) (m) (mole %) 340 C.) 1 500 96.7 4 0.22 2 125 67.7 0.25 0.22 3 125 67.7 2 0.28 4 300 93.1 0.25 0.14 5 300 93.1 2 0.34 6 500 96.7 0.25 0.12 7 500 96.7 0.25 0.13 8 500 96.7 0.25 0.31 9 500 96.7 2 0.34 10 500 96.7 0.5 0.18 11 500 96.7 0.5 0.30 12 500 140 0.5 0.12 13 500 96.7 5 0.62 14 500 96.7 5 0.52 15 500 98.7 4 0.25 16 500 98.7 4 0.203 17 500 98.7 4 0.258 18 500 98.7 4 0.283 19 500 98.7 4 0.324 20 500 98.7 4 0.222 21 500 98.7 4 0.26 22 500 98.7 4 0.269 23 500 98.7 4 0.186 24 500 98.7 4 0.295 25 500 98.7 4 0.406 26 500 98.7 4 1.707 27 500 98.7 4 1.305 28 500 98.7 4 0.853

EXAMPLE 31DIFFERENTIAL SCANNING CALORIMETRY OF POLYARYLETHERKETONES OF EXAMPLES 1 TO 28

[0087] Crystallinity (as reported in Table 2) may be assessed by several methods for example by density, by ir spectroscopy, by x ray diffraction or by differential scanning calorimetry (DSC). The DSC method has been used to evaluate the crystallinity that developed in the polymers from Examples 1-28 using a Mettler Toledo DSC1 Star system with FRS5 sensor.

[0088] The Glass Transition Temperature (Tg), the Cold Crystallisation Temperature (Tn), the Melting Temperature (Tm) and Heat of Fusions of Nucleation (Hn) and Melting (Hm) for the polymers from Examples 1 to 28 were determined using the following DSC method.

[0089] A dried sample of each polymer was compression moulded into an amorphous film, by heating 7 g of polymer in a mould at 400 C. under a pressure of 50 bar for 2 minutes, then quenching in cold water producing a film of dimensions 120120 mm, with a thickness in the region of 0.20 mm. An 8 mg plus or minus 3 mg sample of each film was scanned by DSC as follows: [0090] Step 1 Perform and record a preliminary thermal cycle by heating the sample from 30 C. to 400 C. at 20 C./min. [0091] Step 2 Hold for 5 minutes. [0092] Step 3 Cool at 20 C./min to 30 C. and hold for 5 mins. [0093] Step 4 Re-heat from 30 C. to 400 C. at 20 C./min, recording the Tg, Tn, Tm, Hn and Hm.

[0094] From the DSC trace resulting from the scan in step 4, the onset of the Tg was obtained as the intersection of the lines drawn along the pre-transition baseline and a line drawn along the greatest slope obtained during the transition. The Tn was the temperature at which the main peak of the cold crystallisation exotherm reaches a maximum. The Tm was the temperature at which the main peak of the melting endotherm reach maximum.

[0095] The Heat of Fusion for melting (Hm) was obtained by connecting the two points at which the melting endotherm deviates from the relatively straight baseline. The integrated area under the endotherm as a function of time yields the enthalpy (mJ) of the melting transition: the mass normalised heat of fusion is calculated by dividing the enthalpy by the mass of the specimen (J/g). The level of crystallisation (%) is determined by dividing the Heat of Fusion of the specimen by the Heat of Fusion of a totally crystalline polymer, which for polyetheretherketone is 130 J/g.

[0096] Results are provided in Table 2.

TABLE-US-00003 Polymer Level of from Tg Tn H.sub.n Tm H.sub.m Crystallinity Example ( C.) ( C.) (J/g) ( C.) (J/g) (%) 1 148.00 n/a n/a 305.00 35.47 28.55 2 147.21 204.80 7.30 304.18 33.10 19.54 3 150.27 n/a n/a 303.05 30.42 23.40 4 148.18 n/a n/a 306.47 32.40 24.93 5 149.06 n/a n/a 303.51 32.25 24.81 6 140.47 n/a n/a 305.41 34.87 26.82 7 148.78 n/a n/a 306.73 25.75 27.50 8 147.00 200.10 2.75 302.11 33.17 23.68 9 148.26 n/a n/a 303.19 30.56 23.51 10 150.09 n/a n/a 305.52 32.72 25.63 11 149.19 n/a n/a 303.47 31.79 24.45 12 148.47 n/a n/a 307.68 37.17 28.59 13 153.65 n/a n/a 303.67 26.04 20.04 14 152.76 n/a n/a 302.14 27.38 21.06 15 150.42 n/a n/a 304.57 38.77 29.83 16 149.6 n/a n/a 305.58 39.88 30.68 17 150.03 n/a n/a 306.45 36.99 28.45 18 150.86 n/a n/a 306.32 37.19 28.6 19 150.84 n/a n/a 306.41 36.56 28.12 20 150.2 n/a n/a 307.68 36.82 28.32 21 150.34 n/a n/a 306.67 39.84 30.65 22 150.21 n/a n/a 307.03 35.47 27.28 23 150.03 n/a n/a 306.72 39.64 30.49 24 150.11 n/a n/a 292.36 43.03 33.11 25 149.1 n/a n/a 301.6 n/a 27.00 26 154.0 n/a n/a 294.0 n/a 17.50 27 152.5 n/a n/a 296.5 n/a 20.40 28 151.7 n/a n/a 297.6 n/a 21.60

EXAMPLE 32MECHANICAL PRIORITIES

[0097] The mechanical properties of a blend of the materials of Examples 15 to 19 to give an MV of 0.25 kNsm.sup.2 were assessed in a series of tests and the results are provided in Table 3. Table 3 also quotes results of mechanical tests undertaken on commercially available Victrex PEEK 150 for comparison.

TABLE-US-00004 TABLE 3 Test Conditions Method Units Value PEEK150 Tensile Yield, ISO 527 MPa 94 110 strength 23 C. Tensile Break, ISO 527 % 24 25 Elongation 23 C. Tensile 23 C. ISO 527 GPa 3.5 3.7 Modulus Flexural 23 C. ISO 178 MPa 145 130 Strength Flexural 23 C. ISO 178 GPa 3.5 4.3 Modulus Izod impact Notched, ISO 180/U kJ m.sup.2 5.2 5.0 Strength 23 C.

DISCUSSION

[0098] In general terms, it is found that the process described herein can be used to produce PEEK:PEDEK copolymers which have advantageously higher crystallinities than expected.

[0099] Referring to FIG. 1, the results from Tables 1 and 2 are plotted. The graph describes log.sub.10 (X %) (i.e. log.sub.10 of the % crystallinity measured by DSC as described) v. the melt viscosity (MV) determined as described (i.e. using capillary rheometry operating at 340 C. at a shear rate of 1000 s.sup.1 using a tungsten carbide die 0.5 mm3.175 mm. FIG. 1 shows a first series of points, being the results for Examples 1 and 15 to 28, (represented by squares) which have a crystallinity for a selected MV which is higher than a second series of points, being the results for Examples 2 to 14, (represented by triangles). The first series of points relate to polymeric materials made in processes which use at least 2.5 mole % based on the total moles of hydroxy monomer(s), whereas the second series of points use less than 2.5 mole % potassium carbonate based on the total moles of hydroxy monomer(s). It is clear that the level of potassium carbonate used affects the crystallinity of the PEEK:PEDEK copolymer, resulting in crystallinity which is higher than would be expected for example based on the disclosure in U.S. Pat. No. 4,717,761. The equation of the line for the second series of points is found to be

log.sub.10(X %)=1.450.24 MV

FIG. 1 also includes a first calculated dividing line above the second series of points. The calculated dividing line is included to delineate polymeric materials which are in accordance with preferred embodiments of the invention (i.e. materials found above the dividing line) from those which are not in accordance with preferred embodiments of the invention (i.e. materials found below the dividing line). The equation of the dividing line is:

log.sub.10(X %)=1.500.26 MV

[0100] Thus, for polymeric materials in accordance with preferred embodiments, the following relationship applies:

log.sub.10(X %)>1.500.26MV

[0101] FIG. 1 includes a second calculated dividing line above the first calculated dividing line, the second dividing line defines more preferred embodiments. Thus, more preferred embodiments fall above the second calculated dividing line and the following relationship applies:

log.sub.10(X %)>1.500.23MV

where X and MV are determined as described.

[0102] FIG. 3 includes a third calculated dividing line above the second calculated dividing line.

[0103] The third line defines especially preferred embodiments. Thus, especially preferred embodiments fall above the third calculated dividing line and the following relationship applies:

log.sub.10(X %)>1.510.28 MV+0.06 MV.sup.2

where X and MV are determined as described.

[0104] On the basis of the Examples described and other examples, the relationship graphically represented in FIG. 2 was determined. The reference to poor crystallinity means the crystallinity of the PEEK:PEDEK copolymers was less than 25%; and the reference to good crystallinity means the crystallinity of the copolymer was greater than 25%.

[0105] Referring to FIG. 2, preferred embodiments of the present invention use a process wherein the mole % of potassium carbonate based on the total moles of hydroxy monomer(s) is greater than 2.5 mole % or the following applies:

[00004]$\frac{D.Math..Math.50.Math..Math.\mathrm{of}.Math..Math.\mathrm{sodium}.Math..Math.\mathrm{carbonate}.Math..Math.\mathrm{in}.Math..Math.\mathrm{.Math.m}}{\mathrm{mole}.Math..Math.\%.Math..Math.\mathrm{of}.Math..Math.\mathrm{potassium}.Math..Math.\mathrm{carbonate}}$

is less or equal to 46.

[0106] In view of the differences between polymeric materials in accordance with preferred embodiments of the present invention and other materials described, NMR was used to assess materials as described in Example 28.

EXAMPLE 33NMR ANALYSIS OF PEEK:PEDEK POLYMERS AND COMPARISON WITH PEEK POLYMER

[0107] Pressed films made from the polymeric materials of Example 21 (a material in accordance with a preferred embodiment of the invention), Example 4, Example 10 and PEEK 150 were assessed to determine any structural differences.

[0108] For the analysis a portion of each pressed film was dissolved in methane sulphonic acid/methylene dichloride solvent (the standard solvent used for polyaryletherketone polymers). In each case, the resulting solutions were clear to the naked eye, suggesting total solubility.

[0109] The solutions were examined using a Lambda 300 instrument at 25 C. to produce .sup.13C NMR spectra. The carbonyl region of the spectrum was expanded and three carbonyl groups were identified in slightly different chemical environments as follows:

199.7 ppm PEEK homopolymer (seen in the PEEK 150 material assessed);
199.35 ppm PEDEK homopolymer;
199.5 ppm PEEK:PEDEK interchange unit (nb this resonance would not be present if the sample was a blend of two homopolymers (i.e. PEEK and PEDEK)).

[0110] On the basis that the PEEK:PEDEK copolymers have a 7525 composition, the theoretical areas that would result from the aforementioned resonances if a sample was 100% random was determined. Then, the areas measured in the spectra were compared to the theoretical value yielding a % randomness of each PEEK:PEDEK material as described below.

TABLE-US-00005 Example No. % randomness 10 30 4 23 21 38

[0111] Thus, it appears the process used in accordance with preferred embodiments of the invention results in production of a more random copolymer which results in an increase in crystallinity over and above the level of crystallinity that may be expected.

[0112] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.