Method for preparing poly (ether ketone ketones)

1. A method of preparing a poly (ether ketone ketone) consisting essentially of the repeat unit:

—Ar—O—Ar—C(═O)—Ar—C(═O)—

wherein each Ar is independently an aromatic moiety,

said method comprising polymerising a monomer system in a reaction medium comprising:

(a) a Lewis acid; and

(b) a controlling agent comprising an aromatic carboxylic acid, an aromatic sulphonic acid, or a derivative thereof.

2. A method for producing a poly (ether ketone ketone) consisting essentially of the repeat unit:

—Ar—O—Ar—C(═O)—Ar—C(═O)—

wherein each Ar is independently an aromatic moiety, having a selected particle size distribution, said method comprising:

(i) polymerising a monomer system in a reaction medium comprising:

(a) a Lewis acid; and

(b) a controlling agent comprising an aromatic carboxylic acid, an aromatic sulphonic acid, or a derivative thereof

and

(ii) adjusting a ratio of controlling agent to monomers in the monomer system whereby to control particle size distribution.

3. The method as claimed in claim 2 wherein the particle size is selected by adjusting a ratio of moles of controlling agent to moles of acid halide groups present in the monomer system.

4. The method as claimed in claim 1 wherein the ratio of moles of controlling agent to moles of acid halide groups present in the monomer system is from 0.1 to 10.

5. The method as claimed in claim 1 wherein the controlling agent comprises:

(i) Ar′(COOX) y ;

(ii) Ar′(SO 3 X) y ;

(iii) (Ar′COO − ) z M z+ ; or

(iv) (Ar′SO 3 − ) z M z+

wherein Ar′ is an aromatic group compatible with the remaining components of the reaction medium;

each X independently is a hydrogen atom or an organic group (R);

each y independently is 1, 2 or 3;

each M independently is a metal ion; and

each z independently is an integer equal to the charge on the metal ion (M z+ ).

6. The method as claimed in claim 1 wherein each Ar is independently selected from substituted and unsubstituted phenylene and substituted and unsubstituted polynuclear aromatic moieties.

7. The method as claimed in claim 1 wherein said Lewis acid is aluminium chloride.

8. The method as claimed in claim 1 wherein said controlling agent is benzoic acid.

9. The method as claimed in claim 1 wherein said monomer system comprises bis 1,4(4-phenoxybenzoyl)benzene and a phthaloyl halide in a 1:1 ratio by weight.

10. The method as claimed in claim 9 wherein said phthaloyl halide is a mixture of terephthaloyl halide and isophthaloyl halide.

11. The method as claimed in claim 9 wherein said phthaloyl halide is phthaloyl chloride.

12. The method as claimed in claim 10 wherein a ratio of terephthaloyl halide to isophthaloyl halide is 60:40 by weight.

13. The method as claimed in claim 1 , wherein the poly (ether ketone ketone) is in particulate form.

14. The method of claim 13 , wherein said particulate form comprises substantially spherical particles.

15. The method as claimed in claim 13 , wherein the particulate form comprises particles, which are 0.1 to 3000 μm in diameter.

16. The method as claimed in claim 13 , wherein at least 25% of the particles in the particulate form are less than 100 μm in diameter.

17. The method as claimed in claim 1 , further comprising forming said poly (ether ketone ketone) into an article selected from the group consisting of a biomedical implant, a film, a fibre, or an aerospace component.