Method for the purification of poly(arylene ethers)
The invention relates to a method for the purification of poly(arylene ethers) of formula (I) in which m=0 to 1.0, n=1.0-m, and Ar 1 , Ar 2 , Ar 3 and Ar 4 independently represent divalent arylene groups. The compound of formula (I) is produced in a first step 1, with a raw product being obtained by bringing a metal or ammonium salt of divalent dihydroxy derivatives of Ar 1 or Ar 3 into contact with one or more dihalogenated derivatives of Ar 2 and/or Ar 4 , in the presence of a solvent LM1. A precipitate that is present, if appropriate, is separated (step B) so as to obtain a solution L which then undergoes a membrane filtration (step C).
1. A method for the purification of poly(arylene ethers) of formula (I):
where m=0 to 1.0 and n=1.0-m
and Ar 1 , Ar 2 , Ar 3 and Ar 4 are mutually independently divalent arylene residues,
wherein said method comprises:
A) preparing a crude product of the compound of formula (I) in a first step by bringing a metal salt or ammonium salt of divalent dihydroxy derivatives of Ar 1 or Ar 3 into contact with one or more dihalogenated derivatives of Ar 2 and/or Ar 4 , in the presence of a solvent LM1 to form a solution L or a suspension comprising a precipitate;
B) if a suspension comprising precipitate is formed in step A, removing precipitate to obtain solution L; and
C) filtering solution L by membrane filtration.
2. The method of claim 1 , wherein said crude product is prepared in the presence of a catalyst other than said metal or ammonium salt.
3. The method of claim 2 , wherein said catalyst comprises a metal selected from the group consisting of: copper, palladium and iron.
4. The method of claim 1 , wherein an aprotic polar solvent LM2 is added to the solution or suspension formed in step A.
5. The method of claim 4 , wherein the solvent LM1 in step A is selected from an aliphatic or aromatic, cyclic or acyclic, ether, ketone, ester or a mixture thereof.
6. The method of claim 4 , wherein the solvent LM1 in step A is selected from cyclohexanone, tetrahydrofuran, gamma-butyrolactone or a mixture thereof.
7. The method of claim 6 , wherein said solvent is, or comprises, tetrahydrofuran.
8. The method of claim 4 , wherein an acid is added to the solution or suspension formed in step A.
9. The method of claim 1 , wherein, in step B, precipitate is removed by filtration or centrifugation.
10. The method of claim 1 , wherein said membrane filtration is a nanofiltration.
11. The method of claim 1 , wherein the membranes of said membrane filters have a separating layer selected from polymers, glass, metal, ceramic or mixtures thereof.
12. The method of claim 1 , further comprising:
D) obtaining a solid polymer from a filtered solution produced in step C.
13. The method of claim 1 , wherein, in formula (I), m=1 and Ar 1 is a compound of formula (V):
14. The method of claim 1 , wherein in formula (I), m=1 and Ar 2 is a compound of formula (VI):
15. The method of claim 1 , wherein in formula (I), m=1 and the poly(arylene ether) is a polymer of the formula (IV):
16. The method of claim 15 , wherein said crude product is prepared in the presence of a catalyst selected from the group consisting of: copper, palladium and iron.
17. The method of claim 16 , wherein an aprotic polar solvent LM2 is added to the solution or suspension formed in step A.
18. The method of claim 17 , wherein the solvent in step A is selected from an aliphatic or aromatic, cyclic or acyclic, ether, ketone, ester or a mixture thereof.
19. The method of claim 18 , wherein the solvent in step A is selected from cyclohexanone, tetrahydrofuran, gamma-butyrolactone or a mixture thereof.
20. The method of claim 19 , further comprising:
D) obtaining a solid polymer from a filtered solution produced in step C.