Polyarylethersulfone copolymers
The invention relates to a method for preparing polyarylethersulfone-polyalkylene oxide block copolymers (PPC) comprising the polycondensation of a reaction mixture (R G ) comprising the components: (A1) at least one aromatic dihalogen compound, (B1) at least one aromatic dihydroxyl compound, (B2) at least one polyalkylene oxide having at least two hydroxyl groups, (C) at least one aprotic polar solvent and (D) at least one metal carbonate, where the reaction mixture (R G ) does not comprise any substance which forms an azeotrope with water.
1. A method for preparing a polyarylethersulfone-polyalkylene oxide block copolymer, the method comprising:
polycondensing a reaction mixture comprising:
(A1) an aromatic dihalogen compound,
wherein component (A1) comprises at least 50% by weight of at least one aromatic dihalosulfone compound selected from the group consisting of 4,4′-dichlorodiphenyl sulfone and 4,4′-difluorodiphenyl sulfone, based on a total weight of component (A1) in the reaction mixture,
(B1) an aromatic dihydroxyl compound,
(B2) a polyalkylene oxide comprising at least two hydroxyl groups,
(C) an aprotic polar solvent, and
(D) a metal carbonate,
wherein the reaction mixture does not comprise any substance which forms an azeotrope with water, and
wherein the polyarylethersulfone-polyalkylene oxide block copolymer has a polydispersity of ≦4, wherein the polydispersity is defined as a quotient of a weight average molecular weight M w and a number average molecular weight M n .
2. The method according to claim 1 wherein component (B1) comprises at least 50% by weight of an aromatic dihydroxyl compound selected from the group consisting of 4,4′-dihydroxybiphenyl and 4,4′-dihydroxydiphenyl sulfone, based on a total weight of component (B1) in the reaction mixture.
3. The method according to claim 1 , wherein component (B2) comprises at least 50% by weight of a polyalkylene oxide which is obtained by polymerisation of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, 1,2-pentene oxide, 2,3-pentene oxide or a mixture thereof, based on a total weight of component (B2) in the reaction mixture.
4. The method according to claim 1 , wherein the reaction mixture comprises N-methyl-2-pyrrolidone as component (C).
5. The method according to claim 1 , wherein the reaction mixture comprises potassium carbonate as component (D).
6. The method according to claim 1 , wherein component (A1) is 4,4′-dichlorodiphenyl sulfone, component (B1) is 4,4′-dihydroxydiphenyl sulfone and component (B2) is a polyethylene glycol.
7. The method according to claim 1 , wherein the reaction mixture comprises 0.7 to 0.995 mol of component (B1) and 0.005 to 0.3 mol of component (B2) per one mole of component (A1).
8. The method according to claim 1 , wherein at least 85% by weight of component (B2) present in the reaction mixture are incorporated into the polyarylethersulfone-polyalkylene oxide block copolymer.
9. The method according to claim 1 , wherein the reaction mixture comprises potassium carbonate having a volume weighted average particle size of less than 200 μm as component (D).
10. The method according to claim 1 , wherein the polyarylethersulfone-polyalkylene oxide block copolymer has a weight average molecular weight of from 10 000 to 150 000 g/mol.
11. The method according to claim 1 , wherein the polyarylethersulfone-polyalkylene oxide block copolymer has a polydispersity of from 2.0 to ≦4.
12. The method according to claim 1 , wherein the reaction takes place in a single reaction stage without isolation of an intermediate product.