Copolymer having amphiphilic blocks, and use thereof for manufacturing polymer filtration membranes
A copolymer having amphiphilic blocks includes at least one first hydrophilic block, obtainable from n-butyl acrylate and hydroxyethyl methacrylate monomers, and a second hydrophobic block likely to be obtained from a methyl methacrylate monomer. The copolymer is found to be particularly advantageous for use as an additive for manufacturing a polymer filtration membrane, particularly a PVDF membrane, particularly via a phase inversion method.
1. An amphiphilic block copolymer comprising at least a first hydrophilic block obtainable from n-butyl acrylate and hydroxyethyl methacrylate monomers and a second hydrophobic block obtainable from a methyl methacrylate monomer.
2. The copolymer as claimed in claim 1 , consisting of a diblock copolymer.
3. The copolymer as claimed in claim 1 , wherein said first hydrophilic block is essentially composed of a random copolymer comprising n-butyl acrylate and hydroxyethyl methacrylate monomers.
4. The copolymer as claimed in claim 1 , wherein said second hydrophobic block is composed of at least 50% of polymethyl methacrylate, the remainder being formed of a mixture of methacrylate or acrylate monomers.
5. The copolymer as claimed in claim 4 , wherein the remainder is formed of a mixture of n-butyl acrylate and hydroxyethyl methacrylate monomers.
6. The copolymer as claimed in claim 1 , consisting of a (poly(n-butyl acrylate)-co-poly(hydroxyethyl methacrylate)-b-hydrophobic) block copolymer where the hydrophobic block is composed of at least 50% of polymethyl methacrylate, the remainder being formed of a mixture of methacrylate or acrylate monomers.
7. The copolymer as claimed in claim 6 , wherein the remainder is formed of a mixture of n-butyl acrylate and hydroxyethyl methacrylate monomers.
8. The copolymer as claimed in claim 1 , exhibiting a weight-average molecular weight of between 10 kg/mol and 400 kg/mol.
9. The copolymer as claimed in claim 1 , wherein said first hydrophilic block and/or said second hydrophobic block is obtainable by a controlled radical polymerization process.
10. The copolymer as claimed in claim 9 , obtainable by SFRP polymerization.
11. The copolymer as claimed in claim 10 , wherein said first hydrophilic block and/or said second hydrophobic block is obtainable by SFRP polymerization in the presence of at least one alkoxyamine.
12. The copolymer as claimed in claim 11 , wherein said first hydrophilic block and/or said second hydrophobic block is obtainable by SFRP polymerization in the presence of a monoalkoxyamine of formula (I):
13. A method for manufacturing a polymer filtration membrane, comprising coagulating a collodion comprising a polymer matrix and an amphiphilic block copolymer as claimed in claim 1 as an additive.
14. A polymer membrane, comprising a hydrophobic polymer matrix and an amphiphilic block copolymer as claimed in claim 1 .
15. The polymer membrane as claimed in claim 14 , wherein the hydrophobic polymer matrix comprises a fluoro polymer.
16. The polymer membrane as claimed in claim 15 , wherein said fluoro polymer is a polyvinylidene fluoride homopolymer.
17. The polymer membrane as claimed in claim 14 , comprising from 60 to 90% by weight of said hydrophobic polymer matrix and from 10 to 40% by weight of said amphiphilic block copolymer.
18. The polymer membrane as claimed in claim 14 , obtainable by a phase inversion process starting from a solution comprising said hydrophobic polymer matrix, said amphiphilic block copolymer and, if appropriate, one or more other additives, in solution in a solvent.
19. The polymer membrane as claimed in claim 18 , obtainable by a phase inversion process from a solution comprising the following proportions by weight:
from 10 to 40% of said hydrophobic polymer matrix;
from 0.1 to 30% by weight of said amphiphilic block copolymer;
from 40 to 90% of solvent;
if appropriate, from 0 to 20% by weight of other additive(s).
20. The polymer membrane as claimed in claim 19 , wherein said hydrophobic polymer matrix is PVDF.
21. A method of treating effluents, comprising filtering an effluent through a polymer membrane as claimed in claim 14 .
22. The method as claimed in claim 21 wherein the effluent is water.