Patent ID: 8796403

Claim:
A method for preparing a block copolymer, comprising the step of copolymerizing at least one non-polar monomer, and at least one polar monomer, the copolymerization being carried out in the presence of a catalytic system made up of an organometallic complex of formula: where: a. Met represents a metal belonging to groups 8, 9 and 10, b. Y represents a ligand molecule oxidizing the metal and made up of heteroatomic groups based on C, H and at least one atom selected from: O, S, P and N, c. L represents a complexing molecule made up of heteroatomic groups based on C, H and at least one atom selected from: O, S, P and N, wherein Y and L may be linked by a covalent bond, d. L′ represents a monodentate, electron-donating, complexing molecule, e. R is a hydrocarbon-based group of alkyl or alkylaryl type containing from 1 to 20 C atoms, or of cycloalkyl or phenyl type containing from 6 to 20 C atoms, said method resulting in the formation of a block copolymer which satisfies the following relationships: Σp-a/Σp-p<<1 Σp-a/Σa-a<< 1 Σp-a>1(in each polymer chain), in which: “p-a” represents a bond between a polar monomer (p) and a non-polar monomer (a); “p-p” represents a bond between two polar monomers; “a-a” represents a bond between two non-polar monomers.