Method for synthesising polymers by controlled-radical inverse emulsion polymerisation

A method for preparing a polymer by reverse emulsion polymerization comprising the following steps:

• a) preparing an aqueous phase comprising at least one water-soluble monomer
• and at least one water-soluble precursor of formula (I):
• in which
• Z═O, S or N
• R1 and R2, being identical or different, represent:
• an optionally substituted alkyl, acyl, alkenyl or alkynyl group (i), and/or
• a carbon-based ring (ii), saturated or not, optionally substituted, or aromatic, and/or
• a heterocycle (iii), saturated or unsaturated, optionally substituted, or aromatic, and
• which groups and rings (i), (ii) and (iii) may be substituted by:
• substituted aromatic groups;
• groups selected from alkoxycarbonyl, aryloxycarbonyl (—COOR), carboxy (—COOH), acyloxy (—O2CR), carbamoyl (—CONR2), cyano (—CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidimo, hydroxy (—OH), amino (—NR2), halogen, allyl, epoxy, alkoxy (—OR), S-alkyl, and S-aryl;
• and groups having a hydrophilic or ionic character;
• wherein
• R represents an alkyl or aryl group,
• A is a linear or structured polymer chain comprising n identical or different monomers,
• n is an integer between 1 and 500,
• a) preparing an organic phase comprising a lipophilic solvent and at least one water-in-oil surfactant,
• b) mixing the aqueous phase and the organic phase while stirring to form an inverse emulsion, and
• c) once the inverse emulsion has been formed, adding a radical polymerization initiator to said inverse emulsion, and obtaining a polymer by polymerizing the at least one water-soluble monomer,
• wherein the molecular weight of the polymer obtained is between 1,250,000 and 30,000,000 g/mol.