Process for controlled radical polymerization or copolymerization of (meth)acrylic and vinyl monomers and (co)polymers obtained

A process for controlled radical polymerization or copolymerization of (meth)acrylic and/or vinyl monomers, characterized in that at least one of the said monomers is polymerized or copolymerized in bulk, solution, emulsion or suspension, at a temperature which can be as low as 0.degree. C., in the presence of an initiating system including:

• at least one compound generating radicals, other than bromofluorene;
• and
• at least one catalyst consisting essentially of a complex of palladium in the 0 oxidation state, denoted by the following formula (I):
• Pd(0)L.sup.1 L.sup.2 L.sup.3 L.sup.4
• in which each of L.sup.1, L.sup.2, L.sup.3 and L.sup.4, identical or different, denotes a ligand, optionally chiral ligand, which is chosen from PRR'R", P(OR)(OR')(OR"), NRR'R", ORR', SRR', SeRR', AsRR'R" and SbRR'R", where each R, R', R" independently denotes an optionally substituted C.sub.1 -C.sub.14 alkyl group or an optionally substituted aromatic group, it being possible for at least two of these ligands to be joined to each other by one or more divalent radicals.