Oligomeric alkoxyamines [Field of the invention] The present invention relates to a new family of alkoxyamines exhibiting better storage stability, in particular in the presence of monomers and / or solvent. [002] In particular, the present invention relates to a new family of oligomeric alkoxyamines, obtained by adding one or more monomeric entities to an alkoxyamine. [003] The present invention also relates to the use of these oligomeric alkoxyamines for the synthesis of polymers and copolymers, as well as the polymers obtained with this new family of oligomeric alkoxyamines. [004] The present invention also relates to compositions comprising this new family of oligomeric alkoxyamines in the presence of monomer and / or solvent. [Technical problem] [005] Alkoxyamines are molecules which allow the controlled radical polymerization of monomers having double bonds (vinyl, styrenic, (meth) acrylic, etc.). It is thus possible to access the synthesis of block copolymers. [006] This technology, widely described in the literature, however remains industrially discreet because obstacles remain. Non-compatibility with certain monomers, incomplete conversion, insufficient stability under certain conditions, in particular in the presence of the monomers used for the manufacture of (co) polymers or else of solvent. [007] During the industrial implementation of the synthesis of copolymers by controlled radical polymerization in the presence of alkoxyamines, it is however necessary to allow the alkoxyamines to stay for several hours, or even several days, in the presence of monomers in reactors of pre-mixing or intermediate storage at unregulated temperatures. [008] Thus, faced with the lack of reproducibility of the syntheses carried out by the applicant, numerous studies have been carried out and have demonstrated the lack of stability of an alkoxyamine-monomer system and this sometimes well below the temperature conditions used. for polymerization. [009] These studies have shown that it was not a question of the start of polymerization, but of degradation of the alkoxyamine, without a mechanism or an explanation being able to be given. [0010] Thus, the Applicant has carried out new work with the aim of eliminating or reducing this problem. The Applicant has discovered that the alkoxyamines added to a certain reduced number of monomeric units have the desired stability character. By stability is meant the low reactivity of a given alkoxyamine in the presence of monomer at a certain temperature, but also the constancy of the reactivity of an alkoxyamine left in a solvent for a given time. These new entities of oligomeric alkoxyamine type retain their character of initiation and control of radical polymerization reactions. In the presence of monomer, they are more stable over time at a given temperature, limiting the polymerization reactions. In the presence of a solvent, they retain their kinetic nature of radical initiation over time. [Summary of the invention] [0013] The invention relates to the alkoxyamines of formula: i: number of monomers of monomer j j: type of monomer i taking the values ​​from 1 to 12 j taking the values ​​from 1 to 12 And 1 =