Abstract: The invention relates to the production and use of block copolymers which are obtained by means of controlled radical polymerization in the presence of nitroxides for the purpose of reinforcing fragile polymer matrices. The invention offers advantages such as (i) simplicity of copolymer synthesis and use and (ii) fine dispersion of the copolymer molecules in the fragile matrix, which ensures both the transparency of the material and high reinforcement against impact. More specifically, the invention relates to the radical synthesis of block copolymers comprising at least three blocks, which include one block having a glass transition temperature of less than 0° C. and a thermoplastic end block having a glass transition temperature of more than 0° C., thereby guaranteeing compatibility with the fragile matrix to be reinforced against impact.

Abstract: A subject-matter of the invention is alkoxyamines resulting from ?-phosphorated nitroxides corresponding to the formula: in which R represents an alkyl radical having a number of carbon atoms ranging from 1 to 3, R1 represents a hydrogen atom or a residue: in which R3 represents an alkyl radical having a number of carbon atoms ranging from 1 to 20, and R2 represents a hydrogen atom, an alkyl radical having a number of carbon atoms ranging from 1 to 8, a phenyl radical, an alkali metal, such as Li, Na or K, H4N+, Bu4N+ or Bu3HN+, exhibiting a kinetic dissociation constant kd, measured at 120° C. by EPR, of greater than 0.05 s?1. These compounds can be used as initiators for the (co)polymerizations of at least one monomer which can be polymerized by the radical route.

Abstract: The invention relates to the production and use of block copolymers which are obtained by means of controlled radical polymerisation in the presence of nitroxides for the purpose of reinforcing fragile polymer matrices. The invention offers advantages such as (i) simplicity of copolymer synthesis and use and (ii) fine dispersion of the copolymer molecules in the fragile matrix, which ensures both the transparency of the material and high reinforcement against impact. More specifically, the invention relates to the radical synthesis of block copolymers comprising at least three blocks, which include one block having a glass transition temperature of less than 0° C. and a thermoplastic end block having a glass transition temperature of more than 0° C., thereby guaranteeing compatibility with the fragile matrix to be reinforced against impact.