Process for the controlled radical polymerization or copolymerization of ethylene under high pressure in the presence of initiating free radicals and of controlling indoline nitroxide radicals

摘要

A radical (co)polymerization of ethylene is carried out under high pressure in the presence of at least one initiating free radical (Z&Circlesolid;) and of at least one controlling stable free radical (SFR&Circlesolid;) which comprises the indoline nitroxide backbone represented by the formula (I). Mention may be made, by way of examples, of the radicals (SFR&Circlesolid;) of formula (II). A is a hydrocarbonaceous chain forming an aromatic ring with the two carbon atoms to which it is attached, this ring being able to carry substituents or being able to carry one or more rings placed side by side, which rings are aromatic or aliphatic and optionally substituted, the carbon atoms forming the nitrogenous ring and in the alpha- and beta-position with respect to the nitrogen atom being, able to carry hydrogen atoms or substituents; R1, R2, R3 and R4, which can be identical or different, each independently represent H; alkyl; alkenyl; aryl; aralkyl; OH; -OR5, R5=alkyl, alkenyl, aryl or aralkyl residue; -COOH; -COOR6, R6=alkyl, alkenyl, aryl or aralkyl residue; or CN; it being possible for R3 and R4 to merge together into =X, X representing O or =NR7, R7=alkyl, alkenyl, aryl or aralkyl residue; and it being possible for the alkyl, alkenyl, aryl or aralkyl residues coming within the definition of R1 to R6 to carry substituents.