PROCESS FOR THE PREPARATION OF RADIAL AND BRANCHED BLOCK COPOLYMERS OF MOLYMERIC COMPOSITIONS CONTAINING THE SAME AND THEIR USE FOR OBTAINING BITUMINOUS COMPOSITIONS

摘要

Radial and branched block copolymers show a structure: IMAGE wherein: Z is a radical deriving from a tetrafunctional coupling agent A is a polystyrene block B is a polybutadiene block m, n, P, g are either 1 or zero, with the @@condition that their sum is comprised within the range of from 1 to 4. Compositions of block copolymers comprise the hereinabove disclosed radial and branched block copolymers, blended with a two-block copolymer B-A, and an "A" homopolymer. The process for the preparation of said radial and branched block copolymers and of the related compositions is disclosed, and furthermore their use is disclosed in bituminous compositions, in order to improve the general characteristics