Diblock polymer formed from a polystyrene block and a statistical copolymer block of a branched diene and ethylene and bearing a silanol or alkoxysilane function.

Abstract

The invention relates to a diblock polymer of formula AB in which the symbol A represents a polystyrene block, the symbol B represents a random copolymer block of ethylene and a branched 1,3-diene of formula CH2=CR'-CH=CH2, the symbol R' representing a hydrocarbon chain having 3 to 20 carbon atoms, the diblock polymer bearing at the end of the chain a functional group containing a silanol or alkoxysilane function, the styrene units of block A being present in the diblock in a molar content of less than 15% of the repeating motifs constituting the diblock polymer, the diblock polymer having a Mooney viscosity ML(1+4) at 100°C greater than 30. The invention also relates to its synthesis process and a rubber composition containing it and intended for use in particular in a tire.