The present invention relates to comb block copolymers, combining an elastomeric backbone and rigid pendent blocks and thus having thermoplastic elastomer properties. The invention targets in particular comb block copolymers which may be used as a material as is.According to the invention, the comb block copolymer is a diene/polypropylene thermoplastic elastomer copolymer, characterized in that it consists of a backbone, said backbone being derived from a diene elastomer, and in that it comprises from 5% to 50% by weight, relative to the total weight of the copolymer, of pendent semicrystalline polypropylene groups distributed along the backbone.Another subject of the invention is the process for preparing same, and the compositions comprising same.Finally, a subject of the invention is a tire, one of the constituent elements of which comprises such a composition.