AbstractA new method is described to introduce pure blocks of ethylene, isoprene, and styrene into polymer systems composed of these moieties. This method involves the selective catalytic hydrogenation of 1,4‐butadieine‐1,4‐isoprene and 1,4‐butadieine‐1,4‐isoprene‐styrene co and terpolymers to form ethylene‐1,4‐isoprene and ethylene‐1,4‐isoprene‐styrene co and trepolymers. The properties of these polymer systems are discussed as a function of composition and degree of polymerization. A useful feature of this technique is the preparation of ABA type t