This article presents the synthesis and characterization of diblock, triblock, and tetrablock copolymers of alloocimene (Allo), a terpene from renewable resources, and isobutylene (IB) using the recently reported two-phase living carbocationic system. The addition of a second Allo increment to diblocks of Allo and IB yielded triblock and tetrablock structures. The block copolymers showed thermoplastic elastomeric (TPE) properties. It is demonstrated that the unusual behavior of diblocks exhibiting TPE properties is due to the strain-induced crystallization of the polyisobutylene block. The polyalloocimene blocks can be cured, making this material a potential replacement of halobutyl rubber without halogen content. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1567-1574