Careful combination of multiple polymerization mechanisms can generate truly unique architectures. Incorporation of chain-segments generated by metathesis polymerizations have been explored by a number of researchers (particularly the Matyjaszewski group at Carnegie Mellon University), typically by terminating the ROMP reaction with a functionality that could later be used as an initiator for atom transfer radical polymerization (ATRP). In 2000, the Grubbs group reported a true “one-pot” tandem ROMP-ATRP polymerization (although they achieved higher conversion by separating the polymerizations into separate steps).
ROMP of cyclooctadiene in the presence of chain-transfer agent 1,4-dichloro-cis-2-butene gives the allyl chloride end-capped polybutadiene (PBD) with a “perfect” 1,4-PBD backbone (1,2-linkages lead to reduced elastomeric properties; the 2-bromopropionyl ester end-capped PBD was also made by a similar method). This telechelic PBD was then combined with the radical monomer of choice (styrene or methylmethacrylate) and catalyzed with known CuCl/bipyridine ATRP systems to generate SBS and MBM triblock copolymers.
Block copolymers such as these illustrate just one way that telechelic ROMP units can be combined with other polymerization techniques to chase the perfect balance of thermal and mechanical properties.
 Coca, S.; Paik, H.; Matyjaszewski, K. “Block Copolymers by Transformation of Living Ring-Opening Metathesis Polymerization into Controlled/“Living” Atom Transfer Radical Polymerization,” Macromolecules, 1997, 30, 6513.
 Bielawski, C.W.; Morita, T.; Grubbs, R.H. “Synthesis of ABA Triblock Copolymers via a Tandem Ring-Opening Metathesis Polymerization: Atom Transfer Radical Polymerization Approach,” Macromolecules, 2000, 33, 678.