Multiblock copolymers constitute a basis for an emerging class of nanomaterials that combine various functional properties with high durability and enhanced mechanical characteristics. Cross-metathesis between polymers containing C=C double bonds in the main chain is a recent and actively developing approach to random multiblock copolymers. This rather new interchain cross-reaction proceeds by reshuffling of polymer segments in the macromolecular backbones via breaking of double bonds and formation of new ones according to the olefin metathesis mechanism. We studied the macromolecular cross-metathesis (MCM) using commercial polynorbornene, polyoctenamer, polybutadiene, polyisoprene etc. The advantage of MCM is the simplicity of its experimental implementation. However, the method does not provide the precise control over block sequences in copolymers. Nevertheless, the average block lengths can be easily tailored and the resulting copolymers reveal enhanced mechanical properties, nontrivial crystalline and thermal characteristics, and the ability to self-assemble into ordered structures. Our recent kinetic studies with the use of in situ and ex situ NMR have shed some light on the regularities of the macromolecular cross-metathesis reaction, which appeared to be somewhat opposite to the notions about monomer metathesis copolymerization. For example, during the copolymerization of monomers - the catalyst first interacts with norbornene, then with cyclooctene; whereas in the course of MCM it far more readily attacks polyoctenamer chains than with polynorbornene ones. The range of practical applications of multiblock copolymers can be significantly broadened via their functionalization. We implemented two approaches to multiblock-copolymer functionalization, via modification of initial monomers and via post-modification of resulting copolymers.
The work is supported by the Russian Foundation for Basic Research (Projects 17-03-00596)

Maria L. Gringolts is an Associate Professor and a Chief Researcher at Laboratory for Organosilicon and Hydrocarbon Cyclic Compounds at A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences in Moscow. Previously, she was a Senior Researcher at Russian Institute of Organic Synthesis (VNIIOS) in Novokuibyshevsk and Moscow. She was graduated from Leningrad Technology Institute (Russia). She holds PhD in Petrochemistry from Institute of Organic Synthesis, Russian Academy of Sciences (RAS) (Moscow) and Doctor of Sciences in Petrochemistry from A.V. Topchiev Institute of Petrochemical Synthesis RAS. She has published more than 170 papers in journals, books and conference proceedings, including more than 50 scientific papers in journals, indexed in the Web of Science, Scopus and RSCI (Russian Science Citation Index) such as Macromolecules, Journal of Membrane Science, European Polymer Journal, Polymer Science, RSC Advances, Polymer etc. Currently, she is interested on catalytic olefin metathesis, ring-opening metathesis and addition (co)polymerization of norbornenes and unsaturated cyclic carbosilanes, synthesis of glassy polymer membrane materials for gas separation.