Coordination polymerization of oxiranes

Figure 10 Flip-flop mechanism of anionic coordination polymerization of oxirane involving AIR3.

Christo B. Tsvetanov is a full professor of polymer science at the Institute of Polymers, Bulgarian Academy of Sciences and head of the Scientific Council of the Institute of Polymers. A major focus of his research concerns controlled polymerization methods, water-soluble polymers and hydrogels, and stimuli-responsive copolymers and their self-assembly to polymeric nanoparticles. He is well known for his contributions to the area of anionic coordination polymerization of oxirane and the role of donor and acceptor additives on the mechanism of anionic polymerization. Since 2004 he has been a corresponding member of the Bulgarian Academy of Sciences. 

The discovery of coordinate polymerization of oxirane led to an enormous expansion in the range of polyether structures that could be synthesized. Some of the remarkable synthesis chemistry is outlined in Section III. Coordinate copolymerization further increased the range of polymer structures that could be synthesized in highly controlled ways. Two examples have already been described copolymers of epichlorohydrin and ethylene oxide (71) and of propylene oxide and allyl glycidyl ether (94, 137). The activation energy for copolymerization of epichlorohydrin and maleic anhydride was found to be 14.5 kcal/mol, and the polymerization rate is dependent on temperature and proportional to catalyst concentration (138-140). 

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