Organocatalytic Ring Opening Polymerization of Trimethylene Carbonate

• Published in: Biomacromolecules Vol. 8; no. 1; pp. 153 - 160
• Main Authors: Nederberg, Fredrik, Lohmeijer, Bas G. G, Leibfarth, Frank, Pratt, Russell C, Choi, Jeongsoo, Dove, Andrew P, Waymouth, Robert M, Hedrick, James L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-01-2007
• Subjects: Applied sciences; Biochemistry - methods; Catalysis; Chemistry Techniques, Analytical - methods; Dioxanes - chemistry; Exact sciences and technology; Hydrogen Bonding; Macromolecular Substances; Magnetic Resonance Spectroscopy; Models, Chemical; Molecular Conformation; Organic polymers; Physicochemistry of polymers; Polymerization; Polymers - chemistry; Preparation, kinetics, thermodynamics, mechanism and catalysts; Temperature; Time Factors; Ring opening polymerization; Imidazole derivatives; Organic carbonate; Bulk polymerization; Angular nitrogen heterocycle; Living polymer; Guanidines; Benzyl alcohol; Thioureas; Carbene; Six membered ring; Aliphatic polymer; Preparation; Diblock copolymer; Reaction mechanism; Carbonate copolymer; Catalyst activity; Polycarbonate; Styrene copolymer
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm060795n

A variety of organocatalysts has been surveyed in the ring opening polymerization of trimethylene carbonate. Excellent control was found for several of these catalysts yielding well-defined polycarbonates with molecular weights up to 50 000 g mol-1, polydispersities below 1.08, and high end-group fidelity. Melt or bulk polymerization was accomplished without loss of control of molecular weight or polydispersity, and random ester−carbonate bulk polymerizations were also demonstrated. Furthermore, by combining disparate polymerization techniques using bifunctional initiators, the mild polymerization conditions allow for the preparation of new block copolymers. Hydrogen-bond activation of monomer and initiator/propagating species is proposed as the underlying mechanism, which can be tuned to mitigate adverse side reactions.