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| Version | Summary | Created by | Modification | Content Size | Created at | Operation |
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| 1 | Helena Kang | -- | 179 | 2026-09-23 06:30:45 |
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Reversible deactivation of radical chain ends, such that the number of chains remains constant and molecular weight increases linearly with conversion, defines living radical polymerization (also termed reversible-deactivation radical polymerization). The radical is intermittently trapped as a dormant covalent species—an alkyl halide, a thiocarbonylthio adduct, or a nitroxide—and is reactivated often enough for all chains to grow at a comparable rate. Metal-catalyzed living radical polymerization uses a transition-metal complex to mediate that activation–deactivation equilibrium [1]. Refinement of the metal catalyst and the halogen-transfer step has been directed toward precise molecular-weight and architectural control [2]. External stimuli such as visible light can shift the same equilibrium, providing photocontrol over a living radical polymerization of methacrylates without changing the radical nature of propagation [3]. The concept is distinguished from conventional free-radical polymerization by the suppression of irreversible termination as the factor that determines chain number, and from truly living ionic polymerization by the persistent presence of a dormant–active radical equilibrium.
References
- Masami Kamigaito; Tsuyoshi Ando; Mitsuo Sawamoto; Metal-Catalyzed Living Radical Polymerization. Chem. Rev. 2001, 101, 3689-3746. [CrossRef]
- Makoto Ouchi; Takaya Terashima; Mitsuo Sawamoto; Transition Metal-Catalyzed Living Radical Polymerization: Toward Perfection in Catalysis and Precision Polymer Synthesis. Chem. Rev. 2009, 109, 4963-5050. [CrossRef]
- Brett P. Fors; Craig J. Hawker; Control of a Living Radical Polymerization of Methacrylates by Light. Angew. Chem. Int. Ed. 2012, 51, 8850-8853. [CrossRef]
