Kinetics of Stable Free Radical Mediated Polymerization inside Submicron Particles

✍ Scribed by Hidetaka Tobita

• Book ID: 102496168
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 289 KB
• Volume: 16
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/mats.200700052

✦ Synopsis

Abstract

Controlled/living radical polymerization systems in which the active period is extremely small, ϕ~A~ ≪ 1, such as the cases of stable free radical mediated polymerization (or nitroxide mediated polymerization) and atom transfer radical polymerization, are considered theoretically. The polymerization rate, R~p~, for such systems increases by lowering the trapping agent concentration [X]. When the polymerization is conducted inside small particles, R~p~ decreases with D below the diameter D~p,SMC~ at which a single molecule concentration (SMC) is equal to [X]~bulk~. On the other hand, when the average number of trapping agents in a particle $\bar n_X$ is smaller than about 10, the fluctuation of n~X~ among particles is significant, which leads to a larger R~p~ than in the cases where all particles contain the same n~X~. Because of the effects of SMC and fluctuation, R~p~ may show an acceleration window, D~p,SMC~ < D~p~ < D~p,Fluct~ where R~p~ is slightly larger than that in bulk.

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