Metal-Catalyzed Switching Degradation of Vinyl Polymers via Introduction of an “In-Chain” Carbon–Halogen Bond as the Trigger
Taichi Kimura, Keita Kuroda, Hiroyuki Kubota, Makoto Ouchi
Abstract
In this work, we achieved switching degradation of vinyl polymers made of a carbon–carbon bonded backbone. Crucial in this strategy was a small feed of methyl α-chloroacrylate (MCA) as the comonomer in radical polymerization of methyl methacrylate (MMA) so that the carbon–halogen bonds were introduced as the triggers for degradation. The “in-chain” trigger was activated by a one-electron redox metal catalyst as the chemical stimulus to generate the carbon-centered radical species, and subsequently, the neighboring carbon–carbon bond was cleaved via an electron transfer of the radical species giving the terminal olefin. Particularly, an iron complex (FeCl2) in conjunction with tributylamine (n-Bu3N) was effective as the chemical stimulus to allow the switching degradation, where the molecular weight was gradually decreased over time. The switching feature was confirmed by some control experiments.