Ultrafast synthesis of ultrahigh molar mass polymers by metal-catalyzed living radical polymerization of acrylates, methacrylates, and vinyl chloride mediated by SET at 25 degrees C

• Conventional metal-catalyzed organic radical reactions and living radical polymerizations (LRP) performed in nonpolar solvents, including atom-transfer radical polymerization (ATRP), proceed by an innersphere electron-transfer mechanism. One catalytic system frequently used in these polymerizations is based on Cu(I)X species and N-containing ligands. Here, it is reported that polar solvents such as H2O, alcohols, dipolar aprotic solvents, ethylene and propylene carbonate, and ionic liquids instantaneously disproportionate Cu(I)X into Cu(0) and Cu(II)X-2 species in the presence of a diversity of N-containing ligands. This disproportionation facilitates an ultrafast LRP in which the free radicals are generated by the nascent and extremely reactive Cu(0) atomic species, while their deactivation is mediated by the nascent Cu(II)X-2 species. Both steps proceed by a low activation energy outer-sphere single-electron-transfer (SET) mechanism. The resulting SET-LRP process is activated by a catalytic amount of the electron-donor Cu(0), Cu2Se, Cu2Te, Cu2S, or Cu2O species, not by Cu(I) X. This process provides, at room temperature and below, an ultrafast synthesis of ultrahigh molecular weight polymers from functional monomers containing electronwithdrawing groups such as acrylates, methacrylates, and vinyl chloride, initiated with alkyl halides, sulfonyl halides, and N-halides.

Keyword

terminator multifunctional initiator

organocobalt porphyrin complexes

dissociative electron-transfer

methyl-methacrylate

ambient-temperature

dimethyl-sulfoxide

alpha

omega-di(iodo)poly(vinyl chloride)

sulfonyl chlorides

aqueous-media

dendritic macromolecules

Publication and Content Type

ref (subject category)

art (subject category)