Polychloroalkanes as ATRP Initiators: Fundamentals and Application to the Synthesis of Block Copolymers from the Combination of Conventional Radical Polymerization and ATRP

Polychloroalkanes CCl n R 4-n (n = 2, 3 or 4) are tested as initiators in Cu-catalyzed atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) and methyl acrylate (MA), using the CuCl / 2,2'-bipyridine catalyst. 1,1,1-Trichloroalkanes, RCCl 3, are good initiators. For all the R groups tested, M n increases with conversion and polydispersities are low (1.1 < M w /M n < 1.3). CCl 4 induces a multifunctional initiation, with lower than predicted M n values. This deviation, previously observed with Ru and Ni-based catalysts, has been explained by the doubling of chains resulting from the activation of a central -CCl 2- moiety, followed by a β-scission. Trichloromethyl-terminated vinyl acetate and vinylidene fluoride telomers are synthesized and used to initiate ATRP of various monomers, leading to PVOAc and PVDF-based block copolymers.