Branch-Controlled ATRP Via Sulfoxide Chemistry

A vinyl-containing macroinimer was prepared in situ by utilizing sulfoxide chemistry in an unprecedented manner and allowed for the one-pot synthesis of hyperbranched polymers. Sulfoxide-protected haloalkanes were prepared, and their transformation into vinyl-functionalized haloalkanes through sulfoxide elimination under various reaction conditions was investigated. The protected haloalkanes were employed as an initiator for supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) in a diluted catalytic system to prepare polymers with a high chain-end functionality at a relatively low temperature. Subsequent thermal treatment yielded the macroinimers while preserving the high chain-end functionalities. When the temperature was elevated during the linear polymerization, hyperbranched polymers were afforded in a one-pot process via the in situ generations of the macroinimers. A detailed investigation revealed that the sulfoxide-modified ATRP initiator to protect the vinyl functionality on the polymer chain was successfully utilized for the synthesis of the hyperbranched polymer. This strategy is expected to aid in the synthesis of hyperbranched polymers with a tunable distance between the branch points.