title: Thioketone-mediated polymerization with dithiobenzoates: proof for the existence of stable radical intermediates in RAFT polymerization.
abstract: A novel dithioester control agent [dimethyltetrathioterephtalate (DMTTT)] is presented for the thioketone-mediated radical polymerization (TKMP) of n-butyl acrylate. The rate of polymerization is significantly decreased in the presence of DMTTT indicating formation of dormant radical species. During polymerization, molar masses increase linearly with monomer conversion with reasonably narrow initial molar mass distributions (PDI between 1.3 and 1.8), whereas the dispersity increases during the course of the polymerization due to irreversible termination of both propagating and dormant radicals. The present results thus highlight the possibility of a mixed mechanism operating in RAFT polymerization, which combines slow fragmentation (long-lived intermediates) and intermediate radical termination.
authors.affiliation: Preparative Macromolecular Chemistry, Karlsruhe Institute of Technology, Engesserstr. 18, 76131 Karlsruhe, Germany. thomas.junkers@uhasselt.be
authors.forename: Thomas
authors.initials: T
authors.lastname: Junkers
authors.forename: Guillaume
authors.initials: G
authors.lastname: Delaittre
authors.forename: Robert
authors.initials: R
authors.lastname: Chapman
authors.forename: Fabian
authors.initials: F
authors.lastname: Günzler
authors.forename: Elena
authors.initials: E
authors.lastname: Chernikova
authors.forename: Christopher
authors.initials: C
authors.lastname: Barner-Kowollik
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D000179:Acrylates; D011108:Polymers; C032490:n-butyl acrylate