26504-29-0Relevant articles and documents
Controlled radical polymerization of acrylonitrile in the presence of trithiocarbonates as reversible addition-fragmentation chain transfer agents
Chernikova,Poteryaeva,Belyaev,Sivtsov
, p. 1031 - 1039 (2011)
Specific features of pseudo-living radical polymerization of acrylonitrile in dimethyl sulfoxide solution in the presence of low-molecular-weight and polymeric trithiocarbonates as reversible addition-fragmentation chain transfer agents were studied.
Selective one-pot synthesis of trithiocarbonates, xanthates, and dithiocarbamates for use in RAFT/MADIX living radical polymerizations
Wood, Murray R.,Duncalf, David J.,Rannard, Steven P.,Perrier, Sebastien
, p. 553 - 556 (2006)
We report a facile route for the production of chain transfer agents for reversible addition fragmentation chain transfer (RAFT) and macromolecular design via the interchange of xanthates (MADIX) polymerizations, via a one-pot reaction. 1,1′-Thiocarbonyl diimidazole (TCDI) undergoes controlled monosubstitution when reacted with secondary thiols or alcohols. The intermediate S/O-esters of imidazole-N-thionocarboxylic acid react efficiently with a range of primary thiols, alcohols, and amines to form asymmetrical dithiocarbonates, trithiocarbonates, and dithiocarbamates, respectively. The synthesis provides a facile approach to the controlled radical polymerization of vinyl monomers through the reversible addition-fragmentation chain transfer (RAFT) mechanism.
Norbornene-containing dithiocarbamates for use in reversible addition-fragmentation chain transfer (RAFT) polymerization and ring-opening metathesis polymerization (ROMP)
Foster, Jeffrey C.,Radzinski, Scott C.,Lewis, Sally E.,Slutzker, Matthew B.,Matson, John B.
, p. 205 - 211 (2015)
Two new dithiocarbamate chain transfer agents (CTAs) with norbornene-containing Z-groups were prepared for use in reversible addition-fragmentation chain transfer (RAFT) polymerization. CTA 1b, which contains an electron deficient norbornene imide Z-group, was found to effectively mediate RAFT polymerization of 2° more activated monomers (MAMs) but did not facilitate RAFT of 3° MAMs or less activated monomers (LAMs). In contrast, CTA 2, derived from a norbornene amine, was well suited for the polymerization of LAMs, but did not control RAFT of MAMs. Poly(vinyl acetate) (PVAc), prepared by RAFT polymerization mediated by CTA 2, possessed the expected CTA-derived α- and ω-end groups. Ring-opening metathesis polymerization (ROMP) of 2 was carried out, and full conversion to polymer was achieved within 20 min. Based on this result, ROMP grafting-through of a PVAc macromonomer derived from CTA 2 was carried out, resulting in the formation of a well-defined PVAc bottlebrush polymer with a narrow molecular weight distribution.
Controlled (Co)polymerization of methacrylates using a novel symmetrical trithiocarbonate raft agent bearing diphenylmethyl groups
Enríquez-Medrano, Francisco Javier,Grana, Alvaro Leonel Robles,Maldonado-Textle, Hortensia,Olivares-Romero, José Luis,Thomas, Claude St,Torres-Lubián, José Román,Valencia, Luis,de León, Ramón Díaz
, (2021/08/06)
Herein, we report a novel type of symmetrical trithiocarbonate chain transfer agent (CTA) based diphenylmethyl as R groups. The utilization of this CTA in the Reversible Addition-Fragmentation chain Transfer (RAFT) process reveals an efficient control in the polymerization of methacrylic monomers and the preparation of block copolymers. The latter are obtained by the (co)polymerization of styrene or butyl acrylate using a functionalized macro-CTA polymethyl methacrylate (PMMA) previously synthesized. Data show low molecular weight dispersity values (D 1.5) particularly in the polymerization of methacrylic monomers. Considering a typical RAFT mechanism, the leaving groups (R) from the fragmentation of CTA should be able to re-initiate the polymerization (formation of growth chains) allowing an efficient control of the process. Nevertheless, in the case of the polymerization of MMA in the presence of this symmetrical CTA, the polymerization process displays an atypical behavior that requires high [initiator]/[CTA] molar ratios for accessing predictable molecular weights without affecting the D. Some evidence suggests that this does not completely behave as a common RAFT agent as it is not completely consumed during the polymerization reaction, and it needs atypical high molar ratios [initiator]/[CTA] to be closer to the predicted molecular weight without affecting the D. This work demonstrates that MMA and other methacrylic monomers can be polymerized in a controlled way, and with “living” characteristics, using certain symmetrical trithiocarbonates.
Investigations of the Thermal Responsiveness of 1,4,2-Oxathiazoles
Hewitt, Russell J.,Ong, Michelle Jui Hsien,Lim, Yi Wee,Burkett, Brendan A.
supporting information, p. 6687 - 6700 (2015/10/29)
The first systematic study of the thermal rearrangement/fragmentation of 5,5-disubstituted 1,4,2-oxathiazoles into isothiocyanates is reported. Structure-activity relationships reveal that the choice of substituent at the 5-position of the 1,4,2-oxathiazoles is the predominant factor to influence the ease of fragmentation.