3682-36-8Relevant articles and documents
Ubiquitous Nature of Rate Retardation in Reversible Addition-Fragmentation Chain Transfer Polymerization
Bradford, Kate G. E.,Petit, Leilah M.,Whitfield, Richard,Anastasaki, Athina,Barner-Kowollik, Christopher,Konkolewicz, Dominik
supporting information, p. 17769 - 17777 (2021/11/10)
Reversible addition-fragmentation chain transfer (RAFT) polymerization is one of the most powerful reversible deactivation radical polymerization (RDRP) processes. Rate retardation is prevalent in RAFT and occurs when polymerization rates deviate from ideal conventional radical polymerization kinetics. Herein, we explore beyond what was initially thought to be the culprit of rate retardation: dithiobenzoate chain transfer agents (CTA) with more active monomers (MAMs). Remarkably, polymerizations showed that rate retardation occurs in systems encompassing the use of trithiocarbonates and xanthates CTAs with varying monomeric activities. Both the simple slow fragmentation and intermediate radical termination models show that retardation of all these systems can be described by using a single relationship for a variety of monomer reactivity and CTAs, suggesting rate retardation is a universal phenomenon of varying severity, independent of CTA composition and monomeric activity level.
Intracellular nitric oxide delivery from stable NO-polymeric nanoparticle carriers
Duong, Hien T. T.,Kamarudin, Zulkamal M.,Erlich, Rafael B.,Li, Yang,Jones, Mathew W.,Kavallaris, Maria,Boyer, Cyrille,Davis, Thomas P.
supporting information, p. 4190 - 4192 (2013/05/23)
The encapsulation of S-nitrosoglutathione into polymeric nanoparticles substantially improves NO stability in aqueous media without affecting the efficacy of intracellular delivery. The combination of nano-NO delivery and chemotherapy has been found to enhance antitumour activity of chemotherapeutics, as demonstrated using preliminary in vitro experiments with neuroblastoma cells.
Novel malachite green- and rhodamine B-labeled cationic chain transfer agents for RAFT polymerization
Beija, Mariana,Afonso, Carlos A.M.,Farinha, José Paulo S.,Charreyre, Marie-Thérse,Martinho, José M.G.
experimental part, p. 5933 - 5946 (2012/04/10)
Two novel cationic RAFT agents have been synthesized, one labeled with a Malachite Green (MG) dye and another with a Rhodamine B (RhoB) dye. MG-labeled dithiobenzoate (MGEDBA) was prepared in a straightforward manner after synthesis of MG-ethylammonium chloride that reacted with a precursor dithiobenzoate bearing an activated ester function. However, the analogous reaction with RhoB amino derivative led to a mixture of dithiobenzoate and thioamide derivatives. An alternative approach yielded the RhoB-labeled RAFT agent (RhoBEDBA) with complete conversion. The purification of these dye-labeled RAFT agents was very challenging because of their dual nature (aromatic and ionic). Both MGEDBA and RhoBEDBA were efficient RAFT chain transfer agents to control the polymerization of N,N-dimethylacrylamide (DMA). The resulting α-end-labeled MG- and RhoB-PDMA samples presented low dispersities (1.2) and both chain-ends were preserved. Finally, we showed that the attachment of RhoB and MG to the PDMA polymer chain-end did not influence the photophysical properties of these dyes. Therefore, these new dye-labeled RAFT agents can be used to prepare various labeled polymers and especially water-soluble ones, to study their conformation and dynamics in solution or at interfaces using fluorescence methods, or as labeled probes for imaging and/or diagnosis purposes.
