Organometallic-Mediated Radical Polymerization of Vinylidene Fluoride

Iodine-Transfer Polymerization (ITP) of Ethylene and Copolymerization with Vinyl Acetate

Controlled radical polymerization of ethylene using different commercially available, cheap, and non-toxic iodo alkyls is performed by iodine transfer polymerization (ITP) under mild conditions (≤100 °C and ≤200 bar). The formed well-defined iodo end-capped polyethylene (PE-I) species is very stable upon storage. Narrow molar-mass distributions (dispersities around 1.6) were obtained up to number average molar masses of 7300 g mol^-1 . The ethylene copolymerization by ITP (ITcoP) with vinyl acetate allowed to form a broad range of poly(ethylene-co-vinyl acetate) (EVA) containing from 0 to 85 mol % of VAc unit. In addition, EVA-b-PE block copolymers or EVA-b-EVA gradient block copolymers with different content of VAc in the blocks were obtained for the first time using ITP. Finally, reactivity trends were explored by a theoretical mechanistic study. This highly versatile synthetic platform provides a straightforward access to a diverse range of well-defined PE based polymer materials.

Enabling technologies in polymer synthesis: accessing a new design space for advanced polymer materials

This review discusses how developments in laboratory technologies can push the boundaries of what is achievable using existing polymer synthesis techniques.

Oxygen-Triggered Switchable Polymerization for the One-Pot Synthesis of CO2 -Based Block Copolymers from Monomer Mixtures

Switchable polymerization provides the opportunity to regulate polymer sequence and structure in a one-pot process from mixtures of monomers. Herein we report the use of O₂ as an external stimulus to switch the polymerization mechanism from the radical polymerization of vinyl monomers mediated by (Salen)Co^III -R [Salen=N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine; R=alkyl] to the ring-opening copolymerization (ROCOP) of CO₂ /epoxides. Critical to this process is unprecedented monooxygen insertion into the Co-C bond, as rationalized by DFT calculations, leading to the formation of (Salen)Co^III -O-R as an active species to initiate ROCOP. Diblock poly(vinyl acetate)-b-polycarbonate could be obtained by ROCOP of CO₂ /epoxides with preactivation of (Salen)Co end-capped poly(vinyl acetate). Furthermore, a poly(vinyl acetate)-b-poly(methyl acrylate)-b-polycarbonate triblock copolymer was successfully synthesized by a (Salen)cobalt-mediated sequential polymerization with an O₂ -triggered switch in a one-pot process.

Synthesis of Poly(N-vinylamide)s and Poly(vinylamine)s and Their Block Copolymers by Organotellurium-Mediated Radical Polymerization

Controlled polymerization of acyclic N-vinylamides, that is, N-methyl-N-vinylacetamide (NMVA), N-vinylacetamide (NVA), and N-vinylformamide (NVF), by organotellurium-mediated radical polymerization (TERP) is reported. The corresponding poly(N-vinylamide)s with controlled molecular weight and low dispersity (Ð<1.25) were obtained with high monomer conversion in all cases. This is the first report on the controlled polymerization of NVF. Hydrolysis of the polymers, in particular PNVF, occurred quantitatively under mild reaction conditions, giving structurally controlled poly(vinylamine)s. Block copolymers containing poly(N-vinylamide) and poly(vinylamine) segments were also synthesized in a controlled manner.

Fluoropolymers: The Right Material for the Right Applications

An overview on the synthesis, properties, and applications of fluoropolymers (PFs) is presented. First, a non-exhaustive summary on the homopolymers from conventional radical polymerization of fluoromonomers is proposed. FPs are interesting materials thanks to their outstanding properties such as thermal, oxidative and chemical resistances, low dissipation factor, refractive index, permittivity, and water absorptivity, as well as excellent durability and weatherability. Various strategies of synthesis are proposed, especially on recent studies on radical (co)polymerization of fluoroalkenes, just like their properties and applications ranging from coatings and energy-related materials (e.g. fuel cell membranes, components for lithium ion batteries, electroactive devices, and photovoltaics) to original fluorinated elastomers, surfactants, thermoplastic elastomers, thermostables, and optical devices.

Kinetics of radical copolymerization of vinylidene fluoride with tert-butyl 2-trifluoromethyl acrylate: a suitable pair for the synthesis of alternating fluorinated copolymers

A study of the copolymerization kinetics of vinylidene fluoride with tert-butyl 2-trifluoromethyl acrylate: a suitable pair for the synthesis of alternating fluorinated copolymers.