Isoprene–Styrene Chain Shuttling Copolymerization Mediated by a Lanthanide Half‐Sandwich Complex and a Lanthanidocene: Straightforward Access to a New Type of Thermoplastic Elastomers

Abstract

A lanthanide half-sandwich complex and a ansa lanthanidocene have been assessed for isoprene-styrene chain shuttling copolymerization with n-butylethylmagnesium (BEM). In the presence of 1 equiv BEM, a fully amorphous multiblock microstructure of soft and hard segments is achieved. The microstructure consists of poly(isoprene-co-styrene) blocks, with hard blocks rich in styrene and soft blocks rich in isoprene. The composition of the blocks and the resulting glass transition temperatures (Tg ) can be easily modified by changing the feed and/or the relative amount of the catalysts, highlighting a new class of thermoplastic elastomers (TPEs) with tunable transition temperatures. The materials self-organize into nanostructures in the solid state.

A Catalyst Platform for Unique Cationic (Co)Polymerization in Aqueous Emulsion

“…Besides,t he occurrence of relatively broad but monomodal MWD (Figure 2a)e vidences that branching occurs under these conditions.T he polymer microstructure analyzed by 1 Ha nd 13 CNMR spectroscopy ( Figure S10) revealed predominantly trans-1,4-(72 %) and cis-1,4-units (21 %), whereas 1,2-and 3,4-structures were present only as minor components (4 and 3%,r espectively), in agreement with the cationic polymerization mechanism. [10] Several features observed in previous works [2,18] and reproduced here further advocate for ac ationic polymeri- [30] by metallocenep olymerization (*, &)( the dot line is the fit of Foxequation with T g 'sof102 and À58 8 8Cf or polystyrene and polyisoprene, respectively); c) olefinic part of 13 CNMR spectra (for detailed assignments see Figure S13). …”

Supported Single-Site Organometallic Catalysts for the Synthesis of High-Performance Polyolefins

“…Especially in the case of group 4, these new catalysts and cocatalyst/activators have achieved great success in the production of advanced polyolefin materials [4]. The new systems are able to control product molecular weight, polydispersity, comonomer enchainment level and pattern, the tacticity of poly(a-olefins) [17,56,57], copolymerization of olefins with polar comonomers (group 10) [54,55,[58][59][60][61][62], and the catalytic synthesis of block copolymers by processes such as chain shuttling polymerization [63][64][65][66][67].…”

Isoprene polymerization mediated by vanadium-[ONNO] complexes

“…68,69 In this degenerative chain transfer process, a stoichiometric excess of a chain transfer agent, usually in the form of a main group metal alkyl, is introduced into the reactive medium. 72,73,74,75,76 As far as we know, only one example of vanadium based CCTP has been reported in the literature. 70,71 In the presence of two catalysts, so-called "chain shuttling polymerization" affords the formation of new materials with original multiblock microstructures.…”