Ethylene‐Coordinative Chain‐Transfer Polymerization‐Induced Self‐Assembly (CCTPISA)

Abstract

Block copolymers based on ethylene (E) and butadiene (B) were prepared using the ansa-bis(fluorenyl) complex {Me 2 Si(C 13 H 8 ) 2 Nd(BH 4 ) 2 Li(THF)} 2 in combination with (n-Bu)(n-Oct)Mg (BOMAG) as a chain-transfer agent. The diblock copolymers incorporating a soft poly(ethylene-cobutadiene) segment, called ethylene butadiene rubber (EBR), and a hard polyethylene (PE) one were obtained by simply adjusting the different feeds of monomers during the polymerization. The soluble EBR block was formed first by feeding the catalytic system dissolved in toluene at 70 °C with a mixture of ethylene and butadiene (E/B molar ratio 80 : 20).Then the feeding was stopped leading to the consumption of a large part of the residual monomers. The reactor was finally fed with ethylene to form the PE block. By varying the molar mass of the latter, it is shown that the resulting soft-b-hard block copolymers can self-assemble simultaneously to the growth of the PE block in agreement with a polymerizationinduced self-assembly (PISA) mechanism. The self-assembly is discussed considering the reaction conditions, the crystallization of the PE block, and the polymerization mechanism involved.

Group‐Transfer Polymerization‐Induced Self‐Assembly (GTPISA) in Non‐polar Media: An Organocatalyzed Route to Block Copolymer Nanoparticles at Room Temperature

“…In addition, a large majority of PISA processes have been developed for a use in aqueous or alcoholic formulations [40–42] . Much fewer PISA‐derived block copolymers in non‐polar media have been reported [12,36–39] . PISA carried out by living anionic polymerization (LAP) requiring the use of butyl lithium as initiator and diene and styrenic derivatives as monomers, has also already been reported [43–46] .…”

Coordinative Chain Transfer and Chain Shuttling Polymerization

“…101 Ethene/1,3-butadiene block copolymers were prepared by neodymium ansa-bis(fluorenyl) complex [Me 2 Si(C 13 H 8 ) 2 Nd-(BH 4 ) 2 Li(THF)] 2 (30, Figure 9) and n-Bu(n-Oct)Mg as CTA. 102 The resulting diblock copolymer was composed of a soft poly(ethylene-co-butadiene) block and a hard PE segment (Scheme 37).…”

Group‐Transfer Polymerization‐Induced Self‐Assembly (GTPISA) in Non‐polar Media: An Organocatalyzed Route to Block Copolymer Nanoparticles at Room Temperature

“…For instance, PISA has been adapted to the ring‐opening metathesis polymerization (ROMP) of norbornenyl derivatives, [29–34] and more recently to the ring‐opening polymerization (ROP) of N ‐carboxy‐anhydrides [35–37] . There are also some examples of PISA carried out by coordination polymerization [38,39] . In addition, a large majority of PISA processes have been developed for a use in aqueous or alcoholic formulations [40–42] .…”

“…[35][36][37] There are also some examples of PISA carried out by coordination polymerization. [38,39] In addition, a large majority of PISA processes have been developed for a use in aqueous or alcoholic formulations. [40][41][42] Much fewer PISA-derived block copolymers in non-polar media have been reported.…”

“…[40][41][42] Much fewer PISA-derived block copolymers in non-polar media have been reported. [12,[36][37][38][39] PISA carried out by living anionic polymerization (LAP) requiring the use of butyl lithium as initiator and diene and styrenic derivatives as monomers, has also already been reported. [43][44][45][46] Non-polar dispersion media, such as mineral [47,48] or silicone oils [49,50] or n-alkanes [51,52] have allowed achieving hydrophobic diblock copolymer nanoparticles by PISA.…”