Polyselenonium Salt as a Heterogeneous Catalyst for Living/Controlled Cationic Polymerization

Abstract

Polyselenonium salt was synthesized by using functional polycaprolactone as a precursor for heterogeneous catalysis of living/controlled cationic polymerization of various vinyl ethers. Benefiting from the combination of the bench-stable polyselenonium salt and cationic RAFT agents, controlled cationic polymerization could be achieved under mild conditions such as room temperature, non-inert atmosphere, and the absence of rigorously monomer purification, yielding well-defined poly(vinyl ether)s with controlled molecular weights and low dispersity (Đ < 1.20). The heterogeneous catalyst can be easily separated by simple centrifugation and maintains catalytic efficiency above 90% even after six cycles of use, showing excellent reusability in subsequent polymerizations.

Recent advances in green cationic polymerization

“…76,77 Jian Zhu, V. Kostjuk, et al have also made many outstanding progress in the field of heterogeneous catalytic cationic polymerization. [78][79][80] 3 | NEW REACTION MEDIUM FOR GREEN LIVING/CONTROLLED CATIONIC POLYMERIZATION…”

“…This polymerization technique not only holds great potential in the synthesis of well-defined structure polymers but also revitalizes traditional suspension and emulsion polymerization methods. [76][77][78][79][80][81][82][83][84][85][86]88 Kostjuk 71 has conducted a detailed review on cationic polymerization of vinyl monomers in aqueous media in 2009.…”

“…Sadahito Aoshima used a variety of metal oxides as heterogeneous initiators for living cationic polymerization of isobutyl vinyl 76,77 . Jian Zhu, V. Kostjuk, et al have also made many outstanding progress in the field of heterogeneous catalytic cationic polymerization 78–80 …”

Bidentate selenium-based chalcogen bond catalyzed cationic polymerization of p-methoxystyrene

“…There are solely two examples of selenium compounds utilized to catalyze the cationic polymerization of alkenes, but the cation polymerization of electron-rich styrenic monomers (especially p MOS) is uncontrollable. 12 The electron-rich styrenic monomers are different to vinyl ether monomers due to the difference in the stability of the propagating carbocations. 13 Thus, some challenges still remain using selenium catalysts and the monomer scope needs to be expanded.…”

Zinc-Mediated Living Cationic Polymerization

“…Considering that the use of zinc-containing Lewis acids could enable LCP under mild conditions, we attempted to use zinc wire for the construction of LCP under mild conditions (Figure A). In fact, heterogeneous catalysis of cationic polymerization has a long history with various catalysts. − However, only a limited number of them can achieve living polymerization. ,− Aoshima’s group has devised elegant methods that utilize various metal oxides as heterogeneous catalysts for LCP in conjunction with an added base. − Among these metal oxides, iron oxides have proven to be the most efficient catalysts for LCP. Similar to copper-mediated reversible deactivation radical polymerization (RDRP), , this approach offers several benefits, including facile tuning of the reaction rate, easy catalyst preparation and removal and recyclability.…”