Anionic polymerizations in a microreactor

Abstract

Since the discovery of living polymers by Szwarc in 1956, anionic polymerization has contributed many firsts in polymer synthesis. Advanced macromolecules with well-defined microstructures and commercial polymer materials with high...

Quo Vadis Carbanionic Polymerization?

“…Moreover, a continuous process for the production of multiblock copolymers through anionic polymerization in a loop reactor was reported by He and co-workers . The authors presented the living anionic copolymerization of styrene and 1,3-butadiene; moreover, this strategy can be extended to any other living copolymerization system of suitable monomer pairs. , …”

“…257 The authors presented the living anionic copolymerization of styrene and 1,3-butadiene; moreover, this strategy can be extended to any other living copolymerization system of suitable monomer pairs. 261,262 Recently, the significant difference in the reactivity ratios of isoprene and 4-methylstyrene or styrene led to the synthesis of tapered alternating multiblock copolymers by a one-pot sequential addition of monomer mixtures. 263,264 The resulting polymers contained up to 10 blocks, with molecular weights ranging from 80−400 kg/mol, and exhibited relatively low dispersity values (1.06−1.28).…”

Microreactor-Based Green Synthetic Platform for Flow Synthesis of Biodegradable Polymers

“…27 In contrast to the traditional batch reactor, a microreactor allows for enhanced mixing efficiency, process intensification, and spatial−temporal control with the benefits of a huge surface-tovolume ratio and flow characteristic. 28−34 Accelerated polymerization rate, improved chemoselectivity, and higher level control of the polymerization process in a microreactor have been demonstrated in anionic polymerization, 35,36 cationic polymerization, 37 radical polymerization, 38−40 and photopolymerization. 41,42 The combination of a microreactor and bio/organocatalysis offers a green synthetic platform for the synthesis of biodegradable polyesters and polycarbonates.…”

“…Bottlenecks still remain for bio- and organocatalytic syntheses of biodegradable polymers in the batch reactor, such as long time consuming, low end group fidelity, and poor control of molecular weight and polydispersity. , Moreover, the enzymes and organic molecules usually lose activity at high temperature, and the molecular weights of the biodegradable polymers are not as high as those of metal route products . In contrast to the traditional batch reactor, a microreactor allows for enhanced mixing efficiency, process intensification, and spatial–temporal control with the benefits of a huge surface-to-volume ratio and flow characteristic. − Accelerated polymerization rate, improved chemoselectivity, and higher level control of the polymerization process in a microreactor have been demonstrated in anionic polymerization, , cationic polymerization, radical polymerization, − and photopolymerization. , The combination of a microreactor and bio/organocatalysis offers a green synthetic platform for the synthesis of biodegradable polyesters and polycarbonates. − …”

Continuous Flow Synthesis of Functional Isocyanate-Free Poly(oxazolidone)s by Step-Growth Polymerization

“…While chain-growth techniques, such as ionic, (controlled) radical, or ring-opening polymerizations, have been largely deployed in flow reactors, − examples of step-growth polymerizations conducted in these reactors are rather limited. − This owns to the intrinsic complications and challenges associated with this class of polymerization, such as (a) the long reaction times required to achieve high monomer conversion, (b) the presence of side reactions that prevents achieving decent molar masses, and (c) the concentration issue leading to either high viscosity when too concentrated causing the clogging of the reactor or dramatic slowdown of the polymerization when too diluted. When PUs are considered, to the best of our knowledge, only one recent report described the step-growth polymerization in flow of isocyanate-based PUs ( M n = up to 13000 g/mol) within a short time (3–20 min) at room temperature by copolymerizing 4,4′-methylene diphenyl diisocyanate (MDI) with 1,6-hexanediol and/or PEG macrodiol with a tin catalyst …”