Synthesis of high molecular weight poly(styrene-b-methyl methacrylate) using a plug flow reactor system by anionic polymerization

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

Flow chemistry presents many advantages over batch processes for the fast and continuous production of polymers under more robust, safer, and easily scalable conditions. Although largely exploited for chain-growth polymerizations, it has rarely been applied to step-growth polymerizations (SGP) due to their inherent limitations. Here, we report the facile and fast preparation of an emerging class of nonisocyanate polyurethanes, i.e., CO2-based poly(oxazolidone)s, by SGP in continuous flow reactors. Importantly, we also demonstrate that functional poly(oxazolidone)s are easily prepared by telescoping a flow module where SGP occurs with reagents able to simultaneously promote two polymer derivatizations in a second module, i.e., dehydration followed by cationic thiol-ene to yield poly(N,S-acetal oxazolidone)s. The functional polymer is produced at a high rate and functionalization degree, without requiring the isolation of any intermediates. This work demonstrates the enormous potential of flow technology for the facile and fast continuous production of functional polymers by SGP.

Polymerizations in Continuous Flow: Recent Advances in the Synthesis of Diverse Polymeric Materials

The number of reports using continuous flow technology in tubular reactors to perform precision polymerizations has grown enormously in recent years. Flow polymerizations allow highly efficient preparation of polymers exhibiting well-defined molecular characteristics, and has been applied to a slew of monomers and various polymerization mechanisms, including anionic, cationic, radical, and ring-opening. Polymerization conducted in continuous flow offers several distinct advantages, including improved efficiency, reproducibility, and enhanced safety for exothermic polymerizations using highly toxic components, high pressures, and high temperatures. The further development of this technology is thus of relevance for many industrial polymerization processes. While much progress has been demonstrated in recent years, opportunities remain for increasing the compositional and architectural complexity of polymeric materials synthesized in a continuous fashion. Extending the reactor processing principles that have heretofore been focused on optimizing homopolymerization to include multisegment block copolymers, particularly from monomers that propagate via incompatible mechanisms, represents a major challenge and coveted target for continuous flow polymerization. Likewise, the spatial and temporal control of reactivity afforded by flow chemistry has and will continue to enable the production of complex polymeric architectures. This Viewpoint offers a brief background of continuous flow polymerization focused primarily on tubular (micro)reactors and includes selected examples that are relevant to these specific developments.

A controlled synthesis method of alkyl methacrylate block copolymers via living anionic polymerization at ambient temperature

A series of well-defined diblock copolymers containing PMMA, PEMA and PBMA blocks were synthesized with narrow MWDs and high yields via anionic polymerization, while t-BuOK was selected as initiator in THF at 0 °C. .

Synthesis of poly(n-hexyl methacrylate)-b-poly(methyl methacrylate) via anionic polymerization with t-BuOK as the initiator at ambient temperature

Initiation mechanism of t-BuOK on anionic polymerization of n-HMA in THF.

A controlled synthesis method of polystyrene-b-polyisoprene-b-poly(methyl methacrylate) copolymer via anionic polymerization with trace amounts of THF having potential of a commercial scale

A well-defined PS-b-PI-b-PMMA copolymer with rather narrow MWD was synthesized via anionic copolymerization with trace amounts of tetrahydrofuran.