RAFT Emulsion Polymerization for (Multi)block Copolymer Synthesis: Overcoming the Constraints of Monomer Order

Khan, Murtaza; Guimarães, Thiago R.; Choong, Kenneth; Moad, Graeme; Perrier, Sébastien; Zetterlund, Per B.

doi:10.1021/acs.macromol.0c02415

“…[14] If the glass transition temperature (T g )is greater than the polymerization temperature,l ow diffusion rates of oligomeric z-mer radicals entering the particles (and subsequently propagating within the particles) may restrict access to the RAFT end groups located primarily in the core region, thus negatively impacting RAFT control. [11,15] The T g values for the seed polymers are 20 8 8C(PnBMA;MB1), 54 8 8C (PBzMA;M B2) and 118 8 8C( P tBMA;M B3). [16] Thus,t he T g values of the seeds in MB1 and MB2 are lower than the polymerization temperature (80 8 8C), thus providing ar ationale for the lower values for MB1 and MB2 (1.12 (MB1), 1.22 (MB2) and 1.46 (MB3);Figure S4).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Multicompositional Onion‐like Nanoparticles via RAFT Emulsion Polymerization

Khan

¹

,

Guimarães

²

,

Kuchel

³

et al. 2021

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Synthesis of multicompositional polymeric nanoparticles of diameters 100-150 nm comprising well-defined multiblock copolymers reaching from the particle surface to the particle core was conducted using surfactant-free aqueous macroRAFT emulsion polymerization. The imposed constraints on chain mobility as well as chemical incompatibility between the blocks result in microphase separation, leading to formation of an onion-like multilayered particle morphology with individual layer thicknesses of approximately 20 nm. The approach provides considerable versatility in particle morphology design as the composition of individual layers as well as the number of layers can be tailored as desired, offering more complex particle design compared to approaches relying on self-assembly of preformed diblockc opolymers within particles.M icrophase separation can occur in these systems under conditions where the corresponding bulk system would not theoretically result in microphase separation.

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“…[14] If the glass transition temperature (T g )is greater than the polymerization temperature,l ow diffusion rates of oligomeric z-mer radicals entering the particles (and subsequently propagating within the particles) may restrict access to the RAFT end groups located primarily in the core region, thus negatively impacting RAFT control. [11,15] The T g values for the seed polymers are 20 8 8C(PnBMA;MB1), 54 8 8C (PBzMA;M B2) and 118 8 8C( P tBMA;M B3). [16] Thus,t he T g values of the seeds in MB1 and MB2 are lower than the polymerization temperature (80 8 8C), thus providing ar ationale for the lower values for MB1 and MB2 (1.12 (MB1), 1.22 (MB2) and 1.46 (MB3);Figure S4).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Multicompositional Onion‐like Nanoparticles via RAFT Emulsion Polymerization

Khan

¹

,

Guimarães

²

,

Kuchel

³

et al. 2021

Self Cite

View full text Add to dashboard Cite

Synthesis of multicompositional polymeric nanoparticles of diameters 100-150 nm comprising well-defined multiblock copolymers reaching from the particle surface to the particle core was conducted using surfactant-free aqueous macroRAFT emulsion polymerization. The imposed constraints on chain mobility as well as chemical incompatibility between the blocks result in microphase separation, leading to formation of an onion-like multilayered particle morphology with individual layer thicknesses of approximately 20 nm. The approach provides considerable versatility in particle morphology design as the composition of individual layers as well as the number of layers can be tailored as desired, offering more complex particle design compared to approaches relying on self-assembly of preformed diblockc opolymers within particles.M icrophase separation can occur in these systems under conditions where the corresponding bulk system would not theoretically result in microphase separation.

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“…In the former approach, the involvement of multiple purification and drying steps in between the different polymerizations can make the process cumbersome. Today, if we consider the example of block copolymer synthesis, it can still be challenging to preserve the polymerization active chain‐ends of the first block such that it can initiate the next polymerization, though progress in this area has been substantial 121–123 . If the initiation is not effective, the resultant block copolymer product will contain some unwanted homopolymer as an impurity.…”

Section: Role Of Initiators and Catalysts In Orthogonal Polymerization Systemsmentioning

confidence: 99%

Orthogonal synthesis and modification of polymer materials

Shahrokhinia

¹

,

Biswas

²

,

Reuther

³

2021

Journal of Polymer Science

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In this review, we detail the progress throughout the years toward developing truly orthogonal polymerization mechanisms and modification procedures en route to complex macromolecular structures built from synthetic polymer materials. The orthogonal modifications of polymer side‐chains and end‐groups via sequential click reactions is described providing post‐polymerization routes to functional materials and unique polymer topologies. Further, historical and modern orthogonal polymerization methodologies are thoroughly reviewed showing the evolution of the field through the decades long study of selective polymerization mechanisms that provide unique copolymer structures that are typically difficult to achieve. These include the combinations of reversible deactivation radical polymerization mechanisms with a variety of polymerization mechanisms including ring opening polymerizations, ring opening metathesis polymerizations, and cationic polymerizations, to name a few.

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RAFT Emulsion Polymerization for (Multi)block Copolymer Synthesis: Overcoming the Constraints of Monomer Order

Abstract: How to cite:Please refer to published version for the most recent bibliographic citation information. If a published version is known of, the repository item page linked to above, will contain details on accessing it.

Cited by 47 publications

References 75 publications

Synthesis of Multicompositional Onion‐like Nanoparticles via RAFT Emulsion Polymerization

Synthesis of Multicompositional Onion‐like Nanoparticles via RAFT Emulsion Polymerization

Synthesis of Multicompositional Onion‐like Nanoparticles via RAFT Emulsion Polymerization

Orthogonal synthesis and modification of polymer materials

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