Exploitation of Compartmentalization in RAFT Miniemulsion Polymerization to Increase the Degree of Livingness

Abstract

It is demonstrated that the degree of livingness (chain‐end fidelity) in RAFT polymerization for a given degree of polymerization can be markedly increased in miniemulsion polymerization relative to the corresponding homogeneous bulk system. Polymerization of styrene was conducted using a poly(methyl methacrylate) benzodithioate as macroRAFT agent in both miniemulsion and bulk. The substantially higher polymerization rate in miniemulsion, which is attributed to the segregation effect (compartmentalization) causing a reduction in the rate of bimolecular termination, makes it possible to reach a given degree of polymerization in a significantly shorter time than in the corresponding bulk system. As a consequence, fewer initiating radicals are required throughout the polymerization, leading to higher livingness in the more rapid miniemulsion system. It is demonstrated how this approach facilitates synthesis of high‐molecular‐weight block copolymers comprising slowly propagating monomers such as styrene and methacrylates. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1938–1946

Redox‐Initiated Reversible Addition‐Fragmentation Chain Transfer (RAFT) Miniemulsion Polymerization of Styrene using PPEGMA‐Based Macro‐RAFT Agent

“…In addition, under a restricted environment of initiation (e.g., droplets) and with a high monomer consumption rate, a macro‐RAFT agent can maintain a high degree of livingness, resulting in a high MW polymer. [ 40 ] Figure 2C shows a narrow particle size distribution (25–40 nm, polydispersity index of 0.24) by DLS. Further investigations of particle size and morphology was conducted using TEM.…”

Progress and Perspectives Beyond Traditional RAFT Polymerization

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Synthesis of double-responsive magnetic latex particles via seeded emulsion polymerization using macroRAFT block copolymers as stabilizers

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