Radical Ring-Opening Copolymerization-Induced Self-Assembly (rROPISA)

• DOI: 10.1021/acs.macromol.9b00161
• Publication Date: 2019-05-06T20:41:45Z
• Authors: Elise Guégain; Chen Zhu; Erika Giovanardi; Julien Nicolas
• Keywords: Raft; Chain transfer; Solvophobic

Radical ring-opening copolymerization-induced self-assembly (rROPISA) was performed by copolymerizing benzyl methacrylate and cyclic ketene acetals (CKA), such as 2-methylene-4-phenyl-1,3-dioxolane or 5,6-benzo-2-methylene-1,3-dioxepane, in heptane at 90 °C reversible addition-fragmentation chain transfer (RAFT) polymerization from a poly(lauryl methacrylate) macro-RAFT agent. The lengths of both the solvophilic agent solvophobic block, together with initial amount CKA, were independently varied to achieve various compositions. CKA copolymers ranged 4 ∼40 mol % adjusting monomer stoichiometry, leading nearly complete degradation for contents above ∼15 %. rROPISA led stable nanoparticles all cases, ranging 40 500 nm diameter, depending on experimental conditions, assessed dynamic light scattering transmission electron microscopy. Low average diameters very narrow particle size distributions obtained below 20 %, except targeted length 300 that gave up 50 CKA. Morphological investigation revealed formation spheres copolymer compositions, which assigned nature RAFT used insertion prevent other morphologies.