Ethanolic RAFT Dispersion Polymerization of 2-(Naphthalen-2-yloxy)ethyl Methacrylate and 2-Phenoxyethyl Methacrylate with Poly[2-(dimethylamino)ethyl Methacrylate] Macro-Chain Transfer Agents

Abstract

The ethanolic reversible addition-fragmentation chain transfer dispersion polymerization (RAFTDP), at 21 wt-%, of 2-(naphthalen-2-yloxy)ethyl methacrylate (NOEMA) and 2-phenoxyethyl methacrylate (POEMA) with a poly[2-(dimethylamino)ethyl methacrylate] macro-chain transfer agent (CTA) with an average degree of polymerization of 20 (PDMAEMA 20 ) is described. DMAEMA 20 -b-NOEMA y (y ¼ 20-125) block copolymers were readily prepared under dispersion conditions in ethanol at 708C. However, the polymerization of NOEMA was not well controlled, with size exclusion chromatograms being distinctly bi or multimodal with measured dispersities ( M ¼ M w = M n ) # 1.69. Though NOEMA copolymerization was not ideal, the resulting series of block copolymers did exhibit the anticipated full spectrum of nanoparticle morphologies (spheres, worms, and vesicles). Interestingly, these morphology transitions occurred over a relatively narrow range of block copolymer compositions. In the case of POEMA, copolymerization was also poorly controlled with 1.50 # M # 1.83 for the series of DMAEMA 20 -b-POEMA y copolymers. In contrast to the NOEMAbased copolymers, the POEMA series only yielded nanoparticles with a spherical morphology whose size increased with increasing average degrees of polymerization of the POEMA block. Collectively, though both NOEMA and POEMA can be utilized in ethanolic RAFT dispersion polymerization formulations, these preliminary studies suggest that neither appears to be an ideal aryl methacrylate choice as comonomer, especially if the goal is to combine the synthesis of welldefined copolymers with efficient nanoparticle formation.

Epoxy-functional diblock copolymer spheres, worms and vesicles via polymerization-induced self-assembly in mineral oil

“…The polymerization technique most commonly utilized for PISA syntheses is reversible addition-fragmentation chain transfer (RAFT) polymerization: [8][9][10] there are numerous literature examples of RAFT-mediated PISA formulations for polar solvents such as water [11][12][13][14][15][16][17] or ethanol. [18][19][20][21][22][23] Recently, RAFT dispersion polymerization formulations have also been devised for non-polar solvents such as n-heptane, 24,25 n-octane, 26,27 ndodecane, 28 iso-dodecane, 29,30 n-tetradecane, 27,31,32 mineral oil, [33][34][35][36][37] poly(α-olefins) 33 and silicone oils. 38,39 The three most common copolymer morphologies obtained via PISA are spheres, worms and vesicles.…”

RAFT dispersion polymerization of glycidyl methacrylate for the synthesis of epoxy-functional block copolymer nanoparticles in mineral oil

“…6 For example, The Lubrizol Corporation utilized the versatility of RAFT polymerization to develop a series of commercially successful methacrylic star polymers (Asteric rheology compared to the corresponding copolymer. 6 Many research groups have explored RAFT-mediated polymerization-induced self-assembly (PISA) 7-10 as a highly convenient route to well-defined block copolymer nanoparticles in aqueous, [11][12][13][14][15][16][17] alcoholic [18][19][20][21][22][23][24][25][26][27][28] and non-polar [29][30][31][32][33] media. PISA involves using a solvophilic macromolecular chain transfer agent (macro-CTA) to polymerize a monomer that forms an insoluble polymer block, thus driving in situ selfassembly of the resulting block copolymer chains to form a range of nano-objects (most commonly spheres, worms or vesicles).…”

Stimulus‐Responsive Nanoparticles and Associated (Reversible) Polymorphism via Polymerization Induced Self‐assembly (PISA)

“…To date, the majority of documentation focuses on RAFT dispersion polymerization (RAFTDP)‐based PISA formulations, although other examples of reversible deactivation radical polymerization techniques and anionic polymerization have also been described. The specific interest in RAFTDP‐PISA has been driven, in part, by the recent contributions from the research teams of Armes, Pan, Lowe, An and Zhang who have performed detailed studies on fundamental RAFTDP‐PISA formulations in aqueous, alcoholic and non‐polar systems, which have been detailed in a series of recent reviews …”