Hatton, F.L., Lovett, J.R. and Armes, S.P. orcid.org/0000-0002-8289-6351 (2017) Synthesis of well-defined epoxy-functional spherical nanoparticles by RAFT aqueous emulsion polymerization. Polymer Chemistry , 8 (33). pp. 4856-4868. ISSN 1759-9954
Abstract
The environmentally-friendly synthesis of epoxy-functional spherical nanoparticles has been achieved using polymerization-induced self-assembly (PISA) in aqueous solution. Firstly, a non-ionic hydrophilic stabilizer block, poly(glycerol monomethacrylate) (PGMA), was prepared by reversible addition–fragmentation chain transfer (RAFT) solution polymerization in ethanol. This water-soluble precursor was subsequently chain-extended via RAFT aqueous emulsion polymerization of glycidyl methacrylate (GlyMA) at 50 °C and neutral pH to ensure maximum retention of the epoxy functionality. PISA leads to the formation of well-defined PGMA-PGlyMA spherical diblock copolymer nanoparticles at up to 35% w/w solids and 1 H NMR spectroscopy studies indicated that virtually all of the epoxy groups survive such relatively mild conditions. DMF GPC studies confirmed that relatively low dispersities (Mw/Mn < 1.30) were obtained if the mean degree of polymerization of the core-forming PGlyMA block remained below 100. Well-defined triblock copolymer nanoparticles could also be prepared via seeded RAFT emulsion polymerization of n-butyl methacrylate, with DMF GPC analysis indicating a relatively narrow molecular weight distribution (Mw/Mn < 1.20). The epoxy groups within the nanoparticle cores were ring-opened by adding sodium azide to a 10% w/w aqueous copolymer dispersion at 50 °C, as confirmed by FT-IR spectroscopy. PGMA45-PGlyMA100 diblock copolymer nanoparticles could be conveniently converted into cationic nanogels by utilizing water-soluble diamines as crosslinkers. These nanogels were characterized by DLS and aqueous electrophoresis and remained intact when dispersed in DMF; in contrast, the corresponding linear precursor nanoparticles dissociated to form molecularly-dissolved copolymer chains under the same conditions.
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Copyright, Publisher and Additional Information: | This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. | ||||
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Institution: | The University of Sheffield | ||||
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Chemistry (Sheffield) | ||||
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Depositing User: | Symplectic Sheffield | ||||
Date Deposited: | 20 Nov 2017 09:44 | ||||
Last Modified: | 20 Nov 2017 09:44 | ||||
Published Version: | https://doi.org/10.1039/c7py01107e | ||||
Status: | Published | ||||
Publisher: | Royal Society of Chemistry | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1039/c7py01107e | ||||
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