Synthesis of Poly(propylene oxide)-Poly( N,N' -dimethylacrylamide) Diblock Copolymer Nanoparticles via Reverse Sequence Polymerization-Induced Self-Assembly in Aqueous Solution.

Autor: Farmer MAH; Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K., Musa OM; Ashland Specialty Ingredients, 1005 US 202/206, Bridgewater, New Jersey 08807, United States., Haug I; Institute of Polymer Chemistry, University of Stuttgart, 70569 Stuttgart, Germany., Naumann S; Institute of Polymer Chemistry, University of Stuttgart, 70569 Stuttgart, Germany., Armes SP; Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
Jazyk: angličtina
Zdroj: Macromolecules [Macromolecules] 2023 Dec 17; Vol. 57 (1), pp. 317-327. Date of Electronic Publication: 2023 Dec 17 (Print Publication: 2024).
DOI: 10.1021/acs.macromol.3c01939
Abstrakt: Sterically-stabilized diblock copolymer nanoparticles comprising poly(propylene oxide) (PPO) cores are prepared via reverse sequence polymerization-induced self-assembly (PISA) in aqueous solution. N,N '-Dimethylacrylamide (DMAC) acts as a cosolvent for the weakly hydrophobic trithiocarbonate-capped PPO precursor. Reversible addition-fragmentation chain transfer (RAFT) polymerization of DMAC is initially conducted at 80% w/w solids with deoxygenated water. At 30-60% DMAC conversion, the reaction mixture is diluted to 5-25% w/w solids. The PPO chains become less solvated as the DMAC monomer is consumed, which drives in situ self-assembly to form aqueous dispersions of PPO-core nanoparticles of 120-190 nm diameter at 20 °C. Such RAFT polymerizations are well-controlled ( M w / M n ≤ 1.31), and more than 99% DMAC conversion is achieved. The resulting nanoparticles exhibit thermoresponsive character: dynamic light scattering and transmission electron microscopy studies indicate the formation of more compact spherical nanoparticles of approximately 33 nm diameter on heating to 70 °C. Furthermore, 15-25% w/w aqueous dispersions of such nanoparticles formed micellar gels that undergo thermoreversible (de)gelation on cooling to 5 °C.
Competing Interests: The authors declare the following competing financial interest(s): The industrial sponsor of this study (Ashland) has filed a patent application to protect the associated IP.
(© 2023 The Authors. Published by American Chemical Society.)
Databáze: MEDLINE