Synthesis, Characterization, Conformation in Solution, and Thermoresponsiveness of Polymer Brushes of methoxy[oligo (propylene glycol)-block-oligo(ethylene glycol)]methacrylate and N-[3-(dimethylamino)propyl]methacrylamide Obtained via RAFT Polymerization

The thermo- and pH-responsive polymer brushes based on methoxy[oligo(propyleneglycol)<sub>8</sub>-block-oligo(ethyleneglycol)<sub>8</sub>]methacrylate with different concentrations of N-[3-(dimethylamino)propyl]methacrylamide (from 0% to 20%) were synthesized via RAFT polymer...

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Bibliographic Details
Main Authors: Maria Simonova, Denis Kamorin, Alexander Filippov, Oleg Kazantsev
Format: Article
Language:English
Published: MDPI AG 2023-03-01
Series:Polymers
Subjects:
Online Access:https://www.mdpi.com/2073-4360/15/7/1641
Description
Summary:The thermo- and pH-responsive polymer brushes based on methoxy[oligo(propyleneglycol)<sub>8</sub>-block-oligo(ethyleneglycol)<sub>8</sub>]methacrylate with different concentrations of N-[3-(dimethylamino)propyl]methacrylamide (from 0% to 20%) were synthesized via RAFT polymerization. The “grafting-through” approach was used to prepare the low-molar-mass dispersion samples (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> ≈ 1.3). Molar masses and hydrodynamic characteristics were obtained using static and dynamic light scattering and viscometry. The solvents used were acetonitrile, DMFA, and water. The molar masses of the prepared samples ranged from 40,000 to 60,000 g·mol<sup>–1</sup>. The macromolecules of these polymer brushes were modeled using a prolate revolution ellipsoid or a cylinder with spherical ends. In water, micelle-like aggregates were formed. Critical micelle concentrations decreased with the content of N-[3-(dimethylamino)propyl]methacrylamide. Molecular brushes demonstrated thermo- and pH-responsiveness in water–salt solutions. It was shown that at a given molecular mass and at close pH values, the increase in the number of N-[3-(dimethylamino)propyl]methacrylamide units led to an increase in phase separation temperatures.
ISSN:2073-4360