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Graft modification of starch nanoparticles with pH‐responsive polymers via nitroxide‐mediated polymerization
Author(s) -
Cazotti Jaime C.,
Fritz Alexander T.,
GarciaValdez Omar,
Smeets Niels M. B.,
Dubé Marc A.,
Cunningham Michael F.
Publication year - 2020
Publication title -
journal of polymer science
Language(s) - English
Resource type - Journals
eISSN - 2642-4169
pISSN - 2642-4150
DOI - 10.1002/pol.20200337
Subject(s) - thermogravimetric analysis , grafting , polymer chemistry , dispersity , methacrylate , polymerization , chemistry , styrene , nuclear chemistry , polymer , materials science , copolymer , organic chemistry
The grafting to approach and nitroxide‐mediated polymerization (NMP) were used to graft modify starch nanoparticles (SNP) with pH‐responsive polymers. SG1‐capped poly(2‐(dimethylamino)ethyl methacrylate‐co‐styrene), P(DMAEMA‐co‐S), and poly(2‐(diethylamino)ethyl methacrylate‐co‐styrene), P(DEAEMA‐co‐S), with relatively low dispersity and high degree of livingness was synthesized in bulk via NMP using a commercial available alkoxyamine. These macroalkoxyamines were then grafted to vinyl benzyl‐functionalized SNP (SNP‐VBC) to obtain pH‐responsive materials. The grafted SNP were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis confirming the successful synthesis of these new materials. Low grafting efficiencies (~6%) were observed for both SNP ‐ grafted materials with pH‐responsive polymers, as expected when using the grafting to approach. The pH‐responsiveness of SNP‐g‐P(DMAEMA‐co‐S) and SNP‐g‐P(DEAEMA‐co‐S) was confirmed by measuring the ζ ‐potential at different pH values. At acidic conditions (pH 3–6) the grafted materials were protonated and exhibited positive ζ ‐potential, whereas at basic conditions (pH 10–13) the same grafted materials were deprotonated and exhibited negative ζ ‐potential.