Interplay of thermosensitivity and pH sensitivity of amphiphilic block-gradient copolymers of dimethylaminoethyl acrylate and styrene

0491337 - ÚMCH 2019 RIV US eng J - Journal Article
Rabyk, Mariia - Destephen, A. - Lapp, A. - King, S. - Noirez, L. - Billon, L. - Hrubý, Martin - Borisov, O. - Štěpánek, Petr - Deniau, E.
Interplay of thermosensitivity and pH sensitivity of amphiphilic block-gradient copolymers of dimethylaminoethyl acrylate and styrene.
Macromolecules. Roč. 51, č. 14 (2018), s. 5219-5233. ISSN 0024-9297. E-ISSN 1520-5835
R&D Projects: GA ČR(CZ) GA16-03156S; GA MŠMT(CZ) LM2015064; GA MŠMT(CZ) 7AMB17FR032
Institutional support: RVO:61389013
Keywords : amphiphilic diblock copolymers * pH and thermoresponsive
OECD category: Polymer science
Impact factor: 5.997, year: 2018

Novel pH- and thermoresponsive amphiphilic diblock copolymer, comprising hydrophilic poly(2-dimethylaminoethyl acrylate) (PDMAEA) and amphiphilic poly(styrene-grad-2-dimethylaminoethyl acrylate) (P(S-grad-DMAEA)) blocks, was synthesized by nitroxide-mediated radical polymerization. A series of copolymers (PS-grad-PDMAEA) with controlled molar masses and low dispersities over a wide range of monomer feed ratios (0 < fS,0 < 1) were synthesized. Both conventional linearization and nonlinear least-squares methods were applied to estimate reliable values of the reactivity ratios for S and DMAEA radical polymerization. The calculated values of the reactivity ratios (rDMAEA = 0.25 and rS = 1.15) perfectly fitted the drift in monomer feed ratio versus conversion, showing a gradient distribution along the copolymer chains. The self-assembling behavior of the copolymers in the aqueous medium was investigated by dynamic light scattering and small-angle neutron scattering over a wide range of pH, temperature, and salt concentration. These block-gradient copolymers show reversible self-association into micelle-like structure (Dh ∼ 20 nm) in aqueous solutions triggered by both pH and temperature.
Permanent Link: http://hdl.handle.net/11104/0285582