TY  - JOUR
A1  - Weiss, Jan
A1  - Laschewsky, André
T1  - One-step synthesis of amphiphilic, double thermoresponsive diblock copolymers
T2  - Macromolecules : a publication of the American Chemical Society
N2  - The copolymerization of an excess of a functionalized styrene monomer, 4-vinylbenzyl methoxytetrakis(oxyethylene) ether, with various N-substituted maleimides yields tapered diblock copolymers in a one-step procedure, when applying reversible deactivation radical polymerization (RDRP) methods, such as ATRP and RAFT. The particular chemical structure of the diblock copolymers prepared results in reversible temperature-responsive two-step aggregation behavior in dilute aqueous solution. In this way, a double hydrophilic block copolymer is transformed step by step into an amphiphilic macrosurfactant, and finally into a double hydrophobic copolymer, as followed by turbidimetry and dynamic light scattering. Copolymers in which the maleimide repeat units bear short hydrophobic side chains are freely water-soluble at low temperature and form micellar aggregates above their cloud point. Further heating above the phase transition temperature of the second block results in secondary aggregation. Copolymers with maleimides that bear strongly hydrophobic substituents undergo two thermally induced aggregation steps upon heating, too, but show in addition intramolecular hydrophobic association in water already at low temperatures, similar to the behavior of polysoaps.
Y1  - 2012
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/35896
SN  - 0024-9297
VL  - 45
IS  - 10
SP  - 4158
EP  - 4165
PB  - American Chemical Society
CY  - Washington
ER  -