Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Thermoresponsive (star) block copolymers from one-pot sequential RAFT polymerizations and their self-assembly in aqueous solution

: Herfurth, Christoph; Laschewsky, Andre; Noirez, Laurence; Lospichl, Benjamin von; Gradzielski, Michael


Polymer 107 (2016), pp.422-433
ISSN: 0032-3861
Journal Article
Fraunhofer IAP ()
RAFT polymerization; star block copolymers; rheology modifier; thermosensitivity; LCST; SANS; light scattering

A series of hydrophobically end-capped linear triblock copolymers as well as of three-arm and four-arm star block copolymers was synthesized in a one-pot procedure from . N,N-dimethylacrylamide (DMA) and . N,N-diethylacrylamide (DEA). The sequential reversible addition-fragmentation chain transfer (RAFT) polymerization of these monomers via the R-approach using bi-, tri- and tetrafunctional chain transfer agents (CTAs) bearing hydrophobic dodecyl moieties proceeded in a well-controlled manner up to almost quantitative conversion. Polymers with molar masses up to 150 kDa, narrow molar mass distribution (PDI ⤠1.3) and high end group functionality were obtained, which are thermoresponsive in aqueous solution showing a LCST (lower critical solution temperature) transition. The temperature-dependent associative behavior of the polymers was examined using turbidimetry, static and dynamic light scattering (SLS, DLS), and small angle neutron scattering (SANS) for structural analysis.