|429. Schmalz, A.; Schmalz, H.; Müller, A.H.E.: Double Responsive Hydrogels based on Tertiary Amine Methacrylate Star Block Copolymers, Z. Physik. Chem. 226, accepted (2012) -- DOI: 10.1524/zpch.2012.0240|
Double hydrophilic stimuli-responsive star block copolymers with poly(2-(dimethylamino)ethyl methacrylate) (PDMA) inner blocks and poly(2-(diethylamino)ethyl methacrylate) (PDEA) outer blocks were synthesized using ATRP. Different multifunctional initiators based on sugar scaffolds were employed in a core first approach with sequential polymerization of both blocks yielding stars with 4 and 6 arms, respectively, and varying length of the PDEA outer block. The star block copolymers show pH- and temperature-responsive aggregation as revealed by dynamic light scattering and turbidimetry. The impact of pH, PDEA block length and arm number on the gelation behavior was investigated by tube inversion and rheology.