Synthesis of Poly(2-ethyl-2-oxazoline)-b-poly(styrene) Copolymers via a Dual Initiator Route Combining Cationic Ring-Opening Polymerization and Atom Transfer Radical Polymerization

Becer, C. Remzi; Paulus, Renzo M.; Höppener, Stephanie; Hoogenboom, Richard; Fustin, Charles-Andre; Gohy, Jean-Francois; Schubert, Ulrich S.

Abstract:

Block copolymers of 2-ethyl-2-oxazoline (EtOx) and styrene were synthesized by a combination of cationic ring-opening polymerization (CROP) and atom transfer radical polymerization (ATRP). Initially, a detailed kinetic investigation for the R-bromoisobutyrylbromide (BrEBBr) initiated CROP of EtOx was performed in acetonitrile at different polymerization temperatures ranging from 100 to 180 °C under microwave irradiation. Poly(2-ethyl-2-oxazoline) (PEtOx) homopolymers with controlled molecular weights and narrow polydispersity indices were synthesized in short reaction times. Polymers with relatively high molar masses and low polydispersity indices (Mn,SEC ) 48 500 g/mol, PDI ) 1.29) could also be obtained. Following the synthesis of a PEtOx macroinitiator (Mn,SEC ) 3700 g/mol, PDI ) 1.09), the ATRP of styrene was performed with CuBr and tris[2- (dimethylamino)ethyl]amine (Me6Tren) as catalytic system. The micellization behavior of the obtained amphiphilic block copolymers was further investigated by dynamic light scattering (DLS) and atomic force microscopy (AFM).

Year:

2008

Type of Publication:

Article

Journal:

Macromolecules

Volume:

41

Pages:

5210 - 5215