Synthesis of polystyrene-b-poly(ethylene-co-butene) block copolymers by anionic living polymerization and subsequent noncatalytic hydrogenation

A series of polystyrene-b-polybutadiene (PSt-b-PBd) block copolymers with various chain lengths and compositions were synthesized by sequential living anionic polymerization and then converted into the corresponding polystyrene-b-poly(ethylene-co-butene) (PSt-b-PEB) block copolymers through the selective hydrogenation of unsaturated polybutadiene segments. Noncatalytic hydrogenation was carried out with diimide as the hydrogen source. The microstructures of PSt-b-PBd and PSt-b-PEB were investigated with gel permeation chromatography, H-1-NMR, C-13-NMR, Fourier transform infrared, and differential scanning calorimetry. The results showed that the hydrogenation reaction was conducted successfully and that the chain length and molecular weight distribution were not altered by hydrogenation. (c) 2006 Wiley Periodicals, Inc.