Dresden 2003 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 20: POSTER A
CPP 20.9: Poster
Montag, 24. März 2003, 19:00–21:00, ZEU/250
Real-time SANS and 1H-NMR studies during living anionic polymerisation of butadiene in hydrocarbon media — •Aizhen Niu1, Joerg Stellbrink1, Juergen Allgaier1, Lutz Willner1, Dieter Richter1, and Lew Fetters2 — 1IFF-Neutronenstreuung, Forschungszentrum Juelich, D-52425 Juelich — 2Department of Chemical Engineering, Cornell University, Ithaca, NY 14584, USA
Small angle neutron scattering (SANS) and high-resolution 1H-NMR studies have been carried out in situ on the organolithium polymerization of butadiene in heptane-d16. In a nonpolar solvent, living anionic chains having Li as the countercations generally aggregate with each other through the Li bridges. Reaction kinetics, aggregation behavior and even the microstructure of living polymer chains were studied to elucidate the detailed mechanism of the anionic polymerisation in hydrocabon media. The present data demonstrated a large variety of intermediate aggregated species, in particular the large scale aggregates exist in the early initiation stage, a contradictory to current textbook mechanisms.