% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@ARTICLE{Niu:45560,
author = {Niu, A. Z. and Stellbrink, J. and Allgaier, J. and Willner,
L. and Radulescu, A. and Richter, D. and Koenig, B. W. and
May, R. P. and Fetters, L. J.},
title = {{A}n in situ study of the t-butyllithium initiated
polymerization of butadiene in d-heptane via small angle
neutron scattering and 1{H}-{NMR}},
journal = {The journal of chemical physics},
volume = {122},
issn = {0021-9606},
address = {Melville, NY},
publisher = {American Institute of Physics},
reportid = {PreJuSER-45560},
pages = {134906},
year = {2005},
note = {Record converted from VDB: 12.11.2012},
abstract = {We present a combined 1H-NMR and small angle neutron
scattering in situ study of the anionic polymerization of
butadiene using t-butyllithium as the initiator. Both
initiation and propagation phases were explored. This
combined approach allows the structural and kinetic
characteristics to be accessed and cross compared. The use
of the D22 instrument (ILL Grenoble) permits the attainment
of Q approximately equal to 2 x 10(-3) A. This, in turn, led
to the identification of coexisting large-scale and smaller
aggregates during all stages of the polymerization. The
smaller aggregates contain most of the reacted monomers.
Their structure changes from high functionality wormlike
chains at early stages of the reaction to starlike
aggregates where the crossover occurs at a degree of
polymerization of approximately equal to 40. The initiation
event involved these small, high functionality
(approximately equal to 120) aggregates that apparently
consisted of cross-associated t-butyllithium with the newly
formed allylic-lithium head groups. As the initiation event
progressed the initiation rate increased while the
functionality of these small aggregates decreased and their
size increased. Propagation, in the absence of initiation,
was found to have a rate constant that was molecular weight
dependent. At approximately 11 kg/mol the measured
polymerization rate was found to increase while no further
structural changes were seen.},
keywords = {J (WoSType)},
cin = {IBI-2 / IFF-INS},
ddc = {540},
cid = {I:(DE-Juel1)VDB58 / I:(DE-Juel1)VDB341},
pnm = {Neurowissenschaften / Kondensierte Materie},
pid = {G:(DE-Juel1)FUEK255 / G:(DE-Juel1)FUEK242},
shelfmark = {Physics, Atomic, Molecular $\&$ Chemical},
typ = {PUB:(DE-HGF)16},
pubmed = {pmid:15847501},
UT = {WOS:000228390100055},
doi = {10.1063/1.1866092},
url = {https://juser.fz-juelich.de/record/45560},
}