Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 3, pp. 864−868.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
V.T. Lebedev, D.N. Orlova, V.M. Lebedev, Gy. Törökb, A.B. Mel’nikov, L.V. Vinogradova, 2010, published in Zhurnal Prikladnoi
Khimii, 2010, Vol. 83, No. 3, pp. 811−815.
AND POLYMERIC MATERIALS
Self-Organization of Sulfopolystyrene Ionomers
with Ionic SO
Li Groups in Carbon Tetrachloride
V. T. Lebedev
, D. N. Orlova
, V. M. Lebedev
, Gy. Török
, A. B. Mel’nikov
and L. V. Vinogradova
Konstantinov St. Petersburg Institute of Nuclear Physics, Russian Academy of Sciences, Gatchina, Leningrad oblast, Russia
Research Institute for Solid State Physics and Optics, Budapest, Hungary
St. Petersburg State University, St. Petersburg, Russia
Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Russia
Received February 18, 2010
Abstract—Association of short-chain sulfopolystyrene ionomers containing 5.2 mol % ionic SO
Li groups in
carbon tetrachloride was studied by cold neutron scattering.
Owing to electrostatic dipole interactions of ion
pairs, comparable in strength with hydrogen bonds [1–
4], ﬂ exible-chain polymers containing less than 10 mol
% ionic groups randomly distributed in the nonpolar
chain (ionomers) exhibit pronounced capability for
conformational and structural transformations on the
molecular and supramolecular levels [5–7]. These
factors determine a number of morphological features
of ionomers, owing to which they differ essentially in
physicochemical properties from hydrophobic poly-
meric analogs. For example, ionomers exhibit properties
of thermoplastics and are harder and more resistant to
deforma-tions [1, 2, 4, 8] than the precursor polymers.
Much attention has been given recently to ionomers
derived from sulfonated polystyrene (SPS). The
majority of data concern determination of the molecular
characteristics and structure of long-chain SPS ionomers
with the molecular weights of about 10
and in the solid phase [9–13]. This is largely due to the
interest in self-organization of ionomers on the level
of separate macromolecules, when ionomers undergo
internal ordering (e.g., coil-to-globule transition)
owing to electrostatic interactions with the formation
of multiplets of ionic groups and their segregation
within the chain [4, 14]. Interactions of chains and
intermolecular aggregation phenomena [5, 7, 9] are
considered as factors accompanying intramolecular
association (formation of aggregates, gel particles).
At large contour length the ionomer chain and
high molar content of units with ionic groups, the
probability of the intrachain association is higher than
the probability of bonding of ionic groups belonging to
different molecules. As a result, the groups are mainly
combined in multiplets within a single chain.
In short-chain ionomers, the number of ionic groups
(1–3) per chain is usually insufﬁ cient for the formation
of multiplets within a coil, and competition of intrachain
(intramolecular) and interchain (intermolecular)
association processes can lead to the prevalence of the
association between macromolecules via ionic groups:
Intrachain and interchain association.
In this study we examined the speciﬁ c features of
structuring of short-chain sulfopolystyrene ionomers