Dynamics and structure of an amphiphilic triblock copolymer of styrene and 5-(N,N-diethylamino) isoprene in selective solvents
I. C. Riegel, F. M. de Bittencourt, O. Terrau, A. Eisenberg, C. L. Petzhold,
and D. Samios
Instituto de Química, Universidade Federal
do Rio Grande do Sul, Av. Bento
Gonçalves, 9500, CP 15003, Porto Alegre, RS 91501-970, Brasil
Department of Chemistry, McGill University, 801 Sherbrooke Street West,
Montreal, QC H3A 2K6, Canada
Abstract:
Solution properties of a highly asymmetric aminofunctionalized triblock
copolymer of 5-(N,N-diethylamino)isoprene and styrene were investigated
in dilute regime. Toluene, THF, 1,4-dioxane, or DMF were used to prepare
the solutions. It was found that the solvent selectivity for one or
both block affects the copolymer solution behavior as reflected by the
calculated parameters through light-scattering techniques: weight-averaged,
molecular-weight, radius of gyration, translational diffusion coefficient,
and hydrodynamic radius. According to what was determined, the quality
of the polymer-solvent interactions decreases in the order: toluene,
THF, 1,4-dioxane, and DMF. After quaternization with dimethyl sulfate,
the triblock copolymer consisted of a polystyrene (PS) block with short
poly[5-(N,N,N-diethylmethylammonium)isoprene][methyl sulfate]
block at both chain ends, shows a better solvation in polar solvents.
Transmission electron microscopy (TEM) was used to characterize the
crew-cut aggregates prepared from the quaternized copolymer.
*Lecture presented at the European Molecular Liquids Group (EMLG) Annual Meeting on the Physical Chemistry of Liquids:
Novel Approaches to the Structure, Dynamics of Liquids: Experiments, Theories, and Simulation,Rhodes, Greece, 7-15 September 2002. Other presentations are published in this issue, pp. 1-261.