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Pure Appl. Chem., 2004, Vol. 76, No. 1, pp. 123-131

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.