On the conformation of the hydrophilic (B) chains in ABA and BAB type triblock copolymers

SANS [Sz. Vass, K. Haimer, G. Meier, M. Klapper, S. Borbely, Colloid Polym. Sci. 280 (2002) 245] and SAXS studies of poly(methyl methacrylate)-block-poly(sodium acrylate)-block-poly(methylmethacrylate), pMMA/pNaA/pMMA (ABA), and pNaA/pMMA/pNaA (BAB) triblock copolymer micelles resulted in essentially different types of scattering patterns. Due to the difficulties in fitting the Pedersen-Gerstenberg model [J.S. Pedersen, M.C. Gerstenberg, Macromolecules 29 (1996) 1363], the question arose whether the conformation of the hydrophilic chains is the same for the two block-sequences. From the analysis of the tails of SAXS patterns from ABA and BAB polymer solutions we concluded that the hydrophilic chains are Gaussian with nearly the same Kuhn length, without regard to the block sequence. (c) 2006 Elsevier B.V. All rights reserved.