Anomalous phase behavior in blends of -SO3H terminated polystyrene with poly(n-butyl acrylate) containing a small amount of tertiary amino groups
Abstract Phase behavior in the blend of -SO3H terminated polystyrene (PSS) with poly(n-butyl acrylate-co-N,N-dimethylaminoethyl methacrylate) containing 6.0 mol% N,N-dimethylaminoethyl methacrylate (P1) is investigated by optical microscopy and small-angle X-ray scattering (SAXS). Comparing the miscibility of polystyrene/P1 blend, it is confirmed that the miscibility of the PSS/P1 blend is drastically improved by the hydrogen bonds between -SO3H and tertiary amino group. In addition, two-phase region of the PSS/P1 blend is split into two regions around the stoichiometric composition, in which the molar ratio of -SO3H to tertiary amino group is 1:1 stoichiometry. SAXS result shows that the PSS/P1 blend at stoichiometric composition forms a block copolymer-like aggregate and it takes a disorder state.