Conformational transitions in block copolymers in solution from light scattering data

Abstract

Data obtained from light scattering studies on block copolymers of styrene and isoprene, in the solvent cyclohexane, show a change in apparent radius of gyration as a function of temperature at the same temperature, T_p, as was observed in studies of [η] against T in this solvent. The phenomenon observed in these independent experimental methods is believed to be due to a change in the hydrodynamic volume of the polymer, brought about by an intramolecular rearrangement of the molecule, from a phase-separated to a phase-mixed conformation, as the temperature increases through T_p.