Hydrodynamic studies on micellar solutions of styrene-butadiene block copolymers in selective solvents

Abstract

Hydrodynamic radius of micelles of several block copolymers in different selective solvents (for both types of blocks) was determined from photon correlation spectroscopy. The boundaries of micellar solutions in heptane (good solvent for poly-butadiene block) and dimethylformamide (good solvent for polystyrene block) were established for polymers in terms of their molecular mass and block composition. The photon correlation spectroscopy data in combination with intrinsic viscosities of block copolymers in selective solvents were used to determine micellar molecular mass and aggregation number. The influence of temperature on the micelle size was examined. The block copolymer micelles could solubilize a certain amount of insoluble homopolymer within their insoluble core. 'H nmr spectra were examined to study the influence of temperature on micellar systems.