Block copolymers of styrene and stearyl methacrylate. Synthesis and micellization properties in selective solvents

Abstract

Block copolymers of styrene and stearyl methacrylate were prepared using anionic polymerization high-vacuum techniques by sequential addition of monomers. Narrow molecular weight distribution copolymers of different molecular weight and composition were obtained. The molecular characteristics of the copolymers were obtained by size exclusion chromatography, membrane osmometry, low-angle laser light scattering (LALLS), and differential scanning calorimetry. Comparative studies in the selective solvents for the polystyrene block, ethyl and methyl acetate, showed that mainly unimolecular micelles are formed in the former, whereas larger aggregates are observed in the latter solvent. LALLS, viscometry, and dynamic light scattering were used to characterize the micelles.