Characterization of styrene-ethylene oxide and methyl methacrylate-styrene block copolymers by light scattering

Abstract

Abstract Several polystyrene-poly(ethylene oxide)-polystyrene (PS-PEO-PS) and poly(methyl methacrylate)-polystyrene-poly(methyl methacrylate) (PMMA-PS-PMMA) block copolymers, synthesized by free-radical polymerization, were studied in various solvents by using a light-scattering technique. The copolymers, which have different lengths of central blocks, had molecular weights within the range 3.0 × 104 to 1.6 × 106. It was found that almost all of them were confirmed as block copolymers from the variation of the product M app 〈S 2 app 〉 1 2 with W A v A v , although they were rather heterogeneous. The copolymer compositions determined either from the additivity of the refractive index increments of its constituent parts and the copolymer or from ultra-violet analysis were in excellent agreement with each other.