Interdiffusion in the Partially Miscible Polymer Blend of Deuterated Polystyrene and Poly(styrene-co-bromostyrene)

Abstract

We have used elastic recoil detection (ERD) to measure the interdiffusion in the partially miscible polymer blend of deuterated polystyrene (DPS) and poly(styrene-co-bromostyrene) (PBr_xS). The fraction x of the comonomer and the molecular weights M_w, were chosen such that the upper critical solution temperature (UCST) was well above the glass transition temperature. Annealing took place only in the two-phase region as was assured by interference contrast microscopy (ICT). One of the blend compositions on the binodal line could be extracted from the diffusion profiles at various annealing temperatures. The Flory-Huggins interaction parameter, calculated from the measured blend composition, is compared with SAXS measurements on similar blends of PS and PBr_xS.