Light scattering characterization of tetramethyl polycarbonate blends with polystyrene and with styrene–pentabromobenzyl acrylate copolymers

Abstract

Time resolved light scattering is used to study the phase separation of tetramethyl polycarbonate (TMPC) blends with polystyrene (PS) and with styrene–pentabromobenzyl acrylate copolymers (S–PBBA). Addition of PBBA to the copolymer reduces the lower critical solution temperature with TMPC and slows the rate of phase separation. Both thermodynamic and structural contributions to phase separation are considered. TMPC/PS diffusion coefficients estimated using the linearized Cahn–Hilliard theory are compared with light scattering measurements reported previously and with calculated mutual diffusion coefficients extrapolated from tracer diffusion measurements. The effect of the jump depth into the two phase region on the late stage coarsening process is shown to correlate with the duration of the early stage process of spinodal decomposition.