Spontaneous pinning of domain growth during spinodal decomposition of off-critical polymer mixtures. II. Scaling analysis

Abstract

Later‐stage spinoidal decomposition (SD) of off‐critical mixtures of poly(styrene‐ran‐butadiene) SBR/polyisoprene or SBR/polybutadiene was investigated by time‐resolved light scattering. Changes in the scaled structure factor F(x,t)≡q m (t)3 I(x,t) with x≡q/q m (t) were determined as a function of the composition w of the mixture and of the phase separation temperature T, where q m (t) is the wave number q at the peak position of the scattering intensity profile I(q,t) at time t. It was found that the later‐stage SD for the off‐critical mixture is divided into four stages: intermediate, pseudolate, transition, and pinning. The change in the structure factor F(x,t) at large x implied that the dynamical percolation‐to‐cluster transition occurs before the pinning stage.