Competing growth kinetics in simultaneously crystallizing and phase-separating polymer blends

The kinetic interplay between crystal superstructure growth and late-stage liquid phase coarsening in a polymer blend has been examined. By controlling the relative quench depths for liquid–liquid phase separation and crystallization, the growth kinetics of the characteristic length scales of the simultaneous ordering processes show a crossover from crystallization dominated to phase-separation dominated behavior. Based on a scaling argument for late-stage coarsening during spinodal decomposition, we argue that this kinetic crossover is inevitable in a blend for which the critical temperature of liquid–liquid phase separation is well above the equilibrium melting temperature of the blend.