Effects of Mass Transport on Crystallization From Miscible Polymer Blends

Abstract In the crystallization of miscible polymer blends, the kinetics of transport of crystallizable molecules to a growing entity influences the kinetics of the transformation and controls the ultimate morphology. In the nucleation step, the diffusion of crystallizable molecules to a growing embryo can significantly slow the nucleation rate. This process is modeled as the growth to a critical size of a sphere in a molten blend of crystallizable and uncrystallizable polymers. In the growth phase, the diffusion length δ plays a very large role. The magnitude of δ controls the final apportioning of the noncrystallizing species: between spherulites, between fibrils, or between lamellae. The magnitude of δ also determines whether growth will be linear or parabolic in time.