Retardation of the growth rate of the basal and overgrown lamellar crystals of PCL/PVME miscible binary blends with thickness confinement

Abstract

For bulk crystallization, the growth rate is governed by the nucleation process and depends mainly on the crystallization temperature and composition of the blends. If the crystallization process is confined in ultrathin films, then the diffusion-controlled growth process is remarkably retarded due to the thickness confinement. This study reports the retardation of the growth rate of the basal and overgrown lamellar crystals of neat Poly(ε-caprolactone) (PCL) and poly(vinyl methyl ether) (PVME) crystalline/amorphous miscible binary blends with various thicknesses. The morphological variations and the corresponding crystal growth rate were analyzed using real-time microscopy, and the crystal structures were evaluated by transmission electron microscopy. The growth rate was strongly dependent on the crystallization temperature, film thickness, and composition ratios in the blend. Moreover, the longitudinal and lateral growth rates of basal and overgrown lamellar crystals were discussed. This study revealed that the film thickness significantly retards the growth rate of basal and overgrown lamellar crystals and reduces the number of overgrowths on the basal lamellar crystals.