Crystallization Kinetics of Polyamide 66 Blends

Polyamide 66 (PA66) blends offer a good balance between material properties and cost. A good understanding of the processing of PA66 and its blends at conditions including fast cooling or high undercooling serves immediate industry interest. In order to study crystallization at such conditions, flash scanning chip calorimetry (FSC) has been utilized to study crystallization kinetics of PA66 and its blends with polycaprolactam (PA6). Subsequent experiments using WAXS, Micro-IR, and POM have been carried out on samples mounted on FSC chips. Isothermal analysis of the crystallization rate indicates crystallization in blends becomes slower with a higher blend content. Interestingly, bimodal temperature-dependent kinetics, observed in PA66 homopolymer, gradually merges into a unimodal crystallization kinetics profile as PA66 blend fraction decreases. The mechanism that leads to the changes in isothermal crystallization kinetics will be discussed.