Full-temperature-range crystallization rates of polyamides by fast scanning calorimetry as key to processing

Abstract

For industrial research fast scanning calorimetry (FSC) provides crucial information on polymer crystallization and melting behavior, under conditions where metastability and reorganization occur frequently. Since FSC allows simulating cooling and heating ramps as encountered in practice, not only tuning the industrial conditions towards optimum processability becomes now possible but also predictions of the expected polymer morphologies. Especially the targeted material crystallization rates as a function of temperature offer a solid basis for both starting up and optimizing industrial processes. Selected examples of polyamides (PA6, PA66, PA410, PA46, ForTii) are discussed, together with the FSC technical procedures applied for assessing their thermal behavior. In addition, revealing the link between the crystallization behavior and the processing constraints offers a tool to product developers for tailoring recipes to particular applications. The generated knowledge concerning the effect of additives (herein discussed the effect of crystallization enhancers or retarders) and polyamide modifiers on the crystallization behavior at various temperatures increases nowadays the flexibility of process operation.