Annealing Temperature Effects on the Perfluoroalkoxy Lamellar Thickness and Mechanical Properties

ABSTRACT As a high‐performance melt‐processable fluoropolymer, perfluoroalkoxy (PFA) exhibits mechanical properties that are critically influenced by its crystalline structure. However, capturing detailed insights into the crystallization process of PFA proves challenging due to its exceptionally rapid crystal growth rate. In this paper, the crystallization kinetics and structural reorganization of PFA across three distinct anneal regimes: sub‐melting (280°C–305°C), self‐nucleation (305°C–320°C), and complete melting (> 320°C) were dynamically examined via utilizing multi‐scaled analytical approaches such as differential scanning calorimetry (DSC), X‐ray diffraction (XRD), and polarized optical microscopy (POM), etc. The results demonstrate that annealing in the sub‐melting region significantly improves both crystallinity (by up to 33%) and lamellar thickness (by up to 23.7%), owing to molecular chain rearrangement and crystal perfection. Within the self‐nucleation region, annealing induces partial melting and subsequent recrystallization, resulting in a homogeneous lamellar distribution and optimized mechanical performance. However, annealing in the complete melting region erases the crystal memory effect, yielding a regenerated crystalline architecture with short‐range order similar to that of the untreated sample. These insights bridge laboratory analysis with industrial processing, enabling precise microstructure control for manufacturing high‐reliability PFA components in electronic and power transmission applications.