(692e) The Glass Transition and Crystallization of Poly (?-caprolactone) (PCL) Nanofibers Measured By Flash Differential Scanning Calorimetry

The Mettler Toledo Flash DSC 2+ have added a new dimension to rapid-scanning calorimetry by allowing analysis of the reorganization process and structure development in nanomaterials, particularly during cooling, which is important for materials like polymers and medicines. The study investigates the glass transition and crystallization of poly(ε-caprolactone) (PCL) nanofibers at cooling rates ranging from 0.1 to 2000 K/s. Poly(ε-caprolactone) (PCL) is a semi-crystalline synthetic polyester with a low melting point and glass transition temperature of -60°C. Flash DSC 2+ was used to study PCL nanofiber glass transition and crystallization at cooling rates ranging from 0.1 to 2000 K/s. Five separate chips were utilized to acquire five data sets, and the findings are averages of those five sets. The results indicate that during confinement, the glass transition temperature of PCL nanofiber increased to -45oC when compared to bulk PCL. Crystallization occurred at cooling rates less than 100 K/s; however cold crystallization was observed on heating after cooling at 300 K/s to 2000 K/s. The results show that the critical cooling rate for obtaining amorphous samples is 1000K/s. It could be that homogeneous crystal nucleation takes priority during deep supercooling. Glass transition was identified at lower cooling rates (0.1-30 K/s), while cold crystallization and melting were observed at moderate cooling rates (30-100 K/s). The analysis of the thus-produced amorphous polymer samples at a higher cooling rate reveals new details about the ordering processes of nucleation, crystallization, and cold crystallization, as well as the resulting changes in the glass transition of the remaining amorphous phase, which is the formation of rigid amorphous phases (RAFs). Further research could improve our understanding of PCL nanofiber thermal characteristics and their potential applications in the pharmaceutical industry.