Detecting reorganization in semicrystalline polymers during heating: Insights from Fast Scanning Chip Calorimetry coupled with real-time optical microscopy

•Metastability of polymer crystals leads to their reorganization on heating.•Double melting endotherms do not necessarily indicate reorganization.•Novel setup merges Fast Chip Calorimetry with real-time polarized microscopy.•The setup helps identifying reorganization processes in crystalline polymers.•Critical heating rates above which reorganization processes cease are measured.