Molecular dynamics revealed from frequency dependent heat capacity

Temperature modulated DSC (TMDSC) measurements at reasonably high frequencies allow for the determination of baseline heat capacity. In this particular case vitrification and devitrification of the rigid amorphous fraction (RAF) can be directly observed. 0.01 Hz seems to be a reasonably high frequency for Bisphenol‐A Polycarbonate (PC). The RAF of PC is established during isothermal crystallization. Devitrification of the RAF seems to be related to the pre‐melting peak. For PC the melting of small crystals between the lamellae is thought to yield the pre‐melting peak.