Abstract
The recently developed differential fast scanning calorimetry (DFSC) is used for a new look at the crystal
growth of poly(3-caprolactone) (PCL) from 185 K, below the glass transition temperature, to 330 K, close to the equilibrium melting temperature. The DFSC allows temperature control of the sample and
determination of its heat capacity using heating rates from 50 to 50,000 K/s. The crystal nucleation and
crystallization halftimes were determined simultaneously. The obtained halftimes cover a range from
3 102 s (nucleation at 215 K) to 3 109 s (crystallization at 185 K). After attempting to analyze the
experiments with the classical nucleation and growth model, developed for systems consisting of small
molecules, a new methodology is described which addresses the specific problems of crystallization of
flexible linear macromolecules. The key problems which are attempted to be resolved concern the
differences between the structures of the various entities identified and their specific role in the
mechanism of growth. The structures range from configurations having practically unmeasurable latent
heats of ordering (nuclei) to being clearly-recognizable, ordered species with rather sharp disordering
endotherms in the temperature range from the glass transition to equilibrium melting for increasingly
perfect and larger crystals. The mechanisms and kinetics of growth involve also a detailed understanding of the interaction with the surrounding rigid-amorphous fraction (RAF) in dependence of crystal size and perfection.