Abstract: | The isothermal crystallization behaviour of poly(ε-caprolactone), PCL, has been investigated by dilatometry and optical microscopy. Nucleation rates and spherulitic growth rates have been measured. At all temperatures tested a change in nucleation rate was observed early during the crystallization. Growth rates were linear over the whole of the crystallization range. The experimental results were analysed using the Avrami equation in which the experimentally observed time dependence of nucleation is used. The equation contains integer values of the Avrami exponent and describes adequately the crystallization behaviour of PCL. The difference between the apparent and true nucleation rates is emphasized, and difficulties in the calculation of rate constants are discussed. |