Dielectric spectra of the polyester poly(propylene succinate) were measured upon crystallization. For this model aliphatic polyester the $\alpha$ and $\beta$ relaxations appear simultaneously and are well resolved in the experimental frequency window. During isothermal crystallization, this fact allows one to use the $\beta$ relaxation to characterize the crystalline structural development while the $\alpha$ relaxation provides information about the evolution of the amorphous phase dynamics. In this way structure development and dynamics evolution can be characterized by a single experiment during the crystallization process. The unambiguous analysis of the dielectric loss clearly supports the existence of precursors of crystallization in the induction period.

• Received 30 August 2006

DOI:https://doi.org/10.1103/PhysRevLett.98.037801