CRYSTALLIZATION KINETICS IN RELATION TO POLYMER PROCESSING

Phase distribution of quenched samples has been determined by a deconv olution procedure of WAXS spectra in a wide range of cooling rates. Th e informations collected together with isothermal and DSC results prov ide a very wide set of data on the crystallization kinetics of polymer s relevant which covers conditions encountered in most polymer process ing operations. They have been compared with predictions of a non-isot hermal crystallization model assuming two independent and parallel cry stallization processes competing during solidification. The case of a nucleated Polyamide 6 is described in this work. While amorphous phase increases slowly with cooling rate, alpha-monoclinic phase starts to decrease significantly above cooling rates of a few degrees-C/s wherea s gamma-pseudohexagonal phase starts to grow; above cooling rates of 2 00-degrees-C/s only traces of alpha-form are observed and gamma-phase seems to have reached a plateau. All these features are satisfactorily described by the crystallization kinetics model adopted.