Effect of the melt annealing time on the crystallization of nylon-6 with various molecular weights

The effect of melt annealing duration at 260 °C-high above melting temperature on the crystallization of nylon-6 with various molecular weights (between 5 800 and 255 500) using dilatometric and calorimetric (DSC) techniques has been studied. The samples were laboratory synthesized, purified and characterized by GPC. It was found that the crystallization behavior of nylon-6 depends strongly on the melt annealing duration as well as on the molecular weight. This effect is explained by the gradual destruction of the crystallization centers during annealing of the melt. The experimental data support the well known “memory” effect and the recently observed accumulative “memory” effect on the same polymer