Abstract
The relative amounts of the α- and γ-crystalline forms of nylon 6 obtained from the glassy state under different crystallization conditions have been studied by the X-ray diffraction procedure described in the previous paper. The weight fraction of the γ-form decreases with increasing crystallization temperature above 160°C and that of the α-form increases. Growth of the γ-form is predominant in crystallization at 100°C and of the α-form at 200°C. Differential scanning calorimetry and density data are presented. A large amount of a thermally unstable form is included in the γ-form crystallized from the glassy state at lower crystallization temperatures and is transformed into the a-form with annealing at 200γC. Thermal stability of the γ-form obtained from the glassy state was quantitatively investigated and discussed.