Crystal transitions of Nylon 11 under drawing and annealing

The crystal transitions of Nylon 11 annealed and drawn at different temperatures (Td) with different drawing ratios (n) were investigated by wide-angle X-ray diffraction (WAXD). The α-form of Nylon 11 could be transformed from the δ′-form by annealing at high temperature. The results showed that the crystal transitions of Nylon 11 strongly depended on the thermal history and the conditions of drawing. The δ′-form Nylon 11 could be gradually transformed into the α-form when it was drawn at high temperature and the α-form was only partly transformed into the δ′-form when it was drawn at low temperature. This should be due to the effect of the competition between thermal inducement and drawing inducement. The thermal inducement was favorable to producing the α-form, while the drawing inducement was favorable to producing the δ′-form.