Crystal transitions of Nylon 11 under drawing and annealing

The crystal transitions of Nylon 11 annealed and drawn at different tempera tures (T-d) with different drawing ratios (n) were investigated by wide-ang le X-ray diffraction (WAXD). The alpha -form of Nylon Il could be transform ed from the delta'-form by annealing at high temperature, The results showe d that the crystal transitions of Nylon 11 strongly depended on the thermal history and the conditions of drawing. The delta'-form Nylon Il could he g radually transformed into the alpha -form when it was drawn at high tempera ture and the alpha -form was only partly transformed into the delta'-form w hen it was drawn at low temperature. This should be due to the effect of th e competition between thermal inducement and drawing inducement. The therma l inducement was favorable to producing the alpha -form, while the drawing inducement was favorable to producing the delta'-form. (C) 2001 Elsevier Sc ience Ltd. All rights reserved.