Characterization of strain-induced crystallization of poly(ethylene terephthalate) at fast draw rates using synchrotron radiation

Structural changes during fast drawing of poly(ethylene terephthalate) were studied by wide-angle X-ray scattering using synchrotron radiation. Drawing was studied at 80, 90, 100 and 110 degrees C to a final draw ratio of similar to 4:1 at a draw rate of similar to 10 s(-1). Simultaneous video recording of the sample enabled variation in the X-ray pattern to be correlated with local extension. Essentially all oriented crystallization occurred after final extension. Primary crystallization fits a first-order transformation with little change in the rate of crystallization observed over the 30 degrees C range of temperature. These results show that it can be misleading to rely on crystallinity information obtained when samples from interrupted draw experiments are quenched. Crown copyright (C) 1996 Published by Elsevier Science Ltd.