Morphology of high-pressure crystallized poly(ethylene 2,6-naphthalate)

The high-pressure crystallized poly(ethylene 2,6-naphthalate) (PEN) samples were investigated using wide-angle X-ray diffraction (WARD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). DSC resu lts showed that the melting temperature of high-pressure crystallized PEN s amples was up to 603 K, which is much higher than the equilibrium melting p oint of PEN suggested by Buchner et al. and near to the value estimated by Cheng et al. The striations in the morphology of PEN extended-chain crystal s with thickness of about 1.5 mum were observed with SEM. Some characterist ic spherulitic forms obtained at high pressure are also presented. (C) 2001 Elsevier Science Ltd. All rights reserved.