Morphology investigation of high-pressure crystallized poly(ethylene terephthalate)

Poly(ethylene terephthalate) (PET) is a semicrystalline polymer composed of crystalline and amorphous regions. A great variety of microstructures is developed in PET by changing the crystallization condition. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), wide angle X-ray diffraction (WAXD) and scanning electron microscope (SEM) results for high pressure crystallized PET samples are presented. The morphological transformation along with the increase of crystallization time is shown and extended-chain crystals are formed during high-pressure crystallization. The effect of crystallization time is an important factor for the formation of extended-chain crystals.