In situ FTIR spectroscopy study on the crystallization process of Isotactic Polypropylene in Isotactic Polypropylene/Polyethylene-glycol blends

The crystallization of isotactic polypropylene (iPP) and polypropylene/polyethylene-glycol (iPP/PEG) blends were investigated by in situ Fourier transform infrared spectroscopy (FTIR) and wide angle X-ray diffraction (WAXD). It was found that the existence of polyethylene-glycol (PEG) does not destroy the helical structure of iPP in the melt, but changes the crystal structure of iPP in the bends. Moreover, the variation tendency of ratios of intensity A998 cm(-1)/A1460 cm(-1) for iPP and iPP/PEG blends showed that the the onset crystallization temperature of iPP is improved by addition of PEG until the PEG content reaches to 5 wt%, and beyond this content, the crystallization point decreases.