Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and wide-angle X-ray scattering (WAXS) of polypropylene (PP)/cyclic olefin copolymer (COC) blends for qualitative and quantitative analysis

In this study, polypropylene (PP), a versatile commodity thermoplastic, and cyclic olefin copolymer (COC), an amorphous engineering thermoplastic, were blended over full composition range by melt-mixing technique using a co-rotating twin-screw extruder. PP is likely to be compatible with COC due to its olefinic behaviour, and PP/COC blends provide significant promising properties. FTIR spectra, Raman spectra and wide-angle X-ray scattering (WAXS) patterns of polypropylene, cyclic olefin copolymer and its blends were recorded in solid phases and carried out qualitative and quantitative analysis in detail. The characteristic absorption peaks of PP, COC and PP/COC blends were determined and compared. PP/COC blends did not generate new chemical reactions, while the intensity of fundamental vibration peaks in the spectra tends to vary with respect to the component contents in the blends. The ratio of the integral intensities of polypropylene and cyclic olefin copolymer fundamental vibrations in the Raman spectra were used for the quantitative analysis of PP/COC blends, and the obtained results showed very good agreement with the experimental values. IR spectra, Raman spectra and WAXS patterns of PP/COC blends are useful to track the uniformity of blending and determine the blend composition.