Study of polypropylene peroxidation by ozonization using electron spin resonance and transmission electron microscopy

Abstract Ozonization seems to be an interesting way to create reactive sites when the aim is to optimize radical grafting of vinyl monomers on polypropylene. In order to extensively follow the grafting parameters we used the spin-probe technique of electron spin resonance as well as the spin-trapping technique in conjunction with the diffraction and morphological techniques of transmission electron microscopy. The data indicate that ozonization modifies the diffusion mechanism of liquid monomers in the polypropylene matrix and suggest that grafting takes place in the amorphous phase. We also showed that a core-shell morphological structure can be observed on ozonized polypropylene (granules and fibres). Further, information on peroxide location was obtained.