The effect of different compatibilisers on the morphology and rheological properties of PP/PET polymer blends

In the present study, the compatibilisation of polypropylene/polyethylene terephthalate (PP/PET) blends with different types of compatibilisers including maleic anhydride-grafted polypropylene (PP-g-MA), glycidyl methacrylate-grafted polypropylene (PP-g-GMA) and ethylene propylene diene monomer (EPDM) rubber in different concentrations was examined. Samples were evaluated in terms of morphology, thermal and rheological properties. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) were used. According to the results, all samples had a matrix-droplet morphology. Moreover, with increasing the compatibiliser and its concentration, the droplet sizes in dispersed phase decreased. In other words, compatibilised PP/PET showed a greater dispersed phase size reduction, lower crystallinity percentage and larger storage modulus at low frequencies in comparison with non-compatibilised PP/PET blend. Among different samples, polymer blend compatibilised with PP-g-MA (5 phr) indicated the lowest particle size and significantly improved the compatibilisation of the PP/PET blend.