Effect of compatibilizer on structural rheology of PP/PET blends

The maleic anhydride grafted polypropylene (PP-g-MAH) was used as a compatibilizer to improve the immiscible phase morphology of polypropylene/poly(ethylere terephthalate)(PP/PET) blends. The effect of PP-g-MAH on the phase morphology and structural rheology of the blends was studied. The results show that for PP/PET blends with PET-rich composition, the addition of PP-g-MAH reduces the dispersed PP particle size remarkably, leading to large change in the shape relaxation and deformation as well as break-up behavior of PP drops. For PP/PET blends with the components around the phase inversion point, the coexistence of phase morphology of 'sea-island' and cocontinuous structure disappears with addition of PP-g-MAH. The enhancement in dependency of low-frequency modulus on frequency also indicates that phase interactions increase due to the compatible effect. However, for PP/PET blends with rich PP component,the addition of PP-g-MAH nearly has no influence on both the morphology and rheology.