Processability of PVDF/PMMA blends studied by torque rheometry

The processing characteristic of blends of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA), in different compositions, were studied by torque rheometry. The polymers were mixed in a batch mixer in proportions of 20, 40, 60 and 80% by weight of PVDF, at 190 °C using rotor speeds of 30, 60 and 100 rpm. The results have shown that the increase of the PMMA content improved the processability of the blends, in spite of an increase of the activation energy of flow. Higher speeds of blending caused a reduction of the homogenization blending times of the blends. The PMMA processing at different speeds studied by parallel plate rheometer showed that a similar behavior and did not affect considerably the degradation of PMMA, according the Carreau model.