Publication

Abstract : Miscibility and phase separation in SAN/PMMA blends have been investigated using DSC, İR} spectroscopy and positron lifetime spectroscopy (PLS). Single broad glass transition observed throughout the blend compositions, may be due to overlap of two glass transitions. İR} measurements clearly indicate the absence of strong interactions. This supports miscibility is due to intramolecular repulsive forces in the {SAN} component. On the other hand, free volume data show negative deviation from linear additivity indicating the blends are miscible. The interchain interaction parameter β exhibits a complex behavior and the extent of miscibility is not revealed. Following Wolf’s treatment, we have evaluated the geometry factor γ and hydrodynamic interaction parameter α and found α is a suitable parameter in predicting the miscibility window. The cloud points in SAN/PMMA blends increase with decreasing {PMMA} content. The change in free volume size correlates well with the observed change in cloud point.