Publication Type:

Journal Article


European Polymer Journal, Volume 42, Number 10, p.2655 - 2666 (2006)



Blends, Free volume, Geometric parameter, Hydrodynamic interaction, Miscibility, ortho-Positronium, phase separation


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.

Cite this Research Publication

G. N. Kumaraswamy, Ranganathaiah, C., Urs, M. V. Deepa, and Ravikumar, H. B., “Miscibility and phase separation in SAN/PMMA blends investigated by positron lifetime measurements”, European Polymer Journal, vol. 42, pp. 2655 - 2666, 2006.