Phase behavior and miscibility in blends of poly(sebacic anhydride)/poly(ethylene glycol)

In this research, poly(sebacic anhydride) was synthesized via melt-condensation. The polymer was then blended with poly(ethylene glycol) in various ratios by solvent casting, to obtain the desired polymer blends. A differential scanning calorimeter was employed to investigate the crystalline behavior of the blends. Blends with under 10% poly(ethylene glycol) were found to consist of two partially miscible polymers in the amorphous phase. This compatibility of the two polymers may induce the crystallization of the poly(sebacic anhydride) component from decreasing the glass transition temperature of the poly(sebacic anhydride) component in the blending system due to the presence of poly(ethylene glycol) chain segments. Furthermore, phase separation occurred and the crystallinity of poly(sebacic anhydride) diminished when at least 20% poly(ethylene glycol) was present in the blends. These results were verified by the variation in the absorptions of carbonyl groups in infrared spectra; these spectra exhibit the changes in crystallinity of poly(sebacic anhydride) in the blends.