Miscibility study of Torlon® polyamide-imide with Matrimid® 5218 polyimide and polybenzimidazole

We have discovered two new miscible polymer blend systems, namely, Torlon® 4000T with Matrimid® 5218 and Torlon 4000T with polybenzimidazole (PBI). Both Matrimid 5218 and PBI are miscible at a molecular level with Torlon 4000T over the whole composition range as confirmed by microscopy, DSC, FTIR and DMA. DSC and DMA studies show the existence of a single glass transition in each blend. The Tg-composition curve of Torlon/Matrimid blend system forms a sigmoid curve as a function of composition, while the Tg-composition curve of the Torlon/PBI blend system is double parabola-like. FTIR spectra show the existence of hydrogen-bonding interactions in these two polymer blend systems.