Thermal and Thermooxidative Stability of Polyimide Fibers

PFMB can be used to prepare aromatic polyimides that display solubility in ketone, ether, and polar aprotic solvents. This unusual solubility can be utilized in die facile preparation of thin films that display anisotropy in their structures and properties. The anisotropy in the optical properties of the films makes them promising candidates for use as compensation layers in liquid-crystal displays. Their low dielectric constants and CTEs in combination with their outstanding thennal and thermooxidative stabilities make diem candidates for dielectric layers in microelectronics applications. 

A PFMB-based polyimide (BPDA-PFMB) can be used to prepare fibers with mechanical properties comparable to those of commercial PPTA fibers. However, owing to superior thermooxidative stability, the fibers retain their properties for much longer periods of time when subjected to isothermal aging in air at elevated temperatures. In fact, BPDA-PFMB fibers retain their properties under these conditions better than any other available high-performance fiber. 

Harris andL. H. Lanier, in Structure-Solubility Relationships in Polymers (F. W. Harris and R. B. Seymour, eds.). Academic Press, New York (1977), p. 183. 

Guadiana, in High Performance Polymers and Composites (J. I. Kroschwitz, ed.), John Wiley and Sons, New York (1991), p. 720. 

Application of F-NMR Toward Chemistry of Imide Materials in Solution 

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