Polyimides

To overview the materials chemistry, physics, and applications of polyimides (PIs), this entry briefly describes the classification of PI-related materials, syntheses of PIs and their precursors, film manufacturing processes, structure modification, physical structure formation, characterisation, and properties of PI films. The problems that have emerged while using these items and their solutions are mentioned. In many cases, the properties of PI films can be controlled by the choice of monomers. However, physical structures (crystal and ordered structures and main chain orientations), which depend on the processing conditions, majorly influence the properties in certain cases. The importance of performance balance is also introduced herein.