The invention defines polyimides with good piezoelectric properties at high temperatures having a repeating structural unit of formula (I) wherein X and Y represent hydrogen and cyano, with the proviso that when one of X and Y is hydrogen, the other one is cyano. The invention also defines a process for the preparation of these polyimides. It likewise defines diamines for the preparation thereof and a process for obtaining these diamines. Finally, the invention defines the use of said polyimides in a wide range of industrial applications since they have good remanent polarization values as well as stability at high temperatures and are furthermore flexible and lightweight.
本发明定义了在高温下具有良好压电特性的聚
酰亚胺,该聚
酰亚胺具有式(I)的重复结构单元,其中 X 和 Y 代表氢和
氰基,但条件是当 X 和 Y 中的一个是氢时,另一个是
氰基。本发明还定义了制备这些聚
酰亚胺的工艺。同样,本发明还定义了用于制备这些聚
酰亚胺的二胺以及获得这些二胺的工艺。最后,本发明确定了上述聚
酰亚胺在广泛工业应用中的用途,因为它们具有良好的剩磁极化值和高温稳定性,而且柔韧性好,重量轻。