| abstract |
The invention relates to polyimides with good piezoelectric properties at high temperatures, having a recurring structural unit with general formula (I), in which X and Y represent hydrogen and cyano, on the condition that when either X or Y is hydrogen, the other is cyano. The invention also relates to a method for preparing said polyimides, as well as to diamines for the preparation thereof and to a method for obtaining said diamines. The invention further relates to the use of the polyimides in a wide range of industrial applications, owing to the fact that said polyimides are flexible, light, have good remanent polarisation values and are stable at high temperatures. |