New heat resistant dielectric film

Among the heat resistant polymers, polyimides are the most popular. In spite of all the work performed on polyimides, these materials still exhibit certain shortcomings such as good processability. An approach to improve the processability involves the synthesis of fully cyclized linear polyimides with a good solubility. For this one can introduce in the main chain flexible linkage (either, carbonyl, sulfone), lateral groups with large steric hindrance or polar groups giving strong interactions with solvent. However, this increase of flexibility induces a lowering of thermostability and glass transition. The incorporation of cardo fluorene provides linear polymers with relatively high Tg and good solubility. In the present study the authors have synthetized a soluble heterocyclic polymer coming from di-9,9´(4 aminophenyl fluorene), DAPF. The authors discuss the synthesis and the mechanical, thermal and dielectric properties of the BTDA/DAPF copolymers