| 초록 |
A series of novel porous polyimide films are synthesized based on various diamines and dianhydrides. Poly(amic acid)s of dianhydrides and diamines are synthesized for further chemical imidization and freeze drying. The samples are in the form of xerogels which exhibit excellent mechanical strength and thermal, chemical stability. By modifying the chemical structure of component monomers, the final polyimide films display low dielectric constant and loss even at high frequency regime. The shrinkage of films is effectively reduced by varying the composition of the monomers, which remains dielectric constant and loss low. The thermal, dielectric and mechanical properties, as well as morphology of the final xerogel films are characterized using TGA, TMA, SEM, AFM, UTM, and network analyzer. |
