| 초록 |
A novel dianhydride monomer, 1-(pentafluorophenyl)pyromellitic dianhydride (PFPPMDA) was synthesized via Grignard reaction, followed by Suzuki cross coupling reaction, oxidation and cyclodehydration, and characterized by FT-IR, NMR, EA and m.p. measurement. For comparison, 1-(3´,5´-bis(trifluoromethyl)phenyl)pyromellitic dianhydride (6FPPMDA) and 1-phenyl pyromellitic dianhydride (PPMDA) were also prepared. Then, poltimides were prepared with these dianhydrides as well as bis(3-aminophenyl)-3,5-bis(trifluoromethyl)-phenyl phosphine oxide (mDA6FPPO) via a two-step process; preparation of poly(amic-acid) in p-chlorophenol with isoquinoline as catalyst, followed by solution imidization at refluxing temperature. Molecular weights were controlled to 20,000 g/mol via off-setting stoichiometry. All polymers were characterized by FT-IR, NMR, GPC, DSC, TGA and TMA. Solubility, solution viscosity, moisture absorption, electical and optical properties were also evaluated. |
