| 초록 |
A new diamine containing sulfur atom and phosphine oxide moiety was synthesized through the aromatic substitution reaction. The polyimides (PIs) were derived from diamine containing phosphine oxide moiety and several aromatic dianhydrides such as 4,4’-[p-thiobis(phenylenesulfanyl)]diphthalic anhydride (3SDEA), 4,4’-oxydiphthalic anhydride (ODPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) by the conventional two-step polycondensation. All of the PIs exhibited good thermal stability, including glass transition temperature (Tg) in the range of 212264 oC and optical transparency higher than 80 % at 450 nm at a thickness of about ca. 10 μm. Particularly, all of PIs exhibited a high refractive index (＞1.6), and a low birefringence (＜0.01). These properties are explained that the high level energy of phosphorus and sulfur electronic structure can support stability electronic distortions, induce to high polarizability and a high refractive index. |
