| 초록 |
In this study, we designed new polyimides containing bulky functional groups such as methyl and trifluoromethyl groups to improve thermal and optical properties. The new amines were synthesized by nucleophilic aromatic substitution reaction (SNAr) and then reducted functional groups from nitro to amino and those amines were confirmed by 1H, 13C NMR and FT-IR. The polyimides (PIs) derived from new diamines and aromatic dianhydride (6FDA) synthesized polycondensation of the intermediate poly(amic acid), in sequence heating proceed a ring close condensation reaction cause imide formation. PIs were analyzed thermal properties measured by TGA (thermogravimetric analysis), DSC (differential scanning calorimetry), DMA (dynamic mechanical thermal analysis), and additionally optical properties were studied by UV-vis absorption and prism coupler. Therefore the new PIs containing bulky functional groups loosened the intermolecular packing of polymer and elevated the free volume of the polymers formation. This molecule designs provided a new approach on development of flexible substrates industry such as roll-up displays, portable devices and plastic substrates. |
