Nam, Ki-Ho Jin, Jeong-un Lee, Dong Hoon Han, Haksoo Goh, Munju Yu, Jaesang Ku, Bon-Cheol You, Nam-Ho 2024-01-19T20:04:38Z 2024-01-19T20:04:38Z 2021-09-02 2019-04-15 1359-8368 https://pubs.kist.re.kr/handle/201004/120097 The main challenge to developing future display substrates is to synthesize flexible substrate materials that also have excellent optical and thermal properties, and low thermal expansion number. In this study, a novel trifluoromethylated asymmetric aromatic diamine, 4-[[4-(4-amino-2-trifluoromethylphenoxy)phenyl]sulfonyl-3(trifluoromethyl)]benzenamine (AFPSFB), was synthesized through nucleophilic substitution. Conventional two-step polycondensation of AFPSFB with commercially available tetracarboxylic dianhydrides enabled the fabrication of fully or semi-aromatic polyimides (PIs). The resulting PIs were highly soluble in polar aprotic solvents with good optical and thermal properties. Next, polyhedral oligomeric silsesquioxane containing an amine group (NH2-POSS) was reacted with the resulting soluble PI. All the PI-POSS nanohybrids displayed excellent optical properties, including high transparency (> 91% at 400 nm), low refractive index (< 1.5589), and very small birefringence (< 0.0025 at 637 nm). End-capping of the POSS and chemical bonding between the POSS and PIs significantly enhanced the thermal and electrical properties. The results provide useful information for designing molecular architectures for manufacturing high-performance flexible substrates in future display devices. English ELSEVIER SCI LTD HIGH REFRACTIVE-INDEX DIELECTRIC-PROPERTIES AROMATIC POLYIMIDES SOLUBLE POLYIMIDES HIGHLY TRANSPARENT FLEXIBLE DISPLAYS HIGH-TEMPERATURE GRAPHENE OXIDE NANOCOMPOSITES HYBRID Towards solution-processable, thermally robust, transparent polyimidechain-end tethered organosilicate nanohybrids Article 10.1016/j.compositesb.2018.11.029 1 COMPOSITES PART B-ENGINEERING, v.163, pp.290 - 296 COMPOSITES PART B-ENGINEERING 163 290 296 scie scopus 000461262500031 2-s2.0-85056616440 Engineering, Multidisciplinary Materials Science, Composites Engineering Materials Science Article HIGH REFRACTIVE-INDEX DIELECTRIC-PROPERTIES AROMATIC POLYIMIDES SOLUBLE POLYIMIDES HIGHLY TRANSPARENT FLEXIBLE DISPLAYS HIGH-TEMPERATURE GRAPHENE OXIDE NANOCOMPOSITES HYBRID Soluble polyimide Organosilicate Optical transparency Dielectric constant Thermal stability