Novel polynorbornene (PNB)-polyimide (PI) copolymers were synthesized based on poly(N-phenyl-exo-norbornene-5,6-dicarboximide) (PPhNI) and chlorinated PI (BPDA/ TCDB). Polynorbornene copolymers (PNCs) with diverse compositions of anhydride were synthesized via ring opening metathesis polymerization (ROMP) of N-phenyl-exo-norbornene-5,6-dicarboximide (PhNI) and exo-7-oxanorbornene-5,6-dicarboxylic anhydride(exo-NA), followed by copolymerization through a reaction with aromatic dianhydride (3,3 0 ,4,4 0 -biphenyltetra-carboxylic dianhydride, BPDA) and tetrachlorinated diamine (2,2 0 ,5,5 0 -tetrachlorobenzidine, TCDB). The copolymer (PNIC) films exhibited good optical transparency with a transmittance of around 70% at 400 nm and a good thermal stability with a glass transition temperature at 276-300 C. These flexible films also resisted most organic solvents and chemicals, such as methanol, acetone, tetrahydrofuran, N-methylpyrrolidone, ethyl acetate, hydrochloric acid, sodium hydroxide, and hydrogen peroxide, etc.Indium tin oxide (ITO) coated thin films were prepared at various substrate deposition temperatures with a radio frequency (r.f.) planar magnetron sputtering system. The ITO thin films that were deposited onto the PNIC copolymer substrates had good electrical and optical properties. An organic light-emitting device (OLED) was fabricated using the PNIC copolymer substrate with a structure of PNIC08/ ITO (anode)/hole-transporting layer (HTL)/ emitting & electron-transporting layer (EM&ETL)/aluminum (cathode). The flexible OLED fabricated on the ITO-grown PNIC substrate exhibited a performance that was comparable to corresponding ITO-grown glass substrates. Therefore, the ITO-grown PNIC substrate could possibly be a promising candidate as a substrate for flexible displays.

We synthesized new polynorbornene dicarboximide (PCaNI) functionalized with hole‐transporting carbazole moieties and its copolymer (PCaNA) by ring‐opening metathesis polymerization (ROMP), where the PCaNA was further reacted with 3‐amino‐triethoxysilane to prepare PCaNI/silica hybrid. We also investigated the feasibility of PCaNI and PCaNI/silica hybrid (PCaSi) as a hole‐transporting material for hybrid organic light emitting devices (HOLEDs). To improve the performance of the PCaNI‐based HOLEDs, N,N′‐diphenyl‐N,N′‐(3‐methylphenyl)‐[1,1′‐biphenyl]‐4‐4′‐diamine (TPD) was also introduced into the PCaNI matrix. Results showed that PCaNI exhibited high glass transition temperature (∼260 °C) and high optical transparency in the visible region. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of PCaNI were measured as 5.6 and 2.2 eV, while the TPD‐doped PCaNI showed 5.7 eV (HOMO) and 2.6 eV (LUMO). The PCaNI/silica hybrid nanolayers showed excellent solvent resistance due to the formation of covalent bonds between ITO and PCaNI. The HOLEDs with PCaNI/TPD or PCaSi/TPD hybrid nanolayers exhibited relatively higher luminance (∼10,000 cd/m2), lower operating voltage (∼6.5 V at 300 cd/m2), and higher current efficiency (∼2.7 cd/A). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

The imide-functionalized polynorbornene films exhibited excellent optical transparency in the visible range as well as high thermal stability over 200 degrees C. The indium tin oxide (ITO) thin films were coated on the imide-functionalized polynorbornene films at various deposition temperatures by employing radio-frequency (r.f.) planar magnetron sputtering system. The resulting ITO-coated imide-functionalized polynorbornene substrates showed good electrical and optical properties, while the figure of merit examination revealed that the present substrates are comparable to conventional ITO-glass substrates. This was confirmed from the preliminary result of organic light-emitting devices fabricated using the imide-functionalized polynorbornene substrates.

We synthesized new carbazole-diimide hole-transporting materials with different dianhydride groups by thermal imidization. The imide moieties were introduced to improve thermal stability of a carbazole hole transport molecule. Result showed that the carbazole-diimdes exhibit good thermal stability with glass transition temperature of 142-182 degrees C and degradation temperature of approximately 450 degrees C as well as good optical transparency in the visible region. The organic light-emitting device (OLED) using alicyclic diimide (CBCZ) shows maximum luminance approximately 8,600 cd/m2 at 12 V and current efficiency of 2.1 cd/A. With optimization of fabricating conditions, the thermally stable CBCZ is expected to be used as a promising hole-transporting material with higher efficiency and durability.