Redox-active polytriarylamine with hydroxyl groups is a useful material for optoelectronic applications, especially in the solution-processable multilayer devices. A novel regiocontrolled triarylamine-based polymer, poly(di-5-naphthyl-2-ol)phenylamine, with 2-naphthol units was synthesized via oxidative coupling polymerization. Polymerization in tetrahydrofuran using a Cu-amine complex oxidant under O2 atmosphere produced polymers with number-averaged molecular weights as high as 11,300 g mol−1. The structure of the polymer was characterized by 1H and 13C NMR spectroscopy, showing that the oxidative coupling polymerization occurred at the outer ortho position of the 2-naphthols, preserving the hydroxyl groups. The polymer exhibited good solubility in polar aprotic solvents, with a high thermal stability of 446 °C that corresponded to 5% weight loss. The UV–vis absorption of the polymer was similar to that of DNPA, indicating that the kinked-structured polymer hindered the formation of charge-transfer complexes. These results suggest promising applications of the developed polymer in optoelectronic devices.
Poly(biphenylene oxide)s (PBPOs) containing two pendent trifluoromethyl groups were synthesized from AB-type monomers, 4ʹ-hydroxy-4-fluoro-3,5-bis(trifluoromethyl)biphenyl and its 3ʹ-hydroxyl isomer. The displacement reaction of fluorine leaving group activated by the two trifluoromethyl groups at the ortho-positions produced high-molecular-weight polymers with Mn up to 101,000 g/mol, indicating the nucleophilic aromatic substitution reaction proceeded effectively. PBPOs with para-, meta-, and mixed ether linkages were obtained and well characterized by FTIR and 1H/19F NMR spectroscopies. All PBPOs were amorphous and soluble in a wide range of organic solvents, and exhibited even more enhanced thermal stability than the previously reported two meta-trifluoromethyl substituted analogues. Increasing the para-linkage fraction in the polymer generally improved solubility and increased Tg in contrast to the meta-trifluoromethyl case, where para-linked polymer was poorly soluble and semicrystalline. This suggests that the ortho-trifluoromethyl substituents are more effective for the synthesis of para-linked PBPOs. They also showed low refractive indices and birefringence values.
Kim, Sun Dal; Lee, Byungyong; Byun, Taejoon; Chung, Im Sik; Park, Jongmin; Shin, Isaac; Ahn, Nam Young; Seo, Myungeun; Lee, Yunho; Kim, Yeonjoon; Kim, Woo Youn; Kwon, Hyukyun; Moon, Hanul; Yoo, Seunghyup; Kim, Sang Youl
The key component currently missing for the next generation of transparent and flexible displays is a high-performance polymer material that is flexible, while showing optical and thermal properties of glass. It must be transparent to visible light and show a low coefficient of thermal expansion (CTE). While specialty plastics such as aromatic polyimides are promising, reducing their CTE and improving transparency simultaneously proved challenging, with increasing coloration the main problem to be resolved. We report a new poly(amide-imide) material that is flexible and displays glass-like behavior with a CTE value of 4 parts per million/°C. This novel polymer was successfully used as a substrate to fabricate transparent and flexible indium-gallium-zinc oxide thin-film transistors.
The branching point of the side‐chain of naphthalenediimide (NDI)‐based conjugated polymers is systematically controlled by incorporating four different side‐chains, i.e., 2‐hexyloctyl (P(NDI1‐T)), 3‐hexylnonyl (P(NDI2‐T)), 4‐hexyldecyl (P(NDI3‐T)), and 5‐hexylundecyl (P(NDI4‐T)). When the branching point is located farther away from the conjugated backbones, steric hindrance around the backbone is relaxed and the intermolecular interactions between the polymer chains become stronger, which promotes the formation of crystalline structures in thin film state. In particular, thermally annealed films of P(NDI3‐T) and P(NDI4‐T), which have branching points far away from the backbone, possess more‐developed bimodal structure along both the face‐on and edge‐on orientations. Consequently, the field‐effect electron mobilities of P(NDIm‐T) polymers are monotonically increased from 0.03 cm2 V−1 s−1 in P(NDI1‐T) to 0.22 cm2 V−1 s−1 in P(NDI4‐T), accompanied by reduced activation energy and contact resistance of the thin films. In addition, when the series of P(NDIm‐T) polymers is applied in all‐polymer solar cells (all‐PSCs) as electron acceptor, remarkably high‐power conversion efficiency of 7.1% is achieved along with enhanced current density in P(NDI3‐T)‐based all‐PSCs, which is mainly attributed to red‐shifted light absorption and enhanced electron‐transporting ability.
Soluble and transparent poly(amide‐imide)s (PAIs) with a glass transition temperature over 300 °C were synthesized from the alicyclic diacid monomers containing a biphenyl unit with two trifluoromethyl (CF3) groups. Combination of two isomeric biphenyl units with CF3 groups significantly improves the glass transition temperature of the corresponding PAIs. The increase of unsymmetrical biphenyl units increased the glass transition temperature of the polymers by reducing the average chain packing distance.
본 발명은 블록 공중합체 자기조립을 응용하여 세공 크기가 정밀하게 조절된 다공성 고분자막을 제조할 수 있는 한외여과막용 블록공중합체 및 이의 제조방법에 관한 것이다.
본 발명의 블록공중합체는 블록공중합체를 형성하는 고분자들의 분자량과 함량을 조절하여 세공 크기와 분포를 정밀하게 제어할 수 있으며, 또한, 현재 한외여과막으로 사용되고 있는 폴리이서술폰을 기본 소재로 사용하고 있어 기계적 물성이 우수하다.
본 발명은 현재 한외여과 분리막에 쓰이고 있는 폴리이서술폰을 포함하는 블록 공중합체를 합성하고 이에 기반한 나노다공성 고분자 제조 기술 개발을 통해 차세대 한외여과용 나노다공성 여과막을 구현하였으며, 기존의 상반전법을 통한 폴리이서술폰 한외여과 분리막 제조공정을 적용할 수 있어 평판 분리막 또는 중공사막 분리막으로 쉽게 가공할 수 있으므로 높은 산업적 응용 가치를 가진다.
Two donor-acceptor alternating copolymers based on electron-rich triarylamine, di(1-(6-(2-ethylhexyl))naphthyl)phenylamine (DNPA), and electron-deficient benzothiadiazole and benzoselenadiazole derivatives were designed and synthesized via Suzuki coupling reaction. The resulting triarylamine-based alternating copolymers PDNPADTBT and PDNPADTBS showed good solubility in common organic solvents and good thermal stability. The optical band gaps determined from the onset absorption were 1.93 and 1.81 eV, respectively. By introducing the naphthalene ring into the triarylamine, copolymers had relatively deep HOMO energy levels of −5.48 and −5.45 eV, which led to a high open circuit voltage (Voc) and good air stability for photovoltaic application. Bulk heterojunction solar cells were fabricated with a structure of ITO/PEDOT-PSS/copolymers-PC70BM/LiF/Al by blending the copolymer with PC70BM. Both blend systems showed remarkably high Voc near 0.9 V, and the highest performance of 2.2% was obtained from PDNPADTBT, with Voc = 0.88 V, Jsc = 7.4 mA/cm2, and a fill factor of 34.4% under AM 1.5 G.
