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Hierarchically self-constructed alignment layer of comb-shaped amphiphilic copolymers for spontaneous and stable vertical orientation of liquid crystals. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Zhi XX, Wang HS, Jia J, Gao YS, Wang XL, Zhang Y, Liu JG. Preparation and properties of laterally tert-butyl-substituted cyclohexyl-containing polyimide alignment layers with high pretilt angles for potential applications in twisted-nematic TFT-LCDs. JOURNAL OF POLYMER RESEARCH 2022. [DOI: 10.1007/s10965-022-03262-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Liu Y, Wang Y, Wu D. Synthetic strategies for highly transparent and colorless polyimide film. J Appl Polym Sci 2022. [DOI: 10.1002/app.52604] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Yuan‐Yuan Liu
- Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing China
- School of Future Technology University of Chinese Academy of Sciences Beijing China
| | - Ya‐Kun Wang
- School of Foreign Studies China University of Political Science and Law Beijing China
| | - Da‐Yong Wu
- Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing China
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4
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Zhang T, Yang Z, Piao F, Guo H. Transparent polyimide films with ultra-low coefficient of thermal expansion. HIGH PERFORM POLYM 2022. [DOI: 10.1177/09540083221097384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
According to the application requirements of colorless transparent polyimide (CPI) film for low coefficient of thermal expansion (CTE) in the field of OLED display, the new aromatic dianhydride monomers with amide bond structure were synthesized, namely s-ABDA, i-ABDA, EADA. Furthermore, a series of CPI films were prepared by two-step method from the reaction of as-synthesized dianhydrides with 2.2′-bis (trifluoromethyl) −4.4′-diaminobiphenyl (TFMB) or trans-1.4′-cyclohexanediamine ( t-CHDA). Based on the analysis of performance results, the incorporation of amide group and biphenyl, benzene or ether bond into dianhydride monomer helped this new type of transparent polyimide film with excellent optical properties (T550 nm> 88%), great heat stability (CTE < 4.4 ppm/K; Tg > 314°C; Td5% > 478°C) and good mechanical strength (σ > 208 MPa). The film s-ABDA/TFMB showed ultra-low CTE value at 4.4 ppm/K, aligning with the maximum birefringence, indicating that the role of hydrogen bonding was of great benefit to the regulation of thermal expansion.
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Affiliation(s)
- Tingting Zhang
- College of Science, Yanbian University, Yanji 133000, China
| | - Zhenghui Yang
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China
| | - Fengyu Piao
- College of Science, Yanbian University, Yanji 133000, China
| | - Haiquan Guo
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China
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Ahn JS, Park SH, Kwon NY, Cho MJ, Paek SH, Choi DH. Physical Properties of Thermally Crosslinked Fluorinated Polyimide and Its Application to a Liquid Crystal Alignment Layer. Polymers (Basel) 2021; 13:3903. [PMID: 34833204 PMCID: PMC8621600 DOI: 10.3390/polym13223903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 01/29/2023] Open
Abstract
This study demonstrated the use of a thermally crosslinked polyimide (PI) for the liquid crystal (LC) alignment layer of an LC display (LCD) cell. Polyamic acid was prepared using 4,4'-oxydianiline (ODA) and 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA). The 6FDA-ODA-based polyimide (PI) prepared by the thermal cyclic dehydration of the polyamic acid (PAA) was soluble in various polar solvents. After forming a thin film by mixing trifunctional epoxide [4-(oxiran-2-ylmethoxy)-N,N-bis(oxiran-2-ylmethyl)aniline] with the 6FDA-ODA-based PAA, it was confirmed that thermal curing at -110 °C caused an epoxy ring opening reaction, which could result in the formation of a networked polyimide not soluble in tetrahydrofuran. The crosslinked PI film showed a higher rigidity than the neat PI films, as measured by the elastic modulus. Furthermore, based on a dynamic mechanical analysis of the neat PI and crosslinked PI films, the glass transition temperatures (Tgs) were 217 and 339 °C, respectively, which provided further evidence of the formation of crosslinking by the addition of the epoxy reagent. After mechanical rubbing using these two PI films, an LC cell was fabricated using an anisotropic PI film as an LC alignment film. LC cells with crosslinked PI layers showed a high voltage holding ratio and low residual direct current voltage. This suggests that the crosslinked PI has good potential for use as an LC alignment layer material in advanced LCD technologies that require high performance and reliability.
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Affiliation(s)
- Jong-Soo Ahn
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea; (J.-S.A.); (S.H.P.); (N.Y.K.)
| | - Su Hong Park
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea; (J.-S.A.); (S.H.P.); (N.Y.K.)
| | - Na Yeon Kwon
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea; (J.-S.A.); (S.H.P.); (N.Y.K.)
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea; (J.-S.A.); (S.H.P.); (N.Y.K.)
| | - Sang-Hyon Paek
- Department of Chemical Engineering, Kyung Hee University, 1732, Deogyeong-daero, Giheung-gu, Yongin-si 17104, Korea
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea; (J.-S.A.); (S.H.P.); (N.Y.K.)
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Okamoto S, Sudo A, Endo T. Molecular design and synthesis of crosslinked polyimides using radical isomerization of vinylcyclopropane with thiols. J Appl Polym Sci 2021. [DOI: 10.1002/app.50529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Shusuke Okamoto
- Molecular Engineering Institute Kyushu Institute of Technology Fukuoka Japan
| | - Atsushi Sudo
- Department of Applied Chemistry, Faculty of Science and Engineering Kindai University Osaka Japan
| | - Takeshi Endo
- Molecular Engineering Institute Kyushu Institute of Technology Fukuoka Japan
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Synthesis and characterization of semi-alicyclic poly(amic acid) varnishes via bis-spironobornane dianhydride and the derived polyimide alignment layers for potential applications in TFT-LCDs. Polym Bull (Berl) 2021. [DOI: 10.1007/s00289-021-03710-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Fabrication of TiO 2-Embedded Polyimide Layer with High Transmittance and Improved Reliability for Liquid Crystal Displays. Polymers (Basel) 2021; 13:polym13030376. [PMID: 33530379 PMCID: PMC7865691 DOI: 10.3390/polym13030376] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 11/17/2022] Open
Abstract
Construction of liquid crystal (LC) alignment by introducing polyimide (PI) to indium tin oxide (ITO) electrodes is one of the main methods to realize high-resolution images in liquid crystal displays (LCD). However, the loss of transmittance caused by the difference in refractive index between ITO and PI leads to direct degradation of LCD performance. Thus, we herein fabricated a functional hybrid PI alignment layer that reduces the difference in refractive index and greatly increases the transmittance of the device by introducing inorganic titanium dioxide (TiO2) nanoparticles (NP) to the organic PI. The highly refractive TiO2 NPs were surface-treated with stearic acid comprising long alkyl chains to improve their dispersibility and uniformly dispersed in the PI matrix by simply stirring the mixture. The hybrid PI mixture was spin-coated on the ITO substrate, and the resulting LC cell exhibited excellent electro-optical properties. In addition, the reliability of the LC cells was enhanced by the inclusion of the TiO2 NPs, which was confirmed through the evaluation of voltage holding ratio, residual direct current, and LC cell reliability. Overall, functional hybrid PI can be used in advanced display technology for next-generation LC devices that require high transmittance and reliability.
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Yang Z, Guo H, Kang C, Gao L. Synthesis and characterization of amide-bridged colorless polyimide films with low CTE and high optical performance for flexible OLED displays. Polym Chem 2021. [DOI: 10.1039/d1py00762a] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Starting from three novel amide-incorporating dianhydride monomers, we synthesized a series of amide-bridged cPI films that have ultra-low CTE and high Tg due to the formation of hydrogen bonds as well as great optical performance.
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Affiliation(s)
- Zhenghui Yang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
| | - Haiquan Guo
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Chuanqing Kang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
| | - Lianxun Gao
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
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Wu L, Wu X, Qi H, An Y, Jia Y, Zhang Y, Zhi X, Liu J. Colorless and transparent semi‐alicyclic polyimide films with intrinsic flame retardancy based on alicyclic dianhydrides and aromatic phosphorous‐containing diamine: Preparation and properties. POLYM ADVAN TECHNOL 2020. [DOI: 10.1002/pat.5153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Lin Wu
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Xiao Wu
- ACRE Coking and Refractory Engineering Consulting Corporation MCC Dalian China
| | - Hao‐ran Qi
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Yuan‐cheng An
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Yan‐Jiang Jia
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Yan Zhang
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Xin‐xin Zhi
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
| | - Jin‐gang Liu
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology China University of Geosciences Beijing China
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