• Title/Summary/Keyword: polyimide synthesis

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Synthesis Membrane and Gas Permeation Properties with MMA-FMA Polymer (MMA와 FMA 공중합체 분리막 제조 및 기체투과 특성)

  • 김민수;이용택;최영국;이동진;이수복
    • Proceedings of the Membrane Society of Korea Conference
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    • 1998.04a
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    • pp.37-39
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    • 1998
  • 1. 서론 : 최근 낮은 에너지 소비, 적은 투자설비비로 인하여 분리기술 분야에 분리막을 적용시키는 연구가 활발히 진행되고 있으며 상업화 추진도 진행중에 있다. 특히 기체 분리 시장에서 분리막의 이용이 연구되고 있으나, 일반적인 분리막들이 가지고 있는 공통적인 특징인 투과도가 높아지면 선택도가 낮아지고, 반대로 선택도가 높아지면 투과도가 낮아지는, trade-off현상으로 인하여 분리막의 사용에는 많은 제약이 따르게 되었다. 따라서 이를 방지하기 위한 연구가 진행중이며 그로부터 얻은 결과중 하나가 6FDA를 이용한 polyimide 분리막의 적용이다.(생략)

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Synthesis of Polyisoimides and Their Thermal Imidization in Solution State (폴리아이소이미드의 합성과 용액상태에서의 열적 이미드화 반응)

  • 김지석;김문선;이병춘;손금임;김영준
    • Proceedings of the Korean Fiber Society Conference
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    • 2001.10a
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    • pp.37-40
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    • 2001
  • Aromatic polyimides는 다른 고분자 재료에 비해 고온에서의 열 안정성 및 기계적 물성, 내화학성, 전기 절연성, 난연성 등이 매우 탁월하기 때문에, 최근 들어서 고성능 구조재료, 전자재료(microelectronics devices, electrical insulators of semiconduntor packages), 내열성 접착제, 코팅제 등 그 응용 범위가 점차 확대되고 있는 추세이다. (중략)

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Synthesis and Characterization of Heat Resistant Organophilic Layered Silicate Modified with Oligo(amic acid)s Having Alkyl Side Chains and Their Nanocomposites (알킬기가 도입된 올리고 아믹산 구조를 가진 고내열 친유기 층상 실리케이트의 제조 및 이를 이용한 나노복합재의 특성평가)

  • Han Ji Yun;Won Jong Chan;Lee Jae Heung;Suh Kyung-Do;Kim Yong Seok
    • Polymer(Korea)
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    • v.29 no.5
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    • pp.451-456
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    • 2005
  • In the field of designing of nano-fillers of polyimide nanocomposites, the two strategic points are the heat-resistance and compatibility with polyimide, a matrix polymer. In this study, we designed oligo(amic acid) having alkyl side chains and terminal amine groups to satisfy previous requirements and studied the modification of surface of layered silicates. Oligo(amic acid)s were prepared by the reaction of diamine monomers and PMDA and their molecular weight was controlled in about 2000g/mol. After that, acidification and ion exchange reaction led to the high-temperature organophilic layered silicate (OLS). XRD pauerns of OLS showed the more increased gallery spacing by $4{\AA}$ than that of the pristine layered silicate and the initial decomposition temperatures of OLS were in above $280^{\circ}C$. The polyimide nanocomposite films based on heat resistant OLS showed that the OLSs were well dispersed through the matrix and their CTEs showed a decrease of $26\%$ compared with pristine polyimide films.

Synthesis of Novel Aromatic Polyimides (새로운 방향족 폴리이미드의 합성)

  • Shin Gyo-Jic;Chi Jun-Ho;Zin Wang-Cheol;Chang Tai-Hyun;Ree Moon-Hor;Jung Jin-Chul
    • Polymer(Korea)
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    • v.30 no.2
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    • pp.97-107
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    • 2006
  • In spite of excellent thermomechanical performance the majority of aromatic polyimides are so poor in processability due to their high backbone rigidity that their applications are greatly limited. The introduction of long side chains not only enhances their processiblity but also makes useful contribution to discovering new application fields. In this article, a variety of novel aromatic polyimides with flexible side chains were prepared either from new dimines or new dianhydrides to measure the influence of the side chains on structure and properties of the polymers and their new applications as liquid crystal alignment layers, photosensitive polymers, alternating multilayer nano-films and photoluminescent materials are discussed.

Preparation of Hydroxy Polyimde Membranes for Gas Separation by Phase Inversion Method (상전이법을 이용한 기체 분리용 Hydroxy Polyimide 막의 제조)

  • Woo, Seung-Moon;Choi, Jong-Jin;Nam, Sang-Yong
    • Membrane Journal
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    • v.22 no.1
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    • pp.62-71
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    • 2012
  • In this study, for preparation of gas separation membrane with high permeability, hydroxy polyimide was synthesized using 6FDA and APAF. Synthesis of HPI was confirmed by H-NMR and FT-IR, thermal property of membrane was characterized by Differential scanning calorimetric (DSC) and thermogravimetric analyzer (TGA). Especially, the synthesized HPI can possible to search conversion to PBO at $450^{\circ}C$. To obtain the membrane having high permeability, ternary system consist of polymer, solvent and non-solvent additive was introduced, asymmetric HPI flat sheet membrane was prepared by phase inversion method. Finally, the change of morphology with each component was observed through FE-SEM.

Optimization of Optical Performance of Colorless and Transparent Polyimide Film for Flexible Display using Design of Experiment (실험계획법을 이용한 유연 디스플레이용 무색 투명 폴리이미드 필름의 광학 성능 최적화)

  • Jo, Dawoon;Yu, Yeon-Soo;Nam, Hee-Eun;Chang, Jin-Hae;Oh, Chung-Seog
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.1
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    • pp.79-84
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    • 2022
  • As various flexible display products are released, the demand for high-performance colorless and transparent polyimide (CPI) film is continuously increasing. The primary purpose of this study is to establish a systematic procedure for optimizing the optical performance of CPI films by applying the response surface method. After selecting three key factors (monomer type, stirring time for varnish synthesis, and maximum temperature of vacuum furnace for film production) affecting optical performance based on experiences and references, CPI films were manufactured according to the experimental sequence designed by the central composite design, and then the yellowness index (YI) and optical transmittance (Tr) of the films were measured. When producing a CPI film by pouring varnish into a petri dish, the change in optical properties according to thickness should be considered, and there was a meaningful linear relationship between YI and Tr. The species of monomer and the maximum temperature were the critical factors that had an influence on YI and Tr, respectively. It is expected that the procedure proposed in this study can serve as a starting point for CPI film optimization studies considering the other factors that were not considered and responses such as thermal properties.

Synthesis of Polyimides Derived from 2,2-Bis[4-(4-aminobenzoyl)phenoxy]hexafluoropropane and Aromatic Dianhydrides (2,2-Bis[4-(4-nitrobenzoyl)phenoxy]hexafluoropropane과 방향족 이무수물을 사용한 폴리이미드의 합성)

  • Park, Jung Hye;Ahn, Byung Hyun
    • Applied Chemistry for Engineering
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    • v.27 no.1
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    • pp.50-55
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    • 2016
  • Aromatic diamines containing hexafluoroisopropylidene and ester moiety were synthesized from 4,4'-hexafluoroisopropylidene diphenol and nitrobenzoyl chloride. The reaction of aromatic diamines with hexafluoroisopropylidene phthalicdianhydride (6FDA) or pyromellitic dianhydride (PMDA) gave four kinds of poly(amic acid)s. Their inherent viscosities ranged from 0.196 to 0.346 dL/g. Poly(amic acid)s were converted to polyimides by thermal imidization. The glass transition temperatures ($T_g$) of polyimides were between 241 and $289^{\circ}C$. The 5% weight loss temperatures were recorded in the range of $430{\sim}492^{\circ}C$. The tensile strength of polyimide films were measured as 29.84~64.38 MPa.

The Alignment of Liquid Crystals on the Film Surfaces of Soluble Aromatic Polyimides Bearing t-Butylphenyl and Trimethylsilylphenyl Side Groups

  • Hahm, Suk-Gyu;Jin, Kyeong-Sik;Park, Sam-Dae;Ree, Moon-Hor;Kim, Hyung-Sun;Kwon, Soon-Ki;Kim, Yun-Hi
    • Macromolecular Research
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    • v.17 no.12
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    • pp.976-986
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    • 2009
  • With the study goal of firstly elucidating the anisotropic interactions between oriented polymer chain segments and liquid crystal (LC) molecules, and secondly of determining the contributions of the chemical components of the polymer segments to the film surface topography, LC alignment, pretilt, and anchoring energy, we synthesized three dianhydrides, 1,4-bis(4'-t-butylphenyl)pyromellitic dianhydride (BBPD), 1,4-bis(4'-trimethylsilylphenyl)pyromellitic dianhydride(BTPD), and 2,2'-bis(4"-tert-butylphenyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride (BBBPAn), and a series of their organosoluble polyirnides, BBPD-ODA, BBPD-MDA, BBPD-FDA, BTPD-FDA, and BBBPAn-FDA, which contain the diamines 4,4'-oxydianiline (ODA), 4,4'-methylenediamine (MDA), and 4,4'-(hexafluoroisopropylidene)dianiline (FDA). All the polyimides were determined to be positive birefringent polymers, regardless of the chemical components. Although all the rubbed polyimide films exhibited microgrooves which were created by rubbing process, the film surface topography varied depending on the polyimides. In all the rubbed films, the polymer chains were unidirectionally oriented along the rubbing direction. However, the degree of in-plane birefringence in the rubbed film varied depending on the polyimides. The rubbing-aligned polymer chains in the polyimide films effectively induced the alignment of nematic LCs along their orientation directors by anisotropic interactions between the preferentially oriented polymer chain segments and the LCs. The azimuthal and polar anchoring energies of the LCs ranged from $0.45{\times}10^{-4}\;-\;1.37{\times}10^{-4}\;J/m^2$ and from $0.86{\times}10^{-5}\;-\;4.26{\times}10^{-5}\;J/m^2$, respectively, depending on the polyimides. The pretilt angles of the LCs were in the range $0.10-0.62^{\circ}$. In summary, the soluble aromatic polyimides reported here are promising LC alignment layer candidates for the production of advanced LC display devices.

Soluble Polyimide Binder for Silicon Electrodes in Lithium Secondary Batteries (리튬이차전지 실리콘 전극용 용해성 폴리이미드 바인더)

  • Song, Danoh;Lee, Seung Hyun;Kim, Kyuman;Ryou, Myung-Hyun;Park, Won Ho;Lee, Yong Min
    • Applied Chemistry for Engineering
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    • v.26 no.6
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    • pp.674-680
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    • 2015
  • A solvent-soluble polyimide (PI) polymeric binder was synthesized by a two-step reaction for silicon (Si) anodes for lithium-ion batteries. Polyamic acid was first prepared through ring opening between two monomers, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA) and 4,4-oxydianiline (ODA), followed by condensation reaction. Using the synthesized PI polymeric binder (molecular weight = ~10,945), the coating slurry was then prepared and Si anode was fabricated. For the control system, Si anode based on polyvinylidene fluoride (PVDF, molecular weight = ~350,000) having the same constituent ratio was prepared. During precycling, PI polymeric binder revealed much improved discharge capacity ($2,167mAh\;g^{-1}$) compared to that of using PVDF polymeric binder ($1,740mAh\;g^{-1}$), while the Coulombic efficiency of two systems were similar. PI polymeric binder improved the cycle retention ability during cycles compared to that of using PVDF, which is attributed to an improved adhesion property inside Si anode diminishing the dimensional stress during Si volume changes. The adhesion property of each polymeric binder in Si anode was confirmed by surface and interfacial cutting analysis system (SAICAS) (Si anode based on PI polymeric binder = $0.217kN\;m^{-1}$ and Si anode based on PVDF polymeric binder = $0.185kN\;m^{-1}$).