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SOLUBLE polyimideS FROM A SEMI-ALIPHATIC DIAMINE CONTAINING ESTER,AMIDE AND ETHER GROUPS

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Chinese Journal of Polymer Science 2011年第1期29卷 93-100页

作者： Shahram Mehdipour-Ataei Leila Akbarian-Feizi Iran Polymer and Petrochemical Institute P.O.Box 14965/115TehranIran

A diamine was synthesized by two successive reactions. Nucleophilic reaction of 4-hydroxybenzoic acid with terephthaloyl chloride yielded terephthaloyl bis（4-oxybenzoic） acid. Then reaction of this compound with 1,8-diamino-3,6- dioxaoctane via Yamazaki method resulted in preparation of diamine named terephthalic acid bis（4-{2-[2-（2-amino ethoxy）ethoxy]ethyl carbamoyl}phenyl） ester. After fully characterization it was used to prepare new polyimides through polycondensation with different dianhydrides using trimethylchlorosilane. Characterization of polymers was achieved by common methods and their physical properties including inherent viscosity, thermal behavior, thermal stability, crystallinity and solubility were studied. Prepared polyimides showed improved solubility and good thermal stability.

关键词： polyimide Polycondensation Synthesis Thermal properties

Synthesis and Properties of High Performance Functional polyimides Containing Rigid Nonplanar Conjugated Fluorene Moieties

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Chinese Journal of Polymer Science 2019年第4期37卷 416-427,I0008页

作者： Yi-Wu Liu Li-Shuang Tang Lun-Jun Qu Si-Wei Liu Zhen-Guo Chi Yi Zhang Jia-Rui Xu PCFM Lab GD HPPC LabGuangdong Engineering Technology Research Centre for High-performance Organic and Polymer Photoelectric Functional FilmsState Key Laboratory of Optoelectronic Materials and TechnologiesSchool of ChemistrySun Yat-sen University Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province School of Packaging and Materials EngineeringHunan University of Technology

A diamine(WuFDA) containing vertical rigid non-planar conjugated fluorene moiety and low polarizability group(C―F)was designed and synthesized through three steps of reactions(halogenated reaction, Suzuki coupling reaction, and reduction reaction).Four kinds of high performance functional polyimides(WuFPI-6 F, WuFPI-BP, WuFPI-BT, and WuFPI-PM) were thus prepared by the condensation polymerization of WuFDA with four commercial dianhydride 6 FDA, BPDA, BTDA, and PMDA, respectively. The polyimides exhibited low dielectric constant, excellent thermal stability, outstanding solubility, good film-forming property, and mechanical properties. The dielectric constants of the polyimides were in the range of 2.28-2.88(f = 10~4 Hz). The 5% weight-loss temperatures(Td 5%)in nitrogen were in the range of 555-584 °C, and the glass transition temperatures(T_g) were in the range of 408-448 °C. The weight loss of WuFPI-BP maintaining at 450 and 500 °C for half an hour was only 0.33% and 1.26%, respectively. All the WuFPIs could be dissolved in almost all organic solvents, even chloroform. The tensile strength and tensile modulus of these films were in the ranges of 78.6-85.7 MPa and 3.1-3.2 GPa, respectively. In addition, the polyimides displayed light color with special fluorescent and resistive switching(ON-OFF) characteristics; the maximum fluorescence emission was observed at 422-424 nm in NMP solution and at 470-548 nm in film state. The memory devices with the configuration of indium tin oxide/WuFPIs/aluminum(ITO/WuFPIs/Al) exhibited distinct volatile memory characteristics of static random access memory(SRAM), with an ON/OFF current ratio of 10~5-10~6. These functional polyimides showed attractive potential applications in the field of high performance flexible polymer photoelectronic devices or polymer memory devices.

关键词： Functional polyimide Fluorene derivative moieties Fluorescence polymer Low dielectric constant Thermal stability

SYNTHESIS AND CHARACTERIZATION OF ORGANO-SOLUBLE FLUORINATED polyimideS FROM 4,4'-BIS(3-AMINO-5-TRIFLUOROMETHYLPHENOXY)-BIPHENYL AND VARIOUS AROMATIC DIANHYDRIDES

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Chinese Journal of Polymer Science 2005年第1期23卷 55-61页

作者： Gui-longWu Jin-gangLiu Zuo-bangLi Zi-yiGe LinFan Shi-yongYang LaboratoryofAdvancedPolymerMaterials CenterforMolecularScienceInstituteofChemistryChineseAcademyofSciencesBeijing100080China InstituteofPolymerScienceandTechnology HebeiUniversityofTechnologyTianjin300130China

An aromatic diamine monomer,4,4'-bis(3-amino-5-trifluoromethyl phenoxy)-biphenyl (TFBPDA),wassynthesized via the nucleophilic displacement reaction of 3,5-dinitrobenzotrifluoride and 4,4'-*** monomer wasreacted with various aromatic dianhydrides via the high temperature polycondensation procedure to provide a series *** polyimides,PI-1 to PI-4,show good solubility not only in aprotic solvents,such as N-methyl-2-pyrrolidinone and N,N-dimethylacetamide,but also in many common solvents,such as m-cresol,chloroform ***-4,derived from 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and TFBPDA,was even soluble ***,PI films exhibit good thermal stability,outstanding transparency in the visible light region and acceptablemechanical and electrical *** excellent combined properties of the polyimides make them as a good candidate forfabricating microelectronics.

关键词： Diamine polyimide Trifluoromethyl Nucleophilic displacement Solubility.

A Facile Strategy for Intrinsic Low-Dk and Low-Df polyimides Enabled by Spirobifluorene Groups

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高分子科学：英文版 2023年第2期41卷 288-296页

作者： Wan-Yi Tan Ling-Feng Jian Wei-Peng Chen Yong-Wen Zhang Xiao-Chuang Lu Wan-Jun Huang Ji-Sheng Zhang Jing-Wu Wu Jun-Li Feng Yi-Dong Liu Ting-Ting Cui Yong-Gang Min Guangdong University of Technology(GDUT) Guangzhou510006China Huimai Materials Technology(Guangdong)Co. Ltd.Foshan528200China Shenzhen Customs Industrial Product Inspection Technology Center Shenzhen518026China

Modified polyimides(MPIs)show great potential towards 5G communication applications,due to its excellent thermal stability,mechanical property and chemical stability as compared to most of *** fluoride groups or porous structure is favorable to ultra-low dielectric constant(D_(k))and dielectric loss(D_(f)).However,the cost of the fluorinated MPIs is high and their synthetic processes are complicated,and porous MPIs suffer poor mechanical ***,increasing the fraction of free volume is a very effective way to lower D_(k)through introducing more ultra-low-D_(k)air ***,most of this kind of MPIs lag far behind the fluorinated MPIs and the porous MPIs in terms of ultra-low D_(f),hindering the application of MPIs in high-speed communication ***,it is highly desirable to develop intrinsic ultra-low-D_(k)/D_(f)MPIs at high frequency with less fluoric groups and nonporous ***,we introduce a facile and effective strategy to lower D_(k)and D_(f)through introducing rigid and large sterically hindered aromatic groups into *** the one hand,their large steric hindrance effect leads to low D_(k)by increasing intrinsic free *** the other hand,the resulting highly stiff polymer chain and strong intermolecular interaction are favorable to reduce D_(f)by inhibiting dipole *** on this strategy,the spirobifluorene groups are *** as-prepared MPIs show excellent dielectric performance with low D_(k)of 2.74–2.76 and low D_(f)of 0.00599 at 10 GHz,to some extent,exceeding the multiple fluorinated MPI with D_(k)/D_(f)of 2.67/0.00663 at 10 GHz.

关键词： polyimide High speed communication Low dielectric constant Low dielectric loss

Synthesis and Electrochromic Properties of polyimides with Pendent Benzimidazole and Triphenylamine Units

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Chinese Journal of Polymer Science 2016年第9期34卷 1091-1102页

作者： Wan-an Cai Ji-wei Cai 牛海军 Tian-di Xiao Xu-duo Bai Cheng Wang 张艳红 Wen Wang Key Laboratory of Functional Inorganic Material Chemistry Ministry of EducationDepartment of Macromolecular Science and EngineeringSchool of ChemicalChemical Engineering and MaterialsHeilongjiang UniversityHarbin 150086China School of Material Science and Engineering Harbin Institute of TechnologyHarbin 150080China

Five novel near-infrared electrochromic aromatic polyimides （PIs） with pendent benzimidazole group were synthesized from 4,4＇-diamino-4＂-（1-benzylbenzimidazol-2-yl）triphenylamine （named as DBBT） with five different dianhydrides via two-step polymerization process, respectively. The maximum UV-Vis absorption bands of these PIs locate at about 335 nm for solid films due to the π-π＊ transitions. A reversible pair of distinct redox peaks, that were associated with a noticeable color change from original yellow to blue, was observed in the cyclic voltammetry （CV） test. A new absorption peak emerged at 847 nm in near-infrared （NIR） region with increasing voltage in UV-Vis-NIR spectrum, which indicates that PI can be used as NIR electrochromic material. These novel PIs have good electrochemical stability, appropriate energy levels for the highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO）, in the range of-5.17 eV to -5.20 eV and -2.14 eV to -2.26 eV （versus the vacuum level） determined by cyclic voltammetry method. These values basically consisted with the results of quantum chemical calculation. These polyimides can be used as novel electrochromic and hole transportation materials.

关键词： Triphenylamine Electrochromic Benzimidazole polyimide Near-infrared.

CHARACTERIZATION AND THERMAL STABILITY OF PMR polyimideS USING 7-OXA-BICYCLO[2,2,l]HEPT-5-ENE-2,3-DICARBOXYLIC ANHYDRIDE AS END CAPS

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Chinese Journal of Polymer Science 2011年第6期29卷 741-749页

作者：李彦锋 State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University

An anhydride monomer containing ether oxide bridge, 7-oxa-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic anhydride （ONA）, was successfully synthesized by Diels-Alder reaction of furan and maleic anhydride. The ONA was also studied as an end-cap for the polymerization of monomer reactant （PMR） type polyimides. Three molecular weight levels of the ONA end-capped PMR resins were evaluated. The effects of process conditions of these novel PMR resins on thermal and mechanical properties were investigated. It was demonstrated that the imidized prepolymers using the end-cap have good processability, and the cured polyimide specimens exhibited good thermal stability. The initial decomposition temperature, Td （ca. 580℃） and glass transition temperature, Tg （330℃） of the novel resin （PI-20）, prepared trader optimum process conditions, compare favorably with the Td （ca. 620℃） and Tg （ca. 348℃） of the state-of-the-art resin （PI＇-20）, respectively.

关键词： polyimide End-cap PMR matrix resin Thermal stability

Thermal degradation of organo-soluble polyimides

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Science China Chemistry 1999年第3期42卷 316-325页

作者：黄俐研史燚金熹高 Institute of Chemistry Chinese Academy of Sciences Beijing China Maurice Morton Institute and Department of Polymer Science University of Akron Akron USA

The thermal degradation behavior of two organo-soluble polyimides was investigated by high resolution pyrolysis-gas chromatography/mass spectrometry. The pyrolyzates of the polymers at various temperatures were identified and characterized quantitatively. The relationship between the polymer structure and pyrolyzate distribution was discussed. The kinetic parameters of the thermal degradation were calculated based on thermogravimetric measurements. Finally, the thermal degradation mechanism for the polymers was suggested.

关键词： polyimide thermal degradation high resolution pyrolysis-gas chromatography/mass spectrome-try thermogravimetry.

Highly Soluble Phenylethynyl-terminated Imide Oligomers and Thermosetting polyimides Based on 2,2′3,3′-Biphenyltetracarboxylic Dianhydride

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Chemical Research in Chinese Universities 2019年第3期35卷 530-536页

作者： MENG Xiangsheng LU Gewu LIU Xiuju MENG Qingjie SHI Junwei YUAN Hang KE Hongjun WANG Xianwei FAN Weifeng LIU Jingfeng YAN Jingling WANG Zhen Laboratory of Polymer Composites Engineering Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022P.R.China Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201P.R.China Aerospace Research Institute of Special Materials and Technology Beijing 100076P.R.China Shandong Non-metallic Materials Institute Jinan 250031P.R.China

The properties of a series of imide oligomers were characterized according to their molecular weights, solubility, and thermal and rheological properties. This series of imide oligomers was synthesized via a two-step method using 2,2′,3,3′-biphenyltetracarboxylic dianhydride(3,3′-BPDA) and aromatic diamines as the monomers, and 4-phenylethynyl phtlialic anhydride(PEPA) as the end-capping agent. The imide oligomers based on 3,3′-BPDA showed excellent solubility in low boiling point solvents and low melt viscosity, which were attributed to their unique bent architectures. High-performance thermosetting polyimides were produced from these oligomers via thermal crosslinking of the phenylethynyl groups. The mechanical and thermal properties of the thermosets were studied using tensile testing, dynamic mechanical thermal analysis(DMTA), and thermogravimetric analysis(TGA). The 3,3′EPDA-based thermosets exhibited excellent thermal properties, with glass transition temperatures of up to 455℃, and 5% mass loss temperatures of up to 569℃ in air. The thermosets based on 3,3-BPDA showed superior thermal properties compared to those derived from TriA-X series oligomers.

关键词： 2,2′,3,3′-Biphenyltetracarboxylic dianhydride Phenylethynyl-terminated imide oligomer Solubility Processability Thermosetting polyimide

Synthesis of novel aromatic polyimides containing bulky side chain for vertical alignment liquid crystals

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Chinese Chemical Letters 2008年第3期19卷 359-362页

作者： Jian Wang Ying Han Wang State Key Laboratory of Polymer Materials Engineering of China College of Polymer Science and Engineering Sichuan University Chengdu 610065 China

In this study, a novel 4-（4-octyloxybenzoyloxy）biphenyl-3′,5′-diaminobenzoate and polyimides based on it were synthesized. The polyimide with mesogenic unit side chain exhibited excellent vertical alignment for nematic liquid crystal （LC）. The pretilt angles of LCs above 89° were kept after the rubbing process with 220 mm rubbing strength. The polyimide films as the alignment layer were baked at 120℃ for 12 h, the vertical alignment of LCs was still uniform and stable. Meanwhile, the UV-vis spectra of the noyel polyimide films showed the high transparency in a visible wave length.

关键词： polyimide Liquid crystal Vertical alignment