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Machine-learning-assisted Materials Genome Approach for Designing High-performance Thermosetting Polyimides
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作者 Wan-Xun Feng Song-Qi Zhang +6 位作者 Yin-Yi Xu Xiang-Fei Ye Xin-Yao Xu Li-Quan Wang Jia-Ping Lin Chun-Hua Cai Lei Du 《Chinese Journal of Polymer Science》 2025年第10期1718-1729,共12页
Enhancing the mechanical properties is crucial for polyimide films,but the mechanical properties(Young's modulus,tensile strength,and elongation at break)mutually constrain each other,complicating simultaneous enh... Enhancing the mechanical properties is crucial for polyimide films,but the mechanical properties(Young's modulus,tensile strength,and elongation at break)mutually constrain each other,complicating simultaneous enhancement via traditional trial-and-error methods.In this work,we proposed a materials genome approach to design and screen phenylethynyl-terminated polyimides for films with enhanced mechani-cal properties.We first established machine learning models to predict Young's modulus,tensile strength,and elongation at break to explore the chemical space containing thousands of candidate structures.The accuracies of the machine learning models were verified by molecular dynamics simulations on screened polyimides and experimental testing on three representative polyimide films.The performance advantages of the best-selected polyimides were analyzed by comparing well-known polyimides based on molecular dynamics simulations,and the structural rationale was revealed by"gene"analysis and feature importance evaluation.This work provides a cost-effective strategy for designing polyimide films withenhancedmechanical properties. 展开更多
关键词 Materials genome approach Machine learning Mechanical property POLYIMIDE
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Synthesis and Properties of Heat-resistant Polyimides Films Containing Crosslinkable Group-tetrafluorostyrene
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作者 Tian-Yong Zhang Jia-Ning Yu +5 位作者 Sui-Sui Wang Ya-Mei Chai Shuang Jiang Hong-Li An Ruo-Xi Sun Bin Li 《Chinese Journal of Polymer Science》 2025年第5期863-874,共12页
Polyimide(PI)is widely used in high-tech fields such as microelectronics,aerospace,and national defense because of its excellent optical properties,high-and low-temperature resistance,and good dimensional stability.To... Polyimide(PI)is widely used in high-tech fields such as microelectronics,aerospace,and national defense because of its excellent optical properties,high-and low-temperature resistance,and good dimensional stability.To achieve the desired properties of PI,the monomers 2,6-diaminopyrimidin-4-ol(DAPD)and 6-(2,3,5,6-tetrafluoro-4-vinylphenoxy)pyrimidin-2,4-diamine(DAFPD),which contains crosslinkable functional groups,were designed and synthesized successfully and copolymerized with 4,4'-oxydianiline(ODA)and 4,4-hexafluoroisopropylphthalic anhydride(6FDA).The prepared PI film(PI-3),with rigid backbones and loose packing had excellent heat resistance(Td5%=489℃)and optical properties(T450=82%).Furthermore,a crosslinked PI film(c-PI-3)with more heat-resistant(Td5%=524℃)and better mechanical properties(σ=125.46MPa),can be obtained through thermal crosslinking of tetrafluorostyrene.In addition,the changes in the properties caused by the proportion of DAFPD added during copolymerization are discussed comprehensively.This study provides a promising candidate for heat-resistant PI materials. 展开更多
关键词 Polyimide film COPOLYMERIZATION Thermal crosslinking Heat resistance
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Intrinsically Low Dielectric Constant and Low Dielectric Loss Polyimides Enabled by Rigid-Soft Structure
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作者 Hui Zhang Hui-Shan Hu +7 位作者 Zhi-Yu Lu Ming-Wei Liu Hua Ge Hui-Bo Yuan Jian-Jun Song Wan-Yi Tan Ting-Ting Cui Yong-Gang Min 《Chinese Journal of Polymer Science》 2025年第7期1222-1230,共9页
Modified polyimides(MPIs)possess excellent thermal stability,chemical stability,and mechanical properties,and are considered to be a kind of dielectric material for high-frequency communication.Enhancing the rigidity ... Modified polyimides(MPIs)possess excellent thermal stability,chemical stability,and mechanical properties,and are considered to be a kind of dielectric material for high-frequency communication.Enhancing the rigidity of the polymer chains and intermolecular interactions can ensure low D_(k)/D_(f)at high frequency,which is attributed to the effective restriction of dipole orientations.However,it is difficult to achieve tight chain packing in an overly rigid polymer chain,whereas an overly flexible polymer chain might be insufficient to restrain small-scale molecular motions below T_(g).To balance the trade-off between the rigidity of the polymer chains and tight chain packing,MPI was developed with a rigidsoft structure based on a naphthalene-alkyl-based diamine.On the one hand,incorporating the soft unit can enhance the movability of polymer chains to achieve dense chain packing for polyimides(PIs).On the other hand,the presence of rigid aromatic units can enhance intermolecular interactions and further restrict the motion of polar imide groups below T_(g).As a result,the resultant MPI can prevent small-scale molecular motion below T_(g).In contrast to the reference PI-TFMB-6FDA,D_(k)/D_(f)is significantly reduced from 2.72/0.0075 to 2.73/0.005 at a high frequency of 10 GHz Furthermore,the rigid-soft structure endows PIs with good thermoplasticity owing to the good chain flexibility above T_(g).In addition,PIs based on rigid-soft structures can preserve favorable thermal stability. 展开更多
关键词 High-frequency communication POLYIMIDE Dielectric loss
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A FACILE SYNTHESIS OF HYPERBRANCHED POLYIMIDES FROM 2,6,12-TRIAMINOTRIPTYCENE
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作者 程琳 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2010年第1期69-76,共8页
Based on monomer 2,6,12-triaminotriptycene, hyperbranched polyimides with high molecular weight modified with different terminal functional groups were obtained by polymerization of A2 + B3 system. The prepared hyper... Based on monomer 2,6,12-triaminotriptycene, hyperbranched polyimides with high molecular weight modified with different terminal functional groups were obtained by polymerization of A2 + B3 system. The prepared hyperbranched polyimides had good solubility in CHCl3, DMF and THF, and performed no detective Tgs in the range of 50-330℃ and high TdS (5%) above 455℃. 展开更多
关键词 TRIPTYCENE Hyperbranched polymer polyimides.
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Synthesis and Properties of High Performance Functional Polyimides Containing Rigid Nonplanar Conjugated Fluorene Moieties 被引量:12
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作者 Yi-Wu Liu Li-Shuang Tang +4 位作者 Lun-Jun Qu Si-Wei Liu Zhen-Guo Chi Yi Zhang Jia-Rui Xu 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2019年第4期416-427,I0008,共13页
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 re... 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. 展开更多
关键词 FUNCTIONAL POLYIMIDE FLUORENE derivative MOIETIES Fluorescence polymer Low dielectric constant Thermal stability
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Polyimides as Promising Materials for Lithium-Ion Batteries:A Review 被引量:10
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作者 Mengyun Zhang Li Wang +2 位作者 Hong Xu Youzhi Song Xiangming He 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第9期74-102,共29页
Lithium-ion batteries(LIBs)have helped revolutionize the modern world and are now advancing the alternative energy field.Several technical challenges are associated with LIBs,such as increasing their energy density,im... Lithium-ion batteries(LIBs)have helped revolutionize the modern world and are now advancing the alternative energy field.Several technical challenges are associated with LIBs,such as increasing their energy density,improving their safety,and prolonging their lifespan.Pressed by these issues,researchers are striving to find effective solutions and new materials for next-generation LIBs.Polymers play a more and more important role in satisfying the ever-increasing requirements for LIBs.Polyimides(PIs),a special functional polymer,possess unparalleled advantages,such as excellent mechanical strength,extremely high thermal stability,and excellent chemical inertness;they are a promising material for LIBs.Herein,we discuss the current applications of PIs in LIBs,including coatings,separators,binders,solid-state polymer electrolytes,and active storage materials,to improve high-voltage performance,safety,cyclability,flexibility,and sustainability.Existing technical challenges are described,and strategies for solving current issues are proposed.Finally,potential directions for implementing PIs in LIBs are outlined. 展开更多
关键词 polyimides SEPARATORS Binders Solid-state electrolytes LITHIUM-ION
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The Application of Highly Soluble Amine-terminated Aromatic Polyimides with Pendent Tert-butyl Groups as a Tougher for Epoxy Resin 被引量:7
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作者 Qing Zhao 王幸宜 扈艳红 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2015年第10期1359-1372,共14页
Polyimides (PIs) with various molecular weights synthesized via the reaction of aromatic diamine monomer containing tert-butyl groups with aromatic dianhydride were highly soluble in common organic solvents and some... Polyimides (PIs) with various molecular weights synthesized via the reaction of aromatic diamine monomer containing tert-butyl groups with aromatic dianhydride were highly soluble in common organic solvents and some epoxy resins at room temperature. These PIs can be incorporated in the absence of organic solvent into epoxy resin E51 with the loading below 2 wt% forming EP-PI composites. No phase separation is observed by SEM on cryogenically fractured surfaces of EP-PI composites. The PI can improve mechanical properties, especially impact strength. Adding 2 wt% PI-1.5W, the impact strength reaches to 55 kJ/m^2 with the increase in tensile and flexural strengths by 14% and 3%, respectively. SEM analyses for the fracture surface suggest that PI reduces the crosslink density, improves the plasticity of epoxy resin and changes the mode of fracture from fragile to ductile. Moreover, the glass transition temperature of EP-PI composites was found to increase to a significant extent. 展开更多
关键词 POLYIMIDE Epoxy resin SOLUBILITY Impact strength.
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SYNTHESIS AND CHARACTERIZATION OF HIGHLY SOLUBLE AROMATIC POLYIMIDES 被引量:6
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作者 黄卫 颜德岳 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2011年第4期506-512,共7页
Two highly soluble aromatic polyimides were synthesized successfully from a diamine with two tert-butyl groups (MBTBA) and dianhydrides with a thioether or sulfone moiety (DTDA and DSDA). Both of them showed excel... Two highly soluble aromatic polyimides were synthesized successfully from a diamine with two tert-butyl groups (MBTBA) and dianhydrides with a thioether or sulfone moiety (DTDA and DSDA). Both of them showed excellent solubility in common solvents such as chloroform, tetrahydrofuran and dioxane at the room temperature. The numberaverage molecular weight was 6.0× 10^4 and 8.3 ×10^4 according to gel permeation chromatography relative to a polystyrene standard, and the polydispersity index was 1.80 and 1.82 respectively. The glass-transition temperatures of them were 286℃ and 314℃ (or 315℃ and 358℃) respectively, as measured by differential scanning calorimetry (or dynamic mechanical analysis). The 5% weight loss temperature of both was near 490℃ in N2 by therrnogravimetric analysis. These results indicated that the tert-butyl pendent groups reduced the interactions among polymer chains and the thioether or sulfone moiety was flexible which may improve their solubility in conventional organic solvents without the loss of thermal stability. Transparent and flexible films of the two polyimides were obtained via solution casting. The MBTBA-DTDA membrane had higher storage moduli than those of the MBTBA-DSDA membrane. 展开更多
关键词 Aromatic polyimide SOLUBILITY Sulfone-bridged tert-butyl groups Thioether-bridged.
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Fluorine Substitution Effect on the Material Properties in Transparent Aromatic Polyimides 被引量:5
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作者 Wei-Feng Peng Huan-Yu Lei +2 位作者 Xin-Xin Zhang Lu-Hao Qiu Ming-Jun Huang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2022年第7期781-788,共8页
The recent development of flexible display technology raised additional requirements for optical and electric properties of polyimides,accelerating the structure and property tunning of transparent polyimides.The uniq... The recent development of flexible display technology raised additional requirements for optical and electric properties of polyimides,accelerating the structure and property tunning of transparent polyimides.The unique electronic effect and steric hindrance effect of fluorine substitutions make fluorine-containing polyimides occupy an important position in the transparent polyimide family.In this work,a series of transparent aromatic polyimides were prepared from a fixed 4,4’-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)and biphenyl diamines with different substitute groups at the 2,2’,6,6’-positions.We systematically studied the effects of pendant groups on the thermal,mechanical,optical and dielectric properties of these 6FDA-based polyimides with the aid of density function theory(DFT)calculation.In particular,we paid special attention to the simple but compact fluoro group substitution.The simple fluoro substitution brought the advantages of maintaining the linearity of the backbone and dense polymer chain packing,which would minimize the weakening of polyimides’inherent thermal,dimensional and mechanical properties.Comparing with trifluoromethyl substituted polyimides with the best optical transparency,polyimides containing fluoro substitutes exhibited slightly decreased optical transparency,but increased thermal and dimensional stability and higher mechanical strength.These results could shed light on the ultimate transparent polyimide film development toward the application in extreme working condition,e.g.,the colorless polyimide substrate film for the flexible display technology. 展开更多
关键词 polyimides Fluorine substitution TRANSPARENT DIELECTRIC COLORLESS
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Novel hyperbranched polyimides from 2,6,12-triaminotriptycene 被引量:5
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作者 Zhen Xu Xing Quan Xiong Lin Cheng 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第9期1127-1130,共4页
The monomer 2,6,12-triaminotriptycene was synthesized and the structure was confirmed by IR and 1H NMR spectra. Hyperbranched polyimides modified with different terminal groups were obtained from precursors, anhydride... The monomer 2,6,12-triaminotriptycene was synthesized and the structure was confirmed by IR and 1H NMR spectra. Hyperbranched polyimides modified with different terminal groups were obtained from precursors, anhydride- and aminoterminated hyperbranched poly(amic acid)s from polymerization of A2 + B3 system. From gel permeation chromatograrn (GPC) characterization, representative products had high molecular weight. All polymers had good solubility in CHCl3, DMF and tetrahydrofuran (THF), and performed no detective Tgs in the range of 50-300 ℃ and high Tds above 455 ℃ when 5% weight loss. 展开更多
关键词 TRIPTYCENE Hyperbranched polymer polyimides
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SYNTHESIS AND CHARACTERIZATION OF ORGANSOLUBLE POLYIMIDE AND COPOLYIMIDES FROM ALICYCLIC DIANHYDRIDE 被引量:5
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作者 黄卫 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2007年第4期409-417,共9页
A kind of highly organsoluble polyimide and copolyimides were successfully synthesized from bicyclo(2.2.2)-oct- 7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA), the commercial diamine 4,4'-methylenedianiline (... A kind of highly organsoluble polyimide and copolyimides were successfully synthesized from bicyclo(2.2.2)-oct- 7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA), the commercial diamine 4,4'-methylenedianiline (MDA) and the designed diamine 4,4'-methylenebis-(2-tert-butylaniline) (MBTBA). The polyimide from BCDA and MBTBA is highly soluble in conventional low boiling point solvents (such as chloroform, tetrahydrofuran) at room temperature. But the solubility of the copolyimides in conventional solvents decreased with the molar ratio of MBTBA and MDA decreased. When the molar ratio of MBTBA and MDA was larger than 7/3, the copolyimides can be soluble in low boiling point solvents at room temperature to form a transparent, flexible, tough film by solution casting. When the molar ratio of MBTBA and MDA was between 7/3 and 1/9, they can only be soluble in hot dipolar aprotic solvents (such as DMF, NMP etc.) and form films too. The copolyimide was only soluble in m-cresol when the molar ratio of MBTBA and MDA was lower than 1/9. The number-average molecular weights of the soluble copolyimides were larger than 5.8 × 1064 g/mol by GPC and their polydispersity indices were higher than 1.4. Only one glass transition temperature of these copolyimides was detected around 400℃ by DMA. The copolyimides did not show appreciable decomposition up to 430℃ in N2. 展开更多
关键词 polyimides Bicyclo(2.2.2)-oct-7-ene-2 3 5 6-tetracarboxylic dianhydride 4 4'-Methylenebis-(2-tert-butylaniline) 4 4'-Methylenedianiline.
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多频带轻量化无人机共形天线设计
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作者 王哲 周元武 +2 位作者 李洪峰 邹逢轩 张超 《科学技术创新》 2026年第1期206-211,共6页
无人机天线是实现无人机与地面控制站、无人机集群或其他通信设备之间信息传输的关键部件。针对传统天线频带单一,增益差,气动性差的缺点,开创性地设计了一种多频带轻量化无人机共形天线。采用金属薄膜和柔性聚酰亚胺基板结构使其具备... 无人机天线是实现无人机与地面控制站、无人机集群或其他通信设备之间信息传输的关键部件。针对传统天线频带单一,增益差,气动性差的缺点,开创性地设计了一种多频带轻量化无人机共形天线。采用金属薄膜和柔性聚酰亚胺基板结构使其具备共形能力,实现任意方向变形;结合人工表面等离激元结构技术产生多模谐振,使得天线具备多频带属性;采用环形结构、椭圆形槽和共面波导馈电等方式,提升天线辐射增益,减少辐射盲区,最终使天线具备多频带、高增益、小型化、共形化、低能耗等特点。实验结果显示:该天线检测的频带可实现在三个频带内工作,实测增益最大为3 dBi。多频带轻量化共形天线提升了无人机的通信、续航和隐蔽性能,扩展应用范围。 展开更多
关键词 多频带 共形化 柔性聚酰亚胺 人工表面等离激元结构
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Sulfonated Polyimides Containing 1,2,4-Triazole Groups for Proton Exchange Membranes 被引量:3
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作者 Rui Lei 高连勋 +1 位作者 Ri-zhe Jin Xue-peng Qiu 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2014年第7期941-952,共12页
A series of sulfonated polyimide copolymers as novel proton exchange materials were synthesized by the polycondensation of 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTDA), sulfonated diamine based on pyridine... A series of sulfonated polyimide copolymers as novel proton exchange materials were synthesized by the polycondensation of 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTDA), sulfonated diamine based on pyridine group and diamine containing N-phenyl-1,2,4-triazole moiety. Flexible, transparent and tough membranes with high thermal stability and good mechanical properties were obtained. They exhibited good stability in boiling water and Fenton's reagent at 80 ℃. More interestingly, a nonlinear relationship between proton conductivities of the resulting membranes and the degree of sulfonation (DS) was observed. The membrane with 50% DS exhibited the maximum proton conductivity, which was due to the combinational contributions of sulfonic acid and N-pheny-1,2,4-triazole groups. Thus, the N-phenyl-l,2,4- triazole moiety in this study not only can depress water absorption but also increase proton conductivity, especially at low DS. 展开更多
关键词 TRIAZOLE Acid-base interaction Sulfonated polyimide Proton exchange membrane.
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Fluorinated Colorless Polyimides with High Heat-resistance and Low Birefringence 被引量:3
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作者 Bing-Yu Zou Lu-Hao Qiu +5 位作者 Huan-Yu Lei Jin-Ming Liu Wei-Feng Peng Hong-Qin Zhao Feng Bao Ming-Jun Huang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2023年第10期1599-1608,共10页
The development of optical films with high transparency,high thermal resistance and low birefringence remains a challenge in the flexible display industry.In this work,we designed and synthesized a series of fluorinat... The development of optical films with high transparency,high thermal resistance and low birefringence remains a challenge in the flexible display industry.In this work,we designed and synthesized a series of fluorinated colorless polyimides(CPIs)materials using 2,5-substituted m-phenylenediamine diamine monomers and 1,2,4,5-cyclohexanetetracarboxylic dianhydride(CHDA).We systematically studied the effects of fluorinated group substitutions on the thermal,mechanical,optical and dielectric properties of CPI films.The introduction of alicyclic CHDA dianhydride affords high transparency and low yellowness,while the 2,5-substituted m-phenylenediamine diamines offer the CPIs with quite low birefringence as well as high glass transition temperatures.A particular CHDA/o3FBDA film with simple chemical structure stands out,exhibiting well-balanced overall properties. 展开更多
关键词 Colorless polyimide Low birefringence FLUORINATED Optical flm
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Synthesis and Electrochromic Properties of Polyimides with Pendent Benzimidazole and Triphenylamine Units 被引量:2
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作者 Wan-an Cai Ji-wei Cai +5 位作者 牛海军 Tian-di Xiao Xu-duo Bai Cheng Wang 张艳红 Wen Wang 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2016年第9期1091-1102,共12页
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 diff... 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. 展开更多
关键词 Triphenylamine Electrochromic BENZIMIDAZOLE POLYIMIDE Near-infrared.
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SOLUBLE POLYIMIDES FROM A SEMI-ALIPHATIC DIAMINE CONTAINING ESTER,AMIDE AND ETHER GROUPS 被引量:2
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作者 Shahram Mehdipour-Ataei Leila Akbarian-Feizi 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2011年第1期93-100,共8页
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... 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. 展开更多
关键词 POLYIMIDE POLYCONDENSATION Synthesis Thermal properties
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STUDY ON SYNTHESES AND PROPERTIES OF SOME NOVEL POLYIMIDES CONTAINING BISTHIAZOLE RINGS 被引量:2
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作者 孙维林 高雪松 卢凤才 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1997年第4期325-331,共7页
Some novel polyimides containing bisthiazole rings were prepared by reacting 2,2'-diamino-4, 4'-bisthiazole (DART) with different aromatic dianhydride. The polyimides obtained had inherent viscosities of 0.37-... Some novel polyimides containing bisthiazole rings were prepared by reacting 2,2'-diamino-4, 4'-bisthiazole (DART) with different aromatic dianhydride. The polyimides obtained had inherent viscosities of 0.37-0.82 dl/g. Thermogravimetric analysis of the polyimides showed good thermal stability, the temperature at 5% weight loss being from 450 degrees to 560 degrees C. The permeability of two polymer membranes to H-2, O-2 and N-2 was determined, respectively. Three kinds of polyimide films were converted into electrical conductor by pyrolysis at high temperature in nitrogen atmosphere. The maximum room temperature conductivity as high as 3.9x10(2) S/cm for PI him pyrolyzed at 1200 degrees C for 10 min was obtained, and it was very stable in air. 展开更多
关键词 polyimides containing bisthiazole rings gas separation membrane PYROLYSIS conducting polymer
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CHARACTERIZATION AND THERMAL STABILITY OF PMR POLYIMIDES USING 7-OXA-BICYCLO[2,2,l]HEPT-5-ENE-2,3-DICARBOXYLIC ANHYDRIDE AS END CAPS 被引量:2
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作者 李彦锋 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2011年第6期741-749,共9页
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 al... 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. 展开更多
关键词 Polyimide End-cap PMR matrix resin Thermal stability
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Highly Soluble Polyimides Containing Di-tert-butylbenzene and Dimethyl Groups with Good Gas Separation Properties and Optical Transparency 被引量:2
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作者 Chen-Yi Wang Cai-Rong Jiang +4 位作者 Bin Yu Xiao-Yan Zhao Zhao-Liang Cui Jian Li Qiang Ren 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2020年第7期759-768,I0007,共11页
A rigid aromatic diamine monomer containing di-tert-butylbenzene and dimethyl groups,3,3'-dimethyl-4,4'-diaminophenyl-3",5"-di-tert-butyltoluene,was successfully synthesized by a simple coupling reac... A rigid aromatic diamine monomer containing di-tert-butylbenzene and dimethyl groups,3,3'-dimethyl-4,4'-diaminophenyl-3",5"-di-tert-butyltoluene,was successfully synthesized by a simple coupling reaction using 3,5-di-tert-butylbenzaldehyde and o-toluidine as starting materials.A series of novel polyimides(PI 3a-3c)with large pendant groups were prepared with the obtained diamine monomer and three different commercial aromatic dianhydrides(3,3',4,4'-biphenyltetracarboxylic dianhydride,4,4'-oxydiphthalic anhydride,and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride)by one-step high temperature polycondensation.The prepared polyimides exhibited high solubility and good membrane forming ability:they could be dissolved not only in some high boiling solvents such as DMF,NMP,DMAc,and m-Cresol at room temperature,but also in some low boiling solvents such as CHCl3,CH2Cl2,and THF.Their solubility in most solvents could exceed 10 wt%,and the flexible membranes could be obtained by casting their solutions.The prepared membranes exhibited good gas separation properties.The permeability coefficients of PI 3c for CO2 and O2 were up to 124.6 and 42.8 barrer,respectively,and the selectivity coefficients for CO2/CH4 and O2/N2 were 14.7 and 3.3,respectively.The membranes had light color and good optical transmission.Their optical transmittance at 450 nm wavelength was in the range of 67%-79%,and the cutoff wavelength was in the range of 310-348 nm.They also had good thermal properties with glass transition temperature(Tg)values in the range of 264-302℃.In addition,these membranes possessed good mechanical properties with tensile strength ranging between 77.8-87.4 MPa,initial modulus ranging between 1.69-1.82 GPa,and elongation at break ranging between 4.8%-6.1%. 展开更多
关键词 polyimides Di-tert-butyltoluene Gas separation performance Optical transparency
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Chain Conformation and Local Rigidity of Soluble Polyimides(II):Isomerized Polyimides in THF 被引量:2
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作者 LIU Gui-hua QIU Xue-peng +1 位作者 BO Shu-qin JI Xiang-ling 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2012年第2期329-333,共5页
Two soluble isomerized polyimides(PIs) synthesized from 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA) with either 2,2'-dimethylbenzidine(2,2'-DMB) or 3,3'-DMB were investigated by means ... Two soluble isomerized polyimides(PIs) synthesized from 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA) with either 2,2'-dimethylbenzidine(2,2'-DMB) or 3,3'-DMB were investigated by means of size-exclusion chromatography coupled with multi-angle laser light scattering,a viscometer and a refractive index detector in tetrahydrofuran(THF) with tetrabutylammonium bromide(TBAB) at 35 ℃.The corresponding parameters related to conformations α and ν,evaluated from the scaling relationships [η]=K η M α and R g =K g M ν,respectively,were 0.66±0.01 and 0.55±0.02 for poly(6FDA/3,3'-DMB),and 0.67±0.01 and 0.56±0.01 for poly(6FDA/2,2'-DMB),indicating a random coil conformation for both the samples in this mobile system.The persistence length l p and shift factor M L(relative molecular weight per unit contour length) were estimated from the relationship between intrinsic viscosity and molecular weight for the wormlike cylinder model proposed by Bohdanecky.Both l p and M L showed that the two PIs in THF are flexible chains and exhibit some local rigidity to some extent. 展开更多
关键词 Isomerized polyimide Chain conformation Local rigidity Wormlike chain Persistence length
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