POLYMER INTERNATIONAL
·
2017
·Vol. 66
·期 11
·1633-1639
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IF 2.07
Nafeesa Mushtaq,Lala Rukh Sidra,Guofei Chen,Yongmei Tang,Lubo Xu,Xingzhong Fang
A series of cardo based asymmetric polyimides containing bulky rigid naphthalimide and phthalimide groups were prepared from asymmetric monomer bishaloimide and bisphenols by solution polycondensation. Bishalo(naphthalimide-phthalimide) monomers containing different terminal leaving groups (Cl, F, NO 2 ) were synthesized, and the reactivity difference of these monomers was compared for the successful synthesis of polyimides. The inherent viscosities of the polyimides were in the range 0.51 − 0.60 dL g −1 in N -methyl-2-pyrrolidone at 30 °C. These polyimides demonstrated good organosolubility and mechanical properties with tensile strengths of 93 − 120 MPa, tensile moduli of 3.5 − 5.3 GPa and elongations at break of 2.8% − 4.3%. The polyimides showed high glass transition temperatures ( T g ) ranging from 330 to 363 °C. The 10% weight loss ( T 10% ) of asymmetric polyimides reached 436 − 500 °C in nitrogen and 417 − 476 °C in air. The water uptake of the polyimides was in the range 0.35% − 0.72%. © 2017 Society of Chemical Industry
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
POLYMER INTERNATIONAL
·
2011
·Vol. 61
·期 1
·111-117
·
IF 2.056
Bing Fang,Kai Pan,Qinghan Meng,Bing Cao
This study investigated the preparation of polyimide solvent-resistant nanofiltration membranes by a two-step method (casting the membrane first and then crosslinking by the thermal imidization method). The influences of polymer concentration, thickness of membranes, temperature of the imidization, phase inversion time and thermal imidization procedure were studied. The membranes with the highest rejection rate of Fast Green FCF (molecular weight 808.86 g mol −1 ) were prepared in the following conditions: polymer concentration 13 wt%, phase inversion time 1 h, membrane thickness 150 µm and thermal imidization procedure 200 °C for 2.5 h, 250 °C for 2 h and 300 °C for 2 h in a vacuum environment; the heating rate was 5 °C min −1 . The membrane was stable in most of the solvents tested and the fluxes of some common solvents were equal to or higher than a number of commercial solvent-resistant nanofiltration membranes. A much higher rejection of dyes in water than in methanol was observed in the filtration experiments and a new way to explain it was developed. Copyright © 2011 Society of Chemical Industry
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
Small
·
2025
·
IF 12.1
Man Liu,Feihua Liu,Hongmei Qin,Chuanxi Xiong,Hengxue Xiang,Liping Zhu,Meifang Zhu
Polymer dielectric films are widely used in advanced electronics, hybrid vehicles, etc., however, they encounter critical challenges, including significant thermal degradation and heightened leakage currents, which severely constrain their energy density and efficiency under high-temperature conditions. Herein, a novel strategy is proposed for constructing a polyimide (PI) alloy by incorporating high-bandgap copolymer of perfluoropropyl perfluorovinyl ether and tetrafluoroethylene (P(TFE-PPVE)) and fluorinated polyimide (FPI) as a compatibilizer. The highly oriented structural PI/FPI/P(TFE-PPVE) alloy is fabricated via knife casting, which utilized high shear forces to align the P(TFE-PPVE) blocks within the polyamide acid. Simulation results indicate that the high-bandgap P(TFE-PPVE) phase (9.72 eV) with an oriented structure in the PI matrix can effectively suppress electrical tree growth. Furthermore, deep carrier trap at the PI/P(TFE-PPVE) interface (2.98 eV) further reduces leakage current and enhances breakdown strength while minimizing conduction loss. As a result, the PI/FPI/0.25P(TFE-PPVE) alloy demonstrates remarkable dielectric stability under diverse conditions, achieving a discharge energy density of 3.75 J cm −3 with 90% efficiency at 150 °C and 550 MV m −1 . This straightforward blending strategy provides an effective pathway to modulate the condensed structure of all organic polymers, offering promising potential for high-performance polymer dielectrics.
研究领域:
材料科学
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电子工程
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能源存储
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DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 58
·期 20
·2951-2962
·
IF 0
Kai Ma,Guofei Chen,Yonggang Zhang
A series of cross-linked polyimides (PIs) were prepared via two-step solution polycondensation from 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) and 2,5-furandicarboxylic acid-based diamines, N,N ′-bis(4-amino-2-(trifluoromethyl)phenyl)furan-2,5-dicarboxamide (TFFDA) and N,N ′-bis(4-aminophenyl)furan-2,5-dicarboxamide ( p -FDDA), followed by thermal crosslinking reaction with bismaleimide. The thermal crosslinking reaction and its mechanism were studied by FTIR spectra and model reaction analysis, which showed Diels–Alder reaction between furan group and maleimide group played a main role in the thermal treatment. The properties of cross-linked PIs were characterized using dynamic mechanical thermal analysis, thermogravimetric analyses, tensile testing, ultraviolet-visible spectra, and wide-angle X-ray diffraction. The cross-linked polyimide film showed improved solvent-resistance, thermal and mechanical properties with T g values of 234–306 o C, tensile strengths of 82–98 MPa and moduli of 2.3–3.0 GPa. Graphical Several cross-linked polyimides (PIs) were prepared via polycondensation of dianhydride and 2,5-furandicarboxylic acid (2,5-FDCA)-based diamines, N,N ′-bis(4-amino-2-(trifluoromethyl)phenyl)furan-2,5-dicarboxamide, and N,N ′-bis(4-aminophenyl)furan-2,5-dicarboxamide, and following thermal crosslinking reaction with bismaleimide. These PIs exhibit outstanding thermal and mechanical properties. The crosslinking network of 2,5-FDCA-based PIs and bismaleimide is constructed for the first time by Diels–Alder reaction. The thermal crosslinking mechanism is also studied in detail using model reaction.
研究领域:
材料科学
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化学工程
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产品关联
DOI
COMPOSITES PART B-ENGINEERING
·
2021
·
IF 9.078
Qi Zhao,Xudong Li,Zishang Tian,Hui Ma,Xianglin Hou,Yingxiong Wang,Yuqi Wang
Carbon fiber reinforced bismaleimide resin (CF/BMI) composites are widely used in aerospace field due to their high thermal stability, chemical resistance and excellent mechanical properties . With the large-scale application of CF/BMI composites, it is inevitable to produce a lot of solid wastes, which have a serious impact on the environment, so people have to recycle waste CF/BMI composites. In view of the physical and chemical properties of BMI resin, we developed a green and friendly chemical recovery method of CF/BMI composites by selectively breaking imide bonds for controlled chemical degradation of BMI resin. In 5 wt% NaOH/H 2 O reaction system, the controlled chemical degradation of CF/BMI composites can be realized by selective cleavage of imide bonds, and the 4,4′-Diaminodiphenyl methane (DDM) and 2,2′,2″,2‴-((methylenebis(4,1-phenylene))bis(azanetriyl))tetrasuccinic acid (MBTA) can be recovered, and the carbon fiber (CF) can be recycled at the same time. Under the optimal reaction conditions, the yields of DDM and MBTA reached 6.7 wt% and 27.9 wt% at 180 °C for 8 h, respectively. Meanwhile, CF in CF/BMI composites can be completely recovered, and the tensile strength of recovered carbon fiber (rCF) is about 97.6% of that of virgin carbon fiber (vCF). This work provides a very promising strategy for the recycling of CF/BMI composites. The high value-added CF and chemicals (DDM and MBTA) can be recovered by controlled degradation of CF/BMI composites via selective cleavage of imide bonds.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
DISPLAYS
·
2014
·
IF 1.205
Xia Chen,Tao He,Hongwei Jiang,Biming Wei,Guofei Chen,Xingzhong Fang,Mingliang Jin,Robert A. Hayes,Guofu Zhou,Lingling Shui
We report a screen-printing fabrication process for large area electrowetting display (EWD) devices using polyimide-based materials. The poly(imide siloxane) was selected as hydrophobic insulator layer, and relatively hydrophilic polyimide as grids material. EWD devices that use poly(imide siloxane) as hydrophobic insulator fabricated with conventional methods showed good and reversible electrowetting performance on both single droplet level and device level, which showed its potential application in EWDs. The compatibility of polyimide-based materials (hydrophobic poly(imide siloxane) and hydrophilic polyimide) guarantee the good adhesion between two layers and the capability of printable fabrication. To this end, the hydrophilic grids have been successfully built on hydrophobic layer by screen-printing directly. The resulting EWD devices showed good switch performance and relatively high yield. Compared to conventional method, the polyimide-based materials and method offer the advantages of simple, cheap and fast fabrication, and are especially suitable for large area display fabrication.
研究领域:
材料科学
·
显示技术
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产品关联
DOI
高影响因子
TETRAHEDRON
·
2016
·
IF 2.645
Xinyue Zhu,Hong Gao,Wenyan Zan,Yan Li,Jianjian Zhang,Xiaoyan Liu,Xuan Wei,Fengchao Qi,Xiaojun Yao,Haixia Zhang
It was reported here a devised and synthesized thiol fluorescent probes ortho -Z3 , meta -Z3 and para -Z3 based on photoinduced electron transfer (PET) pathway utilizing fluorophore naphthalimide as the electron donor and responsive group maleimide as the electron acceptor . The fluorescence intensity of these probes varied significantly depending on the position of the maleimide toward the naphthalimide fluorophore. Comparing to the meta and para isomers, the ortho isomer displayed the best fluorescence response performances upon addition of thiols. The results indicated that relative position of the electron acceptor played key role in the PET process, and probe ortho -Z3 could detect endogenous biothiols in serum samples and live cells successfully.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Physics
·
2023
·
IF 11.5
Xianzhe Sheng,Shuhuan Yun,Shengli Wang,Yusong Gao,Xinpei Zuo,Xing Miao,Xuetao Shi,Jianbin Qin,Zhonglei Ma,Guangcheng Zhang
The polyimide (PI) foams possess outstanding properties such as light weight, high temperature resistance, sound absorption and noise reduction, thermal insulation and flame retardant , etc. However, the currently reported PI rigid foams (PIRFs) exhibited poor mechanical properties and heat resistance due to their low crosslinking density , and could not be used for structural materials in areas such as aerospace and military ships, etc. Herein, the highly heat resistant and mechanically strong co-crosslinked polyimide/bismaleimide (PI/BMI) rigid foams were fabricated by the feasible and scalable capping precursor powder foaming method. The norbornene-end-capped polyimide oligomer (NEPIO) was melt copolymerized with 4,4′-bismaleimide diphenylmethane (BDM), incorporating the maleimide structure into the PI molecular chain and constructing the high-density PI/BMI co-crosslinking networks. Four different diamine monomers were used for the fabrication of co-crosslinked PI/BMI rigid foams. The results showed that the PI/BMI rigid foams using m -phenylenediamine (MPD) as diamine monomer exhibited the superior comprehensive performances, including outstanding heat resistance with high glass transition temperature ( T g ) of 386.1 °C and thermal degradation temperature ( T 10 wt% ) of 534.9 °C, as well as excellent compression strength of 6.58 MPa at room temperature and 6.32 MPa at high temperature of 200 °C with a mass density of 290 kg/m 3 , which surpassed all the previously reported PI rigid foams. Moreover, the PI/BMI rigid foams showed superior thermal insulation properties with ultra-low thermal conductivities at room temperature and 200 °C, as well as outstanding flame resistance with high limited oxygen index (LOI) of above 45%. The obtained co-crosslinked PI/BMI rigid foams showed promising application potentials as structural materials in aerospace, military ships, rail transportation and other high temperature resistant special fields.
研究领域:
材料科学
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航空航天工程
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化学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 45
·17225-17235
·
IF 8.067
Man Liu,Yiheng Song,Hongmei Qin,Ziwei Li,Yuheng Fu,Chuanxi Xiong,Feihua Liu
Polymers with both high dielectric breakdown strength and high dielectric constant are vital for a large number of applications. However, most polymer or polymer composites suffer from the problem of deteriorated breakdown strength caused either by undesired submicron voids during film processing or the addition of high dielectric constant filler. In this work, we present a facile blending strategy to fabricate polyamide-imide (PAI)/polyimide (PI) alloy. The strong interchain hydrogen bonds and electrostatic force of the PAI/PI alloy increase chain packing density and decrease possible corresponding imperfect points. The intermolecular forces are simulated and calculated via Materials Studio. It is found that the PAI/PI alloy with 50 wt% PAI possesses the strongest intermolecular forces, which is consistent with the experimental results. The PAI/PI alloy with 50 wt% PAI exhibits enhanced dielectric properties, such as 54.3% improvement in breakdown strength, 68.8% enhancement in dielectric constant and suppressed dielectric loss compared with pristine PI, leading to a high discharged energy density of 5.84 J cm−3 with an efficiency of 91.8% at 545 MV m−1. The excellent performance of the PAI/PI alloy can be attributed to the polar groups in PAI that promote the dielectric constant, strong hydrogen bonds and electrostatic force between the molecule chains in the blend that contribute to the greatly enhanced breakdown strength. This novel molecular engineering strategy is an effective way to fabricate high-performance dielectric polymers for film capacitor applications.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2017
·
IF 3.151
Xuhai Xiong,Xinghua Ma,Ping Chen,Lu Zhou,Rong Ren,Siyang Liu
New aryl-ether-imide/phthalide-containing bismaleimide oligomers (MPEIBMI) with different molecular weight were designed and synthesized by adjusting the addition amount of diamine compound derived from o -cresolphthaleine, and dianhydride 4,4′-(4,4′-isopropylidene diphenoxy)-bis(phthalicanhydride) (mole ratio: 1.25/1.5/2.0). The chemical structures of the oligomers and their intermediate compounds were confirmed by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance ( 1 H and 13 C NMR) spectroscopy and elementary analysis. X-ray diffraction (XRD) results showed a blunt diffraction peak, suggesting an amorphous structure. The oligomers exhibited good solubility in a variety of common organic solvents . The heat flow curves of the oligomers measured by differential scanning calorimeter (DSC) displayed a broad curing exothermic peak. The thermal stability and thermal mechanical properties of the cured resins were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The results indicated that the introduction of phthalide cardo structure and imide rings into the polybismaleimide network could effectively improve the thermal properties. The glass transition temperature and initial thermal decomposition temperature were above 260 °C and 423 °C, respectively, and the residual weight percentages at 700 °C were all > 58%. The mechanical tests revealed that the cured MPEIBMI films had excellent tensile strength and good retention at the temperatures above 200 °C.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ying Chen,Tianjiao Yu,Xiangwu Chang,Zongqiang Guo,Zihan Zhao,Ziyue Huang,Penghao Hu
Enhancing the energy storage capacity of dielectric polymers can be achieved by the introduction of inorganic nanoparticles. However, the difference in surface energy often influences the interfacial compatibility of nanoparticles with polymers, consequently limiting their comprehensive dielectric properties. Here, the magnesium oxide (MgO) nanoparticles were coated with polyimide (PI) shells via in-situ polymerization, which is beneficial to improve the scattered particles in the polyether imide (PEI) matrix. The PI buffer shell is tightly bound to the PEI matrix through automatic electrostatic interaction making the defects decrease, together with the increased dielectric permittivity ( ε r ) attributed to MgO, significantly enhancing the discharged energy density ( U dis ) and storage efficiency ( η ) of the PI@MgO/PEI nanocomposite films in harsh conditions. Thus, the maximal U dis of the PI@MgO/PEI nanocomposites is 4.33 J/cm 3 at 150 °C, twice that of the pristine PEI. Even if an η exceeds 90 %, the U dis of 3.83 J/cm 3 of 1 vol%-PI@MgO/PEI at 500 MV/m and 150 °C is better than that of the most advanced dielectric polymers.
研究领域:
材料科学
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能源存储
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2014
·
IF 4.908
Li-Fen Liu,Zhi-Bin Cai,Jiang-Nan Shen,Li-Xiang Wu,Eric M.V. Hoek,Cong-Jie Gao
A novel poly(amide-urethane@imide) reverse osmosis (RO) composite membrane with chlorine-tolerant property was prepared on a polysulfone supporting film through two-step interfacial polymerization. The crosslinking agent – 5-choroformyloxyisophaloyl chloride (CFIC) was first reacted with 4-methyl-phenylenediamine (MMPD) via interfacial polymerization to get the nascent poly(amide-urethane) base membrane (CFIC–MMPD) without curing treatment. Then the resultant base membrane contacted again with the second aqueous solution containing functional secondary amine – N,N′-dimethyl- m -phenylenediamine (DMMPD) to obtain the poly(amide-urethane@imide) TFC RO membrane (MMPD–CFIC@CFIC–DMMPD). X-ray photoelectronic spectroscopy (XPS) was combined with attenuated total reflectance infrared (ATR-IR) to verify that the ultrathin polyimide film (CFIC–DMMPD) has been successfully grafted on the surface of the MMPD–CFIC base membrane. The images of scanning electronic microscopy (SEM) and atomic force microscope (AFM) showed that the poly(amide-urethane@imide) membrane has much smoother, more hydrophilic surface than the poly(amide/imide-urethane) membrane (MMPD/DMMPD–CFIC) prepared by conventional one-step interfacial polymerization of CFIC and composite MMPD/DMMPD. However, the permeation experiment revealed that the poly(amide-urethane@imide) membrane has a slight loss in both salt rejection and water flux than the poly(amide/imide-urethane) membrane and conventional commercialized polyamide membrane (MPD–TMC), but exhibits better chlorine-tolerant property due to the introduction of ultrathin polyimide film (CFIC–DMMPD) on the outmost surface of the TFC RO membrane, and the combination of IR and XPS analyses shows a good agreement with the chlorine exposure results of membranes.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）