Materials Today Energy
·
2023
·
IF 9.3
Zhiqiang Wu,Yiwen Peng,Ying Song,Haoyu Liang,Lei Gong,Zhenguo Liu,Qiuyu Zhang,Yanhui Chen
In order to balance the breakdown strength and dielectric loss of polymer dielectric materials, a series of cross-linked polyimide (XL-PI) films with outstanding dielectric properties and high temperature energy storage property are prepared by introducing the end-capping agent, i.e. norbornene dioic anhydride, in this work. The cross-linked structure between molecular chains restricts the polarized movement of polar groups and inhibits the directional migration of carriers, which greatly reduces the dielectric loss and improve the electrical insulation properties of cross-linked PI film, compared with pure PI film with linear molecular chains. The dielectric loss of XL-PI films is greatly reduced to 0.003–0.006. Simultaneously, the breakdown strength of the XL-PI sample is up to 545 kV/mm. And the dielectric loss and breakdown strength of the XL-PI samples are relatively stable in the temperature ranging from room temperature to 150 °C. The XL-PI film with 3 wt% norbornene dioic anhydride (XL-PI-3) shows the maximal energy storage density of 9.4 J/cm 3 under 525 kV/mm at room temperature. Moreover, XL-PI-3 can maintain an energy storage density of 6.5 J/cm 3 and an energy efficiency of 82% at 150 °C. This work provides a new idea to prepare PI dielectric film materials for high-temperature film capacitors.
研究领域:
材料科学
·
电气工程
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Yinfu Luo,Long Ni,Lu Shen,Chen Qiu,Pengbo Liu,Mei Liang,Huawei Zou,Shengtai Zhou
Herein, lightweight rigid polyimide foams (PIFs) with excellent mechanical and thermal properties were fabricated by constructing dual crosslinking structures combined with the thermal foaming of polyester ammonium salt (PEAS) precursor powders. The dual crosslinking network relied on the self-crosslinking of pararosaniline base (PA) and active crosslinking derived from the breakage of C═C bonds in 5-norbornene-2, 3-dicarboxylic anhydride (NA) under heating. The results showed that melt viscosity and micro-foaming behavior of PEASs and the cell morphology of PIFs could be regulated by varying the molar ratio of PA/NA and the number of repeating units amid crosslinking points. The compressive strength of PIFP1BMN3-5 (density: 165.5 kg·m–3) with dual crosslinking structures at 10% strain reached 1.36 MPa at room temperature and 0.75 MPa at 200 °C. The PIFs exhibited outstanding thermal properties with the initial thermal degradation temperature falling in a temperature range of 458.2–503.0 °C and the glass-transition temperatures exceeding 310 °C. In addition, PIFs exhibited excellent thermal insulation properties since the thermal conductivity of PIFs was between 0.048 and 0.065 W·m–1 K–1, and the temperature increase of the top surface of the cubic sample block (height: 15 mm) was approximately 20 °C when they were placed on a preheated hot stage at 200 °C for 30 min. Thus, mechanically strong rigid PIFs with dual crosslinking structures were successfully prepared, which show promising applications as lightweight, high-temperature-resistant structural materials in high-end engineering fields.
研究领域:
材料科学
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高分子化学
·
工程热物理
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DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Xiangming Hu,Hongbin Wei,Yurui Deng,Zhiyuan Yang,Xiaoxuan Wei,Guoyu Han
As novel advanced organic materials, polyimide aerogels (PI-AER) exhibit high porosity and excellent thermal stability. For the general and safe application of PI-AER, it is imperative to clarify their thermal decomposition process. The kinetic parameters of PI-ARE pyrolysis were calculated using different traditional kinetic methods, and the results showed that the PI-AER pyrolysis process conformed to the Fn-like mechanistic function model with an average activation energy of 143.984 kJ/mol. The pyrolysis mechanism function model of the main pyrolysis stages was optimized and reconstructed to obtain the optimal solution f(α). In addition, the concentration changes of pyrolysis products with increasing temperature were monitored by TG-MS and the PI-AER bond breaking mechanism was analyzed. Finally, the TG curves were fitted piecewise to obtain Ea and lnA for the two pyrolysis processes. Combined with the pyrolysis mechanism and two-stage kinetic parameter analysis, the effects of the two pyrolysis stages of PI-AER on the kinetic parameters were elucidated. It was shown that the activation energies of solvent volatilization and desorption and PI-AER main chain were 60.1 kJ/mol and 147.76 kJ/mol, respectively. This study provides fundamental industrial parameters for the application of polyimide aerogels in extreme conditions.
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DOI
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Hangzhou Wang,Xiaobin Li,Ending Zhang,Jun Shi,Xiaoyan Xiong,Chenguang Kong,Jianrong Ren,Cunzhi Li,Kun Wu
A waterborne polyurethane pressure-sensitive adhesive (WPUPSA) has the advantages of low pollution and good viscoelasticity. However, its poor thermo-tolerance limits its application in the field of high temperatures. Hence, a novel silicone-modified strong thermo-tolerant waterborne polyurethane/polyimide pressure-sensitive adhesive is developed as a way to remedy this problem. The single-chain structure of waterborne polyurethane (WPU) is transformed into a network structure by introducing the three-position network structure to increase the cohesive energy and heat resistance of the WPUPSA. Meanwhile, the primary chain of waterborne polyurethane (WPU) is modified by the reaction between pyromellitic dianhydride (PMDA) and isophorone diisocyanate (IPDI) to include an imide ring and a benzene ring with more stable structures and heat resistance. Characterization results of the prepared WPUPSA show that the thermo-tolerance index of the WPUPSA increases by 15.2% and the room temperature 180° peel strength and shear resistance of the WPUPSA increase by 80.9 and 231.8%, respectively. Meanwhile, the temperature corresponding to the maximum thermal decomposition rate of the samples is improved. More importantly, at 80 and 100 °C, the 180° peel strength and shear resistance of the modified samples are stronger than those of the unmodified samples. In addition, the energy storage modulus of WPUPSAs is also greater than the loss and increases with the increase of the frequency. Viscoelasticity dominates in the samples. This will provide new insight for the development of WPUPSAs in the field of high-temperature resistance.
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DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Sizhao Zhang,Jing Wang,Zhao Wang,Guangyu Xu,Yonggang Jiang,Yunyun Xiao,Feng Ding
Reusable nanoporous polyimide (PI) aerogels are rather promising for highly efficient thermal insulation of future thermal protection systems demanded in aerospace and domestic applications. However, the development of high-performance PI aerogels is limited by their unsatisfactory high-temperature resistance and poor reusability. Herein, an Al2O3-hybridization strategy toward PI aerogels is demonstrated, and the formed aerogels exhibit a nanoporous structure, unusual reusability, and exceptional high-temperature resistance. Furthermore, the aerogels retain their high-level properties such as the very small changing rates of mass (≤0.3%), shrinkage (≤2.53%), thermal conductivity (≤3%), and bulk density (near-zero difference) even after five cycles of high-temperature assessment (250 °C for 2400 s). The conventional huge heat-induced shrinkage of PI aerogels could be substantially restrained even bearing a high-temperature environment, realizing near-zero thermally insulating degradation, which has an outstanding practical application value. The high-temperature resistance of the aerogel is greatly improved by the Al–O network constructed inside the PI aerogels, and this resistance is retained even after multiple cycles under harsh conditions, ultimately affording superior reusability to PI aerogels for the first time. The high-temperature resistance and ultralow heat-induced shrinkage properties of aerogels, as well as their reusability, make them favorable candidates as thermal protection materials for the future development of aircraft and military.
研究领域:
材料科学
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航空航天工程
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纳米技术
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DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2023
·
IF 4.6
Yue Tian,Yinfu Luo,Haichao Meng,Long Ni,Cuiqing Zhou,Shengtai Zhou,Huawei Zou,Mei Liang
Lightweight polyimide foams (PIFs) with exceptional thermal resistance and compressive properties are fabricated by heating polyester ammonium salts (PEASs) which are prepared by copolymerizing 4, 4’-diaminobenzanilide (DABA), 4, 4’-diaminodiphenyl methane (MDA) and 3, 3’, 4, 4’-benzophenone tetracarboxylic dianhydride (BTDA). Hydrogen bonds are formed between CONH and CO in the PI chains due to the addition of DABA and the melt viscosity of PEAS precursors increase with increasing content of DABA, which is advantageous to bind the foaming gases for cell expansion. The expansion ratio of PEAS precursors is increased from 633% to 1133% when the molar ratio of MDA/DABA is changed from 10:0 to 6:4. The compressive strength and modulus of PIF M9D1 (i.e., the molar ratio of MDA/DABA is 9:1, foam density: 120.8 kg m −3 ) reach as high as 0.59 and 15.0 MPa, respectively. The PIFs possess prominent thermal performance with the initial thermal degradation temperatures (under both nitrogen and air atmosphere) and glass transition temperatures (as assessed by DSC and DMA) exceeding 511 and 292 °C, respectively. The thermal conductivity of PIFs is lower than 0.049 W m −1 K −1 , which exhibits promising applications for serving as high-temperature thermal insulation materials in the fields of aerospace, marine, and nuclear sectors among others.
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
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
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IF 9.5
Guolong Huo,Zhiyong Guo,Zhiguang Zhang,Xiaowei Zhou,Junhao Xin,Yuchen Zhang,Shuanyan Kang,Yanqin Yang,Nanwen Li
Fine-tuning of the physical stacking structure for microporous polyimide (PI) membranes via the stretching processing is a practical way of achieving advanced membrane materials with improved aging resistance as well as high gas separation performance. Here, a fluorinated polyimide 6FDA:BPDA-TFDB(1:1:2) is used as a prototype and a series of stretched membranes X%-PI are fabricated by uniaxially stretching the membrane to different elongation ratio and then annealing. Based on birefringence and wide-angle X-ray diffraction measurements, it's found that regular orientation of polymer chains along the stretching direction and fine-tuning of d -spaces from interchain packing and π-π stacking happen during the uniaxial stretching process. As such, compared to pristine PI membrane, the stretched membranes show better mechanical and thermal stability, especially for the one with higher stretching ratio. In addition, owing to the increased packing density of polymer chains, the highly stretched membrane of 40%-PI shows significantly improved gas perm-selectivity by 32.8%, 24.3%, and 12.6% for He/CH 4 , H 2 /CH 4 , and CO 2 /CH 4 gas pairs, respectively, in comparison to pristine membrane. Furthermore, 40%-PI exhibits much higher gas permeability retention rate than that of other membranes after three months' aging. We expect that this work can offer polymer materials processing guidance for the preparation of high-performance gas separation membrane in future.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Xueshuang Jiang,Kaijin Chen,Chuying Li,Yubo Long,Siwei Liu,Zhenguo Chi,Jiarui Xu,Yi Zhang
Colorless polyimides (CPIs) are a key substrate material for flexible organic light-emitting diode (OLED) displays and have attracted worldwide attention. Here, in this paper, the dispersion and interfacial interaction of aromatic polyamide (PA) in CPI (synthesized from 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and 2,2′-bis(trifluoromethyl)benzidine (TFMB)) were significantly improved by in situ polymerization, and colorless transparent macromolecular polyimide composites (CPI-PAx) were successfully prepared by PA and CPI. By adjusting the ratio of PA to CPI, a high-performance engineering plastic with excellent film-forming properties was obtained. Molecular simulations confirmed the uniform distribution of PA in CPI and its interaction in polymers. In CPI-PAx, the CPI was locked by the PA chain, and numerous molecular chains were mutually entangled to form a hydrogen-bond network structure. Due to the strong interaction between the chains imparted by the hydrogen bonds of the PA, they do not slide under external forces and heating. In addition, the additive PA has excellent dimensional stability, thermal, and mechanical properties, and CPI has outstanding optical properties, so the synthesized CPI-PAx combines the comprehensive properties of PA and CPI. The CPI-PAx has excellent thermal and mechanical properties, with a thermal decomposition temperature of 499 °C, a glass transition temperature of 385 °C, a coefficient of thermal expansion of 0.8 ppm K–1, a tensile strength of 50.9 MPa, and an elastic modulus of 3.9 GPa. Particularly, CPI-PAx has a 90% transmittance in the visible region. These data prove that the strategy of combining PA and CPI by in situ polymerization is an effective method to circumvent the bottleneck of CPI in the current flexible window application, and this design strategy is universal.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2025
·
IF 5.2
Xianzhang Leng,Gaohui Sun,Zuodong Yang,Xinfu Guo,Jun Wang,Rongrong Chen,Shihui Han
Isocyanate-based polyimide (IBPI) films synthesized using isocyanates and anhydrides as reactive monomers exhibit inferior mechanical performance, limiting their practical applicability. This study introduced 4,4′-oxidianiline (ODA) as a “bridging agent” to connect anhydride-terminated oligomer chain segments generated from diphenylmethane diisocyanate (MDI-50) and 4,4′-oxydiphthalic dianhydride (ODPA). A high-performance IBPI film with high solubility in common organic solvents was obtained via a bridging strategy; this work marked it as PI-X. The mechanical, thermal, and electrical properties of the PI-1.0 film were significantly improved. The tensile strength increased from 54.97 to 108.87 MPa, representing a 98% increase over that of the pure IBPI film. The temperature at 5% weight loss increased from 461 to 524 °C. Meanwhile, the dielectric constant and loss tangent decreased to 2.21 and 0.0047 at 1 kHz, respectively. These excellent performances show that IBPI films have great application prospects in the microelectronics industry.
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DOI
高影响因子
Talanta Open
·
2025
·
IF 3.7
Qiao Chen,Xiaoran Zhang,Xinyue Zhou,Peng Huang,Daming Feng,Xu Xu,Chunhua Ge
We report a metal-free perylene-based polyimide framework (PDI-PB) as an efficient electrocatalyst for oxygen reduction reaction (ORR)-enhanced cathodic electrochemiluminescence (ECL). PDI-PB enhances reactive oxygen species (ROS) generation via oxygen reduction that significantly amplify the luminol–dissolved oxygen ECL signal. The resulting biosensor enables ultrasensitive detection of dopamine (DA) over a wide linear range (5 × 10 -5 to 100 μM) with a record-low detection limit of 9.76 pM (S/N = 3). The sensor exhibits excellent selectivity, stability, and reproducibility, and was successfully applied to detect DA in human sweat, serum, and urine, yielding recoveries of 97.0–101.1%. Density functional theory (DFT) calculations reveal that PDI-PB’s superior electronic structure facilitates efficient charge transfer and oxygen activation. This work presents a new strategy for metal-free organic electrocatalyst design, combining mechanistic insight with high-performance ECL biosensing for non-invasive health monitoring and clinical diagnostics.
研究领域:
电分析化学
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生物传感器与生物电子学
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材料科学
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纳米技术
·
临床诊断
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产品关联
DOI
高影响因子
Results in Engineering
·
2025
·
IF 7.9
Zanming Zhu,Faxiang Feng,Jiale Li,Guanhui Wang,Guilin Dong,Runlin Han
As the pharmaceutical industry has evolved, the efficient separation of antibiotics has become a key technical challenge. This study presents a solvent-resistant polyamide/polyimide (PI) composite nanofiltration membrane that overcomes the stability and selectivity issues associated with traditional membrane materials in organic solvents. A high-performance polyamide functional layer was fabricated via interfacial polymerization using a PI ultrafiltration membrane as the substrate. The aqueous monomers were 2,4,6-triaminopyrimidine (TAPI) and m-phenylenediamine (MPD), while the oil-phase monomer was trimesoyl chloride (TMC) dissolved in cyclohexane. Tuning the concentration ratio of the aqueous monomers TAPI and MPD optimized the membrane's structure and properties. Separation performance tests were conducted using salt solutions, such as NaCl, Na₂SO₄ and MgCl₂, as well as antibiotics, such as tetracycline hydrochloride (TC), ciprofloxacin (CIP) and chloramphenicol (CAP). The results showed that when TAPI was used as the monomer in aqueous solution, the polyamide layer formed on the composite membrane exhibited a high permeation flux (above 10.8 L‧m –2 ‧h –1 ) and rejections of 96.7% and 96.5% for TC and CIP, respectively, but a low rejection to NaCl (4.2%). The S NaCl/TC and S NaCl/CIP separation factors were calculated to be 29 and 27, respectively, and the permeation flux was high. The composite membrane maintained stable flux when immersed in 50 wt. % N,N -dimethylacetamide (DMAc) solution, acetone and methanol for 18 days. This study provides a theoretical basis for the antibiotic desalination with organic solvent nanofiltration membranes.
研究领域:
材料科学
·
膜技术
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化学工程
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药物分离
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环境工程
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DOI
高影响因子
POLYMER SCIENCE SERIES B
·
2023
·Vol. 65
·期 2
·120-128
·
IF 1.2
Yang Wu,Ding Chengcheng,Yu Juan,Huang Pei
Abstract Transparent polyimide films with excellent comprehensive properties may be indispensable to next-generation optoelectronic and flexible display applications. To date, the most studied transparent polyimide films are mainly prepared with alicyclic dianhydride as monomer, but the related properties of such films are not satisfactory. In this work, two series of highly optically transparent copolyimide films were prepared by the polycondensation of dicyclohexyl-3,4,3',4'-tetracarboxylic dianhydride, 1,2,4,5-cyclohexane-tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride with 4,4'-oxydianiline via a facile one-step method. Through the optimization of structure and composition, the relationship between structure and properties of copolymerized semi-alicyclic polyimide was studied. The prepared copolyimide films show good thermal stability: glass transition temperatures in the range of 264–315°C and 5% weight loss temperature of 463–527°C, superior optical transparency up to 90%. Specifically, these copolyimide films have tensile strength greater than 90.3 MPa.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）