Gels
·
2025
·Vol. 11
·期 11
·929
·
IF 5.3
Mingkang Wang,Shuai Yu,Jing Wang,Xin Zhao,Changpeng Yang,Ran Wei,Chun Liu,Sizhao Zhang
Polyimide aerogels have garnered considerable attention due to their high-performance combination of a lightweight nature, low thermal conductivity, and high mechanical strength, which renders them ideal candidates for thermal insulators in aerospace. However, the inherent conflict in achieving multifunctional (dimensional stability and mechanical stiffness at high temperatures, and highly efficient thermal insulation) integration presents a great challenge. Here, we present an aerogel skeleton construction strategy based on hybridizing an Al–O network phase to create multifunctional polyimide aerogels. The resulting aerogels partially constructed by Al–O network phase exhibit an outstanding resistance to high temperatures (shrinkage of 0.56% after experiencing 200 °C for 2400 s), which is markedly superior to that of conventional polyimide aerogels. The excellent insulation capability of the aerogel is reflected in its low thermal conductivity (0.0214 W m −1 K −1 ) and its ability to maintain a cold-side temperature of just 59.7 °C under a 150 °C heat source. Furthermore, remarkable enhancements in mechanical properties are found at high-temperature conditions, providing evidence for the compressive stresses of 0.329 and 0.394 MPa under 3% strain at the respective temperatures of 200 and 250 °C, showing a clear trend of enhanced compressive stress with rising temperature. These advancements in high-temperature stability and mechanical properties substantially broaden the scope for their potential applications in aerospace thermal protection systems.
研究领域:
材料科学
·
航空航天工程
·
热防护系统
·
聚合物纳米复合材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Haoyu Ma,Jiaozhu Wu,Le Xi,Zixuan Wang,Jie He,Pengjian Gong,Guangxian Li,Chul B. Park
The supercritical CO 2 (scCO 2 ) foaming method shows potential for fabricating porous polyimide (PI) materials with small pore size and high void fraction. However, conventional PI polymers suffer from low gas solubility and a rigid molecular backbone, resulting in poor foaming dynamics and high foaming resistance. In this work, we synthesized a thermally stable PI polymer with a rigid backbone, into which highly compatible ionic liquids (ILs) molecules were incorporated. The introduced ILs acted as molecular lubricants, simultaneously enhancing foaming dynamics and reducing foaming resistance. The resulting ILs/PI foam materials shows small pore size (9–12 μm), hydrophobic property (water contact angle 126.5 o ), flame retard property, low temperature toughness (−196 °C) and high thermal resistance property (406 °C). Moreover, a heterogeneous layered porous PI structure was fabricated by modulating the ILs content across different layers, creating alternating porous and solid regions. Leveraging this platform, CNT@Fe₃O₄ nanofillers, providing both dielectric and magnetic loss, were introduced into the porous layer, while conductive CNT was incorporated into the solid layer. The resulting heterogeneous porous PI nanocomposite materials exhibited ultra-low reflectivity electromagnetic interference (EMI) shielding performance (average A/R coefficient ratio of 67.1).
研究领域:
材料科学
·
高分子化学
·
功能材料
·
电磁学
·
纳米复合材料
·
热防护材料
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2021
·
IF 8.528
Ku Ren,Qinqin Xia,Yongzhuang Liu,Wanke Cheng,Ying Zhu,Yang Liu,Haipeng Yu
Wood is a common-sense thermostable construction material, but the decrease in its structural stability and mechanical strength due to the degradation of lignin and hemicelluloses limits its practical applications in extreme environments. Here, we synthesize a high-performance wood/polyimide composite via the partial substitution of lignin and hemicellulose with super thermostable polyimide . This method involves the rapid partial removal of lignin and hemicellulose in only 3 min using microwave-assisted deep eutectic solvent (DES) pretreatment and subsequent impregnation of polyimide into the pretreated wood. The microwave-assisted DES pretreatment greatly reduced the processing time for lignin and hemicellulose extraction, while preserving the natural cellular scaffold of wood and opening more channels for polyimide infiltration . The obtained wood/polyimide composite showed a 17% improved Young's modulus and a 63% higher dynamic storage modulus than natural wood. The temperature of the first maximum decomposition rate of the wood/polyimide composite significantly increased to 290 °C due to the infiltration of the thermostable polyimide. Furthermore, the wood/polyimide composite exhibited a smoke suppression property (33% decrease), and the time to produce smoke was delayed by 200 s. Our work provides a rapid pretreatment method for wood and a substitution compositing method to produce wood-framed polyimide composites with excellent thermostability.
研究领域:
材料科学
·
林业工程
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Jianwei Li,Yunfei Xie,Peng Yu,Fuqiang Yu,Baoshan Chai
In this study, two diamine monomers 4,4′-(perfluoro propane-2,2-dial)bis(2-aminophenol)(6FAP) and N, N′-((perfluoro propane-2,2-dial)bis(6-hydroxy-3,1-phenylene))bis(3-aminobenzamide) (HFA) were synthesized and used to prepare polyimide (PI) films. The effects of introducing amide bonds and trifluoromethyl groups into the polymer chains on the film properties were deeply investigated. The prepared PI films have high optical transparency, with a cutoff wavelength ranging from 300 to 330 nm, and a transmittance exceeding 80 % at 500 nm. They also exhibit excellent thermal stability, with a glass transition temperature ( T g ) higher than 300°C, and a 5 % thermal weight loss temperature ranging from T d5 % 482–510°C. Moreover, the films show good mechanical properties. In terms of chemical solubility, they are soluble in common polar aprotic solvents and low-polarity solvents and are resistant to acids and alkalis. The introduction of amide bonds enhances the rigidity of the molecular chains and the intermolecular interactions, further improving the T g without significantly sacrificing optical transparency or thermal stability. This polyimide film with high transparency, good thermal stability, and excellent processing performance is a highly potential candidate material for flexible substrates in flexible displays, advanced electronics, and other photonic applications.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 58
·53319-53323
·
IF 3.289
Tiantian Gu,Min Zhou,Mengyun Liu,Kangli Wang,Shijie Cheng,Kai Jiang
A polyimide–MWCNT composite (PNP@CNT) synthesized from 1,4,5,8-naphthalenetetracarboxylic-dianhydride (NTCDA) and phenylene diamine (PDA) was investigated as a novel anode for aqueous Na-ion batteries. This composite demonstrates a high reversible capacity of 149 mA h g−1 at quite a low potential of −0.65 V (vs. SCE), superior rate capability and long-term cycling stability. The feasibility of PNP@CNTs in aqueous Na-ion full batteries is also confirmed in conjunction with the Na0.44MnO2 cathode, possibly serving as a high performance aqueous Na host anode for large-scale electric energy storage applications.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米复合材料
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Ling Weng,Jinming Liu,Xiaorui Zhang,Hang Xu,Lizhu Guan,Yang Yu
Considering the ongoing evolution of flexible printed circuit boards and the importance of safeguarding the intellectual property of circuit designs, there exists an imperative demand for the development of a black film exhibiting exceptional electrical properties and remarkable light-shielding capabilities. Consequently, this work employs a straightforward strategy to enhance the opacity of polyimide films by incorporating carbon black (CB) and manganese dioxide (MnO 2 ) as black fillers using an in situ doping method. Rigorous tests are conducted, analyzing properties such as dielectric constant, dielectric loss, breakdown field strength, current density, and ferroelectric energy storage. The optimal ratio of CB to MnO 2 (mass fraction) is determined as 1:5, with a total powder doping amount of 6 wt%, providing the best ratio relative to the matrix resin. This ratio ensures an optimal powder dispersion state, resulting in an outstanding breakdown field of 147.4 kV/mm and ultralow dielectric constants, measuring less than 3.78 at 103 Hz. This composite film is anticipated to find applications as a cutting-edge material for electronic devices and the semiconductor industry.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2020
·Vol. 221
·期 12
·2000085
·
IF 2.335
Zhigeng Chen,Sen Zhang,Qi Feng,Yancheng Wu,Shumei Liu,Jianqing Zhao
Both the formation of insoluble salt for aliphatic diamines and the poor reactivity for aliphatic dianhydrides result in semi-aromatic polyimide (SAPI) with low molecular weight and, thereby, in highly brittle SAPI films in nature. To solve the above problems, a cyclic-olefin copolymer synthesized from norbornene and maleic anhydride is used as the third monomer (crosslinking agent) to prepare the crosslinked SAPI (cSAPI) films. The relative viscosity of the precursor solution of cSAPI is increased with the loading of cyclic-olefin copolymer, giving rise to the improvement in mechanical and thermal properties of cSAPI films. The tensile modulus, tensile strength, and elongation at break of cSAPI film with 5 wt% cyclic-olefin copolymer are increased to 4.49 GPa, 137 MPa, and 14.9% from 3.57 GPa, 111 MPa, and 7.6%, respectively, compared to those of the baseline SAPI film. Meanwhile, the glass transition temperature of cSAPI films is increased to 282 from 270 °C of the SAPI film, which is advantageous to better meet the requirement for high-temperature manufacturing processes such as lead-free solder reflowing. In addition, all cSAPI films exhibit good optical transparency in the entire visible region.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Zhiqiang Wu,Huihui Zhou,Qiang Guo,Zhenguo Liu,Lei Gong,Qiuyu Zhang,Ganji Zhong,Zhongming Li,Yanhui Chen
In this work, we prepared the polyimide (PI) nanocomposite films containing barium titanate @polydopamine (BT@PDA) nanoparticles within a core-shell structure by solution casting method. The dielectric constant of these nanocomposite films is significantly improved compared to pure PI film, and increases with the increase of BT nanoparticles. And, the breakdown strength of these nanocomposite films is better than that of untreated BT/PI films at the fixed BT content. The PI composite film containing 1 vol% of BT@PDA nanoparticles exhibits the highest energy storage density of 1.94 J/cm 3 under an electric field of 315 kV/mm, which is 42% over the pristine PI (1.37 J/cm 3 at 295 kV/mm) and about 162% greater than biaxially-oriented polypropylene (BOPP) (≈1.2 J/cm 3 at 640 kV/mm). The presence of PDA shell effectively improves the dispersion uniformity and interfacial compatibility of BT nanoparticles in the PI matrix, giving rise to lower local electric field distortion in the composites. Besides, the BT@PDA/PI nanocomposite films have excellent dielectric thermal stability in the temperature range from 25 to 200 °C and thermal stability up to 500 °C. The BT@PDA/PI composites fabricated in this work have a great potential to be used in the high-temperature film capacitors.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 35
·50869
·
IF 3.125
Xiaoqing Xu,Dechao Hu,Wenshi Ma
Achieving synergetic improvements of mechanical strength, toughness, and thermal stability of epoxy resin has been a crucial but very challenging issue. Herein, to explore a new solution for circumventing this issue, polyimide microspheres were successfully prepared through the inverse nonaqueous emulsion process, and the structure, size distribution and morphologies of polyimide (PI) microspheres were comprehensively investigated. Then the PI microspheres were incorporated in epoxy resin matrix to systematically investigate the mechanical and thermal properties of obtained epoxy/PI microspheres composites. It was found that the PI microspheres can not only enhance the mechanical strength of epoxy resin, but also significantly improve the toughness. Specially, the epoxy-based composites containing 3 wt% PI microspheres exhibit a 47% increase in tensile strength, while the G IC and Charpy impact strength increase by 106% and 200%, respectively. The toughing mechanism of epoxy/PI microspheres composites was discussed. Moreover, the PI microspheres can also endow the epoxy resin with excellent thermal stability and heat resistance. Thus, this work may open a new opportunity to synergistically enhance the mechanical and thermal properties of epoxy-based composites and may also give some valuable inspiration for the rational design of other high-performance thermosetting composites.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2019
·
IF 3.073
Mei-Ling Liu,Jue Wang,Jia-Lin Guo,Tian-Dan Lu,Xue-Li Cao,Shi-Peng Sun
Purification and recovery of polar organic solvents such as dimethylformamide (DMF) with high chemical separation speed and low energy cost nanofiltration membranes has been widely investigated, while it is still a difficult challenge that high permeability of solvents and rejection of solutes are achieved simultaneously. In this study, a novel organic solvent nanofiltration (OSN) membranes was obtained via coating a thin selective graphene oxide (GO) layer on top of the polyimide porous substrate (PI) which was cross-linked to improve the stability in polar solvents. The resultant GO/cross-linked PI (GO/CLPI) composite membranes feature remarkable sieving capability of >94% for RBss molecules (1018 Da), accompanying high pure solvent permeability of 11.1 L h −1 m −2 bar −1 , 4.9 L h −1 m −2 bar −1 and 1.0 L h −1 m −2 bar −1 for water, IPA and DMF, respectively. Different from conventional method of characterization, low field nuclear magnetic resonance technology (LF-NMR) was utilized to confirm that the GO/CLPI membrane shows a higher adsorption capacity for IPA than DMF. This newly technique can be effectively utilized to evaluate the affinity between organic solvents and the surface of membranes.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2019
·
IF 1.584
Yuqi Li,Qiu Zhang,Hong Ruan,Fengan Li,Xu Xu,Xiaohua Huang,Shaorong Lu
To explore the effect of added graphene sheets (GNs) and added perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) on the tribological and mechanical performances of polyimide (PI) matrix, GNs and PTCDA reinforced PI-based composites were synthesized via the blending method. The tribological properties of GNs/PTCDA/PI (GAPI) composites with different weight ratios of GNs and PTCDA under dry sliding, deionized water lubrication, and kerosene lubrication were comparatively investigated. A synergism was found between GNs and PTCDA; this synergism endowed filled PI composites with a lower friction coefficient and showed an improved wear rate under different lubrication conditions, especially when the weight ratio of GNs and PTCDA was 1:1 (GAPI-1). Under dry sliding, deionized water lubrication, and kerosene lubrication, the friction coefficient of GAPI-1 composites decreased by 41.1%, 70%, and 35.7%, respectively, while the wear rate decreased by 39%, 50%, and 25.1%, respectively. Meanwhile, the tensile strength, tensile modulus, and the elongation at break of GAPI-1 films increased by 40.8%, 51.3%, and 49.2%, respectively, relative to those of pure PI. We anticipate that this work can be used to exploit a simple and effective method for preparing materials for bearings and transmission parts that possess good tribological properties under harsh lubrication conditions.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Jun Wang,Hongyan Yao,Chunya Du,Shaowei Guan
Currently, organic electrode materials have shown promising prospects in lithium-ion batteries (LIBs). However, the practical application of organic electrode materials is severely hindered by the intrinsic low electrical conductivity and poor cycle stability. Herein, we present a novel polyimide (NBI-PI) which contains extended π-conjugated naphthalene ring and Schiff-base structure as an anode material . The NBI-PI has abundant active sites and crystallized nature. The organic anode based on NBI-PI for LIBs exhibit good reversible capacity of 627.8 mA h g −1 at 0.25 A g −1 after 200 cycles, and display reasonable rate performance of 217 mA h g −1 at 2 A g −1 . When the batteries are cycled at 2 A g −1 , capacity retention of 85.7% is attained after 1600 electrochemical cycles. This work demonstrates a facile and practical strategy to develop high-performance organic anode materials for lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）