ACS Applied Polymer Materials
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2025
·
IF 4.7
Huifa Meng,Kaijin Chen,Chuying Li,Yanwei He,Zihao Huang,Haitao Huang,Zhenguo Chi,Siwei Liu,Yi Zhang
The use of traditional photosensitive polyimide (PSPI) insulating materials, which possess high coefficients of thermal expansion (CTE) and poor adhesion to copper, easily causes failure issues in the redistribution layers (RDLs). However, there are some trade-offs in the design of the low-CTE PSPI materials such as the ultraviolet (UV) transmittance of the precursors and the dielectric properties of the films. To overcome the above challenges, an AB2-type fluorinated monoamine (ETFPh-NH2) with a nonplanar steric structure was designed and synthesized, which was then used as an end-capper attached to poly(amic ester) (PAE) with a linear/stiff structure. The PSPI solutions were then developed by using the as-prepared PAE resins, solvents, and other additives. Despite the presence of ETFPh-NH2 with a relatively low molar ratio to the total precursor chains, the transparency of the PAE-4 was notably enhanced, resulting in the achievement of the high-resolution lithographic pattern. Meanwhile, the PI-4 film exhibited low-CTE characteristics (23.65 ppm K–1), and its mechanical and low dielectric properties were enhanced by the microbranched cross-link structure, which was constructed by the reaction of the arylethynyl groups during the imidization process. Furthermore, the adhesion between the PI films and Cu was significantly improved by introducing the aromatic silane (TMS). In short, PI-4, which exhibited high-dimensional stability, strong adhesion with Cu, and photopatternable capabilities, could be a feasible and reliable material for use in advanced packaging. In addition, the developed end-groups modification strategy seems to be an effective way to greatly improve the overall performance of PSPI materials.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yutao Hao,Daomin Min,Ziwei Gao,Di Zhang,Jinghui Gao,Yongbin Liu
Electric vehicles and renewable energy consumption have huge demands for high-performance polymer dielectric capacitors. However, the resistivity and breakdown strength of existing polymer dielectrics deteriorate significantly at high temperatures, reducing the energy storage density and charge-discharge efficiency of capacitors below service requirements. The charge transport and molecular chain motion characteristics in linear polymers determine their conductivity, breakdown, and energy storage properties, but the quantitative relationship between them is not clear. An in-situ polymerization method was used to prepare polyimide/Al 2 O 3 nanocomposites (PI/Al 2 O 3 PNCs). Experimental results show that the resistivity, breakdown strength, energy storage density, and charge-discharge efficiency of PNCs increase initially and then decrease with increasing doping content, peaking at 3 wt%. The discharged energy density of PI/Al 2 O 3 -3 wt% PNCs at 180°C is 207.52 % higher than pure PI. A conductance-breakdown-energy storage co-simulation model based on charge transport and molecular chain displacement was used to simulate the voltage-current, breakdown, and energy storage characteristics of PNCs. The simulation results are consistent with the experiments. Comparative studies between simulation and experiments show that the independent interface zone between nanofillers and PI hinders charge transport and molecular chain movement, reducing electric field distortion and molecular chain spacing, thereby improving high-temperature breakdown and energy storage performance of PNCs.
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POLYMER ENGINEERING AND SCIENCE
·
2025
·
IF 3.2
Lu Shen,Xinyue Jiang,Long Ni,Yinfu Luo,Mei Liang,Yunhua Yang,Shengtai Zhou,Huawei Zou
With the rapid development of science and technology, there is an increasing demand for lightweight materials with excellent electromagnetic interference (EMI) shielding and infrared stealth performance for space applications. In this study, a series of polyimide/silica (PI/SiO 2 ) aerogels were fabricated by blending, which were dried using supercritical CO 2 drying method. Then, PI/SiO 2 composite aerogels were carbonized to prepare carbon aerogels with superior thermal insulation and EMI shielding properties. The carbonized PI/SiO 2 aerogels contained mesopores which enhanced the interfacial thermal resistance and improved the thermal insulation performance by 69% when compared with those samples without SiO 2 . The presence of mesopores adjusted the impedance matching of carbon aerogels, which allowed more EM waves to enter inside of the aerogels and dissipate through multiple reflections, thereby achieving absorption-dominant EMI shielding performance. This study proposed a viable approach to preparing PI-based carbon aerogels with excellent infrared stealth and EMI shielding performance, which show promising applications in aerospace and related industries. Highlights The introduction of SiO 2 regulated the microstructure of carbon aerogels. The thermal conductivity of carbon aerogels reached as low as 0.10 W/mK with 3 wt% SiO 2 . The EMI performance of carbon aerogel was enhanced from 22.4 to 33.5 dB.
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ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Xin'ao Li,Yumeng Zong,Wenjuan Li,Jin Qian,Zhe Qiang,Changhuai Ye,Meifang Zhu
Transparent polymer nanofoams offer significant potential for thermal insulation, particularly for energy-saving windows, where both transparency and low thermal conductivity are crucial. However, grand challenges remain in preparing polymer nanofoam monoliths with pore sizes smaller than 40 nm to achieve high optical transparency via minimized light scattering. Herein, the preparation of highly transparent nanofoam monoliths based on fluorinated polyimide (FPI) using CO 2 foaming is reported for the first time. The high CO 2 absorption capacity and robust melt strength of the FPI matrix significantly promote bubble nucleation while minimizing cell coalescence during CO 2 foaming process, resulting in ultra-small pore sizes down to sub-10 nm. These FPI nanofoams, with a thickness of ≈0.2 mm, can exhibit high optical transmittance (>85% in the wavelength range of 500–700 nm) and low haze (≈18%), which is unprecedented for polymer foams prepared using foaming methods. Furthermore, these FPI nanofoams demonstrate superior mechanical and thermal insulation properties compared to micron-sized FPI foams and maintain remarkable mechanical flexibility and structural stability even under harsh conditions, including extreme temperatures and water exposure. Transparent nanofoams prepared using a scalable CO 2 foaming method can serve as the next-generation thermal insulation materials, with broad potential applications in energy-efficient buildings, and aerospace.
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Nanomaterials
·
2024
·Vol. 14
·期 17
·1388
·
IF 4.4
Tian Zhou,Yu Yuan,Luyi Xiao,Wei Ding,Yong Wang,Li-Ping Lv
Redox-active porous organic polymers (POPs) demonstrate significant potential in supercapacitors. However, their intrinsic low electrical conductivity and stacking tendencies often lead to low utilization rates of redox-active sites within their structural units. Herein, polyimide POPs (donated as PMTA) are synthesized in situ on multi-walled carbon nanotubes (MWCNTs) from tetramino-benzoquinone (TABQ) and 1,4,5,8-naphthalene tetracarboxylic dianhydride (PMDA) monomers. The strong π–π stacking interactions drive the PMTA POPs and the MWCNTs together to form a PMTA/MWCNT composite. With the assistance of MWCNTs, the stacking issue and low conductivity of PMTA POPs are well addressed, leading to the obvious activation and enhanced utilization of the redox-active groups in the PMTA POPs. PMTA/MWCNT then achieves a high capacitance of 375.2 F g−1at 1 A g−1as compared to the pristine PMTA POPs (5.7 F g−1) and excellent cycling stability of 89.7% after 8000 cycles at 5 A g−1. Cyclic voltammetry (CV) and in situ Fourier-Transform Infrared (FT-IR) results reveal that the electrode reactions involve the reversible structural evolution of carbonyl groups, which are activated to provide rich pseudocapacitance. Asymmetric supercapacitors (ASCs) assembled with PMTA/MWCNTs and activated carbon (AC) offer a high energy density of 15.4 Wh kg−1at 980.4 W kg−1and maintain a capacitance retention of 125% after 10,000 cycles at 5 A g−1, indicating their good potential for practical applications.
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PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2010
·Vol. 211
·期 6
·698-705
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IF 2.57
Shaozhong Zeng,Limin Guo,Fangming Cui,Zhe Gao,Jian Zhou,Jianlin Shi
Crystalline-branched supramolecular structures (CBSSs) with surface area (Brunauer-Emmett-Teller model) up to 350 m 2 · g −1 were synthesized by in situ self-assembly of the zigzag polyimide macromolecules under solvent-thermal condition. The pore formation mechanism in these polyimides was supposed to be different from any microporous polymers ever reported. Although this family of porous polyimide does not belong to covalent organic frameworks (COFs), their high degree of crystallinity shows the possibilities that the dynamic covalent chemistry for synthesizing COFs could be extended from easily hydrolyzable B O bond to a more stable imido bond. Therefore, we believe that these CBSSs could be useful in many applications, e.g., catalyst carriers and low-K materials.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
·
IF 7.7
Jiawei Chen,Kang Ma,Xin Song,Jian Wang,Jianmin Zhang
Polyimide membranes have long been of great interest in the battery industries due to their outstanding thermal stability and flame retardancy. However, the preparation of polyimide membranes with ideal pore structure and excellent lithium-ion transference remains a challenge. In this study, we reported for the first time, that a nano-porous fluorinated and partially carboxylated polyimide/cellulose composite membrane was successfully synthesized by selected monomers and prepared by thermal imidization, phase separation, and alkaline hydrolysis method. Particularly, an appropriate addition of cellulose acetate (CA) during the synthesis process can optimize the pore structure of the membrane. Besides, CA was converted to cellulose after alkaline hydrolysis, further enhancing the electrolyte affinity and lithium-ion transference of the membrane. Hence, this composite membrane exhibited distinct heat-resistance, high porosity (78 %), electrolyte absorption (344 %), and lithium-ion transfer number (0.84). Most importantly, thanks to the above characteristics of the membrane, the assembled LiFePO 4 /Li cells demonstrated excellent cycling stability compared with the cell with PP membrane, showing a capacity retention rate of as high as 93 % after 500 cycles at 1C. We anticipate that this composite membrane with superior physical and electrochemical properties would shed light on the development of next-generation membranes for high-power and high-safety batteries.
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PubMed
高影响因子
DIAMOND AND RELATED MATERIALS
·
2025
·
IF 5.1
Jintao Huang,Xinfei Zeng,Wentao Yu,Haichen Zhang,Yonggang Min
Electromagnetic wave (EMW) absorption materials play a unique role in both civilian and military domains, hence the creation of high-performance EMW absorbing materials that are “light, thin, broad, and strong” is of significant importance. In this study, we introduced nanoscale nickel metal into the precursor solution during the polymerization phase via in-situ polymerization, and then combined phase separation and high-temperature pyrolysis to prepare polyimide-based porous carbon (PIC)/Ni nano-particles composite (PIC/Ni). The experimental outcomes demonstrate that the introduction of Ni nano-particles, which bring about magnetic loss, has improved the narrow effective absorption bandwidth of the single PIC EMW absorbing material. By controlling the carbonization temperature, it was found that PIC/Ni-700 has a strong capability for EMW loss. Moreover, at a thickness of 4.21 mm, the PIC/Ni-700 exhibits the strongest EMW loss capability at a frequency of 6.16 GHz, recording a minimum reflection loss (RL) of −39.41 dB. PIC/Ni-700 demonstrates effective absorption bandwidth (EABW) of 5.20 GHz (2.0 mm) and 4.16 GHz (2.5 mm), showcasing its characteristic of broadband absorption.
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POLYMER
·
2024
·
IF 4.1
Cuiqing Zhou,Long Ni,Junyu Lu,Haichao Meng,Yinfu Luo,Mei Liang,Huawei Zou
The development of efficient and multifunctional broadband microwave absorption (MA) materials is critical for military applications to cope with complex environments. Herein, polyimide (PI)/carbon nanotube (CNT) composite foams (PCCFs) were successfully fabricated by assembling CNT with PI via the microsphere foaming method, where gradient CNT allowed tunable electromagnetic parameters. Benefiting from the improved the impedance matching characteristics and microwave dissipation, PCCFs displayed a remarkable reflection loss value of −53.5 dB and an EAB that could be extended up to 13.5 GHz through thickness variation, encompassing almost all C, X and Ku bands. Furthermore, the composite foams exhibited outstanding mechanical property with a specific compressive strength up to 6.8 MPa/(g/cm 3 ), as well as low thermal conductivity (0.106 W/(m·K)) and excellent heat resistance, which are important references for the development of high-performance MA structural components for applications in extreme environments.
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高影响因子
POLYMER
·
2024
·
IF 4.1
Zhongli Zhang,Zhensheng Wu,Fan Zou,Fuqiang Tian
Polyimide (PI) refers to a polymer containing an imide ring characteristic structure on the main chain. It has excellent thermal stability, insulation properties and other characteristics. The Tesla transformer is the core component of the primary pulse source of the high-current electron beam accelerator. It is also an essential component of the energy storage pulse power supply. Therefore, it has broad application prospects in the fields of national defense and civil industry. If the insulation performance of the turn-to-turn coils of the Tesla transformer does not meet the standards, it will break down during high-voltage corona discharge, causing transformer failure. Therefore, it is crucial to improve the insulation performance of Tesla transformer inter-turn wrapping materials. The incorporation of fluorine-containing groups has proven to be a transformative strategy that significantly enhances the physical, chemical, optical, and electrical properties of PI films. In addition, numerous studies have demonstrated that introducing inorganic fillers into the polyimide matrix can substantially enhance the insulating properties of polyimide films. This paper specifically concentrates on elevating the insulating and thermal attributes of polyimide. Initially, a range of polyimide films was synthesized for performance assessment by employing various fluorinated dianhydride and diamine components, utilizing them as substrates. Then, we used nano-silicon nitride (nano-Si 3 N 4 ) and nano-alumina (nano-Al 2 O 3 ) as doping phases to prepare PI composite films, which reduced the dielectric constant and increased the breakdown strength.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 37
·e55950
·
IF 2.7
Chen Liu,Boxue Wang,Jin Zhang,Mingpeng Chen,Qingju Liu
Polyimide aerogels are often constrained by the poor mechanical performance when used as thermal insulation. In addition, there is requirement for flame retardant performance in the practical use. In this paper, a fiber-reinforced polyimide aerogel material was prepared by compounding polyisophthaloyl metaphenylene diamine fibers with the aerogel, which present good thermal insulation and excellent mechanical properties, flame retardancy, thermal stability, and certain hydrophobicity, as well as being very lightweight. The compressive strength of the polyimide aerogel was increased from 0.34 to 0.58 MPa by using the fibers as the reinforcing phase; meanwhile, the flame-retardant property was improved, and the limit oxygen index was increased from 33.8 to 36.5. The composite aerogel material has good potential for application in the fields of thermal insulation, building insulation, aerospace, etc.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2024
·
IF 4.1
Zhou Bai-Yang,Ma Ze-Tong,Zhong Shi-Long,Huang Zhen-Jie,Guo Qi,Feng Deng-Chong,Yuan Zhong-Ke,Lu Shao-Lin,Yang Yu-Zhao,Wang Cheng,Yu Ding-Shan,Chen Xu-Dong
The burgeoning growth of the new energy vehicles and aviation industry has escalated the need for energy storage capacitors capable of stable operation in harsh environments. The advent of metal-polyimide complexes has illuminated a novel approach for preparing temperature-resistant capacitors. However, the general application of these metal-polyimide complexes is impeded by the high dielectric loss and low breakdown strength, consequences of main-chain coordination and excessive metal ions content. Herein, our study proposes a novel polyimide-Cu complex material (POP-Cu) predicated on side-chain-type pyridine-Cu coordination, utilizing the structural backbone PMDA-ODA of mature commercial PI (Kapton) with reliable performance. Owing to the high degree of freedom afforded by the side chain with suppressed relaxation activation energy and the long-range electron delocalization formed by d - π coordination, the dielectric constant of this material containing merely 2.7 mol% Cu increases from 3.25 (POPI) to 5.58, while maintaining a remarkably low dielectric loss of 0.0066. Meanwhile, this material exhibits a substantial DC breakdown strength of 436.2 MV·m −1 and a high energy density of 5.42 J·cm −3 , coupled with superior mechanical and thermal properties. Even at 150 °C, it retains over 90% of its room-temperature energy density, demonstrating notable dielectric stability under high temperatures. These attributes underscore its promising application for capacitors operating in harsh environments.
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