CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Haiming Liu,Shihong Chen,Hao-Yang Mi,Yaqiao Wang,Chuntai Liu,Xiangdong Wang
In this study, pyromellitic dianhydride (PMDA) and polyetheramine D230 were used as the primary polymerization monomers, with 2,4,6-triamino pyrimidine (TAP) as a chain extender. By introducing aromatic ring-containing 4,4′-diaminodiphenyl ether (ODA) and precisely controlling its molar ratio with D230, a highly branched, high-temperature-resistant thermoplastic polyimide (TPI), was successfully developed. The optimal thermal imidization temperature was determined to be 250 °C. Incorporating surface-modified short carbon fibers (SCF) via melt blending significantly improved the mechanical properties, with tensile and impact strengths increasing fourfold and sevenfold, respectively, at 10 phr of SCF. TPI foam prepared using supercritical carbon dioxide (scCO 2 ) foaming technology exhibited excellent performance, achieving a regular hexagonal structure, cell sizes of 10.19 μm, and a cell density of 1.68 × 10 10 cells/cm 3 at an ODA to D230 molar ratio of 1:9. The TPI/SCF composite foam, with 3 phr SCF under 20 MPa saturation pressure and 120 °C foaming temperature, achieved a 90 % closed-cell ratio and a 300 % increase in compression strength at the same foam density. Compared to traditional thermoset PI foams, TPI/SCF foam offers smaller cell sizes and higher compression strength, demonstrating significant commercial potential. Backward differentiation shows that TPIF compression is constant at 0.035 ± 0.005 in the [0,0,1] lattice direction. This research provides theoretical and practical insights for preparing high-performance TPI foam for high-temperature applications.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
·
IF 4.9
Yina Zhuge,Haipei Ge,Fujuan Liu
The white-browed penguin can survive in extreme environments due to its unique feather structure. The feather shafts of penguins are porous, separated by the membrane-pore-like structure made of keratin fiber membranes. The feather branches are densely arranged around the feather shafts. This unique structure provides inspiration for researchers. In this work, we developed a simple method to construct polyimide/polysulfone amide (PI/PSA) membrane-pore-like structure nanofibers resembling penguin feather shafts and studied the effects of different low-boiling point solvents (tetrahydrofuran (THF), ethyl acetate (EA), and acetone (AC)) on the morphology, tensile properties, and thermal insulation properties of PI/PSA membrane-pore-like structure nanofibers. Comprehensive characterization was also performed using scanning electron microscope, total reflection infrared spectrometer, X-ray diffractometer, universal testing machine, thermal conductivity meter, pore size analyzer, thermal gravimetric analyzer, infrared thermal imaging instruments, and thermocouple testing instruments. The results showed that when the mass ratio of THF to N, N-dimethylacetamide (DMAC) was 20/80, the prepared PI/PSA membrane-pore-like structure nanofibers exhibited excellent thermal insulation properties, with a low thermal conductivity of 0.0436 W·m −1 ·K −1 , a breaking strength of 7.72 ± 2.64 MPa, and a breaking elongation of 8.19 ± 4.07 %. The biomimetic membrane-pore-like structure with excellent thermal insulation properties is expected to be applied in various fields, such as heat-protective clothing and architectural coatings in harsh environments.
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高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Le Zhang,Enlin Han,Yulun Wu,Xiaodong Wang,Dezhen Wu
The surface decoration of short-cut polyimide (PI) fibers with multi-walled carbon nanotubes (MWCNTs) was performed by fabricating a polydopamine (PDA) coating layer on the fiber surface and then immobilizing MWCNTs onto the coating layer via covalent bonding. This successful surface decoration was confirmed by scanning electron microscopy, X -ray photoelectron spectroscopy, Fourier -transform infrared microscopy and static water contact angle. The application of the surface-decorated PI fibers as reinforcing fibers for reinforcement of polycarbonate (PC)/acrylonitrile–butadiene–styrene copolymer (ABS) alloy was investigated, which indicated that the MWCNTs-decorated PI fibers not only could effectively reinforce the PC/ABS alloy but also generated a significant lightweighting effect on the resulting composites. The maximum mechanical properties were achieved for the composites at a fiber content of 20 wt.% and a fiber length of 3 mm. This significant reinforcement effect is attributed to the enhancement of interaction bonding strength between the fibers and matrix as a result of the surface decoration of PI fibers with MWCNTs. The morphological investigation suggested that fiber rupture was the major energy dissipation mechanism in the tensile and impact failures, whereas fiber debonding and pullout were partly involved in the fracture energy dissipation. In addition, the presence of surface-decorated PI fibers slightly enhanced the thermal stability and load bearing capability of composites. This work can provide a type of high-performance lightweight composite material for automobile and aviation industries.
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ACS Applied Nano Materials
·
2024
·
IF 5.3
Xiaoyan Song,Wanchun Huang,Runbin Ge,Hao Wang,Jinfeng Xing
Conventional polyolefin separators used in lithium-ion batteries face challenges for low porosity, insufficient electrolyte wettability, poor thermal stability, and short circuits caused by dendrite growth. In this work, a unique polyimide/trisilanol isobutyl sesquisiloxane@titanium dioxide fiber separator is prepared by electrospinning and self-assembly, in which polyhedral oligomeric semisiloxane (POSS) serves as a bridge between polyimide (PI) and TiO2. The PI/trisilanollsobutyl (TS)-POSS@TiO2 nanofiber separator with a core–shell structure presenting excellent mechanical strength and electrochemical characteristic effectively inhibits the development of lithium dendrites in lithium-ion batteries. The PI/TS-POSS@TiO2 membrane tensile strength is 17.90 MPa, 152% greater than the pure PI separator tensile strength (7.1 MPa). The lithium-ion battery assembled with a PI/TS-POSS@TiO2 separator has an excellent conductivity of 1.782 mS/cm, which is 92.44% greater than that of a pure PI separator. Its electrochemical stability window also reaches 5.27 V. The lithium-ion battery assembled by the PI/TS-POSS@TiO2 separator exhibits excellent rate performance, cycling stability, and preferable resistance to dendritic penetration. The PI/TS-POSS@TiO2 nanofiber separator has good application prospects in lithium-ion secondary batteries.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhicai Yu,Xueru Qu,Yuhang Wan,Qing Jiang,Yi Qin,Jie Xu,Jinru Liu,Hualing He
Fire warning sensors is crucial to effectively prevent fire accidents in a variety of modes and meet the needs of the connected age. Nevertheless, there is still a formidable challenge in fabricating self-powered fire warning sensors that are flexible and can be integrated in combustible materials. In this work, flexible high-fireproof polyimide (PI)/hydroxyapatite (HAP)/Ag 2 Se composite aerogel fiber (PHA-AF) was fabricated by specific wet spinning technology. The extraordinary thermoelectric effect of Ag 2 Se enabled PHA-AF to achieve precise temperature sensing over a wide temperature range of 100 °C–500 °C. Simultaneously, the PHA-AF-based fire alarm sensor could trigger a fire alarm system in 1.9 s and respond continuously for 14 s under flame attack, while generating output voltage of up to 5.9 mV in self-powered mode. Notably, PI as a flame-retardant material could be formed the 3D networks with HAP, as well as the skeleton support effect provided by Ag 2 Se nanorods enabled PHA-AF based fire alarm sensors with superior breaking tenacity (2.9 MPa), strong heat stability (maximum weight loss rate at 550 °C) and flame retardancy (LOI = 35.8 %), further highlighting its authenticity, repeatability, and reliability in fire. This work offers potential for the preparation of fiber-based self-powered early fire alarm sensors for long-term continuous using in harsh fire environment.
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高影响因子
Journal of Composites Science
·
2024
·Vol. 8
·期 10
·436
·
IF 3
Shujun Han,Yuexin Qi,Xi Ren,Changxu Yang,Zhibin He,Zhenzhong Wang,Duanyi Li,Jingang Liu
Thermoplastic polyimide (PI) matrixes, including PI-a (cc-34ODA) and PI-b (ct-34ODA) were prepared via the hot-pressing procedures of the resins derived from the 3,4′-oxydianiline (34ODA) and two alicyclic dianhydrides of 1S,2R,4S,5R-hydrogenated pyromellitic dianhydride (ccHPMDA) and 1R,2S,4S,5R-hydrogenated pyromellitic dianhydride (ctHPMDA), respectively. The resins exhibited thermoplastic features with good formability at higher temperatures. The afforded semi-alicyclic PI sheets exhibited enhanced properties in comparison to commercially available, wholly aromatic thermoplastic PIs, such as PI-ref1, which are derived from 3,3′,4,4′-oxydiphthalic anhydride (ODPA) and 4,4′-oxydianiline (44ODA), as well as PI-ref2, which is based on pyromellitic dianhydride (PMDA) and 4,4′-bis(3-aminophenoxy)biphenyl (mBAPB). In addition, the developed PI sheets exhibited high heat deflection temperatures (HDT) of 267.4 °C for PI-a and 268.6 °C for PI-b. There values were significantly higher when compared with those of PI-ref1 (Ratem®YS20, HDT: 239.0 °C), PI-ref2 (Aurum®PL450C, HDT: 238.0 °C), PI-ref3 (Ultem®1000, HDT: 206.0 °C), PI-ref4 (Therplim®TO65, HDT: 180.0 °C), and PI-ref5 based on phthalic anhydride-terminated fluorinated PIs (HDT: 215.0 °C). In terms of mechanical properties, the current PI sheets showed superior flexural properties among the polymers with the flexural strength of 189.0 ± 11.7 MPa (PI-a) and 200.5 ± 4.2 MPa (PI-b), respectively. In addition, the PI sheets exhibited comparable compression properties, inferior impact strength, and tensile properties compared with the referenced PI counterparts. Basically, the PI-b sheet showed better comprehensive properties than those of the stereoisomeric PI-a analog.
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高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2024
·
IF 8.1
Xiaofei Wang,Yang He,Xinli Xiao,Yanju Liu,Jinsong Leng
Shape memory polymer (SMP) is a type of smart materials mostly working below 200 ℃, which is difficult to be applied in the ultra-high temperature, even 1000 ℃. Herein, we have prepared shape memory polyimide composites (SMPIC) inspired by nacre “brick-and-mortar” layered structure. The SMPIC has the flame-retardant grade of V0 and the limiting oxygen index of 53.1% when the flame retardants amount is 20%. Besides, it has excellent resistance to high temperature airflow erosion, and the mass ablation ratio is 0.0053 g/s. After rapid thermal processing at 1000 ℃, the mechanical strength is 100 MPa, and the strength retention ratio is 103.3%. Also, the simple actuator can overturn iron blocks that are more than 8 times of its own weight, thus, the smart composite has huge application prospects in the high temperature environment, such as active morphing re-entry parachute, which provides reference for lightweight smart structures.
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高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Wang Zhan,Lingling Tang,Zhiyuan Xu,Le Chen,Lixia Li,Ru Zhou,Mingyi Chen,Qinghong Kong,Juncheng Jiang
Gelatin (GA) was used as a reinforced material in the study to enhance the thermal-mechanical properties of the polyimide (PI) aerogel. The effects of the content and the freezing rate on the thermal-mechanical properties of the composite aerogels were investigated. The internal structure and chemical composition of the composite aerogels were analyzed by using characterization methods. Finally, the mechanism of enhancement of thermal-mechanical of the composite aerogels is further discussed. The results show that GA can effectively enhance the thermal-mechanical properties of PI aerogel, and the appropriate freezing rate can form a dense pore structure inside the composite aerogel to reduce the thermal conductivity and improve the mechanical property. Moreover, the thermal runaway protection result demonstrated that the composite aerogel significantly delayed the time of thermal runaway of the lithium battery.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Jiancheng Sun,Chi Zhang,Rubing Zhang
Conventional rigid patch antennas, constrained by high-permittivity substrates ( ε r > 3.0) with severe dielectric loss ( tanδ > 0.02), suffer from catastrophic performance degradation at elevated frequencies (>3 GHz) and inherent inflexibility that fundamentally prohibits their integration in wearable electronics. This work presents a breakthrough in synthesizing PMMA-reinforced polyimide aerogels (PIAs) via a 10-min ambient pressure drying (APD) strategy, enabling tunable porosity (>90%) and ultra-low dielectric constants ( ε r = 1.35, tanδ < 0.01). The incorporation of PMMA into the PI matrix endows the aerogel skeleton with outstanding mechanical resilience (tensile strength of 7.2 MPa and fracture energy of 45.8 kJ/m 2 ), while effectively suppressing capillary-induced shrinkage to below 2.1% during solvent evaporation. The synergistic interplay between PMMA encapsulation and APD-optimized solvent exchange yields a hierarchical nanoporous structure (30 nm average pore size) with exceptional thermal insulation (0.036 W/m·K). When deployed as a substrate for flexible Sub-6 GHz patch antennas, the aerogel exhibits 106% gain enhancement (9.92 dBi) and broad impedance bandwidth (3.862–3.941 GHz), outperforming conventional FR-4 substrates. This work establishes a scalable, low-cost paradigm for multifunctional aerogels in wearable electronics and high-frequency communication systems.
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高影响因子
COMPOSITES PART B-ENGINEERING
·
2024
·
IF 12.7
Xinjie Ma,Chaohua Peng,Longying Zhao,An Huang,Mengting Wei,Conghui Yuan,Yiting Xu,Birong Zeng,Guorong Chen,Weiang Luo,Lizong Dai
With the rapid development of next-generation optoelectronic devices, there is urgent demand for transparent and highly thermal conductive polymer film materials exhibiting superior performance. However, achieving a balance among these diverse properties remains a significant challenge. In this study, we propose a solution to this dilemma by introducing AlOOH nanowires into colorless polyimide (CPI) films. AlOOH/CPI composite films were prepared using a blade coating strategy. Remarkably, the in-plane arrangement of AlOOH nanowires within the CPI matrix facilitates the formation of thermal conductivity pathways. The resulting optimized composite film demonstrates a substantially higher in-plane thermal conductivity (3.568 W m −1 K −1 ) compared to pure CPI (0.626 W m −1 K −1 ), representing a more than fivefold increase. And the through-plane thermal conductivity showed a marginal enhancement. Moreover, due to the smaller length of the AlOOH nanowires (100 nm) in comparison to the wavelength of visible light, 10 wt% AlOOH/CPI composite film maintains a high transparency of 86.7 %, which is only 2.7 % lower than that of the pure CPI film. Besides, the formation of hydrogen bonds between AlOOH nanowires and the CPI matrix enhances the mechanical properties and dimensional stability of the AlOOH/CPI composite film. The Young's modulus (3.1 GPa) increases to 148 % of the original, while the thermal expansion coefficient (33.7 ppm °C −1 ) decreases to 73 % of the original value. Furthermore, AlOOH/CPI composite films exhibit excellent flexibility, chemical stability, flame retardancy, and electrical insulation property. These remarkable properties render AlOOH/CPI composite films highly promising for application in advanced optoelectronic devices. This study offers valuable insights into the preparation of CPI-based composite films with excellent comprehensive properties.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 21
·9319-9332
·
IF 3.5
Sun He,Wang Cheng,Zhang Xiao,Wang Fengwei
Copper clad laminates (CCLs) with low dielectric constants and dielectric losses are preferred for high-frequency and high-speed printed circuit boards (PCBs). However, the dielectric interlayer of CCLs with improved thermal and electrical performances still requires further exploration. Single component such as polymers or ceramics can hardly meet the developing needs of advanced CCLs. Thus, incorporation of functional nanofillers with polymer resins has been considered as an effective solution. However, chemical or physical modifications are generally conducted for the nanofillers, which is harmful and complex for the fabrication of CCLs. In this work, crystalline polyimide bond-linked covalent organic frameworks (PI-COFs) nanoparticles (NPs) with porous structures have been prepared. Due to the organic nature and preferable particles size, PI-COFs NPs show improved compatibility with epoxy resin (ER). Decreased viscosity, increased settle ability, and improved film-forming capability can be achieved with suitable additive amount of PI-COFs NPs. Due to their high thermal stability and intrinsic low dielectric property, the PI-COFs have been introduced as nanofillers for CCLs. The thermal decomposition temperatures ( T d ) and glass transition temperatures ( T g ) can be improved, while the thermal conductivities show a decreased trend. A lowered dielectric constant of 5.52 with a dielectric loss of 0.00328 can be achieved at 1 MHz for 10 wt% PI-COFs filled CCLs. Higher electrical conductivities and Q factors can be obtained with the addition of PI-COFs NPs. Moreover, the PI-COFs-filled CCLs show improved signal integrity (SI) performances with reduced resonance peaks of insertion loss (IL, S 21 ) and reduced return loss (RL, S 11 ) values. The power integrity (PI) performances of PI-COFs-filled CCLs show reduced filtering effects due to the decreased dielectric properties. Considering the diversity of chemical compositions and porous structures of COFs, their application as resin-compatible nanofillers may provide a new avenue toward advanced high-frequency and high-speed CCLs. Graphical Abstract
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Nano-Micro Letters
·
2025
·Vol. 17
·期 1
·1-28
·
IF 36.3
Shi Tao,Gao Xing,Liu Huan,Wang Xiaodong
A “five-in-one” multifunctional phase-change composite is developed for magnetothermal, electrothermal, solar-thermal, and thermoelectric energy conversion and electromagnetic shielding applications.
The developed composite is based on an innovative combination of carbonized polyimide/Kevlar/graphene oxide@ZIF-67 complex aerogel as a supporting material and paraffin wax as a phase-change material.
The developed composite exhibits excellent solar-thermal, thermoelectric, electrothermal, and magnetothermal energy conversion performance along with high electromagnetic interference shielding effectiveness.
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高影响因子
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