Advanced Materials Interfaces
·
2023
·Vol. 10
·期 7
·2201563
·
IF 5.4
Haonan Li,Libo Wang,Liang Li,Han Li,Yahui Dai,Qianku Hu,Aiguo Zhou,Xuqing Liu
In order to improve the high-temperature friction and wear properties of polyimide (PI), Mo 2 CT x /PI nanocomposite materials are prepared by using 2D Mo 2 CT x MXene as reinforcement. Compared with the properties of pure PI, Mo 2 CT x /PI nanocomposites exhibit significant improvement on thermal stability, hardness, and tribological performance. Especially, the addition of Mo 2 CT x can reduce friction coefficient and wear rate of PI significantly at different temperatures ranging from room temperature (RT) to 200 °C. The hardness and the thermo-degradation temperature of composites increase due to the formation of an organic inorganic structure. In addition, this structure helps to form a protective film containing Mo 2 CT x nanoflakes, iron oxide, molybdenum oxide, and organic compounds during friction, and improve the tribological properties of PI composite.
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高影响因子
ACS Applied Polymer Materials
·
2023
·
IF 5
Jing Li,Jian Lu,Haoqi Sang,Yu Zhang,Benkun Qi,Jianquan Luo,Yinhua Wan,Yongbing Zhuang
Direct separation of lignin from fully acidic deep eutectic solvent (DES) is challenging because of its high viscosity and acidity. In this study, three synthesized DES-resistant polyimides (PIs), namely, B-PI, 6F-PI, and P-PI based on 4′,6-diamidino-2-phenylindole (DAPI) with 4,4′-(4,4′-isopropylidenediphenoxy)bis-(phthalic anhydride) (BPADA), 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and pyromellitic dianhydride (PMDA), respectively, were used to prepare ultrafiltration (UF) membranes for the direct separation of sodium lignosulfonate (LS) from its DES (choline chloride:lactic acid) solutions for the first time. The morphology, pore size, surface property, degree of swelling, LS separation performance, and long-term stability of the resulting UF membranes were investigated in detail. The average pore sizes were in the range of 3.60–5.06 nm, and the LS rejections, as well as the DES fluxes, were 44.0–66.4% and 4.71–16.55 L·m–2 h–1, respectively, both higher than those from commercial ZrO2/TiO2 membrane (25.6% and 1.91 L·m–2 h–1). Among them, the B-PI membrane had the best separation performance and excellent operating stability for 20 h due to its low fractional free volume and poor affinity with DES. Swelling and positive charges of membrane surface in the DES system decreased LS rejection. In addition, a higher degree of swelling and affinity with DES led to an increased DES flux when compared with the aqueous system. Herein the PI-based UF membranes are promising for the direct lignin separation process, especially in an acidic DES system.
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ACS Applied Polymer Materials
·
2022
·
IF 4.855
Sizhao Zhang,Zhao Wang,Jing Wang,Yunyun Xiao,Zhouyuan Yang,Hui Ji,Guangyu Xu,Shixian Xiong,Zhengquan Li,Feng Ding
High performance polyimide aerogels (PIA) are highly desirable as a part of thermal protection systems for aircraft. However, the large drying shrinkage and insufficient thermal insulation of PIA limit their practical applications in the aerospace field. Herein, the strategy of two-step prepolymerization and polycondensation route was proposed to fabricate PIA with ultralow drying shrinkage, outstanding thermal insulation, hydrophobicity, machinability, compressive strength in cryogenic/high-temperature atmospheres, flame resistance, and fantastic dimensional stability. In more detail, the drying shrinkage rate of PIA series can be lowered to 1.84%, mainly owing to the strengthened skeletons by chemical bond formation and physical entanglement of molecular chains. Excellent thermal insulation is reflected upon keeping an ink drop state as long as 265 s despite placing it on a cold surface with a temperature of −196 °C. PIA-O2B2 are imparted with hydrophobic properties (with water contact angle of 135°) depending on the hydrogen-bonding interaction between polyimide networking chains and 1H,1H,2H,2H-perfluorodecyltriethoxysilane that was introduced. In addition, the exceptional flame retardant is endowed completely, which is attributed to the evidence of the presence of aromatic ring structures in constructing the aerogel. The high-temperature shrinkage rate of PIA series is as low as 4.81% due to the relative small free volume of the molecular chains. Our study would provide a method for designing ultralow drying shrinkage and superb thermal insulation in cryogenic conditions for PIA in aerospace uses.
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ADVANCED POWDER TECHNOLOGY
·
2022
·
IF 4.969
Huabo Huang,Kejia Wu,Ruping Ma,Juan Huang,Xiaoqing Zhang,Liang Li,Yanbo Liu,Chuanxi Xiong
Polyimide is a kind of promising organic-based electrode material for zinc ion batteries (ZIBs), with the merits of resource sustainability, environmental friendliness and structural diversity. At present, however, the study on polyimide-based electrode for ZIBs is fairly few, and the limited conductivity and capacity are also needed to be overcome. Here, a polyimide cathode material denoted as PUI is synthesized by using perylene-3,4,9,10-tetracarboxylic dianhydride and urea, and the zinc-storage performance is comprehensively optimized by taking advantage of a 3-D porous polyaniline (PANI) xerogel carrier, for instance, the specific capacity of PUI/PANI composite is 72 % higher than that of PUI, and the rate performance and cycling stability are both improved as well. The analysis of electrochemical kinetics reveals that the 3-D porous PANI can facilitate fast electron/ion transportation and high capacitive contribution during discharging and charging. Moreover, the mechanism analysis demonstrates the synergistically enhanced zinc-storage capacity of C O (in PUI) and N (in PANI) in PUI/PANI. This work promotes the application potential of polyimide-based cathode materials, and also highlights the valuable role of porous conducting polymer ( e.g. , PANI) in constructing high-performance cathode materials for ZIBs.
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ACS Applied Polymer Materials
·
2022
·
IF 4.855
Lu Yu,Han Zhang,Fang Yu,Yibo Liu,Luna Jia,Weiran Zhao,Pan Li,Hao Wang,Pengfei Zhu,Bo Li
Developing adsorption materials for organic solvents with both high adsorption capacity and recyclability provides a broad prospect for contaminated water treatment. In this study, PI/SiO2 composite nanofibrous sponges with hydrophobicity, high oil adsorption capacity, and excellent cycling performance fabricated by blow spinning have been reported. The improvement of hydrophobicity of PISi-3 was credited to the SiO2 nanoparticles, resulting in excellent oil adsorption capacity (103.95 g/g for ethanol, 320.99 g/g for motor oil, and 386.81 g/g for silicone oil). The recyclability after 10 cycles of PISi-3 was improved by 23% compared with the pure PI sponge owing to the supporting effect of SiO2 nanoparticles. Sponges with higher cycling performance could be obtained by regulating the temperatures of thermal treatment. PISi-3 after heat treatment at 450 °C exhibited good oil adsorption ability (98.12 g/g for ethanol, 261.92 g/g for motor oil, and 315.81 g/g for silicone oil) and excellent cycling performance. The adsorption capacity decreased by only 0.22% after 10 cycles. Therefore, the fabrication strategy of the sponges has great prospects in maritime oil spill recycling and industrial water treatment.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 44
·e53103
·
IF 3.057
Hao Xing,Yanyu Mao,Yang Yang,Chunyan Qu,Dezhi Wang,Xupeng Fan,Liwei Zhao,Dongpeng Zhou,Changwei Liu
In response to the theme of environmental protection and green development in the world in the recent years, waterborne epoxy resin has received more and more attention. Waterborne epoxy resin has lower toxicity, but its low toughness limits the application range of waterborne epoxy resin. Here, we first proposed a method of toughening waterborne epoxy resin with aqueous polyamide salt solution. In this article, a series of waterborne polyamic acid salts is used as modification polymer to improve the high-temperature resistance and other properties of waterborne epoxy resins by copolymerization modification. Waterborne polyamic acid salt is dispersed uniformly in the epoxy resin. After curing, by compared with the pure epoxy resin, a semi-interpenetrating network is formed, the cross-linking density and the high-temperature resistance of the material are increased, and the glass transition temperature increases from 105°C to 116°C. The storage modulus at 300°C increases from 6.15 to 15.76 MPa. Thermogravimetric Analysis results reveal that the corresponding temperatures of 5% and 10% weight loss increase from 403°C and 419°C to 415°C and 435°C, respectively. At the same time, the toughness of the imide chain segment and polar groups lead to the improved adhesion of the epoxy system, the peeling strength increase from 0.51 to 1.24 N cm −1 , and the lap shear strength at high temperature (100°C) increase from 0.58 to 16.97 MPa. The water absorption decreases from 1.51% to 0.66%. The developed waterborne epoxy resin is expected to be used as a high-temperature waterborne epoxy coating in high-temperature coatings and other applications.
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EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Feng Gan,Senjie Jiang,Jinli Zhou,Junkang Wang,Jiaxiang Wen,Jinpeng Mo,Shaobo Han,Longfei Fan,Ningbo Yi,Yancheng Wu
Polyimide-based nanofiltration membranes (NF) featuring customizable chemical structure and outstanding comprehensive performance have garnered tremendous interest for potential applications in ions rejection. Coordinated interactions can build supramolecular networks in polyimide that reshuffle phase separation behavior during membrane formation, thus conferring microstructural flexibility to nanofiltration membranes. In this paper, novel nanofiltration membranes were prepared by constructing dual coordination interactions in polyimide, and the structures were confirmed by NMR, FTIR, EDX, and XPS analyses. As expected, the skin and supporting layers of the PI-based NF membranes can be controlled by designing coordination conditions during membrane formation. A promising result is that the resulted NF membranes occur higher reject of metal ions than the pristine membranes prepared by conventional non-solvent induced phase separation methods. The optimized performance showed significantly higher permeability for removing Mg 2+ ions, giving water permeance of 477.7 L m −2 h −1 ·bar −1 and a rejection of over 80%. Moreover, the resulted PI-based NF membranes occur better solvent resistance than the pristine NF membranes due to the enhanced coordination structures. As a preliminary study, this work gives a new strategy to regulate the microstructure of nanofiltration membranes, promising further potential for applications in ion removal.
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HIGH PERFORMANCE POLYMERS
·
2022
·
IF 1.73
Hongge Jia,Shijun Zhao,Pengfei Jiang,Boyu Jing,Guoxing Yang,Shuangping Xu,Mingyu Zhang,Yanqing Qu,Yonglan Zou
A set of ionic liquid capped polyimide membranes was prepared using 1-aminoethyl-3-methylimidazolium hexafluorophosphate (IL1) and 1-aminopropylimidazolium bis(trifluoromethylsulfonyl)imine (IL2) as the terminal groups. The products’ molecular weights, mechanical properties, and separation permeability (CO2/CH4) were investigated. For CO2/CH4 separation, the selectivity of the ionic liquid capped polyimide membranes was higher than that of noncapped ones. Among them, the membrane synthesized by 4.4′- diaminodiphenyl ether and 4.4′-(hexafluoroisopropyl) diphthalic anhydride (6FDA) as monomer, with IL1 as terminal group, displayed the best selectivity. Its permeability was 7.47 Barrer and selectivity 102.42, which exceeded the 1991 Robeson curve. Polyimide membranes capped by ionic liquid showed high gas selectivity and good gas permeability as well as good physical and chemical properties. Consequently, it can be concluded that introducing an ionic liquid structure to polyimide chains could make attractive membrane materials for various gas separation and related applications.
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Advanced Fiber Materials
·
2022
·Vol. 4
·期 5
·1118-1128
·
IF 12.958
Xue Tiantian,Zhu Chenyu,Feng Xueling,Wali Qamar,Fan Wei,Liu Tianxi
Application of aerogel fibers in thermal insulating garments have sparked a substantial interest. However, achieving a high porosity and low thermal conductivity for aerogel fibers remain challenging, despite the innovative designs of porous structure. Herein, we fabricated lightweight and super-thermal insulating polyimide (PI) aerogel fibers via freeze-spinning by using polyvinyl alcohol (PVA) as a pore regulator. The high affinity of PVA with water enables it to accelerate the ice crystal nucleation, adjust pore formation, and construct a controllable porous structure of PI aerogel fiber. The as-fabricated PI aerogel fiber has a considerable reduced pore size, high porosity (95.6%), improved flexibility and mechanical strength, and can be woven into fabrics. The PI aerogel fabric exhibits low thermal conductivity and excellent thermal insulation in a wide range of temperature (from − 196 to 300 °C). Furthermore, the PI aerogel fabrics can be easily functionalized to expand their applications, such as in intelligent temperature regulation and photothermal conversion. These results demonstrate that the aerogel fibers/fabric are promising materials for next-generation textile materials for personal thermal management. Graphical abstract
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JOURNAL OF POLYMER RESEARCH
·
2022
·Vol. 29
·期 6
·1-11
·
IF 3.061
Deng Wei,Qu Kexin,Yang Meng,Li Guoan,Ren Yichen,Cui Weiwei
As the development of integrated and flexible devices, polymer-based composites with simultaneously improved thermal conductivity, breakdown strength and mechanical properties have become urgent demands. In this study, tetrabutylammonium bromide modified graphene oxide (TGO) is utilized to fabricate the electrospun TGO/polyimide fiber membranes (E-TGO/PI), and then impregnated in polyamic acid (PAA) glue and performed thermal imidization to obtain the impregnated TGO/PI composite films (I-TGO/PI). The thermal conductivity almost linearly increases with the increasing of TGO content, and the 1wt%I-TGO/PI composite materials achieve a thermal conductivity of 0.499 W/mK and a breakdown strength of 124 kV/mm, with 16% and 311% enhancement compared to the corresponding 1wt%E-TGO/PI without impregnation. Meanwhile, the tensile strength and elongation at break of 1wt%I-TGO/PI increase by over 4 times than the pristine E-PI. Besides, the dielectric permittivity and dielectric loss of I-TGO/PI composite materials maintain at relatively low value throughout. The present work demonstrates that the combination of electrospinning and impregnation is an efficient strategy to improve the comprehensive properties of polymer composites for thermal management applications.
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ACS Applied Polymer Materials
·
2022
·
IF 4.855
Qinghong Zhai,Jingwen Yang,Wei Qiao,Jiaxiao Qiao,Hejun Gao,Zexia Li,Peng Wang,Chengchun Tang,Yanming Xue
The application of highly superelastic foamlike materials has gradually expanded to various high-end areas, such as filtration purification, mechanical power generation, and energy storage, showing their considerable and expected prospects. In this paper, facile freeze-drying technology combined with a gradual thermal-imidization process was employed to prepare a series of boron nitride nanosheet (BNNS)-filled polyimide (PI) composite foams. These foams can exhibit excellent mechanical properties, including their cyclic stability for considerable cycles under long compressive loading–unloading processes, and their relatively low irreversible deformation. After 10000 cycles at the compression strain of 60%, the total strain loss of the composite filled with 12 wt % is only 14%, which is 2/3 that of pure PI foam. Based on these excellent mechanical characteristics, the foam composites exhibit well a compression-driven triboelectric performance. The effects of BNNS content, compression strain, and rate on the triboelectric properties of the composites were studied in detail. We found that a higher compression strain and compression rate will lead to stronger electrical signals. More significantly, on the basis of the one-to-one relationship between electrical signal and compressive deformation, BNNSs/PI foam will likely be used in the field of control sensing. Finally, the electrical generation device based on composites was used in an insole and keyboard to transform mechanical energy generated by human movement into electrical signals.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Zan Chen,Zongping Hong,Hong Wu,Cheng Li,Zhongyi Jiang
Hybrid membranes based on the Tröger’s base polyimide (PI-TB) as a rigid microporous polymer matrix containing a kinked N-heterocycle and a kind of CO2-philic porous UiO-66-NH2 nano-filler were successfully fabricated for gas separation. This new hybrid membrane exhibits good interfacial compatibility through hydrogen bonds and charge transfer interactions between the PI-TB matrix and the UiO-66-NH2 nano-filler, thus enabling a relatively high loading and well dispersion of nano-filler. Meanwhile, the as-synthesized UiO-66-NH2 nanoparticles increase the average inter-chain spacing distance of PI-TB by interfering with the packing of polymer chains and thus providing additional transport pathways in the membranes. The pure gas permeabilities and ideal selectivities for CO2/CH4, CO2/N2, and O2/N2 systems were investigated at 35 °C and a feed pressure of 1 bar. Among them, the hybrid membrane containing 30 wt % UiO-66-NH2 exhibits the optimal gas separation performance with enhanced permeabilities of CO2 and O2 increased by ∼166% (415 and 92.3 Barrer, respectively) while maintaining comparable CO2/CH4, CO2/N2, and O2/N2 gas pair selectivities (25.0, 18.9, and 4.2, respectively) with the pristine PI-TB membrane. This work enriched the studies on the post-modification of PI-TB as a potential candidate membrane material for gas separation.
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