JOURNAL OF APPLIED POLYMER SCIENCE
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2022
·Vol. 139
·期 44
·e53103
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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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高影响因子
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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IET Nanodielectrics
·
2022
·Vol. 6
·期 3
·76-85
·
IF 0
Xiaodi Dong,Baoquan Wan,Lin Qiu,Ming-Sheng Zheng,Jiefeng Gao,Jun-Wei Zha
A series of high-performance linear and cross-linked polyimide (PI) aerogels with different molecular structures have been successfully synthesised using the freeze-drying process. In this study, the comprehensive regulation of microstructure, thermodynamic, thermal insulation and dielectric properties of PI aerogels are achieved by controlling the rigid/flexible structure and composition of polymerised monomers. The increase in rigidity of PI molecular structure could promote the formation of denser pores, which is beneficial to improve the thermodynamic and thermal insulation properties of aerogels. Notably, the cross-linked PI aerogel prepared by introducing cross-linking agent (tris(4-aminophenyl) amine, [TPA]) into linear PI exhibits high thermal stability ( T d 5% > 560°C), excellent ultralow permittivity ( ε r = 1.31, f = 10 6 Hz) and good thermal insulation property ( k = 0.056 W/m · K). This innovative strategy promotes the wider application of the cross-linked polyimide aerogel in the field of integrated circuits and aerospace exploration.
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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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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 Flow Chemistry
·
2022
·Vol. 12
·期 1
·91-100
·
IF 3.264
Xu Wenhua,Pan Yizhe,Chen Liuyang,Su Yuanhai,Shang Minjing,Lu Xuemin,Lu Qinghua
The combination of continuous-flow microreactors and photoreaction is one of the important researches in flow chemistry. Dimethyl-substituted cyclobutanetetracarboxylic dianhydride (DM-CBDA) was prepared through photodimerization in photomicroreactors and applied in the preparation of polyimide films. It was found that ethyl acetate as the solvent and an appropriate concentration of substrate could benefit this photodimerization process in the capillary photomicroreactor. Higher photonic efficiency and higher DM-CBDA yield were obtained in the photomicroreactor as compared to batch photoreactors. DM-CBDA was applied to prepare the colorless transparent polyimide films, which showed a high polymerization activity for the preparation of poly(amic acid) with high molecular weight. A PI film of DM-CBDA/ODA with the UV cutoff wavelength of 295 nm, the glass transition temperature of 376 °C, and the elongation at break of 11.3% was prepared. This work broadens the application of photomicroreactors for the preparation of polyimide monomers in flow chemistry and its films with good transparent, thermal and mechanical properties.
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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 POWER SOURCES
·
2022
·
IF 9.794
Xiang Li,Jianwei He,Yucong Liao,Shaoshan Zhu,Yayun Tang,Hanyang Li,Ning Lv,Yuexin Xu,Yadong Wang
Herein, a conjugate carbonyl polyimide (MF-PI) and nano-silicon composite (MF-PI/Si) is designed and synthesized through a simple one-pot method to confront rapid capacity fading and complicated electrode material preparation in silicon-based electrodes for lithium ion battery . This composite can be directly used to prepare electrode without the need of further adding of binding materials. In this composite, MF-PI acts as binder for powder electrode, active reversible lithiation material, buffering media to alleviate volume change of silicon particles, and coating shell to avoid the direct contact between silicon particles and electrolyte. These functions from MF-PI collectively assigned the MF-PI/Si composite anode material a relative high specific capacity and excellent cycling stability. The electrode prepared by this as-synthesized MF-PI/Si shows preferable electrochemical interface and surface area, further enhancing the electrode kinetics and then electrochemical performance. The improved ionic and electronic conductivity compared to other binder materials also contributes the excellent performance.
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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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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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高影响因子
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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高影响因子
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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