JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 9
·49911
·
IF 2.52
Jian-Ni Liu,Da-Yong Wu,Wei-Hua Liang,Jian-Hua Cao
Achieving excellent thermal stability, good mechanical strength, and low-density in one product, is a big challenge in the design and synthesis of polyimide (PI) foams. We selected a rigid diamine monomer, 2-(4-aminophenyl)-5-aminobenzoxazole (DAPBO) to partially replace 4,4′-oxydianiline (ODA) in BTDA-ODA system, and studied the effect on properties of foamed PI products. With various molar ratio between DABPO and ODA (0:5, 1:4, 2:3, 3:2, 4:1, 5:0), the diamine(s) polymerized with 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and produced six PI precursors (PAE-0 ~ PAE-5). After foaming and thermal imidization, corresponding PI foams (PI-0 ~ PI-5) prepared. Among them, PI-3 has a glass transition temperature of 386°C, which is 95°C higher than PI-0, and its compressive strength reaches 1.32 MPa. Moreover, PI-3 has a uniform cell structure with an average pore size of ~200 μm. The analysis results show that PI-3 is in a transition state from amorphous to partial crystalline, maintaining a balance between flexibility and rigidity. The addition of DABPO not only increases the rigidity of polymer molecular segments, but also introduces N and O atoms that can form intermolecular hydrogen bonds between molecules, which increases the packing density and arrangement regularity of polymer molecules.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 39
·51007
·
IF 3.125
Qian Chen,Xiao Feng Cui,Wen Jiang Zheng,Wei Zou,Yanli Li,Jie Yan,Hu Yang,Fan Yang,Hai Bo Zhang
Hydrogels containing a large amount of water have been widely studied as fireproof materials. However, the organic networks that composed the gel easily burns as water evaporates. In this work, the widely used intumescent flame-retardant ammonium polyphosphate was modified by carbon–carbon double bonds (abbreviated as MAPP) and introduced in alginate/poly (acrylamide-co-stearyl methacrylate) [alginate/P(AAm- co -SMA)] hydrogel by free radical polymerization. The resultant MAPP@alginate/P(AAm- co -SMA) hydrogels show good mechanical strength of 650 kPa and healing efficiency of 80%. Thermal analysis and thermal protective performance tests indicate that the MAPP particles improve the thermal stability and heat resistance of gel. The fireproof test shows that the MAPP@alginate/P(AAm- co -SMA) gel composite shows twice of fire proof time over the pure hydrogels.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 5
·1953-1958
·
IF 3.269
Yulu Zhang,Jin Wang,Yong Wei,Xuetong Zhang
Molecular bridged silica aerogels have received extensive interest in recent years due to their easily controlled mechanical properties varying with different organosilane precursors, and without any further post-modification. In this work, a series of novel and robust molecular bridged silica aerogels were prepared by using a symmetrical urethane-bridged monomer, named N,N-bis(propyltriethoxysilyl)carbamide (bPTSCA), which was synthesized via a solvent-free exothermic reaction between 3-isocyanatopropyltriethoxysilane (IPTES) and 3-aminopropyltriethoxysilane (APTES) for several minutes at normal temperature and pressure. The influence of catalysts on the obtained gels and aerogels was studied in detail. It was found that NH4F aqueous solution showed the most effective catalysis capability, and the corresponding aerogels were intact with slight shrinkages. The mechanical strength of these aerogels could reach as high as 100 times more than that of the native silica aerogels (unbridged), and the strength could be easily adjusted from a rigid region to an elastic region simply by varying the sample density. Moreover, these aerogels possessed an interesting character of regional shrinking when encountering with water, which made it possible to fabricate artistic aerosculptures with water or other polar solvents as a graver.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2019
·Vol. 29
·期 28
·1901058
·
IF 15.621
Zenghe Liu,Luzhi Zhang,Qingbao Guan,Yifan Guo,Jiaming Lou,Dong Lei,Shuliang Wang,Shuo Chen,Lijie Sun,Huixia Xuan,Eric Meade Jeffries,Chuanglong He,Feng-Ling Qing,Zhengwei You
Natural tissues possess superior material properties such as self-healing, mechanical robustness, and mechanical gradients that allow organisms to adapt and survive in dangerous environments. Although highly desired, imparting synthetic materials with these biomimetic protective features remains a challenge. Here, the versatile dimethylglyoxime–urethane (DOU) moiety is used to create a multifunctional polyurethane (DOU-PU). The reactivities of DOU including reversible dissociation, metal coordination, photolysis enabled self-healing, high strength and toughness, mechanical gradient formation, and spatially controlled functionalization. By incorporating DOU, a multifunctional protective film is produced with superior resistance to mechanical damage, rapid room temperature self-healing, and anti-counterfeiting features. This super biomimetic film is expected to be very useful for the protection of various types of valuable objects such as electronics, diplomas, currency, and automobiles.
研究领域:
材料科学
·
生物医学工程
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Linli Xu,Linhong Xiao,Pan Jia,Karel Goossens,Peng Liu,Hui Li,Chungui Cheng,Yong Huang,Christopher W. Bielawski,Jianxin Geng
High-performance flame-retardant materials are urgently needed to address outstanding issues that pertain to safety. Traditional flame retardants are toxic to the environment and/or lack the physical properties required for use in many contemporary applications. Here, we show that isocyanate-based polyimide (PI) foam, a flammable material, can exhibit unusually superior flame retardancy as well as other excellent properties, such as being lightweight and displaying high mechanical strength, by incorporating red phosphorus (RP)-hybridized graphene. The covalent bonds formed between the graphene platelets and the PI matrix provide the resultant PI foam with a specific Young’s modulus (83 kNm kg–1) that is comparable to or even higher than those displayed by state-of-the-art foams, including silica aerogels, polystyrene foams, and polyurethane foams. In addition, even a low content of the RP-hybridized graphene (2.2 wt %) results in an exceptionally higher limiting oxygen index (39.4) than those of traditional flame-retardant polymer-based materials (typically 20–30). The resultant PI foam also exhibits thermal insulation properties that are similar to that of air. Moreover, the RP-hybridized graphene is prepared using a one-step ball milling process in 100% yield, and does not require solvent or produce waste. The preparation of the flame-retardant PI foams can be scaled as the starting materials are commercially available and the techniques employed are industrially compatible.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2017
·Vol. 83
·期 1
·100-108
·
IF 1.575
Liu Benxue,Ju Wei,Zhang Jing,Fan Huili,Wang Qichun,Yi Xibin,Yu Zhichao,Wang Xinqiang
Abstract In the present work, RF/SiO 2 aerogels reinforced by zirconia (ZrO 2 ) were fabricated by a sol–gel process combined with N 2 -ethanol supercritical drying. The physical properties and microstructures of the aerogels were investigated by uniaxial compression, X-ray diffraction, N 2 physico-adsorption, scanning electron microscopy, X-ray photoelectron spectroscopy, and infrared spectrum. The compressive strengths of the aerogels were improved obviously with the addition of ZrO 2 . The composite aerogels remained amorphous state even the percentage of ZrO 2 reached up to 6.77 wt%. The pore sizes of the aerogels with various ZrO 2 were hierarchical and the Brunauer-Emmett-Teller surface area increased distinctly with the increase of ZrO 2 . On the contrary, the aerogel particle sizes decreased as the increase of ZrO 2 . In our opinion, the enhanced compressive strengths derive from both of the varied pore structures and the decrease of the particle sizes. Graphical Abstract
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Hongwei Lu,Danling Wang,Daye Huang,Luyao Feng,Huapeng Zhang,Peng Zhu
PNIPAM as a stimuli-responsive polymer has generated extreme interests due to its versatile applications. However, there is no research report on whether PNIPAM micro/nano-particles can be extracted from its suspension after phase separation. In the present work, LCST-type phase separation in self-synthesized PNIPAM/water system was investigated in depth by dividing the DLS testing process into four stages. In addition to quenching duration, temperature rise process, quenching temperature and PNIPAM concentration all have a great influence on particle size of the suspension. Meanwhile, the steady-state rheology and dynamic viscoelasticity results show that PNIPAM micro/nano-particles in the suspension are “soft” that can deform. Finally, FE-SEM was used to observe the morphology of dehydrated PNIPAM extracted by sessile droplet evaporation under different conditions. The results indicate that these “soft” particles are easier to fuse together, do not have sufficient mechanical strength to maintain their spherical morphology after dehydration. But the above fusion can be suppressed by adjusting evaporation conditions to acquire smaller PNIPAM particles which have sufficient mechanical properties to keep their basic particle morphology . Further, by changing evaporation pressure to positive or negative pressure, dehydrated PNIPAM micro/nano-particles with excellent uniformity and separation can be obtained. This work will provide guidance for extracting micro/nano-particles from polymer/diluent systems with LCST .
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 5
·1673-1678
·
IF 6.641
Zhangshuo Liu,Yu Zhang,Hao-Bin Zhang,Yang Dai,Ji Liu,Xiaofeng Li,Zhong-Zhen Yu
High-performance and flexible electrically conductive materials with satisfactory mechanical strength are vital in shielding electromagnetic interference (EMI) and radiation for portable electronics and wearable devices. Two-dimensional transition metal carbides/nitrides (MXenes) with remarkable metallic conductivity are considered as ideal candidates for ultrathin EMI shielding films, but their poor mechanical performances often impede their practical applications. Herein, we fabricate highly conductive MXene-based films with remarkable EMI shielding performance and excellent mechanical strength by enhancing the interfacial adhesion among the adjacent MXene nanosheets with multivalent aluminum ions. The tensile strength of the MXene film is significantly enhanced by 190% from 28.7 to 83.2 MPa with the introduction of aluminum ions and its conductivity is retained at 265 600 S m−1, exhibiting superior comprehensive performances to the previously reported results with other reinforcements. The strong and highly conductive MXene film with a small thickness of 39 μm exhibits one of the highest EMI shielding performances of over 80 dB in the X-band. This work provides a simple and efficient strategy for designing and fabricating high-performance MXene-based materials for efficient EMI shielding applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2025
·
IF 12.5
Jin Xu,Qirong Li,Jiugang Yuan,Xuerong Fan,Weidong Gao
Starch-based films suffer from brittleness and poor tensile properties, limiting their industrial applicability. In this study, magnetically modified starch (MMS) was prepared by covalently grafting azide-Fe 3 O 4 @SiO 2 nanoparticles onto the reducing ends of soluble starch via reductive amination and Cu(I)-catalyzed azide–alkyne cycloaddition (click chemistry). During film formation, application of a 1.4 T NdFeB magnetic field promoted chain alignment and crystallization. X-ray diffraction revealed a 19 % increase in crystallinity (from 9.6 % to 11.4 %), while FTIR analysis showed a 27 % enhancement in the (994 + 1047)/1022 ratio, indicating greater short-range molecular order. As a result, the tensile strength of MMS films increased to 19.8 ± 1.9 MPa, representing an 81.7 % improvement over native starch films (10.9 ± 1.4 MPa, p < 0.01). Meanwhile, the elongation at break decreased from 3.9 ± 0.8 % to 2.3 ± 0.3 %, reflecting enhanced molecular packing and reduced chain mobility. Superparamagnetic behavior ensured chain mobility only under field exposure, minimizing agglomeration after field removal. This work demonstrates a scalable, field-guided strategy to tailor starch film structure and performance, offering promising applications in eco-friendly packaging and biomedical materials.
研究领域:
材料科学
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食品科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Hanqi Qian,Yue Yao,Qingyuan Cao,Tao Liu,Nan Li,Yudong Huang,Regina Maratovna Islamova,Bo Jiang
Developing coating materials, which are thermally insulating and high-strength support in extreme environments, is a hot spot for the thermal protection of aerospace. However, the lack of stable ceramic construction after prolonged thermal attack creates a risk of mechanical performance degradation. Herein, a silicon-based porous thermal protection composite was proposed by enveloping an innovative silicone resin on melamine frame. The thermostability of silicone resin was significantly improved by just 2 wt% addition of a multifunctional silane monomer, due to the incorporated diphenylamine and its derived quinonimine structure. Meanwhile, the uniform distribution of ammonium polyphosphate (APP) in the system effectively filled defects and cracks during pyrolysis. These facilitated the formation of an ordered porous polymer-derived ceramic framework under high temperature, thus significantly enhancing the material's mechanical strength (1200 °C, 3.39 MPa) and thermal insulation. Notably, even when subjected to prolonged high-temperature flame impact, the 3 mm-thick quinonimine-incorporated coating maintained its intact structure and preserved a backside temperature 77 °C lower than that of traditional silicone/melamine coating. This work provides a strategy for developing thermal protection composites that exhibit machinability, high strength, and superior thermal insulation performance in extreme environments.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2025
·
IF 12.5
Xianchun Li,Xin Li,Wuliang Ma,Jinxia Ma
Developing degradable plastics with excellent mechanical strength and wet stability from renewable and biodegradable biomass resources remains challenging. Here, we propose a simple one-step strategy for the in-situ multiscale dissolution of cellulose and crosslinking with 1,4-butanediol diglycidyl ether (BDDE) within a mixture of BDDE and AlCl 3 /ZnCl 2 aqueous solution at room temperature. This strategy enables the synthesis of cellulosic paper-based bioplastics with high mechanical strength and wet stability from cellulose paper. In this process, conventional cellulose paper is partially dissolved, and simultaneously, BDDE forms chemical crosslinking with undissolved micro-level, nano-level cellulose fibers and dissolved cellulose macromolecules through an autocatalytic effect from AlCl 3 /ZnCl 2 aqueous solution, resulting in multiscale physicochemical entanglements and multiple hydrogen bonds. Hence, the prepared bioplastic's dry and wet strength reached 58.2 MPa and 24.2 MPa, respectively, about 6.9 times and 71.2 times higher than untreated paper-based materials. The prepared bioplastic showed excellent wet stability, biosafety, and biodegradability. The density functional theory (DFT) simulation data indicates that Al 3+ , Zn 2+ ions, and freely hydrated hydrogen protons are crucial to the dissolving-co-crosslinking system. This strategy involves only green and recyclable chemicals, offering a promising pathway for producing strong and biodegradable cellulosic paper-based bioplastics as an alternative to nondegradable plastics.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2024
·Vol. 25
·期 4
·2418
·
IF 4.9
Runing Liang,Dan Zhang,Junwei Guo,Shaohuang Bian,Cheng Yang,Lusi A,Weiwei Zhang,Feng Huang
Chitosan is widely used in the production of various hydrogels due to its non-biological toxicity, good biocompatibility, and strong biodegradability. However, chitosan-based hydrogels have not been widely used in tissue engineering due to their poor mechanical strength, poor stability and high biotoxicity of cross-linking agents. As a green technology, low temperature plasma is rich in active groups that can be involved in various chemical reactions, such as replacing the components on the chitosan chain, contributing to the cross-linking of chitosan. In this study, a plasma-assisted preparation method of chitosan-based hydrogels was developed and the properties, including mechanics, water absorption, and degradation (or stability), were characterized and analyzed. It is proved that plasma treatment plays a significant role in improving the mechanical strength and stability of hydrogels.
研究领域:
生物材料学
·
组织工程学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）