HIGH PERFORMANCE POLYMERS
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2020
·
IF 1.568
Yi Wang,Mengyao Huang,Yi Lei
Polyimides are usually synthesized over a long period of time, and the process is complex. In order to shorten the synthesis time and simplify the process, we developed an improved synthesis method, namely, microwave-assisted polycondensation. The 3,3′-4,4′-benzophenone tetracarboxylic dianhydride (BTDA)–2,4-tolylene diisocyanate (TDI)/1,1′-methylenebis(4-isocyanatobenzene) (MDI) ternary copolyimides prepared in this work have been synthesized using microwave heating at rather short reaction times (15 min), without the need for either the once-off addition of TDI/MDI or the drop-wise addition of that mixture. The structure of the desired ternary copolyimide was confirmed by proton nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. Its glass-transition temperature is above 400°C, and the temperature for 5% thermal loss under nitrogen atmosphere is 508.8°C. The tensile strength is 141 MPa, which shows that the microwave-assisted copolyimide has excellent heat resistance and mechanical properties.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Zhiwei Huang,Robert S. Gurney,Yalun Wang,Wenjiao Han,Tao Wang,Dan Liu
Durability under UV illumination remains a big challenge of TiO2-based superhydrophobic coatings, with the photocatalytic effect causing degradation of low-surface-energy material over time, resulting in the surfaces losing their hydrophobicity. We report surfaces made from tolylene-2,4-diisocyanate (TDI)/TiO2 hybrid networks that demonstrate superhydrophobicity and superior UV durability. Structural and morphological studies reveal that the TDI/TiO2 hybrid networks are composed of TiO2 nanoparticles interconnected with TDI bridges and then encapsulated by a TDI layer. Through controlling the fraction of TDI in the synthesis process, the thickness of the TDI encapsulation layer around the TDI/TiO2 hybrid networks can be varied. When the weight ratio of TDI/TiO2 is 5:1, the superhydrophobicity of the hybrid network surface remains almost unchanged after a month of continuous UV illumination. This hybrid network surface can also clean methylene blue solution through the synergistic effects of cation adsorption and photocatalysis, holding promising potential for applications toward reducing cation pollutions in both liquid and air environments.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2023
·Vol. 48
·期 8
·e202300047
·
IF 1.8
Kai Han,Zhanxiong Xie,Lingyu Deng,Shijiao Li,Chenyang Li,Yi Liu,Chongwei An,Jingyu Wang
In order to solve the short stabilization time of the water-in-oil emulsion binder system and the shortcomings of the critical blast size of the explosive ink molding sample, a water-in-oil emulsion binder was designed with polyvinyl alcohol (PVA) aqueous solution as the aqueous phase, fluorocarbon resin (FEVE) ethyl acetate solution as the oil phase, and toluene diisocyanate (TDI) added to modify the water-in-oil emulsion binder. The hexanitrohexaazaisowurtzitane(CL-20)based explosive ink was made by incorporating submicron CL-20 into the binder system, and the print-formed samples were tested for microscopic morphology, crystallographic analysis, mechanical susceptibility, and detonation transmission performance. The results showed that the explosive ink‘s viscosity was moderate and suitable for direct printing, and the formed sample‘s surface particles were uniformly dispersed and had a honeycomb structure. The crystal form of CL-20 explosive in the explosive ink did not change, the molded sample‘s impact and frictional sensitivities were 1 J and 32 N lower than those of submicron CL-20, respectively, and the detonation velocity of the molded sample was 6655 m/s. The critical detonation size and critical detonation thickness were 1×0.0078 mm and 0.1 mm, respectively, and a critical detonation corner turning of 90°–160° could be achieved. The results show that the prepared binder system is stable for a long time, and the explosive ink molding samples have excellent blast transmission performance.
研究领域:
化学工程
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材料科学
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爆炸力学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2025
·Vol. 10
·期 21
·e06152
·
IF 2
Shuai Wang,BingXi Song,Ze Su,Yijie Cai,Long Liu,Chang Su,Yanqiang Zhang
Graphical A new ionic liquid plasticizer [NTAZ][NTf 2 ] was synthesized. Compared with the traditional plasticizer DOA, [NTAZ][NTf 2 ] can significantly improve the energy of the propellant formulation. Energetic plasticizer is an important means to improve the energy performance of solid propellants, but there is no suitable energetic plasticizer for HTPB/TDI system. In this work, a nitrate-functionalized ionic liquid plasticizer of 1-Methyl-4-(8-(Nitrooxy)octyl)-1,2,4-triazolium bis((trifluoromethyl)sulfonyl)imide ([NTAZ][NTf 2 ]) was synthesized, and the energy was increased by the combination of nitrate functional group and 1,2,4-triazole cation. The hydrogen bond between the anion and the cation and HTPB achieves a good plasticizing effect. When 6% [NTAZ][NTf 2 ] was added to HTPB/TDI system, the glass transition temperature decreased from −63.41 °C to −64.84 °C, the tensile strength increased from 0.52 MPa to 0.79 MPa, and the storage modulus increased from 64.02 MPa to 110.32 MPa. When 4% DOA is replaced by the same amount of [NTAZ][NTf 2 ] in the HTPB formulation system, the specific impulse is increased from 261.0 s to 271.4 s. This study will guide the design and application of new energetic solid propellant plasticisers, both theoretically and experimentally.
研究领域:
材料科学
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推进剂化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 15
·3212
·
IF 4.967
Xiaojun Xi,Zhanping Zhang,Yuhong Qi
To explore the influence mechanisms of polyurethane soft segments on modified silicone coatings, a series of modified coatings was prepared by introducing different contents of hydroxypropyl-terminated polydimethylsiloxane (PDMS2200) into the soft segment of polyurethane. ATR-FTIR, NMR, CLSM, AFM, contact angle measurement, the tensile test, bacterial adhesion, and the benthic diatom adhesion test were used to investigate the structure, morphology, roughness, degree of microphase separation, surface energy, tensile properties, and antifouling properties of the modified coatings. The results show that PDMS2200 could aggravate the microphase separation of the modified coatings, increase the surface-free energy, and reduce its elastic modulus; when the microphase separation exceeded a certain degree, increasing PDMS2200 would decrease the tensile properties. The PED-TDI polyurethane-modified silicone coating prepared with the formula of PU-Si17 had the best tensile properties and antifouling properties among all modified coatings.Keywords:antifouling coating;silicone;polyurethane modification;composition of the soft segment
研究领域:
材料科学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 31
·e55717
·
IF 2.7
Xiongfei Zhang,Pengyun Li,Dan Huang,Xiang Shi,Yana Shi,Chunxiao Qu,Qianya Tan
Although significant efforts have been undertaken to explore the toughening of epoxy resins, it remains challenges to establish a simple and effective toughening technique which does not compromise its strength, thermal stability and processing performance. In this paper, toluene-diisocyanate-trimer (TDI-T) was utilized to manufacture a novel epoxy-terminated dendritic modifier TDI-T glycol diglycidyl ether (TDI-T GLDE). When the addition of TDI-T GLDE reaches 20% of the resin mass, the tensile strength, tensile elongation, compressive strength and impact strength were increased by 28.1%, 75%, 24.8%, and 138.0% respectively, compared to E-51. The thermal properties of the samples have been improved, including an increased glass transition temperature (Tg) from 68.2 to 73.2°C, as well as an increase in the initial decomposition temperature from 240.6 to 257.7°C. The toughening mechanism of TDI-T GLDE was studied through a combination of mechanical performance tests, thermal performance tests, and resin fracture surface morphology analysis.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Lidong Chen,Jin Wu,Gaojian Zhu,Chao Liu,Tingting Xu,Liulian Huang,Weibing Wu,Jiaqi Guo,Huining Xiao,Hongqi Dai,Chen Huang,Zhen Zhang,Huiyang Bian
A large number of polluting substances, including chlorinated organic substances that were highly stable and hazardous, has been emitted due to the rapidly developing chemical industry, which will affect the ecological environment. Nanocellulose aerogels are effective carriers for adsorption of oil substances and organic solvents , however, the extremely strong hydrophilicity and poor mechanical properties limited their widespread applications. In this study, TEMPO-oxidized cellulose nanofibrils was modified with 2, 4-toluene diisocyanate (TDI) and 4,4′-diphenylmethane diisocyanate (MDI) to prepare strong and hydrophobic aerogels for oil adsorption. The main purpose was to evaluate and compare the effects of two diisocyanates on various properties of modified aerogels. It was found that the modified aerogel had better hydrophobic properties, mechanical properties and adsorption properties. In particular, the modified aerogel with TDI as crosslinker showed a better performance, with a maximum chloroform adsorption capacity of 99.3 g/g, a maximum water contact angle of 131.3°, and a maximum compression stress of 36.3 kPa. This study provides further evidence of the potential of functional nanocellulose aerogel in addressing environmental pollution caused by industrial emissions.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Xia Wang,Qihui Chen,Yangqing Zheng,Maochun Hong,Heqing Fu
First, Layered double hydroxide (LDH) was modified by toluene diisocyanate (TDI), 2-hydroxyethyl acrylate (HEA), and LDH-TDI-HEA was prepared. Then LDH-TDI-HEA was modified by vinyl triethoxysilane (VTES), and LDH-TDI-HEA-VTES composites were obtained. Finally, acrylate was modified by LDH-TDI-HEA-VTES, and flame retarded LDH-TDI-HEA-VTES-Acrylate composites were successfully synthesized by in situ polymerization. The structures of LDH, LDH-TDI-HEA, LDH-TDI-HEA-VTES and LDH-TDI-HEA-VTES-Acrylate composites were characterized by Fourier transform infrared spectra , X-ray diffraction, X-ray photoelectron spectroscopy and Scanning electron microscopic. The effect of LDH-TDI-HEA-VTES content on the thermal stability, mechanical properties , adhesion properties and flame retardant properties of LDH-TDI-HEA-VTES-Acrylate composites was studied. At the same time, the thermal stability, mechanical properties, adhesion properties and flame retardant properties of LDH-Acrylate composites and LDH-TDI-HEA-VTES-Acrylate composites were also studied. The experimental results showed that with the increasing of LDH-TDI-HEA-VTES content, the thermal stability, mechanical properties, flame retardant properties, and shear resistance of LDH-TDI-HEA-VTES-Acrylate composites were improved, while the tack and 180° peel strength decreased. When the content of LDH-TDI-HEA-VTES was 7 wt%, the LOI, after-flame time and the UL 94 grade of LDH-TDI-HEA-VTES-Acrylate composites were 27%, 0 s, and V-0, respectively. LDH-TDI-HEA-VTES-Acrylate Composites have good flame retardant properties. At the same time, the flame retardant mechanism of LDH-TDI-HEA-VTES composites was also analyzed.
研究领域:
材料科学
·
高分子化学
·
消防安全工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）