Polymers
·
2019
·Vol. 11
·期 9
·1417
·
IF 3.164
Wei Wang,Zufeng Xiao,Chaofan Huang,Kewang Zheng,Yin Luo,Yumin Dong,Zitong Shen,Wei Li,Caiqin Qin
Chitosan microspheres modified by 2-pyridinecarboxaldehyde were prepared and used in the construction of a heterogeneous catalyst loaded with nano-Cu prepared by a reduction reaction. The chemical structure of the catalyst was investigated by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS). Under mild conditions, such as no ligand at room temperature, the catalyst was successfully applied to catalyze the borylation of α,β-unsaturated receptors in a water-methanol medium, yielding 17%–100% of the corresponding β-hydroxy product. Even after repeated use five times, the catalyst still exhibited excellent catalytic activity.Keywords:chitosan microspheres;copper;organoboron compounds
研究领域:
材料科学
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催化化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 37
·45291
·
IF 1.86
Shuang Yang,Qiaoxin Zhang,Yefa Hu
In this article, a novel flame retardant (coded as BNP) was successfully synthesized through the addition reaction between triglycidyl isocyanurate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and phenylboronic acid. BNP was blended with diglycidyl ether of bisphenol-A to prepare flame-retardant epoxy resin (EP). Thermal properties, flame retardancy, and combustion behavior of the cured EP were studied by thermogravimetric analysis, limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The results indicated that the flame retardancy and smoke suppressing properties of EP/BNP thermosets were significantly enhanced. The LOI value of EP/BNP-3 thermoset was increased to 32.5% and the sample achieved UL94 V-0 rating. Compared with the neat EP sample, the peak of heat release rate, average of heat release rate, total heat release, and total smoke production of EP/BNP thermosets were decreased by 58.2%–66.9%, 27.1%–37.9%, 25.8%–41.8%, and 21.3%–41.7%, respectively. The char yields of EP/BNP thermosets were increased by 46.8%–88.4%. The BNP decomposed to produce free radicals with quenching effect and enhanced the charring ability of EP matrix. The multifunctional groups of BNP with flame retardant effects in both gaseous and condensed phases were responsible for the excellent flame retardancy of the EP/BNP thermosets. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45291.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 11
·3751-3758
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IF 6.4
Jingyu Li,Xueting Wang,Changshuai Dong,Sihui Deng,Junli Hu,Jun Liu,Yichun Liu
Organoboron polymers containing boron–nitrogen coordination bonds are a new class of n-type thermoelectric polymers. Their n-doping with a traditional hydride donor dopant suffers from low thermoelectric performance and unsatisfactory stability. In this manuscript, we report the n-doping of an organoboron polymer, PBN-19, with an N-heterocyclic carbene (NHC) based dopant, 1,3-dimethylimidazolium-2-carboxylate (DMImC). The DMImC doped PBN-19 film exhibits an electrical conductivity of 1.55 S cm−1 and a power factor of 5.62 μW m−1 K−2, and maintains 80.0% of its initial electrical conductivity after 1 day storage at room temperature under a nitrogen atmosphere. Detailed examinations indicate that DMImC decomposed into NHC radicals upon thermal activation, which then reacted with the CO, CC and CN bonds on the PBN-19 skeleton realizing n-doping. The doping did not significantly disturb the π–π stacking and crystallization of PBN-19 and thus led to high thermoelectric performance. The covalent bonding of dopants on the polymer probably inhibited their diffusion out of the polymer matrix and thus slowed down the dedoping process. This work provides some new insights into the n-doping of organic thermoelectric materials.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
Petroleum Science
·
2023
·
IF 5.6
Zong-Lun Wang,Jin-Sheng Sun,Jing-Ping Liu,Kai-He Lv,Zi-Hua Shao,Xian-Fa Zhang,Zhe Xu,Zhi-Wen Dai,Ning Huang
With the exploration and development of deep and ultra-deep oil and gas, high torque and high friction during the drilling of deep and ultra-deep wells become one of the key issues affecting drilling safety and drilling speed. Meanwhile, the high temperature and high salt problem in deep formations is prominent, which poses a major challenge to the lubricity of drilling fluids under high temperature and high salt. This paper reports an organic borate ester SOP as an environmentally friendly drilling fluid lubricant . The performance evaluation results show that when 1% lubricant SOP is added to the fresh water-based mud, the lubrication coefficient decreases from 0.631 to 0.046, and the reduction rate of lubrication coefficient is 92.7%. Under the conditions of 210 °C and 30% NaCl, the reduction rate of lubricating coefficient of the base slurry with 1% SOP was still remain 81.5%. After adding 1% SOP, the wear volume decreased by 94.11% compared with the base slurry. The contact resistance experiment during the friction process shows that SOP can form a thick adsorption film on the friction surface under high temperature and high salt conditions, thus effectively reducing the friction resistance. Molecular dynamics simulation shows that lubricant SOP can be physically adsorbed on the surface of drilling tool and borehole wall through hydrogen bond and van der Waals force . XPS analysis further shows that SOP adsorbs on the friction surface and reacts with metal atoms on the friction surface to form a chemically reactive film. Therefore, under high temperature and high salt conditions, the synergistic effect of physical adsorption film and chemical reaction film effectively reduces the frictional resistance and wear of the friction surface. In addition, SOP is non-toxic and easy to degrade. Therefore, SOP is a highly effective and environmentally friendly lubricant in high temperature and high salt drilling fluid.
研究领域:
石油工程
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材料科学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2021
·
IF 4.354
Yuanyuan Tang,Kuan Liu,Jinjin Zhang,Long Liu,Tianzeng Huang,Chunya Li,Zhi Tang,Tieqiao Chen
A palladium-catalyzed difunctionalization of bicyclic alkenes with organoammonium salts and organoboronic compounds was reported. A wide range of functionalized cyclic products, including those bearing functional groups, were produced stereoselectively in good to excellent yields. The gram-scale experiment, one-pot operation, and synthetic application of β-borylated products further demonstrated the synthetic value of this new reaction in organic synthesis.
研究领域:
有机化学
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合成化学
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DOI
高影响因子
Nanomaterials
·
2018
·Vol. 8
·期 5
·326
·
IF 3.504
Wu Wen,Biao Han,Feng Yan,Liang Ding,Bojie Li,Liansheng Wang,Lei Zhu
We describe here the preparation of copper nanoparticles stabilized on a chitosan/poly (vinyl alcohol) composite film. This material could catalyze the borylation of α,β-unsaturated acceptors in aqueous media under mild conditions. The corresponding organoboron compounds as well as their converted β-hydroxyl products were all obtained in good to excellent yields. It is noteworthy that this catalyst of copper nanoparticles can be easily recycled eight times and remained catalytically reactive. This newly developed methodology provides an efficient and sustainable pathway for the synthesis of organoboron compounds and application of copper nanoparticles.Keywords:chitosan composite film;copper nanoparticles;organoboron compounds;easily recyclable
研究领域:
化学
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材料科学
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催化反应
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 22
·13466-13474
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IF 3.361
Yanling Wang,Chuanbao Zhang,Ning Xu,Jincheng Lan,Baoyang Jiang,Lingtao Meng
The traditional organoboron crosslinker used in the guar gum fracturing fluid has the disadvantages of a larger amount of guar gum and crosslinker and higher susceptibility to pH. Nanoparticles have special properties such as large specific surface area and many active groups, so the organic boron crosslinker and nanoparticles are combined to obtain nano crosslinkers. In this paper, rod-shaped nano-cellulose particles were prepared by acid hydrolysis, and a nanocellulose crosslinker was synthesized by combining with organic boron and KH550. Nanocellulose cross-linker has good temperature and salt resistance. It can meet the requirements of cross-linking guar gum fracturing fluid with a mass fraction of 0.3 wt% under neutral conditions. The residual viscosity is higher than 50 mPa s under shear at 170 s−1 and 110 °C for 60 minutes when the pH increases from 7 to 13, and NBC crosslinking can withstand a temperature of 160 °C under pH = 10. The crosslinking mechanism of the widely accepted nano-crosslinker is that the organoboron on the surface of the nanoparticle combines with the homeopathic ortho hydroxyl of the guar gum molecule to form a hydrogen bond and thereby form a complex network structure. This research shows that the hydrogen bonding between the nano-cellulose crosslinker and HPG molecules, and the resulting gel has a more complex network structure because of the formation of inter-chain cross-links.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
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2023
·
IF 9.5
Dong Liu,Zheng Lu,Zehua Lin,Chunxiao Zhang,Kuan Dai,Weifeng Wei
Solid-state polymer electrolytes (SPEs) are deemed as a class of sought-after candidates for high-safety and high-energy-density solid-state lithium metal batteries, but their low ionic conductivity, narrow electrochemical windows, and severe interfacial deterioration limit their practical implementations. Herein, an organoboron- and cyano-grafted polymer electrolyte (PVNB) was designed using vinylene carbonate as the polymer backbone and organoboron-modified poly(ethylene glycol) methacrylate and acrylonitrile as the grafted phases, which may facilitate Li-ion transport, immobilize the anions, and enlarge the oxidation voltage window; therefore, the well-tailored PVNB exhibits a high Li-ion transference number (tLi+ = 0.86), a wide electrochemical window (>5 V), and a high ionic conductivity (σ = 9.24 × 10–4 S cm–1) at room temperature (RT). As a result, the electrochemical cyclability and safety of the Li|LiFePO4 and Li|LiNi0.8Co0.1Mn0.1O2 cells with in situ polymerization of PVNB are substantially improved by forming the stable organic–inorganic composite cathode electrolyte interphase (CEI) and the Li3N–LiF-rich solid electrolyte interphase (SEI).
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
MOLECULES
·
2020
·Vol. 25
·期 2
·253
·
IF 3.267
Lan-Fang Hu,Dan-Jing Chen,Jia-Liang Yang,Xing-Hong Zhang
The copolymerization of biorenewable succinic anhydride (SA) with propylene oxide (PO) is a promising way to synthesize biodegradable aliphatic polyesters. However, the catalytic systems for this reaction still deserve to be explored because the catalytic activity of the reported catalysts and the molecular weights of produced polyesters are unsatisfied. Herein, we investigate the copolymerization of SA with PO catalyzed by the organoborane/base pairs. The types of Lewis bases, organoboranes, and their loadings all have a large impact on the activity and selectivity of the copolymerization. High ester content of >99% was achieved when performed the PO/SA copolymerization using triethyl borane (TEB)/phosphazene base P1-t-Bu (t-BuP1) pair with a molar ratio of 1/1 at 30–80 °C. Using TEB/t-BuP1pair with the molar ratio of 4/1 at 80 °C, the turnover of frequency (TOF) was up to 128 h−1and clearly higher than the known TOF values (0.5–34 h−1) of the PO/SA copolymerization by previously reported catalysts. The number-average molecular weights (Mns) of the resultant polyesters reached up to 20.4 kg/mol when copolymerization was carried out using TEB/t-BuP1(1/1, in molar ratio) at 30 °C.Keywords:succinic anhydride;propylene oxide;aliphatic polyester;organoborane;Lewis base
研究领域:
化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 98
·55179-55186
·
IF 3.708
Yanming Hu,Zhongfu Zhao,Xue Bai,Xuecheng Yuan,Xuequan Zhang,Toshio Masuda
Triarylborane-containing polyacetylene derivatives (2a–c) were synthesized by the polymerization of the corresponding monomers with Rh+(nbd)[C6H5B−(C6H5)3] catalyst. The anion sensing ability of 2a–c was examined by using tetra-n-butylammonium salts of a series of halide ions. UV-vis absorption and emission measurements revealed that these polymers could selectively detect F−, while they did not show any response for Cl−, Br−, and I−. The fluoride sensing properties of these polymers are highly dependent on the structure of the spacers between the conjugated main chain and boron atoms. Namely, 2a containing fluorenyl moieties exhibited a “turn on” fluorescence F− sensing ability. 2b having phenyl spacers displayed emission quenching upon addition of F− in solution, and a signal amplification phenomenon was observed compared to the corresponding monomer. Addition of F− changed the color of the biphenyl group-containing 2c in THF from yellow to orange, indicating that 2c can be used as a colorimetric sensor.
研究领域:
有机化学
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材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2022
·
IF 8.321
Yutao Tong,Ruihua Cheng,Huan Dong,Zhen Liu,Jinxing Ye,Boping Liu
A series of bifunctional hexanuclear organoboron catalysts with dual-arm structures were facile prepared via a two-step procedure in ~100% yields featuring six boron centers and two quaternary ammonium bromides for the epoxides/CO 2 copolymerization . The boron active sites within the p- Hexa B , m- Hexa B , and o- Hexa B catalysts were like two stretched “arms” presenting the cooperative intramolecular structures as para-, meta-, and ortho-locations, respectively. For propylene oxide (PO)/CO 2 copolymerization, the catalysts exhibited > 99% polymer selectivity under 25 – 60 ℃. The p- Hexa B catalyst provided the highest carbonate linkages (88%) in the poly(propylene carbonate)s while the o- Hexa B catalyst generated much more ether linkages as 45%. The o- Hexa B catalyst performed higher activity in cyclohexane oxide (CHO)/CO 2 copolymerization, obtaining fully alternating poly(cyclohexane carbonate)s with > 99% polymer selectivity under 25 – 150 ℃. For electron-withdrawing epichlorohydrin (ECH) monomer , the catalysts showed highly selective copolymerization (>99% polymer selectivity) and enhanced activity in comparison with tetraboron catalysts, providing poly(chloropropylene carbonate)s with > 99% carbonate linkages under 25 – 40 ℃. A novel bilaterally sequential copolymerization mechanism for alternating epoxide/CO 2 insertion was proposed and verified by density functional theory (DFT) calculations. Bearing dual-arm intramolecular structures, the catalysts withstood the simultaneous growth of two polymer chains, achieving the enhanced activity for the copolymerization. Thus, up to seven effective boron pairs were found in the o- Hexa B catalysts within the unique cooperative structure, leading to the PO homopolymerization in the copolymer with high ether linkages. Meanwhile, the o- Hexa B catalyst with enough steric space exhibited higher activity than p- Hexa B and m- Hexa B catalysts during the copolymerization.
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2021
·
IF 4.354
Qi Xia,Xiang Li,Xi Fu,Yaxuan Zhou,Yanqing Peng,Jiayi Wang,Gonghua Song
A novel three-component reaction of α-ketoaldehydes, 1,3-dicarbonyl compounds, and organic boronic acids catalyzed by CuO in water has been developed to give a wide range of products containing 1,3/1,4-diketones. The method has some advantages such as the use of readily available starting materials, wide substrate scopes, excellent yields, gram-scale synthesis, and mild reaction conditions.
研究领域:
有机化学
·
合成化学
✓ 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）