INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
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IF 8.025
Lan Chen,Zhanming Liang,Xiaoxuan Zhang,Liming Zhang,Shuangfei Wang,Changzhou Chen,Ling Zeng,Douyong Min
Lignin is the most naturally abundant source of aromatics for phenolic chemicals, bioenergy sources, and functional materials. Recent works are devoted to the acid-catalyzed organosolv extraction for improving the lignin valorization. However, β –aryl ethers are mostly cleaved to form carbon–carbon bonds under the acidic condition. In this work, lignin isolated with methanolic hydrochloric acid (MHL) was compared with conventional milled wood lignin (MWL). The methanol incorporated into lignin as α –OCH 3 to prevent the cleavage of β –aryl ethers. As a result, the yield of MHL was over 12 times that of MWL. The MHL appeared a regular granular structure with an average diameter of 100 nm. Analysis of 13 C– 1 H HSQC NMR spectra showed that MHL contained 42.6 % β –O–4 linkages whereas 35.9 % for the MWL, as well as 6.5 % β –5 and 3.2 % β – β , which was less than MWL. Moreover, 13 C NMR spectroscopy confirmed that MHL was mainly isolated by the cleavage of the associated carbohydrates rather than the degradation of β –aryl ether bonds. Therefore, MHL can be utilized more as a native lignin representative than MWL for studying the physicochemical properties and the interior structures of the protolignin.
研究领域:
生物化学
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材料科学
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DOI
PubMed
高影响因子
POLYMER INTERNATIONAL
·
2012
·Vol. 62
·期 10
·1457-1464
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IF 1.902
Youmei Bao,Jing He,Yuesheng Li
Hyperbranched polyesters with thioether linkages were facilely prepared from methyl 10-undecenoate, a castor oil-derived renewable chemical. The monomer was obtained in excellent yield through thiol–ene click chemistry in the presence of catalytic amounts of photoinitiator under UV irradiation. Subsequent bulk polycondensation via a transesterification process catalyzed by Ti(OBu) 4 , Sb 2 O 3 or Zn(OAc) 2 gave hyperbranched polyesters with high molecular weights and unusual crystalline properties. The degree of branching in the range 0.45 − 0.54 calculated from quantitative 13 C NMR spectroscopy and low inherent viscosities of 0.16 − 0.25 dL g −1 strongly confirmed the hyperbranched structures of the resultant polymers. © 2012 Society of Chemical Industry
研究领域:
材料化学
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可再生资源化学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2015
·Vol. 18
·期 5
·3884-3892
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IF 4.493
Xinyuan Che,Shiming Gong,Heng Zhang,Bin Liu,Yinghan Wang
Polyimides (PI-N9 and PI-N12) were synthesized from two kinds of functional diamines, whose junction modes between backbones and side chains were different. Side chains of PI-N9 were linked to the backbones with an ether bond spacer; and side chains of PI-N12 were directly linked to the backbones without any spacer. The PI alignment layer surfaces were investigated by atomic force microscopy, surface free energy measurements, X-ray photo-electron spectroscopy and polarized attenuated total reflection Fourier transformed infrared spectroscopy. It was found that PI-N9 lost the vertical alignment capability after high-strength rubbing, while PI-N12 could still induce liquid crystals (LCs) to align vertically under the same condition. The mechanism of the macroscopic molecular orientation of the PI surface is proposed. During the high-strength rubbing process, the side chain could rotate around the flexible ether bond which existed between the side chain and the main chain of PI-N9 and then fell over. Therefore, PI-N9 could not induce the vertical alignment of LCs anymore. But PI-N12 could keep LCs aligning vertically all the time, which proved that the stability of LC alignment induced by PI-N12 was better.
研究领域:
材料科学
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高分子化学
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2019
·
IF 8.456
Naeem Akhtar Qaisrani,Lingling Ma,Manzoor Hussain,Jiafei Liu,Lv Li,Ruiting Zhou,Yabin Jia,Fengxiang Zhang,Gaohong He
Anion-exchange membranes (AEM) with high ion content usually suffer from excessive water absorption and dilution effects that impair conductivity and mechanical properties. We herein report a novel ether containing a cross-linking strategy without adopting high ion-exchange capacity (IEC). The ether-containing cross-links and the quaternized structure are created simultaneously by introducing an ether-containing flexible hydrophilic spacer between two 1,4-diazabicyclo[2,2,2,2]octane or DABCO molecules; the resultant bi-DABCO structure was further employed to react with chloromethylated polysulfone. The long spacer with the ether moiety may benefit the hydroxide ion transport, and the cross-links will control the swelling and water absorption of the AEM. The two ether groups in the long spacer of the cross-links will also shield the DABCO cation from OH– attack due to an electron-donating effect. The prepared membranes exhibited an improved conductivity of 31 mS/cm (at 25 °C) at a comparatively low IEC (1.08 mmol/g) with a rational water absorption and low swelling ratio (95.0 and 27.1%, respectively); they also displayed an enhanced alkaline stability in 1 M NaOH aqueous solution at 80 °C for 150 h. The density functional theory study and physical characterization after the alkaline treatment further confirm the better chemical stability of the cross-linked membrane over its counterpart. Our work presents an effective strategy to balance AEM conductivity and robustness.
研究领域:
材料科学
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化学工程
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2018
·Vol. 135
·期 22
·46326
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IF 1.901
Weining Du,Yong Jin,Jiezhou Pan,Wuhou Fan,Shuangquan Lai,Xiaopeng Sun
Herein, we synthesized a series of polyurethane copolymers (PUs) with poly(1,4-butylene adipate) glycol as soft segment and 2,4-toluene diisocyanate as well as extenders including 1,4-butanediol and di(1-hydroxyethylene) diselenide as hard segment. The chemical structure, thermal property, crystallization behavior, shape memory, and self-healing performances of the PUs were systematically characterized by a series of experiments. It was found that the PU2 containing a higher diselenide component (∼33 mol %) exhibited both shape memory and self-healing behaviors under a moderate temperature (∼57 °C). Meanwhile, the PUs showed a good repeatability of shape memory function, and their fixity and recovery ratios were all above 90%. Additionally, the dynamic exchangeable feature of diselenide bonding endues the PUs chains with an acceptable reprocessability and self-healing performances, and the PU2 sample could be healed for five times by thermal treatment with the healing efficiencies above 70%. This work provides a heuristic perspective for the development of shape memory and self-healing materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46326.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
RSC Advances
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2019
·Vol. 9
·期 24
·13458-13464
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IF 3.049
Hao Guo,Mingyue Wang,Rui Xue,Jing Yao,Xuejiao Wang,Longwen Zhang,Jianfeng Liu,Wu Yang
A new COF (NWNU-COF-4) linked by an aryl ether bond (Ar–O–Ar) was synthesized by the condensation reaction of 2,4,6-trihydroxypyrimidine and trinitrophenol under simple and easy reaction conditions. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption, thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized to characterize the product. The BET specific surface area of NWNU-COF-4 was 21.33 m2 g−1, and its pore size was about 1.351 nm. Additionally, this method of preparation was simple and cheap. The electrochemical measurements showed that the synthesized NWNU-COF-4 had excellent pseudocapacitive performance with maximum specific capacitance of 133.44 F g−1 at 0.3 A g−1 in 6 mol L−1 KOH electrolyte. When the current density increased by 10 times (3.0 A g−1), the specific capacitance was 114.12 F g−1, and the retention rate was 82%. After 10 000 GCD cycles, the capacitance still kept 94% of its initial capacitance.
研究领域:
材料科学
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电化学
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DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
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2021
·
IF 7.033
He Li,Shisheng Liang,Yucui Hou,Yupeng Wang,Shuhang Ren,Weize Wu
Direct coal liquefaction (DCL) is not only for fuel but also for chemicals, which shows high efficiencies in atom utilization and energy. The study on coal structure is important to select coal for direct liquefaction . Naomaohu coal is a kind of subbituminous coal and a typical coal for direct liquefaction . In this work, the structure of Naomaohu coal was investigated via alkali‑oxygen oxidation , ruthenium ion catalyzed oxidation and physical analyses and a representative structural model with a model size of 128,755 amu was constructed. The structural characteristics show that the ratio of single-, double-, triple-, and quadruple-aromatic rings is 149:164:102:63. The triple- and quadruple-rings aromatic structures are mainly connected by C C bonds of 2–4 carbon atoms. The single- or double-ring is connected on the triple- and quadruple-rings aromatic structures through ether or ester bonds , which can be broken easily under mild conditions. Long alkyl side chains with carbon atoms from 13 to 25 accounting for 0.91 wt%. The high H/C, high oxygen content (mainly weak bonds such as ether and ester bonds between aromatic clusters), abundant single-, double-, triple, and quadruple-aromatic rings, and alkyl bridge bonds of 2–4 carbon atoms are beneficial to the mild liquefaction of Naomaohu coal
研究领域:
化学工程
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能源科学
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DOI
高影响因子
MOLECULES
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2020
·Vol. 25
·期 9
·2109
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IF 3.267
Changzhou Chen,Peng Liu,Haihong Xia,Minghao Zhou,Jiaping Zhao,Brajendra K. Sharma,Jianchun Jiang
It is of great importance to explore the selective hydrogenolysis of β-O-4 linkages, which account for 45–60% of all linkages in native lignin, to produce valued-added chemicals and fuels from biomass employing UV light as catalyst. TiO2exhibited satisfactory catalytic performances in various photochemical reactions, due to its versatile advantages involving high catalytic activity, low cost and non-toxicity. In this work, 20 wt.% Ni/TiO2and oxidant PCC (Pyridinium chlorochromate) were employed to promote the cleavage of β-O-4 alcohol to obtain high value chemicals under UV irradiation at room temperature. The Ni/TiO2photocatalyst can be magnetically recovered and efficiently reused in the following four consecutive recycling tests in the cleavage of β-O-4 ether bond in lignin. Mechanism studies suggested that the oxidation of β-O-4 alcohol to β-O-4 ketone by oxidant PCC first occurred during the reaction, and was followed by the photocatalysis of the obtained β-O-4 ketone to corresponding acetophenone and phenol derivates. Furthermore, the system was tested on a variety of lignin model substrates containing β-O-4 linkage for the generation of fragmentation products in good to excellent results.Keywords:lignin;β-O-4;photocatalyst;Ni/TiO2;oxidant PCC
研究领域:
化学工程
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环境科学
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PubMed
高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
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2021
·Vol. 74
·期 9
·632-639
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IF 1.321
Haiyang Yang,Duxin Li,Jun Yang,Jin Wang,Shunchang Gan,Yufeng Liu,Kaikai Cao
In this paper, diamine monomers with ether bonds in the main chain are selected for molecular structure design, and four polyamide-imide (PAI) materials are prepared by the acyl chloride method. A diamine monomer containing an ether group can reduce the friction coefficient and improve the wear performance of PAI material. The wear mechanism of PAI material can also change due to ether linkages. PAI synthesized using m-phenylenediamine without an ether bond has the highest friction coefficient and abrasion loss, and the wear mechanism is mainly adhesive wear. With the increase of the number of ether bonds in the diamine monomer structure, the friction coefficient of the material decreases from 0.5445 to 0.4216 (22.57 %). The abrasion loss of the PAI material synthesized using 4,4′-diaminodiphenyl ether is the smallest, which is 84.4 % lower than m-phenylenediamine. The wear mechanism is abrasive wear and slight adhesion wear. With the increase of the number of ether bonds, the heat r esistance of PAI decreases slightly, while the hydrophobic property increases and the water absorption decreases. To summarise, PAI material synthesized using 4,4′-diaminodiphenyl ether has a low friction coefficient, the best wear resistance, the highest tensile strength and elongation at break, and the best comprehensive properties of the materials reported here.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Zichun Ding,Siying Wang,Runze Liu,Yuhang Wang,Jianing Guo,Xuedong Wu,Jiaming Wang,Xigao Jian,Lishuai Zong,Jinyan Wang
Phthalonitrile (PN) resin is renowned for its absence of small molecule release during curing, high processing stability, and exceptional thermal stability, positioning it favorably in the realm of high-temperature resin applications. However, its narrow processing window and high melting point present challenges to its development and practical use. To address these limitations, this work synthesized PN prepolymers 4,4′-bis (sulfonylbiphenyl) thiophtalonitrile (BSPS) and 4,4′-bis(carbonylbiphenyl) thiophtalonitrile (BSPC) by introducing thioether bonds as a substitute for ether bonds, aiming to expand the prepolymers' processing window. Meanwhile, building upon the oxidation process of thioether to sulfone observed in pharmaceutical production, the potential for in-situ oxidation of thioether bonds during the curing of phthalonitrile prepolymers was investigated. A comprehensive analysis of the curing behavior, viscosity changes, and thermal stability was conducted using differential scanning calorimetry (DSC), rheological analysis, and thermogravimetric analysis (TGA). The DSC and rheological test results reveal that the experimental group prepolymers BSPS and BSPC exhibit lower melting points (BSPS 179 °C; BSPC 180 °C) and broader processing windows (BSPS 52 °C; BSPC 79 °C) than blank. Additionally, the thermal performance of resins show improvement over the blank, with BSPS achieving a decomposition temperature of up to 530 °C ( T d5% ). XPS analysis of the curing process confirmed that the enhanced thermal stability is attributable to the partial oxidation of thioether bonds into stable sulfone groups. This innovative structural approach allows for satisfactory processing performance in the initial stage, followed by a spontaneous transformation into a more robust and thermo-resistant structure post-shaping. This finding carries significant implications for the development of a balanced phthalonitrile system that harmonizes processing ease with superior thermal endurance.
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
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
·
IF 8.5
Tianyuan Xiao,Jiahui Song,Wenchao Jia,Yanning Sun,Yanzhu Guo,Pedram Fatehi,Haiqiang Shi
The chemical bond cleavage of lignin is a research focus for achieving depolymerized lignin for such applications as adhesives, fuels, fertilizers, etc. The depolymerization of an industrially available sustainable material, i.e., industrial alkali lignin, in LiBr·3H 2 O/HBr-γ-valerolactone (GVL) was systematically investigated in this study. It was observed that using 3/1 mL/g of HBr/lignin and 8/1 mL/g of GVL/lignin at 110 °C for 90 min, i.e., optimized conditions, resulted in lignin derivatives with an M w of 1889 g/mol and M n of 895 g/mol. The characteristics of the products were studied using FTIR, NMR, SEM, and DLS techniques. The results confirmed that the Hibbert-ketone end group was formed, while the structure of the aromatic ring was not changed on the depolymerized lignin. After the depolymerization process, the hydroxyl content in lignin increased from 1.91 mmol/g to 2.96 mmol/g. The product derived from the LiBr·3H 2 O/HBr-GVL depolymerization system displayed a spherical particle morphology. The addition of GVL to lignin depolymerization processes improved the bonding between lignin and inorganic molten salts, thereby promoting the acid-catalyzed cleavage of aryl ether bonds in lignin. Current research supports the conclusion that LiBr·3H 2 O/HBr-GVL lignin depolymerization is a sustainable and effective chemical pathway for generating depolymerized lignin.
研究领域:
化学工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
HIGH PERFORMANCE POLYMERS
·
2018
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IF 1.047
Li Zhang,Xian Wu,Shanyou Liu,Jinwu Peng,Baijun Liu
Some multi-ether linked polyimides (PIs) derived from two diamine monomers containing various amount of cyano groups are synthesized by a typical two-step polymerization. Meanwhile, the PIs with similar chemical structure but without cyano groups are prepared as counterparts for comparison purposes. The obtained PIs exhibit low glass transition temperature values of 211–258°C, which are associated with their multi-ether chemical structure. Furthermore, these PIs have high thermal stability, and the temperatures at 10% weight loss are in the range of 524–616°C under nitrogen atmosphere. It is found that the introduction of cyano groups would have a great influence on the properties of the PIs. The tensile strength and Young’s modulus of one cyano-containing PI reach 121 MPa and 1.4 GPa, respectively, which are much higher than those cyano-free ones. In addition, the cyano-containing PIs exhibit different behaviors of dielectricity and solubility in comparison with the corresponding cyano-free counterparts.
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
危险品化学品经营许可证（带存储）