MACROMOLECULAR RAPID COMMUNICATIONS
·
2022
·Vol. 44
·期 5
·2200765
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IF 5.006
Yanlong Yin,Yang Xu,Xuhao Zhang,Baorong Duan,Zhirong Xin,Chunyang Bao
The development of degradable polymeric materials such as degradable polyurethane or polyurea has been much highlighted for resource conservation and environmental protection. Herein, a facile strategy of constructing mechanically strong and tough poly(urea-urethane) (PUU) thermosets that can be degraded under mild conditions by using triple boron-urethane bonds (TBUB) as cross-linkers is demonstrated. By tailoring the molecular weight of the soft segment of the prepolymers, the mechanical performance can be finely controlled. Based on the cross-linking of TBUB units and hydrogen-binding interactions between TBUB linkages, the as-prepared PUU thermosets have excellent mechanical strength of ≈40.2 MPa and toughness of ≈304.9 MJ m −3 . Typically, the PBUU900 strip can lift a barbell with 60 000 times its own weight, showing excellent load-bearing capacity. Meanwhile, owing to the covalent cross-linking of TBUB units, all the PUU thermosets show initial decomposition temperatures over 290 °C, which are comparable to those of the traditional thermosets. Moreover, the TBUB cross-linked PUU thermosets can be easily degraded in a mild acid solution. The small pieces of the PBUU sample can be fully decomposed in 1 m HCl/THF solution for 3.5 h at room temperature.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2024
·
IF 2.2
Yucong Song,Mingchuan Pang,Xiaoshu Ding,Guirong Wang,Xinqiang Zhao,Yanji Wang
The solubilities of 2,4-diaminotoluene (2,4-TDA), methyl 3-amino-4-methyl- N -phenyl carbamate (4-TMC) and dimethyl toluene-2,4-dicarbamate (2,4-TDC) in dimethyl carbonate (DMC) and di(2-ethylhexyl) phthalate (DOP) were determined by dynamic method at 298.15 ∼ 398.15 K under atmospheric pressure. The solubility data were correlated by the modified Apelblat equation, polynomial equation and simplified two-parameter equation. The modified Apelblat equation was more accurate than the others. In addition, the thermodynamic properties of the solution process, including the Gibbs energy, enthalpy and entropy were calculated by the modified Van't Hoff equation. The dissolution process of 2,4-TDC in DOP solvent is a non-spontaneous entropy reduction endothermic process. The dissolution processes of 2,4-TDA, 4-TMC and 2,4-TDC in DMC solvent and 2,4-TDA and 4-TMC in DOP solvent are all non-spontaneous entropy-increasing endothermic processes.
研究领域:
物理化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Tiping Wei,Liguo Wang,Jiajun Zhang,Yan Cao,Xiang Hui,Jianhui Shi,Shuang Xu,Liyan Zhao,Peng He,Huiquan Li
Bio-based pentamethylene dicarbamate (PDC) belongs to N-substituted carbamates, which are important fine chemicals and organic intermediates. In this work, well-defined CeO2 rods, cubes, and octahedrons were successfully prepared to catalyze the synthesis of PDC by carbonylation of 1,5-pentanediamine (PDA) with methyl carbamate (MC). Among them, CeO2 rods with higher amounts of acid–base sites and abundant oxygen vacancies showed superior intrinsic activity in the PDA carbonylation reaction. In situ FTIR results showed that intermediate polyureas were readily formed in the reaction, and then, CeO2 rods promoted the alcoholysis of polyureas to PDC. In situ DRIFTS results indicated that the surface of CeO2 rods is more favorable for the adsorption and activation of the reactants. CeO2 rods can also be used for the efficient synthesis of a series of N-substituted carbamates. We believe that this work will contribute to the efficient, green, and sustainable production of N-substituted carbamates.
研究领域:
催化
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化学工程
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绿色化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
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2018
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IF 0
Jinrong Lu,Xiaonan Wu,Yao Li,Wenquan Cui,Yinghua Liang
The electron-donating group dithiocarbamate functionalized silica gel (SG-PDC) was prepared and used for adsorption of metal ions from aqueous solution. The modified silica gel was characterized by fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA) and scanning electron microscopy (SEM). It showed excellent adsorption selectivity for Hg(II) ions over other metal ions, such as Cu(II), Cd(II), Pb(II). Kinetics and equilibrium isotherms of Hg (II) sorption were determined in batch equilibrium experiments. The adsorption capacity for Hg (II) of SG-PDC was more than five times as much as that of unmodified silica gel. X-ray photoelectron spectroscopy (XPS) was applied to study the adsorption mechanism and it confirmed that the improvement in mercury adsorption was related to the ligand groups containing S and N atoms anchored on the surface of silica gel. The adsorbent had high reusability after several adsorption–desorption cycles. This study provided a feasible strategy to develop the effective sorbent for Hg (II) ions by covalently modification of silica gel with ligand containing multiple coordination sites.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
WATER AIR AND SOIL POLLUTION
·
2017
·Vol. 228
·期 11
·1-15
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IF 1.702
Zhao Chuanliang,Zheng Huaili,Sun Yongjun,Liu Bingzhi,Zhou Yuhao,Liu Yongzhi,Zheng Xinyu
Modified natural biosorbents have been the research hot spot in wastewater treatment field. Natural polyphenol compounds, tannins with many functional groups can be easily modified to produce biosorbents. This work presents an environmentally friendly tannin-based dithiocarbamate (TDTC) with enhanced function of adsorption. TDTC was successfully synthesized by a two-step method involving Mannich reaction and esterification. The structure and synthetic mechanisms of TDTC were discussed through instrumental analysis. The BET-specific surface area analysis results showed that TDTC exhibited a mesoporous structure with an increased surface area. Parameters affecting adsorption such as initial pH, adsorbent dosage, contact time, initial concentration, and temperature were systematically examined. Results showed that the maximum adsorption capacity toward Ni(II) of TDTC was 112.49 mg/g. In addition, TDTC exhibited a fast adsorption rate and 80% of the Ni(II) was removed within just 20 min. The adsorption kinetics and adsorption isotherm were well described by the pseudo-second-order model and Langmuir model, respectively. Moreover, TDTC could be easily regenerated without obvious loss of adsorption capability after five adsorption–desorption cycles. All these results indicate that TDTC is an ideal candidate for the efficient removal of Ni(II).
Removal of Ni(II) from water using environmental-friendly tannin-based dithiocarbamate biosorbents.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Zhaowei Sun,Jie Kang,Yihang Zhao,Xiaozhong Zhao,Xue Xu,Miao Du,Mengge Liu,Jiaze Tang,Bo Hu,Haibo Weng
The overuse of pesticides has seriously threatened human safety and health, while their detection is still limited by complex procedures. An inkjet printable test card was created in this study for the quick and broad screening of organophosphorus (OP) and carbamate (CM) pesticides in one step. To ensure sensitivity and accuracy, slow-release polyvinyl alcohol (PVA) films were used as the printing substrate to separate the reaction system from the acetylcholinesterase (AChE) film. When the pesticide-containing sample was introduced to the test card, the activity of AChE was initially inhibited by pesticide residues. Subsequently, the PVA membrane dissolved, and the remaining AChE reacted with the substrate and chromogenic agent, resulting in the production of yellow products. Therefore, the levels of pesticide residues in the sample can be determined by observing color changes. Experimental results demonstrated that this test card exhibited high sensitivity, stability, and reproducibility. Moreover, this method is quick and straightforward, showing great potential in both commercial and domestic applications.
研究领域:
食品安全
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生物化学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2023
·
IF 5.2
Xiaoping Huang,Xulu Yuan,Huifang Yang,Rui Zhang,Guoqing Liu,Jianxian Zeng
The selective adsorption of surfactants on minerals can strengthen the differences of physical and chemical properties of mineral surfaces, thereby improving the separation efficiency of the refractory minerals. Herein, a novel surfactant S-carboxyethyl- N -benzoyl thiocarbamate (CEBTB) was prepared and utilized as a collector to selective separation of chalcopyrite from pyrite. The adsorption performances and mechanism of CEBTB on chalcopyrite and pyrite surface were studied. It showed that the functional groups (C O, C S and –COOH) of CEBTB could selectively anchor on the chalcopyrite surface and increase its surface hydrophobicity, whereas the adsorption of CEBTB on pyrite surface was weak with the surface hydrophobicity improved insignificantly. Flotation experimental indicated that CEBTB exhibited superior flotation selectivity for chalcopyrite against pyrite than the common collector of SIBX. Batch adsorption experimental results demonstrated that the adsorption of CEBTB onto chalcopyrite surface was performed by a monolayer chemisorption, as well as the adsorption process was endothermic and spontaneous.
研究领域:
矿物加工工程
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表面化学
✓ 已验证
产品关联
DOI
高影响因子
Science China-Chemistry
·
2024
·Vol. 67
·期 10
·3458-3467
·
IF 10.4
Zuo Han,Zhang Luzhi,Xuan Huixia,Gu Shijia,Xu Xinxin,Neisiany Rasoul Esmaeely,Wu Qilin,You Zhengwei
Polymeric materials have penetrated all aspects of society and play an irreplaceable role. However, there is an inherent contradiction between their mechanical properties and processing behavior. Here, inspired by cement, a crucial construction material renowned for its excellent fabricating behavior and self-strengthening properties, we have developed dynamic cross-linked poly(oxime-urethane) (CPOU). The synthesized CPOU showed good self-healing ability and 3D printability owing to the dynamic dissociation and re-association of oxime-carbamate bonds. Simple objects printed through the fused deposition modeling technique were able to be readily assembled into complex architectures through intrinsic self-healing. Furthermore, the self-strengthening of CPOU was successfully realized through multiple-step tandem reactions. The dissociation of dynamic oxime-carbamate bonds produced–NCO groups, which reacted with the surrounding water to form polar urea bonds in the polymer network, leading to an increase in the tensile strength of CPOU from 11.95 to 19.37 MPa. This work not only develops the polymers with combined self-healing, facile fabricating, and self-strengthening properties but also provides a new molecular strategy to modulate the properties of polymers, which could be potentially applied in diverse areas.
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
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Pengwu Xu,Ning Ding,Hong Wang,Jieyu Guan,Yirui Shen,Deyu Niu,Weijun Yang,Piming Ma
Thermoset polyurethanes face significant deterioration of physical properties after damage self-healing or reprocessing. It is still a great challenge to design the structure of polyurethanes to realize damage self-healing and reprocess ability under mild conditions. In this work, a series of double-crosslinked networked polyurethanes with different crosslinking densities were synthesized by designing a synergistic crosslinking strategy of oxime-carbamate bonding and hydrogen bonding arrays. By regulating the density of the crosslinked network and the content of strong and weak hydrogen bonds, the tensile strength of the polyurethanes was increased from 13.1 to 24.3 MPa, and the toughness was increased from 66.5 to 129.2 MJ/m 3 . Meanwhile, the synergistic effect of the oxime-carbamate with low activation energy and hydrogen bonding arrays enabled the polyurethanes to have an excellent self-healing (97 %) and reprocessing. The polyurethanes could be rapidly reprocessed after only 5 min of hot pressing at 120 °C by virtue of the thermal response of the dual network. More importantly, the tensile strength retention rate can still maintain more than 96 % after reprocessing. Finally, we propose the concept of a wearable device that can intelligently detect changes in resistance values during human movement. Therefore, this work provides a new idea for the preparation of polyurethanes with excellent damage self-healing and reprocessing, which is expected to expand its application.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2019
·
IF 3.674
Wei Wang,Feng Xu,Wenqiao Du,Long Zhang
A facile and efficient one-pot synthesis of methyl carbamate (MC) by urea and methanol was studied using metal modified fluorapatite as a catalyst. M 5 Ca 5 (PO 4 ) 6 F 2 (M 5 FAP, M = Co, Ni, Cu, Zn) was synthesized by co-precipitation. Among the catalysts, Zn 5 Ca 5 (PO 4 ) 6 F 2 (Zn 5 FAP) displayed the higher activity, selectivity and excellent stability after five times of reuse. A possible synthesis reaction mechanism over Zn 5 FAP catalyst was discussed.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2025
·
IF 14.2
Baozheng Zhao,Fei Song,Zheng Pan,Yijiao Xue,Linfeng Tian,Tiancheng Zhang,Li Tan,Rui Yang,Yonghong Zhou,Meng Zhang
At present, thermoset polyurethane foams were mainly derived from petroleum-based resources and faced inherent challenges such as difficulty in recycling and fire hazard. In this study, tung oil and catechol were used to prepare tung oil-derived polyphenols via Friedel-Crafts alkylation reaction. These polyphenols were combined with isocyanate to synthesize tung oil-derived polyurethane (TPU) foam. With the presence of dual dynamically cross-linked phenol-carbamate bonds, the TPU foam could be hot-pressed several times into a smooth and homogeneous TPU film. To improve the fire resistance and compressive strength of TPU foam, phytic acid functionalized metal-organic frameworks (UiO-66-NH 2 @PA) flame retardants were successfully synthesized by one-pot solvothermal method. By adding 20 wt% of flame retardants, the TPU composite foams achieved a UL-94 V-0 flammability rating with a limiting oxygen index of 28.1 vol%. The total heat release, total smoke release, CO production and CO 2 production of the TPU composite foams were reduced by 43.1 %, 57.8 %, 63.6 % and 62.1 %, respectively, compared to the pure TPU foam. Furthermore, the compressive strength of the TPU composite foam continued to increase with increasing flame retardants content, reaching a maximum of 0.55 MPa. Importantly, the introduction of the flame retardants didn't affect the hot-press recycling performance of the TPU foam, but instead improved the tensile strength and flame retardancy of the recycled TPU film. This work paved the way to produce bio-based PU foam with excellent flame retardancy and recyclability.
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 POWDER TECHNOLOGY
·
2023
·
IF 5.2
Shouxing He,Chengwang Wang,Zhihui Cheng,Xingshi Li,Ziwen Si,Yaoguo Huang,Linlin Chen,Yali Zhang
In this paper, 5-methyl hexyldithiocarbamate-1,3,4-oxadiazole-2-thione (MHCODT) was synthesized for the first time and introduced as a flotation collector in malachite flotation separation process from quartz and calcite. During the micro-flotation experiment, it was found that MHCODT showed stronger flotation ability and selectivity for malachite than conventional collector octyl hydroxamic acid (OHA), and achieved effective separation and enrichment of malachite. Measurements of contact angles, ζ-potentials and UV spectra demonstrated that MHCODT specifically adhered to the surface of malachite rather than quartz and calcite. Then, FTIR and X-ray photoelectron spectroscopy (XPS) demonstrated that Cu of malachite surface combined with S and N of MHCODT to form MHCODT-Cu(I) complexes, accompanied by the reduction of divalent Cu. The result of density functional theory (DFT) method indicated that the C S bonds and N H bonds in oxadiazole thione and the dithiocarbamate groups were the chemical reaction center. Based on the above test results, the adsorption models of MHCODT-Cu + and MHCODT-Cu 2+ were proposed.
研究领域:
矿物加工工程
·
化学
✓ 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）