JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 141
·期 2
·e54792
·
IF 3
Qian Chen,Dayong Ren,Weichen Sheng,Kan Zhang
Two novel bio-based benzoxazine monomers containing imide or amide group (HPIDD-fa and HPBA-fa) were synthesized from raw materials of benzoyl chloride/phthalic anhydride, tyramine, furfurylamine and paraformaldehyde via a two-step reaction. Fourier transform infrared spectroscopy (FT-IR), proton and carbon nuclear magnetic resonance (NMR) spectroscopies were performed to characterize the structures of the benzoxazine monomers. The curing behavior was investigated by using differential scanning calorimetry (DSC) and in situ FT-IR, and the DSC results indicate that the peak curing temperatures of HPIDD-fa and HPBA-fa are centered at 248.5 and 230.1°C, respectively. In addition, thermogravimetric analysis (TGA) suggests that the newly developed bio-based benzoxazine-derived polybenzoxazines present excellent thermal stability with T d10 (temperature at 10% weight loss) of 385 and 368°C for poly(HPIDD-fa) and poly(HPBA-fa), respectively. The current investigation suggests that our newly obtained bio-based thermosetting resins are promising materials for high-tech applications.
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
Chinese Journal of Natural Medicines
·
2020
·
IF 2.014
Yong-Jiang WANG,Li WANG,Xin HE,Dong-Dong XU,Jun TANG,Ya-Tuan MA,Yi-Jun YAN,Yu-Cheng GU,Jing YANG,Sheng-Xiong HUANG
Inthomycins are polyketide antibiotics which contain a terminal carboxamide group and a triene chain. Inthomycin B ( 1 ) and its two new analogues 2 and 3 were isolated from the crude extract of Streptomyces pactum L8. Identification of the gene cluster for inthomycin biosynthesis as well as the 15 N -labeled glycine incorporation into inthomycins are described. Combined with the gene deletion of the rare P450 domain in the NRPS module, a formation mechanism of carboxamide moiety in inthomycins was proposed via an oxidative release of the assembly chain assisted by the P450 domain.
研究领域:
微生物学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AICHE JOURNAL
·
2023
·Vol. 69
·期 5
·e18023
·
IF 3.7
Qing Sun,Yan Dong,Shuai Wang,Zhanfang Cao,Xin Ma,Hong Zhong
Modified surfactants can regulate their adsorption at the target surface and are essential for various separation applications such as froth flotation. Thioether-containing hydroxamic acid (BTHA) is an excellent oxidized-ore collector with poor dispersibility. Herein, acylamino, which possesses the ability to improve the surfactants' self-assembly and dispersion, was introduced to synthesize N-[6-(hydroxyamino)-6-oxohexyl] benzylthioacetamide (BTAHA); thus, applying it to cassiterite flotation. Surface tension, adsorption capacity, in situ AFM, and surface energy results reveal BTAHA displays strong bubble stability and readily adsorbs onto the mineral's surface, promoting hydrophobic flotation. BTAHA is an effective cassiterite collector and has good separation effects on cassiterite against calcite. It can form Van der Waals forces and five-membered hydroxamate-(O,O)-Sn rings with Sn atoms on cassiterite surfaces via thioether and hydroxamate groups. Meanwhile, the presence of intermolecular hydrogen bond between the amide groups facilitates the self-assembly of the collectors on the cassiterite surface, and has broad industrial application prospects in various separation processes.
研究领域:
矿物加工工程
·
界面化学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Yizhou Feng,Daohui Lin,Kun Yang,Wenhao Wu
Knowledge of antibiotic desorption from high-temperature biochar is essential for assessing their environmental risks, and for the successful application of biochar to remove antibiotics. In previous studies, irreversible pore deformation, formation of charge-assisted hydrogen bonds or amide bonds were individually proposed to explain the desorption hysteresis of antibiotics on biochars, leading to a debate on hysteresis mechanism. In this study, desorption of sulfamethoxazole (SMX), ciprofloxacin (CFX) and tetracycline (TET) on a wood chip biochar produced at 700 °C (WBC700) and its oxidized product (O-WBC700) was investigated to explore the underlying hysteresis mechanism. Significant desorption hysteresis was observed for SMX, CFX and TET on WBC700 and O-WBC700. Hysteresis index (HI) of each antibiotic was higher on O-WBC700 with more oxygen-containing groups than WBC700, and was higher at lower equilibrium concentration. HI of antibiotics on WBC700 (or O-WBC700) increased in the order of SMX < CFX < TET. The calculated adsorption enthalpy of each antibiotic on WBC700 was positive, indicating an endothermic process. These phenomena together with FTIR, XPS spectra confirmed that the desorption hysteresis mechanism of antibiotics on high-temperature biochar is the formation of amide bonds by amidation reaction, but not the pore deformation or the hydrogen bond. Moreover, antibiotic can form amide bonds with WBC700 only if the amine group with p K a > 4.0, and the HI values were positively correlated with their p K a values. Amine group of antibiotics with higher p K a value show more nucleophilicity and could form stronger amide bonds with carboxyl group of biochar. The obtained results could help to solve the debate on desorption hysteresis mechanism of antibiotics on high-temperature biochars, and provide a new insight into the role of amine groups and amidation reaction on the hysteresis.
研究领域:
环境科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 130
·期 2
·1058-1063
·
IF 1.395
Xiulan Zhao,Qin Zhang,Lixin Xue,Qianru Shi,Kang Tao
Poly(ether ether ketone) with pendent sulfonimide groups (B-SPEEK) was prepared from poly(ether ether ketone), sulfuric acid, thionyl chloride, para -toluene sulfonate, and pyridine. The prepared B-SPEEK was characterized by Fourier transform infrared spectroscopy, 1 H-NMR, and thermogravimetric analysis. The swelling of the gels was examined in N,N -dimethylacetamide (DMAC), N,N -dimethylformamide (DMF), 1-methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), and a DMSO/water mixture. The gel showed extremely high swelling in DMSO, DMF, DMAC, and NMP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1058-1063, 2013
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 39
·期 1
·122-132
·
IF 3.154
Yu Man-Man,Yang Wei-Jun,Niu De-Yu,Cai Xiao-Xia,Weng Yun-Xuan,Dong Wei-Fu,Chen Ming-Qing,Xu Peng-Wu,Wang Yang,Chu Hong,Ma Pi-Ming
In this work, hydroxyl-terminated oxalamide compounds N 1 , N 2 -bis(2-hydroxyethyl)oxalamide (OXA1) and N 1 , N 1′ -(ethane-1,2-diyl)bis( N 2 -(2-hydroxyethyl)oxalamide (OXA2) were synthesized to initiate the ring-opening polymerization of L-lactide for preparation of oxalamide-hybridized poly(L-lactide) (PLA OXA ), i.e. , PLA OXA1 and PLA OXA2 . The crystallization properties of PLA were improved by the self-assembly of the oxalamide segments in PLA OXA which served as the initial heterogeneous nuclei. The crystal growth kinetics was studied by Hoffman-Lauritzen theory and it revealed that the nucleation energy barrier of PLA OXA1 and PLA OXA2 was lower than that of PLA. Consequently, PLA OXA could crystallize much faster than PLA, accompanied with a decrease in spherulite size and half-life crystallization time by 74.8% and 86.5% (T = 125 °C), respectively. In addition, the final crystallinity of PLA OXA1 and PLA OXA2 was 6 and 8 times higher, respectively, in comparison with that of neat PLA under a controlled cooling rate of 10 °C/min. The results demonstrate that the hybridization of oxalamide segments in PLA backbone will serve as the self-heteronucleation for promoting the crystallization rate. The higher the content of oxalamide segments (PLA OXA2 compared with PLA OXA1 ) is, the stronger the promotion effect will be. Therefore, this study may provide a universal approach by hybridizing macromolecular structure to facilitate the crystallization of semi-crystalline polymer materials.
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
Materials
·
2021
·Vol. 14
·期 6
·1402
·
IF 3.623
Yi Zeng,Yiwu Liu,Jinghua Tan,Jie Huang,Junjie Liu,Ao Tang,Chengliang Chen,Hong Chen
In order to meet the increasingly stringent requirements for heat resistance and barrier properties in the packaging and electronic device encapsulation field. A high-barrier polyimide (NAPPI) contains naphthalene ring and amide group was prepared by polymerization of a novel diamine (NAPDA) and pyromellitic dianhydride. The structure and properties of diamine monomers and polymers were characterized. Results show that the NAPPI exhibits superior barrier properties with extremely low water vapor and oxygen transmission rate values of 0.14 g·m−2·day−1and 0.04 cm3·m−2·day−1, respectively. In addition, the NAPPI presents outstanding mechanical properties and thermal stability as well. This article attempts to explore the relationship between NAPPI structure and barrier properties by combining experiment and simulation. Studies on positron annihilation lifetime spectroscopy, Wide angle X-ray diffractograms and molecular dynamics simulations prove that the NAPPI has smaller interplanar spacing and higher chain regularity. In addition, the strong chain rigidity and interchain cohesion of NAPPI due to the presence of the rigid naphthalene ring and a large number of hydrogen bond interactions formed by amide groups result in compact chain packing and smaller free volume, which reduces the solubility and diffusibility of small molecules in the matrix. In general, the simulation results are consistent with the experimental results, which are important for understanding the barrier mechanism of NAPPI.Keywords:polyimide;naphthalene ring;amide group;barrier properties;molecular simulation
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
PubMed
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 10
·5453-5462
·
IF 10.733
Yanling Qiu,Hexiang Zhong,Wenbin Xu,Taotao Zhang,Xianfeng Li,Huamin Zhang
The conversion of CO2 into value-added chemicals by employing renewable energy via an electrochemical process has received increasing attention. However, the low reaction rate and efficiency, as well as poor selectivity, have limited its further development. The low solubility of CO2 in an aqueous solution is one of the main factors that limit the reaction rate and selectivity of the electroreduction of CO2 (ERC) at a high overpotential. In this study, an organic additive containing an –NH2 group (methyl carbamate, MC) was incorporated into the ERC electrolyte for the first time. By utilizing the affinity interaction between a Lewis acid (the –NH3+ group formed by protonation of the –NH2 group) and a Lewis base (CO2), the ERC reaction rate was increased by 17%, and the faradaic efficiency for the production of CH4 reached 81.6%, which represented a large increase of 34% and surpassed that of most reported Cu electrodes. Furthermore, the partial current density for the production of CH4 was 31 mA cm−2 at −2.13 V (vs. RHE), which represents an increase of 30% in comparison with that in the blank system. In addition, the competitive hydrogen evolution reaction was substantially inhibited, and the decline in faradaic efficiency increased from 38.5% to 48.1% when the potential decreased gradually from −1.63 V to −1.98 V (vs. RHE). DFT calculations further indicate that the –NH3+ group can significantly promote the adsorption of CO* and CHO* on the Cu surface and increase the surface coverage of both intermediates. CHO* can be further stabilized by the –NH3+ group via the facilitation of partial electron transfer from Cu to C and the formation of H-bonds, which is favorable for further hydrogenation to form hydrocarbons. These results provide a simple and powerful way to increase the reaction rate and product selectivity of the reduction of CO2.
研究领域:
电化学
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材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2023
·
IF 10.7
Shuhan Feng,Jianyong Yi,Youchuan Ma,Jinfeng Bi
Gelation of amidated pectin in the acid environment with the absence of calcium has been found, but the mechanism and gel properties are still not fully understood, especially the role of amide groups. In this study, a series of pectins with different degrees of amidation (DA) were prepared by ammonia reaction, and their structural characteristics including neutral sugar contents, molecular weight contribution, and molecular morphology were fully identified. Acid-induced hydrogels with various DA were then obtained to investigate the impact of amino groups on pectin gelation. Results showed that the higher the DA, the faster the gelation process, and the more stable the gel network. Dynamic rheological and pH stability tests confirmed the essential roles of low pH value (<3.5) and high DA (>49.76%) on the amidated pectin gelation without calcium. Hydrogen bonds were identified as the main interaction for the amidated gel mechanism and enabled the thermo-reversible properties of amidated gels. High content of amide groups allowed the formation of a denser gel network structure with greater mechanical strength, stronger thermo-reversibility, and higher pH stability.
研究领域:
食品科学
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高分子化学
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2019
·
IF 2.268
Xiangtian Cheng,Zhuojian He,Yuancong Luo,Xiaoqing Zhang,Caihong Lei
To gain a better understand the correlation between the amount of polar functional groups and interfacial properties, we propose to functionalize carbon fiber (CF) with amine-capped cross-linked polyphosphazene (ACP) and tailor the polycondensation time, aiming to control the amount of amine groups on CF surface. The chemical composition and surface morphology of modified CF were systematically investigated. The results show that the ACP was uniformly distributed on CF surfaces. X-ray photoelectron spectroscopy results confirmed that the quantity of amine groups is proportional to that of grafted ACP as the reaction time prolong, and it reaches the plateau when the reaction time exceed 35 h. The microbond testing results reveal a positive correlation of the amount of amine groups and interfacial shear strength, and the ACP-grafted CF with 35 h reinforced composites possess best IFSS (92.1 MPa), with an increase of about 33.5% compared with that of oxidized CF-reinforced composites. POLYM. COMPOS., 40:E1831–E1839, 2019. © 2019 Society of Plastics Engineers
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
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Yuandong Cui,Bin He,Yu Lei,Yu Liang,Wanting Zhao,Jian Sun,Xiaomin Liu
High and cost-efficient capture of CO 2 is a prerequisite and an inevitable path of carbon emission reduction. To address the challenges (high cost, low efficiency, less sustainability, etc .) of existing petroleum-based CO 2 absorbents, herein, a class of efficient and sustainable lignin-based absorbents were resoundingly prepared by grafting the active amine group on a lignin derived compound vanillin and alkali lignin. The results demonstrated that vanillin modified by acrylamide achieved the excellent absorption capacity among the three absorbents, whose ability was 0.114 g CO 2 per gram of absorbent under 25 °C and 100 kPa. In addition, the absorbent retained stable absorbability of CO 2 after 6 cycles. The absorbing capacity of the absorbent formed by the coupling of vanillin and acrylamide to CO 2 was much greater than their own ( i.e. 0 g CO 2 ·g −1 vanillin, 0.01 g CO 2 ·g −1 acrylamide, respectively). Detailed information revealed the multi-site synergistic absorption mechanism, in which CO 2 has C and O double interactions with the amide group of the absorbent, and single interaction with the hydroxyl oxygen on the benzene ring of the absorbent. The absorption capacity of modified lignin for CO 2 is as high as 0.12 g CO 2 per gram of absorbent, which is comparable with that of model compound vanillin. This work not only provides a new idea for the design of bio-absorbents for CO 2 capture, but explores the application potential of lignin-based materials.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Encheng Liu,Zhenzhen Wang,Zhonghua Sun,Zhihui Zhang,Mingyang He,Qun Chen,Junfeng Qian
The chemical microenvironment modulation of active sites holds promise for facilitating their catalytic performance. Herein, single-atom Ru anchored by ZrSBA-15 modified with diverse organic amine groups has been fabricated and enabled CO2 hydrogenation to produce formic acid (FA) under mild conditions. However, the reaction cannot be achieved without the modification of organic amines. The functional groups as the microenvironment around Ru active sites effectively regulated the activity, in which Ru encapsulated in ZrSBA-15 bearing –NH2 groups exhibited the highest activity, with turnover number (TON) and turnover frequency (TOF) values of 505 and 64 h–1, respectively. Both characterization and experimental results validated that the functional group manipulated the adsorption capacity of the reactant, the electronic state of Ru and hydrophilicity/hydrophobicity of the materials, and thus the catalytic performance.
研究领域:
催化化学
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材料科学
✓ 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）