INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
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2018
·Vol. 53
·期 6
·1494-1502
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IF 2.383
Fang-Fang Chen,Jie Sang,Yao Zhang,Jun Sang
Summary This study aimed to develop a green two-dimensional HPLC-DAD/ESI-MS method for analysing anthocyanins from Prunus cerasifera var. atropurpurea leaf and improve their stability in energy drinks by the addition of phenolic acids. Ethanol and tartaric acid solutions were used as mobile phases for one-dimensional HPLC-DAD for quantitative analysis of anthocyanins, and the primary anthocyanins were identified as cyanidin-3- O -galactoside, cyanidin-3- O -glucoside and cyanidin-3- O -rutinoside using two-dimensional HPLC-MS. Method validation showed that the developed method was accurate, stable and reliable for the analysis of P. cerasifera anthocyanins. The effects of gallic, ferulic and caffeic acid on the stability of cyanidin-3- O -galactoside, cyanidin-3- O -glucoside, cyanidin-3- O -rutinoside and total anthocyanins from P. cerasifera leaf in energy drinks were evaluated, and the degradation of P. cerasifera anthocyanins ideally followed a first-order model ( R 2 > 0.98). Gallic acid showed stronger protective effects on P. cerasifera anthocyanins in energy drinks, and adding/increasing ferulic and caffeic acids accelerated the degradation reactions.
研究领域:
分析化学
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食品科学
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植物化学
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DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Shuai Zhang,Qiusha Li,Jiajia Ye,Hongyi Sun,Xiaobo Liu
Aromatic heterocyclic polymers play key roles in high performance polymers . Among the various unsaturated functional groups, alkynyl and cyano groups stand out because they may form rigid and thermally stable six-membered rings such as benzene and triazine rings. In this work, monocyclic benzoxazine is used as a platform to integrate the alkynyl and/or cyano groups and the polymerization of these compounds are studied in detail. The curing behavior is investigated by differential scanning calorimetry (DSC), the chemical structures of the polymers are studied by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Moreover, the thermal and dielectric properties of the polymers are also probed. It is found that trimerization of alkynyl groups occur more easily than cyano groups. As the ratio of the two functional groups varies, pyridine rings can be formed more easily than pyrimidine rings. Moreover, more cyano groups may lead to reduction of glass transition temperature ( T g ) because of the low reactivity of cyano groups, but formation of pyridine rings could greatly improve the thermal stability of the polymer and char yield could reach 69%, which is much higher than the other polybenzoxazines prepared in this work.
研究领域:
材料科学
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化学
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DOI
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 48
·7427-7435
·
IF 5.687
Nafeesa Mushtaq,Guofei Chen,Lala Rukh Sidra,Yang Liu,Xingzhong Fang
Two novel series of highly organosoluble and curable polyimides containing pendant nitrile groups PI (a–d) and phthalonitrile-terminated polyimides PN-PI (a–d) were prepared by solution polycondensation of isomeric bis(chlorophthalimides)s and 2,6-dichlorobenzonitrile with 4,4′-thiobisbenzenethiol. The inherent viscosities of these copolymers were in the range of 0.37–0.59 dL g−1 in N-methyl-2-pyrrolidone (NMP) at 30 °C. The phthalonitrile and pendant nitrile groups in isomeric poly(thioether-ether-imide)s were thermally crosslinked without a catalyst through thermal curing up to 280–360 °C, which led to the transformation from thermoplastic polymers to thermosetting polymers. All PIs before and after crosslinking were characterised by gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. PN-PI (a–d) and PI (a–d) were found to be highly soluble in some solvents, such as chloroform, dimethylacetamide, m-cresol, dimethlyformamide and N-methyl-2-pyrrolidone, while the crosslinked polymers were insoluble in all tested solvents. The crosslinking results of pendant nitrile and terminal phthalonitrile groups are also compared. Both series of PIs showed high thermal stability based on 5% weight loss temperature (T5%) in the range of 471–509 °C and increased up to 35 °C after thermal curing. Polyimides showed high glass transition temperatures (Tgs) ranging from 191–213 °C as determined by DSC, but no detectable Tg was observed after thermal heating, indicating the crosslinked structure of PIs. The mechanical properties also enhanced after the crosslinking of the copolymers. The tensile modulus and strength of the cured PI films were in the range of 3.3–4.7 GPa and 68–122 MPa, respectively, which were up to 62% and 35% higher than the uncured films.
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
CELLULOSE
·
2024
·Vol. 31
·期 10
·6141-6153
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IF 4.9
Song Jun,Wang Linfeng,Shan Jicheng,Li Chuanmeng,Wang Mengdie
Cellulose liquid crystal solutions have been extensively studied, and the methylene length of mesogenic units has a significant influence on the properties of cellulose liquid crystal solutions. In this study, 4-(ω-(methylimidazole)alkyloxy)-4’-(cyano)-biphenyl (CBP-n) with 4–7 methylene lengths were synthesized as mesogenic units to prepare cellulose side chain liquid crystal in 1-Allyl-3-methylimidazolium chloride (AMIMCl). And their liquid crystal properties were studied by differential scanning calorimetry (DSC), in-situ infrared spectrometer (IR), torque rheometer, and polarizing microscope (POM). The results showed that CBP-n with 4–7 methylene lengths were thermotropic liquid crystal, and the cellulose/CBP-n/AMIMCl solutions were lyotropic liquid crystal when the concentration of cellulose is 6wt% and the concentration of CBP-n with methylene length 4 and 6 is 3wt%. In-situ IR proved that the liquid crystal formation of cellulose/CBP-n/AMIMCl solution was caused by the hydrogen bonding formed between cellulose and CBP-n. And the solutions have a fewer entanglement number and lower viscosity than those of methylene length 5 and 7, indicating that the hydrogen bonding interaction between CBP-n with even methylene length and cellulose molecule is stronger than that of odd methylene length. This study provides a new approach to produce cellulose fibers using cellulose/CBP-n/AMIMCl as a new renewable resource.
研究领域:
材料科学
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化学
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Yajun Li,Chuanli Lu,Ruirong Chen,Kui Wu
The solubility of 1,4-dicyanobenzene (DCB) in 17 neat solvents, that is, methanol, ethanol, n-propanol, isopropanol, acetone, ethyl acetate, ethyl formate, methyl acetate, cyclohexanone, cyclopentanone, tetrahydrofuran, 2-butanone, acetonitrile, chloroform, 2-pentanone, dichloromethane, and diethyl ether, was measured via a gravimetric method from 272.95 to 324.15 K under ambient pressure. Within the experimental temperature range, the mole fraction solubility of DCB increased with the rising temperature in all selected solvents, and the order of magnitude is cyclopentanone > dichloromethane > cyclohexanone ≈ tetrahydrofuran > chloroform > (acetone, 2-butanone) > 2-pentanone ≈ methyl acetate > ethyl formate > ethyl acetate > acetonitrile > diethyl ether > methanol > ethanol > n-propanol > isopropanol. The solubility of DCB in ketones was much higher than that in ethers and alcohols. The Wilson model, nonrandom two-liquid model, Apelblat equation, and λh equation were employed to mathematically express the solid–liquid phase equilibrium data of DCB. The maximum values of the root-mean-square and relative average deviations were 9.83 × 10–5 and 5.21 × 10–3, respectively, which indicated that good correlation was recorded between the experimental and calculated data. The dissolution enthalpy, entropy, and Gibbs free energy were calculated on the basis of thermodynamic relations and the Wilson model, which revealed that the dissolution of DCB was a spontaneous and endothermic process.
研究领域:
化学工程
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物理化学
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DOI
高影响因子
Coatings
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2021
·Vol. 11
·期 11
·1396
·
IF 2.881
Min Zhang,Dong Peng,Feifei Peng,Anwei Huang,Kaiqiang Song,Qingbing He,Changqing Yin,Jinsong Rao,Yuxin Zhang,Haitao Chen,Dalong Cong,Zhongsheng Li
The Al coatings were electrodeposited on the Cu substrate from AlCl3-EMIC ionic liquid (AlCl3:EMIC = 2:1 molar ratio) containing three cyanopyridine additives with different positions of the substituent group on the pyridine ring, which were 2-cyanopyridine, 3-cyanopyridine, and 4-cyanopyridine. The effects of cyanopyridine additives on the deposition potential, morphology, brightness, and corrosion properties of Al coatings were investigated. It was considered that the deposition potential of Al shifted to more negative overpotentials, the quality of Al coatings was promoted, and the corrosion property was improved by the cyanopyridine additives to a varying degree. Especially in the presence of 4-cyanopyridine, the flattest mirror bright Al coating was obtained, which had the smallest homogeneous nanocrystal grain size and strongest Al (200) crystallographic orientation. The average roughness Ra value was as low as 31 nm compared to that in the absence of cyanopyridine additives, which was 417 nm. Furthermore, the corrosion current density of the bright Al coating was three orders of magnitude lower than the rough Al coating, which resulted from the dense nanocrystal structure.Keywords:bright Al;electrodeposition;ionic liquids;cyanopyridine;additives
研究领域:
材料科学
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电化学
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表面工程
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DOI
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 16
·2481-2489
·
IF 5.582
Tianwen Zhu,Qiaoxi Yu,Weiwen Zheng,Runxin Bei,Wenhui Wang,Minming Wu,Siwei Liu,Zhenguo Chi,Yi Zhang,Jiarui Xu
The precision regulation of the dielectric polarization and dielectric loss of polymer materials, developing intrinsic high-performance polymers with high dielectric constant, low dielectric loss and excellent temperature resistance is very challenging. In this work, a facile molecular design strategy was developed by directly introducing two ortho-position aromatic nitrile groups into the rigid polyimide backbone. Compared with similar polyimides without nitrile groups (0CN-PIs), the polarizability and dielectric constant of the designed polyimide (2CN-PIs) can be greatly increased. Meanwhile, the polarization motions of the nitrile groups can be limited at room temperature, which is beneficial to lowering the dielectric loss. Among the designed polyimides, 2CN-BTDA shows a high k value of 4.80, low dielectric loss of 1.57 × 10−3 at 1 kHz (25 °C), and breakdown strength of 219.4 kV mm−1 with high maximum discharge energy density of 1.023 J cm−3. Moreover, its Tg value is as high as 325 °C, much higher than that of most traditional dielectric polymers. The essence of designing high-k–low-loss intrinsic polymers was revealed by reconsidering the Clausius–Mossotti equation, where the total polarizability should be maximized while the chain stacking should be as tight as possible; that is, a rigid polymer backbone, small sized polar groups (like nitrile groups), and a spatial position in favor of orientation polarization are preferred. The results are helpful to promote the research progress of dielectric polarization and of great significance to the development of high-performance high-k–low-loss dielectric materials for potential applications in modern electronic information and microelectronic industry.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Bing Zhang,Shan Wang,Chuntian Qiu,Yangsen Xu,Jiandong Zuo
Porous carbon nitride photocatalysts with sufficient cyanide groups were facile fabricated through simple calcination process with cheap salt as porogen. The introduction of cyanide groups can enhance charge separation efficiency and reductive activities of photogenerated electrons of carbon nitride. The optimized CN-S catalysts can selectively oxidize alcohols to aldehydes with broad scope as well as reduce oxygen to H 2 O 2 . The tandem strategy can photocatalytic produce H 2 O 2 with a rate of more than 200 μmol h −1 g −1 which is nearly 19 times than that without alcohols and fulfilled utilization of both photo-generated electrons and holes.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Yu-Lin Hong,Jian Sun,Hong-Wei Yang,Chang Wang,Yun Liu,Zhi-Wei Tan,Cheng-Mei Liu
Nitrile-rich polymers have found applications in carbon fibre, functional materials and rubber industry, though nitrile-rich polyelectrolytes have seldom been reported before. Here we present a nitrile-rich reactive phosphonium-based polyelectrolyte (PVBzTCPC) synthesized by the RAFT polymerization of 4-vinylbenzyl-tris(2-cyanoethyl)phosphonium chloride (VBzTCPC), a CN-rich phosphonium monomer prepared from tris(2-cyanoethyl)phosphine (TCP) and 4-vinylbenzyl chloride. The RAFT polymerization behaviour of the monomer was studied and it was found that the polymerization of monomer proceeded in a controlled/living manner. PVBzTCPC underwent the Wittig reaction and vinyl groups were introduced into the polymer chain as polymerizable pendant groups. Post-polymerization modifications of PVBzTCPC through the nitrile group proceeded successfully and the modified polymers were also phosphonium-based polyelectrolytes. PVBzTCPC showed a high tendency to form an undissolved polyelectrolyte complex with sodium perfluorooctanoate in aqueous solution, which provided a possible way of removing this persistent organic pollutant from water. The DMF solution of CN-rich PVBzTCPC showed LCST-type (lower critical solution temperature) phase transition without adding any foreign salts over 100 °C, and a possible mechanism of LCST transition was proposed.
研究领域:
材料科学
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化学工程
·
环境科学
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产品关联
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Chengwen Gu,Jiahui Li,Yi Zhao,Cijian Zhang,Qianqian Fan,Qian Liu,Shouhai Zhang,Yunhe Zhang,Xigao Jian,Zhihuan Weng
High-temperature poly(aryl ether ketone) dielectrics have attracted application prospects in the field of polymer film capacitors. However, the investigations on improving the capacitive properties of poly(aryl ether ketone) based on molecular structure design strategies were absent. Herein, a series of poly(aryl ether ketone) bearing phthalazinone moiety were synthesized, and the effect of chemical structures on the capacitive properties of the resultant polymers was investigated by experimental data and density functional theory calculation. The introduction of the sulfone group could not only improve the permittivity but also construct deep carrier traps to enhance the breakdown strength , leading to high discharge energy density ( U e ) value of the poly(phthalazinone ether sulfone ketone) (PPESK). For the poly(phthalazinone ether nitrile ketone) (PPENK), the introduction of the nitrile group could improve the U e at room temperature, but reduce the value at elevated temperatures. As a result, at room temperature, the maximum U e of both the PPESK (4.56 J/cm 3 ) and the PPENK (3.40 J/cm 3 ) was higher than that of the PPEK (3.02 J/cm 3 ). Notably, the maximum U e of the PPESK reached 3.07 J/cm 3 at 150 °C, which is twice that of commercially bi-oriented polypropylene (BOPP) film (1.5 J/cm 3 at 70 °C). Additionally, at the electric field of 200 MV/m and 150 °C, the PPESK films exhibited the U e of 0.72 J/cm 3 with charge-discharge efficiency ( η ) of 97.2 %, which was obviously superior to those of the BOPP ( U e = 0.4 J/cm 3 with η of 96 % at 70 °C). This study presents an in-depth analysis regarding the relationship between the sulfone and nitrile groups and the capacitive performance of poly(aryl ether ketone) bearing phthalazinone moiety, which is informative for designing high-temperature dielectric polymers.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
Molbank
·
2022
·Vol. 2022
·期 2
·M1373
·
IF 0
Jialuo Chen,Lili Duan,Kunming Liu,Jin-Biao Liu
This short note elaborates a concise protocol for the synthesis of two novel vicinal haloethers bearing a malonontrile group, 2-bromo-2-(methoxy(phenyl)methyl)malononitrile (1) and 2-iodo-2-(methoxy(phenyl)methyl)malononitrile (2). The structures of the synthesized compounds were confirmed by 1H, 13C-NMR spectroscopy. The final products indicate that methanol not only acts as solvent but also participates in and dominates the reaction result.Keywords:β;β-dicyanostyrene;difunctionalization;vicinal haloether
研究领域:
有机化学
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合成化学
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DOI
REACTIVE & FUNCTIONAL POLYMERS
·
2025
·
IF 5.1
Xudong Wang,Zhicheng Wang,Zhigang Yuan,Qiufei Chen,Tao Liu,Athar Ali Khan Gorar,Wenbin Liu,Jun Wang
Benzoxazine resins with cyano groups, characterized by abundant nitrogen functionalities and excellent properties after curing, play an important role in the field of advanced materials. In this work, a noval high-performance trifunctional benzoxazine monomer (TH-apn) containing cyano groups was successfully synthesized by using green solvents (PEG 200). The chemical structure of TH-apn was verified by proton nuclear magnetic resonance ( 1 H NMR), 13 C nuclear magnetic resonance ( 13 C NMR), and fourier transform infrared (FTIR) spectrum. The curing behavior and curing kinetic of TH-apn were investigated by differential scanning calorimetry (DSC) and the thermal properties of poly (TH-apn) at different post-cure temperatures were characterized by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Flame retardancy was assessed through using the UL-94 standard vertical flame test and the limiting oxygen index (LOI). Results revealed that poly(TH-apn-280) exhibited higher thermal performance (glass transition temperature ( T g ), initial decomposition temperature ( T 5 ), and char yield at 800 °C ( Y c ) of 395 °C, 459 °C, and 74.9 %, respectively), which was attributed to the cross-linking of cyanine to form a more stable structure after curing at high temperatures. Poly(TH-apn-280) demonstrated outstanding flame retardancy, achieving an LOI of 35.9 %. However, its flexural strength was 24.4 % lower than poly(TH-apn-240). TH-apn resin showed great potential for high temperature ablative materials, which resulted in excellent thermal stability and flame retardancy.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）