JOURNAL OF APPLIED POLYMER SCIENCE
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2024
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IF 2.7
Zhangcheng Gao,Lianfang Feng,Xueping Gu,Jintang Duan,Mingzhe Jiang,Cailiang Zhang
The combination of aromatic and aliphatic structures can endow polyurea with distinct performance advantages. A one-step feeding method is used to synthesize linear hybrid aliphatic/aromatic copolyureas by varying the ratio of m -phenylenediamine (MPD) and polyoxypropylenediamine (D2000) reacting with 4,4′-diphenylmethane diisocyanate (MDI). Real-time Fourier-transform infrared spectrometer monitoring reveals that D2000 exhibits higher reactivity than MPD. Consequently, in the MDI/MPD/D2000 system, D2000 initially reacts with MDI to form an isocyanate-terminated prepolymer, which subsequently reacts with MPD. Compared with the two-step feeding method, this approach successfully eliminates biuret formation and enhances tensile strength. Additionally, decreasing the molar ratio of D2000 to MPD ( λ m ) reduces the size and degree of microphase separation in the polyurea by increasing the ordered hydrogen bonding and benzene conjugation, leading to an increase in tensile strength. Specifically, as λ m decreases from 70 mol% to 30 mol%, the degree of microphase separation decreases from 0.47 to 0.2, causing the tensile strength to rise from 28 to 48 MPa. Further reducing λ m to 30 mol% decreases the degree of microphase separation to 0.16, resulting in an increase in tensile strength to 78 MPa.
研究领域:
材料科学
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化学工程
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2025
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IF 5.2
Yixuan Wang,Zhenmin Cheng,Quanjie Liu,Chao Yang,Liming Jia,Chen Yang,Hongxin Bai
Anthracene is characterized by its unique electronic and organic properties as the cornerstone for various applications. Particularly in the synthesis of anthraquinone derivatives, anthracene serves as the key raw materials in the alkylation and oxidation, acting as the hydrogen carrier for hydrogen peroxide production via AO process. However, inadequate knowledge about its dissolution behavior in solvents has been one of the main limitations for its purification and practical applications, commonly resulting in its unsatisfactory commercial products and thus leads to insufficient efficiency of chemical synthesis. In this study, the solubility behavior of anthracene in various solvents was specifically investigated by the synthetic method at temperatures ranging from 304.15 to 338.15 K under atmospheric pressure. To facilitate decent solvent s screening, aromatics such as benzene and its derivatives were specifically exploited as the working solution components in this work. The experimental solubility values and their corresponding activity coefficient of anthracene were analyzed and correlated on the basis of modified Apelblat and λ-h models. Furthermore, thermodynamic analysis, including the changes of enthalpy, entropy, and Gibbs free energy, was subsequently conducted using the modified Van’t Hoff equation. As a result, the dissolution of anthracene is an endothermic and entropy-driven process in studied solvents, among which chlorobenzene seems to be the most actively interactive with anthracene and thus results to the best dissolving capacity for anthracene.
研究领域:
化学工程
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物理化学
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2024
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IF 3.8
Juanjuan Wang,Qiangqiang Yan,Yinzhong Guo,Lucy Bai,Tom Kalantar,Amy Song,Wayne Zhang,Yingfeng Yu
With increasingly strict requirements for environmental protection, degradable adhesives are urgently required to enable recycling challenge. In this paper, an aromatic chain extender, Fmoc-BHA, which can undergo 1,4-elimination under alkaline conditions, and polyurethane adhesives, which readily decompose after deprotection, are synthesized. The molecular weight of the degradable polyurethane decreased from 6.5 × 104 to 1.1 × 104 g/mol after alkaline treatment. The process and mechanism of degradation was studied by nuclear magnetic resonance, Fourier transform infrared, and gel permeation chromatography. The evolution of bond shear strength under different alkaline conditions was tested; the results showed the practicality of using a degradable polyurethane laminating adhesive to enable film detachment.
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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高影响因子
ATMOSPHERIC ENVIRONMENT
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2022
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IF 5.755
Jingrong He,Li Li,Yunxiang Li,Mei Huang,Ying Zhu,Shihuai Deng
In this work, six aromatic organosulfates (phenyl, 2-/3-/4-methylphenyl, benzyl and phenethyl sulfates) were synthesized, with the purpose to obtain the standards and apply them to quantify the organosulfates in ambient aerosols. The purity of the synthesized organosulfates was determined by high performance liquid chromatography/ultraviolet detector (HPLC/UV). Meanwhile, the organosulfate standards and atmospheric PM 2.5 samples were measured by high performance liquid chromatography/electrospray ionization/tandem mass spectrometry (HPLC/ESI/MS/MS). The characteristic ion fragments were phenolate anion m/z 93 for phenyl sulfate, creylate anion m/z 107 for methylphenyl sulfate, sulfate radical anion ·SO 4 − ( m/z 96) for benzyl sulfate, and hydrogen sulfate anion HSO 4 − ( m/z 97) for phenethyl sulfate. The characteristic fragment ions used for quantification can improve the identification of target compounds in chromatograms, obtain lower detection limits, and will minimize analytical errors caused by the introduction of surrogates. The concentrations of phenyl, methylphenyl, benzyl and phenethyl sulfates in winter PM 2.5 in Wenjiang District of Chengdu were 0.58 ± 0.56, 2.37 ± 3.59, 1.79 ± 3.51, 0.04 ± 0.08 ng/m 3 , respectively.
研究领域:
环境科学
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分析化学
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高影响因子
MOLECULES
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2023
·Vol. 28
·期 13
·4889
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IF 4.6
Meng Lian,Feng Zheng,Lingbin Meng,Fei Zhao,Jun Liu,Jimei Song,Qinghua Lu
Heteroaromatic polyimides (PIs) containing benzimidazole have attracted tremendous attention due to their positive impact on the properties of PIs. Some research on PIs containing 4,4′-[5,5′-bi-1H-benzimidazole]-2,2′-diylbis-benzenamine (4-AB) has been reported. However, reports are lacking on homo-polyimides (homo-PIs) containing 3,3′-[5,5′-bi-1H-benzimidazole]-2,2′-diylbis-benzenamine (3-AB), which is one of the isomers of4-AB. In this paper, the influence of amino groups’ positions on the performance of homo-PIs was investigated. It was found that the net charge of the amine N group in4-ABwas lower than that of3-AB, resulting in higher reactivity of4-AB. Consequently, PIs containing4-ABdisplayed better mechanical performance. Molecular simulation confirmed that3-ABand its corresponding PI chain exhibited distorted conformation, leading to the PI films containing3-ABhaving a lighter color. In addition, the3-ABstructure was calculated to have higher rotational energy compared to4-AB, resulting in a higher glass transition temperature (Tg) in PIs prepared from3-AB. On the other hand, PIs containing4-ABexhibited a higher level of molecular linearity, leading to a lower coefficient of thermal expansion (CTE) compared to PIs prepared from3-AB. Furthermore, all PIs showed higher thermal stability with a 5% weight loss temperature above 530 °C andTghigher than 400 °C.Keywords:heteroaromatic polyimides;isomeric diamine;bis-benzimidazole
研究领域:
材料科学
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化学工程
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PubMed
高影响因子
Polymer Chemistry
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2024
·Vol. 15
·期 25
·2590-2597
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IF 4.1
Huixuan Xu,Weigang Sun,Zhonglin Wei,Jungang Cao,Dapeng Liang,Yingjie Lin,Haifeng Duan
Herein, we provide details of the synthesis and characterization of a novel 2-carbon-extended diol derived from isomannide, 2,2′-((3S,3aR,6S,6aR)-hexahydrofuro[3,2-b]furan-3,6-diyl)bis(ethan-1-ol) and the corresponding semi-aromatic copolyester (PIeT) based on it and dimethyl terephthalate. This new polyester (PIeT) has a weight-average molecular weight of about 40 000 g mol−1. The NMR analysis showed that the isohexide unit was retained under applied conditions. DSC and WAXD analyses demonstrated that the polyester is semicrystalline.
研究领域:
材料科学
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有机化学
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2018
·Vol. 135
·期 23
·4634159
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IF 1.901
Sheng Zhou,Xiaolu Wang,Wei Zhang,Mengyao Zhang,Xiaoli Zhang,Ning Zhao,Ruigang Liu,Jian Xu,Zhihao Shen,Xinghe Fan
It remains a problem to prepare cost-effective aramid with good solubility via a simple method since the commercialization of aromatic polyamides such as Kevlar and Nomex by DuPont in 1960s. Herein, we report the facile preparation and properties of an aromatic polyamide copolymerized by 2,6-naphthalene dichloride (26N-COCl), 4,4′-oxydianiline, and m -phenylenediamine. The synthetic route is very facile and cost-effective. The modified aramids possess excellent comprehensive properties. The polymers are soluble in some organics. Their thermal stabilities are excellent, with 5% weight loss temperatures ( T d ,5% 's) in air higher than 460 °C and glass transition temperatures ( T g 's) higher than 280 °C. These polymers are easily processed into films, fibers, and tubes. The products exhibit high strength. For example, the films have excellent mechanical strength, with a tensile strength up to 139 MPa, a tensile modulus up to 3.45 GPa, and an elongation of 11%. The films are also transparent and fluorescent. The overall properties are better than those of the commercial Nomex. The facilely prepared aramids with good solubility are very promising for commercial use. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46341.
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
HIGH PERFORMANCE POLYMERS
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2016
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IF 1.045
Lu Sun,Wei Wang,Guofei Chen,Xingzhong Fang
Novel imide oligomers (calculated molecular weights: 1250–5000 g mol−1) based on the mixture of thioetherdiphthalic anhydride isomers (m-TDPA) with 2-phenyl-4,4′-diaminodiphenyl ether (p-ODA) in the presence of 4-phenylethynylphthalic anhydride (PEPA) as reactive endcapping agent were prepared. Then pyromellitic dianhydride (PMDA) was introduced to the polymerization of m-TDPA/p-ODA (molem-TDPA:molePMDA = 1:1). The effect of molecular weights and polymer chemical structures of the aromatic oligomers on their processability and solubility as well as the thermal and mechanical properties of the thermal-cured polyimides (PIs) was systematically investigated. All the oligomers showed good solubility (more than 30 wt%) in N-methyl-2-pyrrolidone and very low melt viscosities. The minimum melt viscosities of Oligo-5 was 61.5 Pa s at 321°C. The melt viscosity of the oligomers increased with the increase of molecular weight. After thermally curing at 370°C for 1 h, the thermoset PIs exhibited good thermal properties. The glass transition temperatures of oligomers measured by differential scanning calorimetry were in the range of 264–337°C, and the temperature of 5% weight loss was higher than 505°C. The cured films also demonstrated good mechanical properties with tensile strength and modulus greater than 52 MPa and 2.9 GPa, respectively.
研究领域:
材料科学
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化学工程
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高影响因子
Polymers
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2020
·Vol. 12
·期 3
·586
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IF 3.426
Changbo Zhao,Caijuan Huang,Qin Chen,Ian D. V. Ingram,Xiankui Zeng,Tianhua Ren,Haibo Xie
The design and preparation of polymers by using biobased chemicals is regarded as an important strategy towards a sustainable polymer chemistry. Herein, two aromatic diols, 4-(hydroxymethyl)-2-methoxyphenol and 2-(4-(hydroxymethyl)-2-methoxyphenoxy)ethanol, have been prepared in good yields through the direct reduction of vanillin and hydroxyethylated vanillin (4-(2-hydroxyethoxy)-3-methoxybenzaldehyde) using NaBH4, respectively. The diols were submitted to traditional polycondensation and polyaddition with acyl chlorides and diisocyanatos, and serials of new polyesters and polyurethanes were prepared in high yields with moderate molecular weight ranging from 17,000 to 40,000 g mol−1. Their structures were characterized by1H NMR,13C NMR and FTIR, and their thermal properties were studied by TGA and differential scanning calorimetry (DSC), indicating that the as-prepared polyesters and polyurethanes have Tgin the range of 16.2 to 81.2 °C and 11.6 to 80.4 °C, respectively.
研究领域:
材料科学
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有机化学
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DOI
高影响因子
POLYMER
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2024
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IF 4.1
Yue Gong,Teng Fu,Xiu-Li Wang,Yu-Zhong Wang
Polymer dielectric materials in high-frequency communication applications needs to meet strict requirements, and the future development trend is high performance and environmental friendly materials. Herein, we propose a design strategy for simultaneously adjusting multiple performances by building blocks (naphthyl, diphenyl ether , and phenyl). The synthesized copolyester containing phenylene ether structures exhibits good comprehensive properties, including high thermal stability (the temperature at 5 wt% weight loss, 475–495 °C) and inherent flame retardancy (limiting oxygen index 37.8 %∼40.1 %, UL-94 V-0 level), low water absorption (0.16 %∼0.46 %), low dielectric constant (3.04–3.31 @10 GHz) and low dielectric loss (0.0020–0.0028 @10 GHz). The crankshaft naphthyl and bent diphenyl ether structures together change the free volume or spacing of polymer chains, thereby effectively affecting the density or motility of the polarizable groups. These aromatic structures also possess high charring-ability, thus enabling the polymers with the inherent high flame retardancy. Since only carbon, hydrogen, and oxygen elements are introduced into the copolyesters, it supplies a solving approach to eliminate the potential chemical concern arising from introducing heteroatoms such as halogen or phosphorus into polymers.
研究领域:
高分子材料科学
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材料化学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Dongyao Yue,Zhe Wang,Jing Chang,Shaopo Wang,Jingjie Yu,Hongying Meng,Rui Zhang
In the O 3 self-decomposition process, the poor HO 2 − formation efficiency limits O 3 decomposition and •OH production. Although the addition of Fenton’s reagent facilitates this process, H 2 O 2 consumption and Fe(III) sedimentation must be addressed. In this study, carbon-coated Fe 3 O 4 (Fe 3 O 4 @C) samples were prepared using the metal–organic frameworks (MOFs) modification method for the catalytic ozonation of aromatics, which effectively solved the above challenges. The fabricated 4-Fe 3 O 4 @C catalyst not only exhibited a yolk-shell structure, but also increased •OH production by 9-fold, resulting in optimal target removal, mineralization, and O 3 decomposition efficiency. Further investigation confirmed that the activity of 4-Fe 3 O 4 @C was owing to the combined action of Fe(II) on the catalyst surface and the H 2 O 2 produced from aromatic degradation. Furthermore, the outer carbon layer with reducing properties regenerated Fe(II) in a timely manner, ensuring catalyst durability. Finally, a clear pathway for enhancing O 3 decomposition and •OH generation is proposed.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Journal of Energy Storage
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2023
·
IF 9.4
Rong Li,Zhigao Sun
The motivation of this study is to investigate the effect of side chain groups of amino acids on hydrate formation . To confirm their effects on hydrate nucleation and growth, we use aromatic amino acids (tryptophan, phenylalanine, tyrosine), heterocyclic amino acids (histidine, proline) and aliphatic acids (arginine, alanine) as biological additives. The effect of different side chain groups of amino acids on hydrate formation kinetics is investigated. It is found that the hydrophobic groups of amino acids have a significant influence on promoting hydrate formation compared with the hydrophilic groups . Among the hydrophobic groups, aromatic groups are superior to aliphatic groups in improving hydrate nucleation and growth rate, while aliphatic groups are more advantageous in increasing hydrate production, cold storage capacity (CSC) and hydrate conversion rate. Heterocyclic amino acids have no obvious effect on hydrate formation. In addition, foam is not produced during hydrate dissociation , which is good for practical application.
研究领域:
生物学
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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）