FUEL
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2021
·
IF 6.609
Jiu Chen,Bin Li,Cheng-Yang Cao,Si-Yuan Zhou,Li-Feng Xie,Dan Zhang
As a novel rich nitrogen content material, 5-Amino-1 H -Tetrazole (5AT) has been considerably popularized in the propellants area recently. The pyrolysis is deemed as the prelude of combustion for solid phase 5AT, which plays a crucial role in combustion process and grasping the pyrolysis characteristics will be more beneficial to further explore the combustion properties of 5AT-based propellant. In this paper, several efforts have been made to enhance the pyrolysis behaviors of 5AT, including employing metal particles as catalysts, and modifying the surface treatment method. Due to the calorific value, the boron and copper powder are selected as the potential catalysts. The solvent/non-solvent (S/NS) and solution recrystallization method are compared to explore the impact of these two modification methods. TG-FTIR technique is applied to capture evolved signals of organic compounds to further deduce the most probable decomposition pathway. Moreover, model-free and model-fitting methods are both employed to calculate the kinetic parameters. The results reveal that, for the modified 5AT samples with the same boron powder catalyst, the activation energies and reaction model (all governed by F4) in the initial stage (100–330 °C) are not significantly impacted by these two modification methods. However, during the latter stages (400–750 °C), the catalytic actions of boron powder appear to be more active, and solution recrystallization method exerts better modification effect, the activation energies was reduced 18.3 kJ/mol and 10.9 kJ/mol respectively for the latter stages compared to S/SN method. Also, the reaction model is transformed from n th -dimensional model (D3) to n th -order model (F1) in the third stage. Particularly, the catalytic actions of copper powder results in the simplification of decomposition steps for 5AT, the activation energies was 138.8 kJ/mol and the catalytic effect of which was improved about 25% compared to the catalytic effect of boron powder in the first stage and its reaction model is also found to be changed into F3. It illustrates that copper powder could embody a better catalytic effect than boron powder under the same modification method. The conclusions of this study could provide a worthwhile guidance for the understanding, designs and applications of the 5AT-based propellants.
研究领域:
化学工程
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材料科学
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燃烧科学
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DOI
高影响因子
HIGH PERFORMANCE POLYMERS
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2017
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IF 1.179
Lala Rukh Sidra,Nafeesa Mushtaq,Guofei Chen,Xingzhong Fang
A series of poly(N-arylene benzimidazole ether imide) copolymers PEIBIs were prepared from 1H,3′H-5,5′-bis-benzimidazole, bisphenol-A and 4,4′-bis(4-fluorophthalimido)diphenyl ether by nucleophilic displacement polymerization. The resulting copolymers PEIBI(10–90) demonstrated moderate to good solubility in polar aprotic solvents and high glass transition temperatures (Tgs) of 228–336°C, good thermal stability with 10% weight loss temperatures in the range of 503–548°C. All copolymer films showed good mechanical properties with tensile strengths of 101–130 MPa, tensile moduli of 3.3–4.0 GPa, elongations at break of 5–7%, and also presented low water uptake (0.15–0.34%). The wide-angle X-ray diffraction results revealed the amorphous nature of copolymers. The copolymer PEIBI-80 showed good balance in solubility, thermal and mechanical properties.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2026
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IF 6.7
Yuhang Li,Haifeng Jiang,Jiahao Qi,Junyu Chen,Wenpeng Hong
This study investigated the catalytic pyrolysis of pine sawdust over transition-metal-modified g-C 3 N 4 catalysts (Ni/g-C 3 N 4 , Zn/g-C 3 N 4 , and Co/g-C 3 N 4 ) to enhance phenolic selectivity and elucidate metal–support synergistic effects. Among these catalysts, Co/g-C 3 N 4 exhibited the best performance in enhancing the relative content of phenolic compounds. Compared with non-catalytic pyrolysis at 550 ℃, the phenolic content increased by 24.66%. In addition, the results indicated that a CO 2 atmosphere negatively affected phenolic formation. The temperature-programmed TG-FTIR and evolved-gas analyses revealed that the presence of the Co/g-C 3 N 4 catalyst could promote the formation of CO and limit the generation of CH 4 and C 2 -C 3 hydrocarbons during the catalytic pyrolysis process. The related mechanism analysis showed that the interaction between Co 2 + /Co 3+ species on g-C 3 N 4 and Lewis-basic N sites enabled an interfacial synergistic effect for the selective formation of catechol and methyl-catechol. Furthermore, the exploratory multi-output regression analysis further verified that catalyst type primarily governed phenolic enrichment, whereas temperature mainly influenced syngas formation. Overall, this study provides a deeper understanding of the reaction pathways for the selective generation of phenolic compounds in biomass catalytic pyrolysis, and offers a practical approach for the integration of experimental analysis and data-driven methods.
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DOI
高影响因子
GREEN CHEMISTRY
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2026
·
IF 10.6
Yumeng Zhang,Yang Yu,Ziyi Feng
The development of fully bio-based polyesters with distinguished performance and facile chemical closed-loop recycling in aqueous environment still faces a challenge. Herein, a series of N-substituted pyrrolidone carboxylic acid monomers (xPCA) were synthesized from renewable itaconic acid (IA) with six amino acids with solvent-free and water-catalyzed conditions. xPCA was polymerized with ethylene glycol to prepare biobased six homopolyesters with number average molecular weights (Mn) up to 37.8 kDa. These polyesters exhibited high glass-transition temperatures (Tg) in the range of 47.8-106.2 ℃. Among these, L-tryptophan imparts the highest Tg (106.2 ℃) due to the addition of the indole heterocycle, which was higher than that of most of the commercial polyesters, such as polyethylene terephthalate (PET). In addition, these amorphous polyesters display excellent UV shielding properties with UV shielding cut-off values up to 241-323nm. The pyrrolidone structure improves the hydrophilicity of the polyester, thereby promoting the chemical cycle using deionized water at 80 ℃ as the solvent and low-toxicity zinc acetate as the catalyst. The recovered monomer can be polymerized again to obtain the original polyesters, which still retains its original properties. In addition, this polyester exhibits significant tolerance to common organic solvents and possesses long-term stability in water. Overall, this series of fully bio-based polyesters realizes the greening of the whole chain from raw material synthesis, product preparation to recycling treatment.
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DOI
高影响因子
FUEL
·
2019
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IF 5.128
Rongbin Li,Kai Wei,Qian Huang,Hongde Xia
The unburnt carbon content of fly ash is an important index for evaluating the combustion efficiency of boilers. Measurement by traditional loss-on-ignition (LOI), approximate and elemental analyses causes large errors due to mixing minerals such as portlandites, carbonates, or sulfates with the unburnt carbon. In this paper a new method of Equivalent Characteristic Spectrum Analysis (ECSA®) based on Thermogravimetric Mass Spectrometry (TG-MS) was adopted to determine the unburnt carbon in fly ash. The measuring mechanism, accuracy, superiority, sensitivity, and reliability of ECSA® were discussed. The intrinsic measuring mechanism of ECSA® and its sensitivity were explored through analyzing the reaction characteristics of model compounds that were used to simulate the real fly ash. Five types of real fly ashes collected from boiler plants were used to calibrate and verify the reliability and accuracy of ECSA® method. The ECSA® was finally validated to be more precise and accurate by improving 2 to 3 orders of magnitude in error compared with the LOI and elemental analysis on determining the unburnt carbon in fly ash, and can provide reliable information to assess the operating status of boilers.
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2026
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IF 5.1
Hao Chen,Huimin Gao,Wenbo Jiang,Xiaohua Lu,Hongliang Qian
Skeleton activated carbon retains the natural cellulose skeleton structure of biomass, resulting in a large surface area and green preparation. However, various biomass types make it difficult to obtain which biomass under what conditions the skeleton can be preserved through experiments. Seeking the temperature range where oxidants react preferentially with carbonized lignin over carbonized cellulose is the key to the successful preparation of skeleton activated carbon. Herein, based on the assumption that combining kinetic modeling with peak-splitting technique and generalizing the model enables prediction of whether the biomass can be prepared into skeleton activated carbon and the preparation conditions based solely on its composition. The combination of the CR method and peak-splitting technique can be used to fit biomass’s pyrolysis process and obtain the reaction temperature window between oxidants and carbonized cellulose/lignin. To enhance universal applicability, modified parameters E’ and n were incorporated into the predictive model. Finally, a universal biomass screening model was established by correlating modified parameters with biomass composition, eliminating the need for extensive experimentation in traditional screening processes.
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DOI
高影响因子
BIOMACROMOLECULES
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2026
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IF 5.9
Linlin Wang,Yunlong Sun,Lei Song,Lu Li,Yumei Gong,Rui Wang
Biobased degradable polyesters have emerged as a promising alternative to mitigate plastic pollution and reduce dependence on petroleum resources. However, the utilization of tricyclic rigid diols derived from biomass remains limited, which restricts the overall performance of degradable polyesters. In this study, a novel diglycolicaldehyde xylose (DGX) diol containing a rigid tricyclic structure, synthesized from D-xylose and glyoxylic acid hydrate, is reported. Both the single- and multiple-stereoisomer forms of DGX were polymerized with linear diacids of varying carbon chain lengths to produce biobased poly(xylosediethylene alkylenedicarboxylate)s (PXAs) and m-PXAs polyesters. The high rigidity of the single-regioisomer DGX conferred enhanced thermal properties to PXAs, with a 5% weight loss temperature (Td,5%) reaching 372 °C and a glass transition temperature (Tg) of up to 93.8 °C. The structural regularity of the PXAs polymer backbone, combined with their higher molecular weights, resulted in a higher Tg relative to the m-PXAs analogues. Furthermore, the tricyclic unit endowed the polyesters with a superior gas barrier performance. Notably, the PXD film exhibited oxygen (O2) and carbon dioxide (CO2) barrier capabilities that were 3 and 7 times greater than those of polylactic acid (PLA), respectively. All amorphous polyesters allowed efficient recovery of DGX under mild conditions, with a yield of 93% achieved, and the recycled polymers displayed properties comparable to those of the virgin materials, thus demonstrating the potential for closed-loop recycling. This work presents a viable strategy for designing high-performance, sustainable biobased polyesters with end-of-life utility.
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DOI
PubMed
高影响因子
PROGRESS IN REACTION KINETICS AND MECHANISM
·
2026
·Vol. 51
·期 1
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IF 13.8
Donghua Xu,Haoyu Xiao,Shengwei Feng,Yingquan Chen,Xianhua Wang,Hanping Chen,Haiping Yang
A limited understanding of the pyrolysis mechanisms hinders the efficient thermochemical conversion and recovery of nylon waste. This study investigates the pyrolysis behavior, volatile evolution, and backbone degradation mechanisms of nylon 6/6 by integrating thermogravimetry-Fourier transform infrared spectroscopy-gas chromatography/mass spectrometry (TG-FTIR-GC/MS) and density functional theory (DFT) calculations. According to TG analysis, nylon 6/6 undergoes pyrolysis mainly in the range of 390–515 °C, with a mass loss of 95.86 wt%, and exhibits the most intense degradation at approximately 480 °C. Kinetic analysis using the Coats-Redfern integral and Achar differential methods indicates that nylon 6/6 pyrolysis follows the first-order reaction model with an apparent activation energy of 278 kJ/mol. Online FTIR and offline GC/MS identify the characteristic gaseous products, including CO2, NH3, 1-amino-5-hexene (13.54%), and cyclopentanone (79.64%). Furthermore, DFT calculations elucidate the electrostatic potential (ESP) distribution, Fukui function indices, and bond dissociation energies (BDEs) of the nylon 6/6 model molecule. Results demonstrate that the nucleophilic attack of the terminal amino group and the free radical attack of H· facilitate the cleavage of the amide structure. The generated hexamethylenediamine and adipic acid segments subsequently undergo deamination and cyclization reactions to form 1-amino-5-hexene and cyclopentanone, respectively. By elucidating the backbone degradation mechanisms and product formation pathways during nylon 6/6 pyrolysis, the multi-scale study provides a theoretical basis for the recovery of high-value fuels and chemicals from nylon waste.
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高影响因子
International Journal of Pharmaceutics-X
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2026
·
IF 7.9
Wenling Zheng,Hui Chen,Rongrong Xue,Ziqing Wu,Yongming Liu,Fenghua Chen
Poor aqueous solubility limits the oral bioavailability of many BCS II drugs, while conventional spray drying of amorphous solid dispersions (ASDs) often relies on organic solvents. Here we develop an aqueous spray-drying (AQSD) strategy that couples temperature-boosted solubility with poloxamer-enabled micellar solubilization and a high-Tg polymer matrix. Using celecoxib (CEL) as a model drug, heating increased intrinsic solubility and poloxamer 407 (P407) further raised apparent solubility to a ≥ 1 mg·mL −1 feed window suitable for atomization. Binary CEL–P407 produced wax-like solids, whereas adding soluble starch (SS) or polyvinylpyrrolidone (PVP) improved solidification and yielded powdery, amorphous products. PXRD and vibrational spectroscopy supported amorphization and a P407-rich hydrophobic microenvironment in the hot feed. Compared with the binary, ternary systems improved powderability/yield (e.g., ∼50% for CEL–P407–SS vs ∼40% for CEL-P407), maintained target drug loading with minimal net loss during drying, and enhanced non-sink dissolution, with CEL remaining amorphous after storage. The framework was further validated using indomethacin, sulfamerazine, and aripiprazole, while highlighting limitations for thermally labile compounds. Overall, AQSD provides a practical green rule—hot-feed micellar solubilization coupled with a Tg-raising matrix—for early ASD formulation screening and solvent-free manufacturing.
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DOI
PubMed
高影响因子
POLYMER
·
2024
·
IF 4.1
Ge Zhu,Jinglei Xing,Nafeesa Mushtaq,Xingzhong Fang,Guofei Chen
Four new diamines (3TFDABA, 2TFDABA, 22TFDABA and TFAPTA) were successfully synthesized to investigate the effect of different trifluoromethyl (CF 3 ) substitution position on poly(amide-imide)s (PAIs) properties. High-performance PAIs were prepared from high-temperature polycondensation of these diamines with 6FDA dianhydride. All the PAI films exhibited good heat resistance with glass-transition temperatures ( T g s) of 311–392 °C, good 5% weight loss temperatures ( T d5% s) of 480–510 °C in nitrogen, and excellent optical transparency with T 450 ranging from 52% to 84%. According to the monomer structural design, a high heat resistant and colorless poly(amide-imide) film (PAI-2-6FDA), with excellent optical properties ( T 450 of 82%), outstanding thermal properties ( T d5% of 499 °C and T g of 392 °C), and good mechanical properties (tensile strength of 123 MPa, tensile modulus of 4.4 GPa) was achieved. A comprehensive structure-to-property relationship study revealed that the CF 3 in ortho -position of the amino group effectively inhibited the rotation between imide ring and benzene, thus improved the heat resistance of the film. Moreover, it could also weaken the generation of charge transfer complexes through strong electron-withdrawing ability, which is beneficial for the synthesis of colorless polyimides.
研究领域:
材料科学
·
高分子化学
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高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2025
·
IF 6.2
Liwei Ma,Jing Weng,Junjie Xue
Catalytic co-pyrolysis of biomass and hydrogen donors is one of the important ways to improve the quality of bio-oil. The hydrogen transfer pathways in co-pyrolysis are significant yet remain vague. In this study, an isotopic labeling method to label glucose (G) with deuterium (D) atoms was used to trace the hydrogen. The results show the catalysts influence the hydrogen transformation significantly and selectively. The shift of the infrared (IR) peaks proves that the hydrogen atoms in products - phenols, alcohols, carboxylic acids, aldehydes, and olefins contain both hydrogen from polypropylene (PP) and deuterium from G. While the hydrogen in aromatic rings, - CH 3 and - CH 2 all come from polypropylene. Furthermore, the deuterium atoms from G only enter the olefin products with catalyst potassium chloride (KCl) or activated carbon (AC). On the other hand, the oxygenated compound products mainly contain hydrogen atoms from polypropylene with any of the three catalysts. The potassium chloride helps the hydrogen from polypropylene transfer to the products of mainly phenols, aldehydes and alcohols. The AC transfers the hydrogen from polypropylene to the products of carboxylic acid, aldehydes, and phenols. For the ZSM-5, it helps the hydrogen from polypropylene transfer to the products of carboxylic acid and aldehydes. The results of this study are useful for improving the effective hydrogen content of the mixed pyrolysis reaction of biomass.
研究领域:
能源化学
·
催化化学
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DOI
高影响因子
POLYMER
·
2026
·
IF 5.1
Chang Liu,Yuming Cui,Yunbo Mo,Qian Xu,Kai Wang,Jianwu Lan,Shaojian Lin
Commercial poly(butylene adipate-co-terephthalate) (PBAT), a biodegradable aromatic–aliphatic copolyester, is considered a promising alternative to conventional plastics in various fields. However, its relatively low mechanical strength and low glass transition temperature (T g ) often restricts broader applications. In this study, bio-based 1,3-propanediol (PDO) was employed to completely replace 1,4-butanediol in PBAT, and a series of poly(trimethylene terephthalate- co -trimethylene adipate) (PPAT) copolyesters were synthesized via melt polycondensation. Structural characterization confirmed the targeted copolyester compositions and random chain segments (R ≈ 1), with intrinsic viscosities of 0.89-1.01 dL/g. Crystallographic analysis revealed that the crystallinity of PPATs varied with the adipic acid/dimethyl terephthalate molar ratio while preserving a monoclinic crystal structure. Notably, PPAT55 exhibited a significantly higher T g (−7.8 °C) than PBAT (−26.1 °C), and all copolyesters showed good thermal stability for melt processing. Importantly, PPAT55 fibers achieved a tensile strength of 0.71 cN/dtex after threefold drawing, representing a 51.06% enhancement over PBAT fibers. Furthermore, the increased aliphatic segment content promoted by hydrolytic susceptibility, as demonstrated by enzymatic degradation tests, with PPAT55 showing a 9.93% mass loss after 42 days, demonstrating satisfactory biodegradability comparable to PBAT. The degradation mechanism was further elucidated at the molecular level through theoretical calculations. This work provides a feasible strategy for developing high-performance sustainable polyester materials with good spinnability.
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高影响因子
危险品化学品经营许可证（带存储）