JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2024
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IF 5.8
Hongfeng Gao,Xiongchao Lin,Yukun Zhang,Caihong Wang,Zhe Sheng,Hongcun Bai,Yonggang Wang
This study developed a novel method for synthesis highly spinnable pitch through thermal polymerization of halogenated polycyclic aromatic hydrocarbons (PAH-X) and anthracene oil (AO). The characteristics, average molecular model, and polymerization mechanism of the as-prepared pitches were systematically elucidated. Results show that the thermal cleavage of C-X bonds of the PAHs-X could generate large number of free radicals that greatly facilitate the cross-linking reaction of the active fragments. Namely, the formation of benzyl radicals with high reactivity of the raw materials made it possible to synthesize pitches at lower temperature. The softening point of the as-prepared pitches showed a decreasing trend with increasing of AO proportion due to the abundant carbon content and lower reactivity of AO. Higher temperature could elevate the polymerization activity of aromatic fragments, thus significantly promoted the formation of macromolecular aromatic structures to obtain the spinnable pitch with suitable softening point. The average models validated by calculating the NMR spectra was successfully constructed to demonstrate the condensation degree, which was found be conducive to probe the spinnability of the pitches. Further, the average molecular models could well describe the correlation of the molecular structure, spinnability of pitches, as well as the mechanical properties of carbon fiber.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2023
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IF 5.2
Chunting Cui,Chenqian Yang,Shenghua Ma,Hui Wang,Jintao Bai
Bismuthate glasses have garnered increasing attention in the fields of optics, packaging, and electronic pastes due to their remarkable stability and high visible light transmission. Nevertheless, high sealing temperature, high expansion coefficient, and poor wettability remain significant challenges in their application. Herein, we report a carefully designed approach that begins with bismuthate glasses of well-defined composition and coats them with various carbon materials to form different C@aminated glass composites by hydrothermal synthesis . This work investigates the effects of different carbon materials on the glass structure and properties, such as melting temperature, crystallinity, wettability, and expansion coefficient, and establishes the redox reaction mechanism involved in glass crystallization formation. Graphene oxide , with its different number of functional distributions and oxygen content, exhibits the largest decrease in softening point and softening-to-melting point temperature difference, the highest increase in wettability, and the greatest reduction in expansion coefficient compared to other carbon materials. In addition, different carbon materials promote a greater variety and strength of crystallization. GO@glass exhibits the most moderate reactivity and generates a significant amount of crystallization at the interface when co-sintered with Si substrates, indicating that the inclusion of crystalline phases can improve the bond strength of the glass. This work provides new insights into designing high-performance bismuthate glasses and promoting their applications.
研究领域:
材料科学
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光学工程
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产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
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2018
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IF 3.485
Xiong Xu,Jianying Yu,Lihui Xue,Bianyang He,Wei Du,Huang Zhang,Ying Li
The excellent comprehensive performance of SBS modified bitumen (SMB), during a long-term thermo- and photo-oxidative exposure, will fail to satisfy the pavement requirement. In this paper, the synergistic effect of 4,4′-diphenylmethane diisocyanate (MDI) and 1,4-butanediol diglycidyl ether (BUDGE) on the molecular weight of aged SBS was firstly studied, through a simulation, to confirm whether a new polymer structure can be obtained. Then, the reactive rejuvenating system containing MDI, BUDGE and bituminous composition returning agent (MDI-BUDGEs) was applied in the rejuvenation of aged SMB. The results show that the rebuilt molecular structure of aged SBS can be obtained with the combination of MDI and BUDGE. Meanwhile, MDI-BUDGEs can improve the low-temperature ductility and inhibit the sharp fall of the softening point of aged SMB, while decrease the viscosity-temperature response at 120–165 °C. Also, MDI-BUDGEs can contribute for increasing the viscous component, improving the fatigue resistance and remaining the high-temperature performance grade of aged SMB, and moreover, decrease the limited elastic modulus and the elastic-plasticity transition rate to avoid the occurrence of the brittle failure within a small strain range.
研究领域:
道路工程材料
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高分子材料老化与修复
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沥青化学
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流变学
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建筑材料耐久性
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DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2024
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IF 3.7
Hongyan Shen,Lingrui Cui,Xingguo Wei,Yuanqin Zhang,Lian Cen,Jun Xu,Fahai Cao
Efficient utilization strategy of ethylene tar (ET), the main by-product of ethylene cracking unit, is urgently required to meet demands for modern petrochemical industry. On the other hand, condensed polynuclear aromatic resin of moderate condensation degree (B-COPNA) is a widely used carbon material due to its superb processability, the production of which is however seriously limited by high cost of raw materials. Under such context, an interesting strategy was proposed in this study for producing B-COPNA resin using crosslinked light fractions of ethylene tar (ETLF, boiling point < 260 °C) facilitated by molecular simulation. 1,4-Benzenedimethanol (PXG) was first selected as the crosslinking agent according to the findings of molecular simulation. The effects of operating conditions, including reaction temperature, crosslinking agent and catalyst content, on the softening point and yield of B-COPNA resin products were then investigated to optimize the process. The reaction mechanism of resin production was studied by analyzing the molecular structure and transition state of ETLF and crosslinking agent. It was shown that PXG exhibited a superior capacity of withdrawing electrons and higher electrophilic reactivity than other crosslinking agents. In addition to the highest yield and greatest heat properties, PXG-prepared resin contained most condensed aromatics. The corresponding optimized conditions of resin preparation were 180 °C, 1:1.9 (PXG:ETLF) and 3% (mass) of catalyst content with a resin yield of 78.57%. It was the electrophilic substitution reaction occurred between the ETLF and crosslinking agent molecules that was responsible for the resin formation according to the experimental characterization and molecular simulation. Hence, it was confirmed that the proposed strategy and demonstrated process can achieve a clean and high value-added utilization of ETLF via B-COPNA resin preparation, bringing huge economic value to the current petrochemical industry.
研究领域:
化学工程
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材料科学
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石油化学
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产品关联
DOI
高影响因子
IRANIAN POLYMER JOURNAL
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2025
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IF 2.8
Hu Rongyan,Liu Zuguang,Ren Xiuxiu,Wang Xiao,Ma Shihao,Wang Xinyi
Terpene phenolic resin with high softening point and strong adhesion has been increasingly studied worldwide, and it is widely used in the field of rubber and adhesives. A low-cost and easy-to-prepare heterogeneous catalyst, silica-loaded perchloric acid (HClO 4 /SiO 2 ), was prepared from perchloric acid and fumed silica, and utilized to synthesize terpene phenol resins for the first time. The polymerization conditions were optimized by single factor experiments, and the terpene phenol resin obtained under the optimal conditions achieved a yield of 85.1%, a softening point of 112.6 °C, a Ghanaian color number of 8, and an acid value below 1.00 mg KOH g −1 without washing with water, respectively. The possible copolymerization mechanism was inferred through other characterization methods such as infrared spectrum and hydroxyl value determination. After three cycles of the polymerization, the catalyst HClO 4 /SiO 2 still achieved a relative high yield of 65.2%, and no significant desorption for perchloric acid was observed. This means that the washing with water to remove desorbed perchloric acid in the resin can be avoided, which may prevent wastewater pollution to the environment, save production costs and simple production process. Therefore, HClO 4 /SiO 2 presents a promising option for the clean and cost-efficient production of terpene phenolic resins, with potential applications in large-scale manufacturing. Graphical abstract
研究领域:
高分子化学
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催化化学
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材料科学
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环境科学
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化学工程
✓ 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）