EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Yazhou Tian,Meng Ke,Xiuli Wang,Guangdong Wu,Junying Zhang,Jue Cheng
Preparing and designing an epoxy system with ultrahigh glass transition temperature (T g > 300 °C) is always a big challenge, which restrict its applications in some cutting-edge areas such as aerospace engineering and electrical electronics. Herein, a biomass-based epoxy resin (REEP) was prepared from resveratrol, and then curing behavior, thermal–mechanical properties, mechanical performance, thermal stability, dielectric properties and optical properties of REEP/HDDM, REEP/DGEBA/HDDM and DGEBA/HDDM were respectively studied systematically. Results suggested that the T g of REEP/HDDM was above 320 °C, higher than those of most reported epoxy systems, both derived from biomass-based and petroleum-based materials. Moreover, the tensile strength of REEP/HDDM, REEP/DGEBA/HDDM and DGEBA/HDDM were 77.8 MPa, 70.8 MPa and 63.6 MPa, respectively, and the T d5% of REEP/HDDM, REEP/DGEBA/HDDM and DGEBA/HDDM were 319.9 °C, 335.1 °C and 348.1 °C, respectively, indicating excellent mechanical performance and thermal stability of the cured epoxy system. Interestingly, the REEP/HDDM exhibited outstanding blocking properties in the range of 220–400 nm (UV-light) and low flammability with compact and continuous char residues. In short, REEP, with a well-defined chemical structure, has a stiffness conjugated stilbene structure to prevent the molecular from motioning in the crosslinked network structure and three epoxy groups, thereby increasing the crosslinked density dramatically, which endows REEP/HDDM network with outstanding comprehensive properties.
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
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Hailan Wang,Ruobin Dai,Zhiwei Wang
Deciphering the structure and composition of the scaling layer is crucial for understanding its formation mechanisms in the reverse osmosis (RO) process. However, conventional characterization techniques face challenges in providing high three-dimensional resolution and precise compositional analysis of mixed scales, which hinders in-depth elucidation of the underlying mechanisms. In this study, we combined the exceptional depth resolution of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the superior mixed-scale discrimination capability of thermogravimetry-infrared spectroscopy (TG-IR) to analyze Si/Al scaling, a common issue in industrial RO systems. Under acid conditions, ToF-SIMS measurements revealed Al species enrichment on the membrane surface, attributed to the strong affinity between Al3+ and the membrane. The preferential deposition of Al3+ further facilitated the heterogeneous nucleation of polymerized silica through the electrostatic shielding effect, leading to the rapid formation of a thin and dense scaling layer. In contrast, neutral and alkaline conditions produced a slower-developing, uniform, thicker, and loosely structured scaling layer through physical deposition of supersaturated Si/Al complex scales. TG-IR analysis revealed that neutral conditions favored coprecipitated adsorption-bound Si/Al species (6-coordinate Al) and Si/Al polymers (4-coordinate Al), whereas alkaline conditions primarily produced coprecipitated silica and Al(OH)4−. These findings advance the mechanistic understanding of Si/Al scaling and provide a foundation for targeted control strategies in silica-metal combined scaling in RO systems.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
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2016
·Vol. 34
·期 9
·1103-1116
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IF 1.811
Han Guo,Yang Zhen,Yang Xiao-xue,Zhang Xiao-a,Jiang Sheng-ling,Lu Ya-fei
Carborane bisphenol novolacs ( 3 and 4 ) were synthesized in the presence of acid catalyst from carborane bisphenols ( 5 and 6 ) and formaldehyde. Further epoxidization of carborane bisphenol novolacs with epichlorohydrin gave carborane bisphenol epoxy novolacs ( 1 and 2 ). The molecular weight and epoxy value of obtained resins were determined using the molecular weight of their precursors. The epoxy values of 1 and 2 were 0.48 and 0.52 respectively, higher than the maximum theoretical epoxy value (0.45) of difunctional carborane bisphenol epoxy resins. FTIR and NMR were utilized to characterize 1 and 2 . The curing behaviors were also studied by DSC and the optimized curing conditions were obtained. TGA analysis indicated that carborane moiety could shield its adjacent organic structures against initial decomposition. On the other hand, B―H on carborane cage could react with oxygen to form a three-dimensional network linked by B―O―B and B―C bonds, which further blocked the movement of formed radicals and thus the degradation process was inhibited.
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
EUROPEAN POLYMER JOURNAL
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2021
·
IF 4.598
Xiaoying Yan,Fengna Dai,Zhao Ke,Kuangguo Yan,Chunhai Chen,Guangtao Qian,Hui Li
To prepare colorless polyimide (CPI) films with high thermal properties, an effective design strategy is incorporating asymmetric and twisted structures in the polymer chain-segments. Based on this strategy, 6,4′-diamino-2′-methyl-1-methyl-2-phenylbenzimidazole (5a) and 6,4′-diamino-2′-trifluoromethyl-1-methyl-2-phenylbenzimidazole (5b) were synthesized, and two series of their polyimides (semi- and fully aromatic series) were prepared, respectively. The obtained poly(benzimidazole imide)s (PBIIs) with loosely packed but rigid backbones possessed not only high glass transition temperature (T g ) but also improved optical transparency. In particular, the semi-aromatic system achieved an excellent transmittance about 80% at 400 nm and an outstanding T g exceeding 400 °C. Furthermore, the influence of various 2′-substitutions on the combination properties of these poly(benzimidazole imide)s was systematically analyzed. These data expand the poly(benzimidazole imide)s as optical materials and provide a feasible method to prepare heat-resistant colorless polymers.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Yue Wu,Junfei Gao,Songhong Fan,Qun Gu,Qianqian Liu,Qinhong Wang,Xudong Tang,Qiang Fang
The precise synthesis of acrylate derived from protocatechuic acid was reported for the first time via a simple two-step reaction route. Copolymerizing the monomer with methyl methacrylate in the presence of radical initiator gave the copolymers. The copolymer exhibited high glass transition temperature ( T g ) and thermostability, excellent ultraviolet-shielding efficiency and good dimensional stability. Moreover, the modified polymethyl methacrylate (PMMA) also showed good mechanical properties while the transparency lightly decreased in visible light. The best results were obtained when the weight ratio of methyl methacrylate and protocatechuic acid -based acrylate was 1:1. In that case, the cured polymer showed T g of 159.6 °C and a coefficient of thermal expansion (CTE) of 69.54 ppm/°C. The shielding rate of copolymer reached 99.38% in ultraviolet light (320–400 nm) and 82.56% in short-wave blue light (400–450 nm). These indicated that it may be applied to lenses, and this contribution would provide a new way for the conversion of bio-based glucose to the high-performance polymers.
研究领域:
高分子化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Shiliang Wu,Dekui Shen,Jun Hu,Huiyan Zhang,Rui Xiao
The pyrolytic characteristics of cellulose, cellobiose and glucose were examined by TG-FTIR combined with Py-GC–MS, in order to gain the effect of β -O-4 glycosidic bond on the pyrolysis process. In TG-FTIR analysis, two mass loss peaks were observed for cellobiose and glucose, indicating dehydration in low temperature stage and consequently intensive cracking of glycosidic bond and fragments for cellobiose. The samples were tested in Py-GC–MS at the temperature of 300, 500 and 900 °C according to their mass loss characteristics from TG-FTIR. Formation of furans from cellobiose, which involved the cracking of β -O-4 glycosidic bond, was prominent over other products, compared to that of cellulose and glucose. Four possible chemical pathways for the cleavage of β -O-4 glycosidic bond have been proposed with regard to the formation of furans and anhydrosugars from cellulose. Besides, another two reaction pathways leading to the formation of levoglucosan were also suggested.
研究领域:
生物质化学
·
热化学转化
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2021
·
IF 17.881
Shiqi Ding,Xin Dai,Yuxin Tian,Bo Song,Lei Wang,Guicun Li,Shaoxiang Li,Jianfeng Huang,Zhenjiang Li,Alan Meng
Multi-electron reaction as the appealing alternative can offer higher specific capacity, however, it delivers a tendency to collapse the structure causing cycling instability. Herein, K + pre-intercalation strategy is applied to modify VS 4 /N-TG as cathode for MIBs . As opposed to the structural breakdown caused by multi-electron reaction, pre-intercalated K + not only modulate electronic state, making V 2+ present as instead of partial V 4+ achieving multi-electron reaction, but also act as pillar ions for coordinating the interaction of guest-ions with adjacent host ions to strengthen the framework to maintain structural stability, therefore, K 0.20 VS 4 /N-TG delivers high specific capacity of 190 mAh g –1 , and excellent cycling stability with about near 100% capacity retention after 2000 cycles. This finding gives insights into enabling multi-electron transfer reaction while achieving high structural stability via K + pre-intercalation, shed light on designing viable multi-electron reaction in intercalation type cathode without destroying stable structure for high performance magnesium ions batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2025
·
IF 6.2
Haoxin Jiang,Yuyan Zheng,Zhuoya Dong,Hui Ming,Xuqiang Guo,Lihua Cheng,Libo Zhang
The co-pyrolysis of petroleum coke with lignocellulosic biomass components offers a promising route for the high-value utilization of petroleum-refining by-products and sustainable biomass conversion. This study employs coupled Thermogravimetric analysis-Fourier-transform infrared spectroscopy (TGA-FTIR) to systematically examine the co-pyrolysis behaviour and interaction mechanisms between petroleum coke and model lignocellulosic components (cellulose, hemicellulose and lignin) across the temperature range 30–850 °C at heating rates of 5, 10, 15 and 20 °C·min −1 . The results demonstrate that the cellulose–petroleum coke system exhibits optimal volatile-release kinetics at 10 °C·min −1 , with a diffusion coefficient (D = 9.65 × 10 −10 min −2 °C −3 ) and a maximum mass-loss rate (DTG max = −1.47 %·min −1 ). In contrast, the lignin–petroleum coke system shows pronounced synergistic effects at high temperatures (>600 °C), as supported by activation energies of 57.60–84.14 kJ mol −1 and Gibbs free-energy changes (ΔG = 72.23–98.01 kJ mol −1 ), indicating catalytic and flame-retardant potential. Mechanistic insights reveal that lignocellulosic components exert phase-dependent modulation on pyrolysis dynamics, suppressing petroleum-coke hydration, fine-tuning volatile-diffusion kinetics and facilitating graphitization via co-carbonization pathways. These findings provide a scientific basis for the precise engineering of pyrolysis-product characteristics and advance the development of tailored thermochemical conversion strategies.
研究领域:
能源工程
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化学工程
·
热分析
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可持续能源
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Lala Rukh Sidra,Guofei Chen,Cuiyun Li,Nafeesa Mushtaq,Kai Ma,Xingzhong Fang
Two novel unsymmetric diamine isomers, 6-amino-2-(4-(4-aminophenoxy)phenyl)-1H-benzimidazole (3p) and 6-amino-2-(3-(4-aminophenoxy)phenyl)-1H-benzimidazole (3 m), were synthesized and employed to react with several aromatic dianhydrides to yield two new series of poly (benzimidazole imide)s (PBIPIs), PI-4 (a-e) and PI-5 (c-e) through two-step and one step polymerization method, respectively. The effect of chain isomerism on molecular packing and physical properties of PBIPIs is investigated. Both series exhibited excellent thermal stability ( T 5% = 503–559 °C), high T g values (276–383 °C) and good mechanical properties (tensile strengths of 98–151 MPa and tensile moduli of 3.5–5.2 GPa). The PI-5 (c-e) showed high solubility compared to PI-4 (a-e) series. Such improved solubility attributed to the flexible ether connecting groups with non-coplanarity. Furthermore, controlled molecular weight ( Mw ) polymer PI-5e-PA derived from 3 m, demonstrated good solution and melt processability.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Jinggang Wang,Sakil Mahmud,Xiaoqin Zhang,Jin Zhu,Zhisen Shen,Xiaoqing Liu
Almost all biobased polyesters are semicrystalline polymers with relatively low glass transition temperature (Tg). Amorphous polyesters derived from renewable resources with Tg higher than 100 °C are highly desired. In this work, both rigid (2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO)) and flexible (1,4-cyclohexanedimethanol (CHDM)) cyclic diols were polymerized with 2,5-furandicarboxylic acid (FDCA), leading to copolyesters (PECTFs) showing a Tg range 80.3–105.7 °C. Results showed that CBDO units contributed positively to high Tg, and the presence of CHDM could increase the molecular weight. When the content of CBDO units was 45%, PECTF-45 showed a Tg of 103.1 °C, tensile strength of 88 MPa, and tensile modulus of 2140 MPa. In addition, the transparency by cutoff at 700 nm for PECTF-45 was 89.8%, and it showed better solvent resistance compared to polycarbonate (PC). The biobased polyesters demonstrating a satisfying performance were reported in this work.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER JOURNAL
·
2022
·Vol. 54
·期 8
·995-1008
·
IF 3.135
Fei Xuan,Zhang Xiaoqin,Liu Jingkai,Wang Jinggang,Liu Xiaoqing
A biobased diol (BDBE) is synthesized from vanillin, guaiacol, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to generate a series of fire-retardant polyesters (PECBFs) via melt polymerization with ethylene glycol (EG), 1,4-cyclohexanedimethanol (CHDM), and 2,5-furandicarboxylic acid (FDCA). The chemical structure, sequence distribution, and molecular weights of the obtained polyesters are confirmed by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The results show that BDBE units contribute positively to the high glass transition temperature ( T g ) and fire retardancy, while the CHDM moiety provides flexibility and chain propagation activity. As the content of BDBE is increased from 0 to 25%, the T g of PECBFs increases from 82 to 95 °C, and the limiting oxygen index (LOI) increases from 22.4 to 27.5%. In the UL-94 combustion test, when BDBE units are more than 15%, the samples almost self-extinguish immediately once the flame is moved away. Their mechanical properties are also investigated, and their tensile modulus is stabilized between 1.7 and 1.8 GPa, while the elongation at break ranges from 5 to 56%. Biobased polyesters demonstrating satisfactory properties are reported in this work.
研究领域:
材料科学
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聚合物化学
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阻燃性
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生物基材料
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2022
·
IF 5.767
Junrui Duan,Haowei Hu,Jie Ji
In this study, arabinose was selected as the model compound of hemicellulose . The pyrolysis experiments were conducted by combined thermogravimetry-Fourier infrared spectroscopy-gas chromatography-mass spectrometry (TG-FTIR-GC–MS) technique. The evolution of functional groups was observed. Experimental results indicated that the main gas products were H 2 O, CO 2 , and CH 4 . And volatiles also contained many furan derivatives, sugar derivatives, aromatic hydrocarbon derivatives, and other trace products. In addition, the quantum chemistry calculations were utilized to reveal the formation mechanisms and pathways of the significant products from arabinose pyrolysis. Initially, arabinose prefers to undergo a ring-opening reaction to form acyclic D-arabinose with the activation energy of 177.6 kJ/mol, which is the primary source of each product. Furfural (PD) is the most abundant furan derivative. The ring-condensation reaction first of arabinose and the isomerization reaction first of D-arabinose are the favorable paths to form it in terms of energy. The C1-C2 bond scission of D-arabinose is more favorable to form furan (PA) and formic acid . The dehydration mechanism first of arabinose is the dominant path to generate 2,7-dioxabicyclo[2.2.1]heptan-5-one (PE). The formation of acetic acid (PB) is kinetically and thermodynamically favorable. Once it is formed, it is easy to decompose into CO 2 and CH 4 . The formation of 2(5H)-furanone (PC) is restricted by the decarboxylation reaction of D-arabinose, which has a high energy barrier of 384.8 kJ/mol. To conclude, a deep understanding of the pyrolysis mechanism of arabinose could be obtained through the combination of experiments and quantum chemistry calculations.
研究领域:
生物质能
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化学工程
·
理论化学
✓ 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）