JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2010
·Vol. 48
·期 24
·5679-5692
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IF 3.971
Hongxia Peng,Yiwang Chen,Lie Chen,Xiaohui He,Fan Li
Mesogen jacketed liquid crystalline poly(1-alkyne) and poly(1-phenyl-1-alkyne) linked pendants of terphenyl mesogens with hexyloxy tails at the waist position ( {RCC [(CH 2 ) 3 OOC-terpheyl-(OC 6 H 13 ) 2 ]} n , where RH, PHATP(OC6)2 ; RC 6 H 5 , PPATP(OC6)2 ) were synthesized. The influences of structural variations on the thermal, mesomorphic, and luminescent properties were investigated. Polymerizations of all monomers are carried out by WCl 6 -Ph 4 Sn catalysts successfully. The polymers are stable ( T d ≥ 340 °C) and soluble in common solvents. The monomers and polymers show enantiotropic SmA phases in the heating and cooling processes, and the lateral side chains of the mesogenic units are perpendicular to the main chain. The “jacket effect” of chromophoric terphenyl core “shell” around the main chain also contributes to polymers with high photoluminescence, and the pendant-to-backbone energy transfer path is involved in the luminescence process of this polymers. In comparison with monosubstituted polyacetylene PHATP(OC6)2 , the disubstituted polyacetylene PPATP(OC6)2 shows better photoluminescence in both THF solution and film, and exhibited about 40 nm red-shifted than PHATP(OC6)2 , indicating that the “jacket effect” of terphenyl mesogens forces poly(1-phenyl-1-alkyne) backbone to extend in a more planar conformation with a better conjugation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
研究领域:
材料科学
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高分子化学
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高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2017
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IF 1.753
Wenlu Pan,Yuming Zhou,Man He,Xiaohai Bu,Binbin Ding,Tingyuan Huang,Shuang Huang,Shiwei Li
Novel chiral N -propargylamide based on stigmasterol (M1, HC CCH 2 NHCOCH 2 CH 2 COO-R, R = stigmasteryl) and achiral N -propargylamide based on pivalic acid (M2) were prepared and (co)polymerized with rhodium zwitterions catalyst in CHCl 3 to afford helical polyacetylenes with moderate molecular weights (8997–26777) in good yields. The polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), 1 H nuclear magnetic resonance ( 1 H NMR), gel permeation chromatography (GPC). Ultraviolet–visible spectroscopy (UV–Vis) and circular dichroism (CD) absorption spectra demonstrated that the as-prepared polymers could form helical structures with a preferential helicity. The formation of hydrogen bonds of poly(M1) in CHCl 3 was investigated according to the solution sate IR spectroscopic data . The single-handed helical conformation and polymerization degree of the new-typed poly( N -propargylamide)s could be controlled by the changing the feed ratio of chiral and achiral monomers . Furthermore, the infrared emissivity values (0.536–0.798) of copolymers were investigated at 8–14 μ m by the Infrared Emissometer.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Deng Zhao,Yu Wang,Guanwei Wang,Wenming Han,Hua Liu,Huashan Wang,Hui Liu,Shuai Guo
Although alkali metal potassium (K)-catalyzed char gasification has been widely studied, the detailed mechanism of this process is still not fully understood. To study this catalytic mechanism in more detail, high-temperature in-situ DRIFTS experiments were carried out for the gasification of cellulose char with K and cellulose char without K under H 2 O and O 2 atmospheres, transient gasification experiment of char with K under H 2 O atmosphere, and char with K gasification under isotope water atmospheres. Peaks at 1945 cm −1 and 2020 cm −1 were observed. Combined with the theoretical spectra obtained by quantum chemical simulations and the prediction of catalytic gasification intermediates by molecular dynamics simulations, these two peaks were confirmed to represent char-polyynes species. Based on this result, a new mechanism is proposed: K interacts with carboxyl groups and aromatic ketones to promote desorption, thereby exposing active sites. Then, K reacts with the edge of the activated char to form numerous highly active char-polyynes species. The polyynes edge of this char-polyynes phase provides ideal adsorption–desorption sites, enabling further reaction with the gasifier. Thus, gas desorption is promoted. The adsorption and desorption peaks of catalytic gasification under the H 2 O atmosphere were located at 1400 cm −1 and 1300 cm −1 , and these peaks represented stable adsorption states and unstable desorption precursors, respectively. Based on this, adsorption–desorption theory was analyzed more comprehensively, and the adsorption–desorption process was divided into three stages: initial adsorption, intermediate conversion, and desorption. The comprehensive new mechanism proposed in this paper provides a better understanding of the nature of char catalytic gasification at a deeper level.
研究领域:
化学工程
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能源科学
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DOI
高影响因子
Journal of Fungi
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2025
·Vol. 11
·期 3
·209
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IF 4
Jiao Yao,Sai Huang,Lingfeng He,Shengyun Wei,Wei Yang,Qiangxin Zhang,Weihua Wang,Xiaoqin Yang,Sida Xie,Yunxian Li,Ping Zhao,Guolei Zhu
One novel C10polyacetylene rhamnoside, 4,6,8-decatriyne-1-O-α-L-rhamnopyranoside, named xylariside A (1), together with two novel C10polyacetylene quinovopyranosides, 4,6,8-decatriyne-1-O-α-D-quinovopyranoside, xylariside B (2), and 8E-decaene-4,6-diyne-1-O-α-D-quinovopyranoside, xylariside C (3), were obtained from the solid fermentation ofXylariasp. VDL4, an endophytic fungus isolated fromVaccinium dunalianumwight (Ericaceae). Their chemical structures were elucidated through a combination of spectroscopic techniques. The antifungal activities of these compounds were evaluated in vitro against four phytopathogenic fungi (Fusarium oxysporum,Botrytis cinerea,Phytophthora capsici, andFusarium solani). Compound2demonstrated significant antifungal activities, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 7.81 μg/mL. Compound2’s effectiveness levels were similar to those of the reference drugs thiabendazole and carbendazim (each MIC = 0.98−15.62 μg/mL). Xylariside B (2) was further evaluated againstB. cinereain vivo. It exhibited remarkable efficacy in both the prevention and treatment of tomato and strawberry gray mold. Molecular docking studies confirmed the antifungal mechanism of compound2by revealing its binding interactions with key enzyme targets inB. cinerea, thereby supporting the observed in vitro and in vivo results. Additionally, compound2showed effective inhibition of α-glucosidase, with IC50values of 5.27 ± 0.0125 μg/mL.
研究领域:
植物化学
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药理学
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分子生物学
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 137
·期 23
·48783
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IF 2.188
Zhongqi Liu,Yanchun Huang,Shifeng Deng
A novel polyacetylene-terminated silicone (PTS) resins possessing low curing temperature and high heat resistance has been prepared by Grignard reaction using m -diacetylenylbenzene (DEB), 1,3,5-triacetylenylbenzene(TEB), and dichlorosilane as original materials. The reaction of the functional groups was characterized by in situ Fourier transform infrared spectrometer. The experimental results indicated that Si─H and C≡CH bonds are almost exclusively involved in the crosslinking reaction, while ─C≡C─ bonds only partially react. Further, Si─H and C≡CH bonds can participate in the curing reaction at relatively low temperatures, but ─C≡C─ bonds require higher temperature, indicating the higher activity of Si─H and C≡CH bonds than ─C≡C─ bonds. As determined by differential scanning calorimetry, PTS resins have low peak exothermic temperature at 184.5 °C, which is lower than MSP resin (~ 210 °C); in addition, rheological test showed that PTS resins have a very wide processing window from 40 to 163.3 °C, indicating that the PTS resins have excellent processability with a low curing temperature and wide processing window. What is more, TGA results of thermal-cured PTS resins revealed that T d5 (5% weight loss temperature) of PTS-H10 reached the highest of 684.4 °C. Compared with PTS-H0 resin, there is an increase of 124.2 °C and the remarkably increased heat resistance correlated with a higher m -DEB input ratio. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48783.
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
Polymer Chemistry
·
2023
·Vol. 14
·期 24
·2878-2887
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IF 4.6
Lu Wang,Yongliang Zhan,Linhui Zhang,Hongkun Li
Exploration of efficient polymerization strategies is critical in polymer science. Alkyne polycyclotrimerization reactions have become powerful synthetic tools for constructing hyperbranched polyarylenes (hb-PAs). However, most of the polymerization reactions suffer from the requirement of using transition metal catalysts, and yield mixtures of 1,2,4- and 1,3,5-trisubstituted benzene isomers in their products. In this work, we provide the first example of metal-free polycyclotrimerization of internal diynes to synthesize regioregular hb-PAs. The polymerizations of trimethylsilyl-protected aromatic diynes (1a–e) proceeded smoothly in the presence of p-toluenesulfonic acid monohydrate, producing soluble hb-PAs, hb-P1a–e, with high molecular weights (Mw up to 32 200) and perfect 1,3,5-regioregularity in satisfactory yields. The degree of branching of hb-P1e was calculated to be 0.68. The polymerization reaction was insensitive to moisture and oxygen. The hb-PAs exhibited high thermal stabilities with 5% weight loss at temperatures up to 391 °C and electrochemical activities. Moreover, the hb-PAs containing tetraphenylethene moieties are weakly emissive in solution but highly fluorescent in the aggregated state, displaying aggregation-induced emission properties.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）