Polymer Chemistry
·
2025
·
IF 3.9
Xianqiang Zeng,Chen Liu,Xue Wang,Yan Cao,Zheng Zheng,Peng He,Huiquan Li,Liguo Wang
Poly(1,2-butylene oxide) (PBO) with ethyl side chains exhibits enhanced hydrophobicity, lower glass transition temperatures, and more nonpolar characteristics compared to poly(propylene oxide) (PPO). However, the presence of large steric hindrance from side groups of 1,2-butylene oxide (BO) makes its ring-opening polymerization (ROP) inefficient. We report a metal-free Lewis pair catalytic system comprising triethylborane (Et3B) and tetrabutylphosphonium bromide (TBPBr) that overcomes these limitations. This catalyst enables quantitative BO conversion under mild conditions (−20 °C), delivering high molecular weight PBO with a narrow polydispersity index (Mn = 37.2 kg mol−1, Đ = 1.07) through controlled chain propagation. Notably, the exceptional active hydrogen tolerance of the system allows precise synthesis of low molecular weight PBO polyols (Mn = 1.4–3.5 kg mol−1, Đ ≤ 1.05) using diols as initiators, with MALDI-TOF analysis confirming hydroxyl end-group fidelity. Furthermore, PBO polyols can be used directly in the synthesis of polyurethanes without the need for refining. We examined the influence of interactions between Lewis acids and Lewis bases on polymerization, and the results indicate that moderate interaction is critical for achieving optimal polymerization activity. This research demonstrates that a rational combination of a two-component Lewis pair catalyst offers a straightforward and practical approach for synthesizing polyethers with long side chains.
研究领域:
有机化学
·
高分子化学
✓ 已验证
DOI
高影响因子
SPECTROSCOPY LETTERS
·
2015
·
IF 0.852
Bo Zhang,Yanbin Su,Lei Chen,Zhuofu Wu,Fengrong Zhang,Yanwen Su,Gang Zhao,Zhengqiang Li
The characteristic changes in UV-visible and Raman spectra of lithocholic acid on E-2-Butenal for antiglioma are the maximum absorption peak of E-2-Butenal from 302 to 319 nm, the decreases of Raman signal of 1688 cm−1 and 1641 cm−1 in E-2-Butenal by lithocholic acid with the phenomenon of 1688 cm−1 splitting, and the disappearance of the band at 932 cm−1, which clearly displays the change of wagging in methyl. In the presence of mitochondrial protein deriving from glioma, the above mentioned effects of lithocholic acid on E-2-Butenal are more significant by Raman spectra detections. The molecular targets of lithocholic acid on E-2-Butenal are carbonyl group, conjugated double bonds, and methyl, respectively. The study concludes that the interaction between lithocholic acid and E-2-Butenal decreases the carbonyl group bond strength in E-2-Butenal and then changes the structure and function of E-2-Butenal. The internal cause of the interaction between lithocholic acid and E-2-Butenal leading to the change of the carbonyl group bond strength is the electronic delocalization near the carbonyl group bond in E-2-Butenal. Since E-2-Butenal derives from glioma in the process of lipid peroxidation of mitochondria, our investigation significantly contributes to understanding the mechanism of action of lithocholic acid as a potential antiglioma drug.
研究领域:
生物化学
·
药物学
·
肿瘤学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2016
·
IF 3.611
Pengcheng Hu,Yadong Wang,Xianghai Meng,Rui Zhang,Haiyan Liu,Chunming Xu,Zhichang Liu
Alkylate is an ideal blending component for motor gasoline. The alkylation of isobutane with 2-butene to produce high-quality alkylate was catalyzed by several amide-AlCl 3 -based ionic liquid (IL) analogues with different structures and CuCl modification. The influences of the amide structure, amide/AlCl 3 molar ratio, and CuCl modification on the catalytic performance were investigated in an autoclave operated in semicontinuous mode. Results showed that the N -methylacetamide-AlCl 3 -based IL analogue (molar ratio of N -methylacetamide to AlCl 3 was 0.75, marked as 0.75NMA-1.0AlCl 3 ) with bidentate coordination and low viscosity was an efficient catalyst for isobutane alkylation. Furthermore, CuCl modification further enhanced the catalytic performance of 0.75NMA-1.0AlCl 3 . The selectivity of C8 increased from 76.18 wt% to 94.65 wt%, in which the molar ratio of trimethylpentanes to dimethylhexanes (TMPs/DMHs ratio) and the research octane number (RON) of alkylate reached up to 14.98 and 98.40, respectively. The effects of reaction conditions on the alkylation performance were investigated in an autoclave operated in batch mode. The results indicated that the alkylation of isobutane with 2-butene catalyzed by CuCl-modified 0.75NMA-1.0AlCl 3 was a short-time and fast reaction. The optimal reaction temperature, reaction time, stirrer speed, and isobutane/2-butene molar ratio were 15 °C, 30 s, 1500 r/min, and 100:1, respectively. Under these optimal reaction conditions, the selectivity of C8, TMPs/DMHs ratio, and RON were 84.10 wt%, 14.86, and 96.54, respectively.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Yang Li,Chunyan Ma,Hongling Yang,Zhongshen Zhang,Xin Zhang,Nanli Qiao,Junhui Wang,Zhengping Hao
The traditional reaction temperatures of 1-butene isomerization to 2-butene tend to above 100 °C, while here we report the unique catalytic performance of a Pd loaded silica nanospheres catalyst for 1-butene double-bond-shift isomerization at room temperature and showed 2-butene yield of 37.0%. Furthermore, the introduction of O 2 into the reaction mixture dramatically improved the yield efficiency to 57.2% without the formation of by-product CO 2 . The reaction process is proved that the ratio of trans -2-butene to cis -2-butene in the final product was determined by the trans : cis ratio of the butenylcarbenium ion intermediate, and the ratio of trans -2-butene to cis -2-butene decreased with the increasing reaction temperature. Unlike other palladium catalyst systems, Pd 0 nanoparticles were proved to act as catalytic active sites, and their oxidation and aggregation resulted in a decrease in activity. Most importantly, the catalyst acidity affected the catalytic performance, which provides theoretical basis for the choice of catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Xianqiang Zeng,Liguo Wang,Yan Cao,Chen Liu,Peng He,Huiquan Li
Poly(1,2-butylene oxide) (PBO) is a highly promising and innovative polyether lubricating oil due to its excellent lubricating properties and unique oil miscibility. However, the development of catalysts with low cost, high stability, and excellent catalytic performance for the synthesis of PBO remains a challenge. In this study, we report a series of highly active heterogeneous catalysts composed of layered Zn–Co double-metal cyanides supported by beta zeolite (L-DMC/Al-Beta) for the synthesis of PBO by ring-opening polymerization (ROP) of 1,2-butylene oxide (BO). The catalyst’s superior performance can be attributed to the high dispersion of L-DMC on the surface of the Al-Beta support, which increases the availability of Zn active sites. The inclusion of Al-Beta provides additional Lewis acid sites, which facilitate the coordination and ring opening of BO, resulting in an improved polymerization rate. Through semibatch polymerization processes, well-controlled PBOs with a narrow polydispersity index (D̵ = 1.08–1.53) and desired molecular weights (Mn = 1400–4500 g mol–1) can be obtained. In particular, PBOs exhibit excellent lubricating properties, with a viscosity index of up to 242, a flash point of up to 238 °C, and a pour point as low as −45 °C. Furthermore, PBOs demonstrate excellent miscibility with mineral lubricating oils and can serve as additives to significantly improve their viscosity index. The combination of low cost, easy preparation, and outstanding catalytic performance makes L-DMC/Al-Beta an extremely promising catalyst for the industrial production of high-performance PBO lubricating oils.
研究领域:
材料科学
·
催化化学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2024
·
IF 3.2
Chao Xiong,Chenyong Jiang,Hualei Xu,Lei Wang,Cheng Fang,Jing Ding,Hui Wan,Guofeng Guan
The distribution of acidic sites in molecular sieves has a decisive impact on catalytic skeletal isomerization of 2-butene. Accurately adjusting the acidic site to meet high selectivity and stability of the catalyst is crucial. Herein, magnesium embedding into NiAPO-11 zeolite was prepared by static hydrothermal method. The introduction of magnesium increased the proportion of weak Brønsted acid, resulting in a significant enhancement of catalytic activity. When the molar ratio of magnesium to aluminum oxide was 0.2:1, Mg-NiAPO-11 exhibited the best catalytic performance with the conversion of 2-butene being 65.06 % and the selectivity of isobutene being 71.02 %, which was comparable or even better than those reported previously. Furthermore, Mg-NiAPO-11 had good stability. The conversion of 2-butene only decreased by 3 %, while the selectivity of isobutene increased by 8 % during the 72-h reaction. Obviously, it was found that a small amount of carbon deposition led to an increase in the relative amounts of weak Brønsted acid, which resulting in an increase in the selectivity of isobutene. Our work put forward an effective strategy for accurately tuning the acidic sites of molecular sieves to effectively catalyze 2-butene to isobutene.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Jinhu Liang,Ruining He,Shashank S. Nagaraja,A. Abd El-Sabor Mohamed,Haitao Lu,Yousef M. Almarzooq,Xiaorui Dong,Olivier Mathieu,William H. Green,Eric L. Petersen,S. Mani Sarathy,Henry J. Curran
2,3-Dimethyl-2-butene (TME) is a potential fuel additive with high research octane number (RON) and octane sensitivity ( S ), which can improve internal combustion engine performance and efficiency. However, the combustion characteristics of TME have not been comprehensively investigated. Thus, it is essential to study the combustion characteristics of TME and construct a detailed chemical kinetic model to describe its combustion. In this paper, two high-pressure shock tubes and a constant-volume reactor are used to measure ignition delay times and laminar flame speeds of TME oxidation . The ignition delay times were measured at equivalence ratios of 0.5, 1.0, and 2.0 in “air”, at pressures of 5 and 10 bar, in the temperature range of 950 – 1500 K. Flame speeds of the TME/ “air” mixtures were measured at atmospheric pressure, at a temperature of 325 K, for equivalence ratios ranging from 0.78 to 1.31. Two detailed kinetic mechanisms were constructed independently using different methodologies; the KAUST TME mechanism was constructed based on NUIGMech1.1, and the MIT TME mechanism was built using the Reaction Mechanism Generator (RMG). Both mechanisms were used to simulate the experimental results using Chemkin Pro. In the present work, reaction flux and sensitivity analyses were performed using the KAUST mechanism to determine the critical reactions controlling TME oxidation at the conditions studied.
研究领域:
燃料化学
·
燃烧科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Xin Gao,Yiwei Wang,Rui Wang,Chengna Dai,Biaohua Chen,Jiqin Zhu,Xingang Li,Hong Li,Zhigang Lei
1,2-Butene carbonate (BC) is an important five-membered cyclic carbonate with a high commercial value, but its massive production is limited by the lack of raw material 1,2-butanediol (1,2-BDO). 1,2-BDO is coproduced with ethylene glycol (EG) in the hydrogenation process in the coal-to-EG route, one-pot conversion of biomass to liquid fuels and chemicals, and fermentation of broths. However, the separation and purification of 1,2-BDO are difficult. In this paper, an intensified reactive distillation process for the separation of the EG and 1,2-BDO azeotropic mixture via dimethyl carbonate assisted chemical looping technology and coproduction of BC and EG products is proposed. The transesterification reactions of EG and 1,2-BDO were investigated individually in the presence of basic resin catalyst KIP321, and the kinetic parameters were imbedded into Aspen plus (V11) for the design of the reactive distillation column to perform the transesterification process. The proposed flowsheet, which includes the transesterification unit, a DMC and methanol separation unit, and an EG recovery unit, was designed and simulated. Remarkably, the conversions of diols are over 0.998, the yield of 1,2-butylene carbonate is 99.86%, and the yield of the EG product is theoretically 100%, which shows excellent potential for industrial application.
研究领域:
化学工程
·
工艺化学
·
催化
·
分离技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2024
·
IF 2.8
Fei Yang,Yi-Yi Cao,Jing Xi,Yang Luan,Na Li,Xin Dong,Xin-Yu Zhang
1,3-Butadiene (BD) is a carcinogenic air pollutant. N -acetyl- S -(4-hydroxy-2-buten-1-yl)-L-cysteine (MHBMA3 or 4HBeMA), an urinary BD metabolite with unspecified configuration, is considered the most sensitive BD biomarker and has been used in routine biomonitoring since 2012. However, two issues remain unaddressed: why its concentrations are unusually high relative to other urinary BD biomarkers and why some authors reported no detection of the biomarker whereas other authors readily quantitated it. To address the issues, we synthesized and structurally characterized the authentic trans - and cis -isomers of MHBMA3 (designated NE and NZ, respectively), developed an isotope-dilution LC-MS/MS method for their quantification, and examined 67 urine samples from barbecue restaurant personnel (n = 47) and hotel administrative staff (n = 20). The restaurant personnel were exposed to barbecue fumes, which contain relatively high concentrations of BD. The results showed that NE and NZ had highly similar NMR spectra, and were difficult to be well separated chromatographically. The NMR data showed that the MHBMA3 isomer investigated in most previous studies was NE. We did not detect NE and NZ in any samples; however, an interfering peak with varying heights was observed in most samples. Notably, under the chromatographic conditions used in the literature, the peak exhibited indistinguishable retention time from that of NE. Thus, it is highly likely that the interfering peak has been mis-identified as NE in previous studies, providing a reasonable explanation for the high MHBMA3 concentration in urine. The contradiction in the presence of MHBMA3 in urine was also caused by the mis-identification, because the researchers who reported the absence of MHBMA3 were actually detecting NZ. Thus, we clarified the confusion on MHBMA3 in previous studies through correctly identifying the two MHBMA3 isomers. The presence of NE and NZ in human urine warrants further investigations.
研究领域:
环境科学
·
分析化学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Russian Journal of Physical Chemistry A
·
2025
·Vol. 98
·期 13
·3009-3016
·
IF 0.8
Zhe Wang,Li Junzhi,Zhao Wei,Li Xiao Liang
The isobaric vapor-liquid equilibrium data for the four systems consisting of 1-octene + 2-methyl-thiophene, cyclohexene + 2-methylthiophene, 2,3-dimethyl-1-butene + 2-methylthiophene, and 2,3-dimethyl-2-butene + 2-methylthiophene were determined by using a modified Rose-Williams equilibrium still at 90.00 kPa. All the vapor-liquid equilibrium data measurements passed the thermodynamic consistent test by employing the Herington method. The azeotropic behavior was observed in the 1-octene + 2-methyl-thiophene system. Additionally, the experimental data were correlated by the Wilson model, and they were also compared with the original UNIFAC and UNIFAC Dortmund predictive models. All the results indicated that the measured data were in good agreement with the calculated values obtained from the Wilson. Meanwhile, the UNIFAC Dortmund model can provide better prediction result than the original UNIFAC model.
研究领域:
化学工程
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Honghua Zhang,Jiakuo Xu,Hongguo Tang,Zhiqiang Yang,Ruixia Liu,Suojiang Zhang
Different metal compositions based on metal-ion-modified X-type zeolite in the isobutane/2-butene alkylation reaction were investigated. Bimetallic (rare earth (RE) and Cu) supported zeolites catalysts owned better lifetime and selectivity than those modified by the single metal (La, Ce, or Cu). CuLaX performed best with a 15 h catalytic lifetime obtained after hydrogen activation when the content of copper was 0.197 mmol/g. The possible reason is that the RE X-type catalyst modified with copper ion increases the concentration of strong Brønsted acid sites, which is more favorable for the hydride transfer in the alkylation. Herein, the valence of copper ions is of importance to the alkylation performance. A mechanism was proposed wherein the existence of Cu+ inhibited the progress of the oligomerization reaction and then prolonged the lifetime of the catalyst through decreasing the desorption concentration of 2-butene in the active site.
研究领域:
化学工程
·
催化
·
石油化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Kaikai Liu,Tiefeng Wang,Minghan Han
The catalytic isomerization of 2-methyl-3-butenenitrile (2M3BN), a model reaction in the DuPont process, has been performed using NiL 4 (L=tri- O - p -tolyl phosphite) as a catalyst. The lowered catalytic activity in the isomerization with coexistence of 2-pentenenitrile (2PN) and 2-methyl-2-butenenitrile (2M2BN) indicates that both 2PN and 2M2BN are the catalyst inhibitors , and the quantitative relationship between the conversion of 2M3BN and the content of 2M2BN and 2PN is provided. DFT calculation results suggest that the inhibition effect is attributed to the generation of dead-end intermediates (2PN)NiL 2 and (2M2BN)NiL 2 , both of which take nickel atom out of the catalytic cycle in the isomerization process. To suppress the inhibition effect, new catalytic intermediates are rationally designed based on their computational %V bur . An efficient method that adding extra ligand 1, 5-bis(diphenylphosphino)pentane (dppp5) to the NiL 4 catalyst is selected experimentally. Compared to the results obtained with NiL 4 as catalyst, the (dppp5)NiL 2 increases the conversion of 2M3BN from 74.5 % to 93.4 % at 3 h of reaction and provides a high selectivity to 3PN (> 98 %) at optimal conditions.
研究领域:
催化
·
有机化学
·
计算化学
✓ 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）