Efficient one-pot synthesis of n-butyl levulinate from carbohydrates catalyzed by Fe_2(SO_4)_3

Butyl levulinate(BL) is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the catalysis of metal sulfates was developed. The catalytic activity of a series of metal sulfates for the synthesis of BL from fructose was investigated. Among various metal sulfates, ferric sulfate Fe_2(SO_4)_3 was found to be the most efficient catalyst, which gave a remarkably high BL yield of 62.8 mol% under the conditions of 463 K, 3 h, a catalyst dosage of 5.0 g/L, and fructose concentration of 25 g/L. Different carbohydrates including glucose, cellulose, inulin and sucrose were also used for one-pot synthesis of BL with the catalysis of Fe_2(SO_4)_3, showing the yields of 39.6, 30.5, 56.6 and 50.1 mol%, respectively. In addition,the recycling and reuse of Fe_2(SO_4)_3 was studied by characterizing them using powder X-ray diffraction(XRD), scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS). A plausible reaction pathway for the one-pot synthesis of BL from fructose was proposed. This study provides a facile and feasible way for the synthesis of BL from biomass.

Reactive dividing-wall column for the co-production of ethyl acetate and n-butyl acetate

Reactive dividing-wall column(RDWC) technology plays a critical role in the energy saving and high efficiency of chemical process.In this article, the process of co-producing ethyl acetate(EA) and n-butyl acetate(BA) with RDWC was studied.BA was not only the product, but also acted as entrainer to remove the water generated by the two esterification reactions.Experiments and simulations of the co-production process were carried out.It was found that the experimental results were in good agreement with the simulation results.Two kinds of RDWC structures(RDWC-FC and RDWC-RS) were proposed, and the co-production process operating parameters of the two types of RDWC were optimized by Aspen Plus respectively.The optimal operating parameters of the RDWC-FC were determined as follows: 0.6 of the reflux ratio of aqueous phase(RR), 0.66 of the vapor split(R_V) and 0.51 of the liquid split(R_L).And the optimal operating parameters of the RDWC-RS were shown as follows: RR was 0.295 and R_V was 0.61.Furthermore, the energy saving analysis of the co-production process was based on the annual output of 10000 tons of EA, compared with the traditional reaction distillation(RD) to prepare EA and BA, the reboiler duty of the RDWC-FC column could save 20.4%, TAC saving 23.6%; RDWC-RS reboiler energy consumption could save 17.0%, TAC 22.2%.

Reactivity Ratios for Microemulsion Copolymeriration of N-butyl Maleimide and Styrene

The oil-in-water microemulsion containing N-butyl maleimide（NBMI. M1） and styrene（St, M2） was prepared. The complexation properties of NBMI and St in microemulsion were investigated by means of 1H-NMR. With the participation of charge-transfer complex（CTC）. four reactivity ratios and the relative reactivity of free monomers and CTC were obtained. The result was compared with that measured by Mayo-Lewis method.

Percutaneous transcatheter super-selective renal arterial embolization with N-butyl cyanoacrylate for iatrogenic renal hemorrhage

Background:To evaluate the safety and efficacy of percutaneous transcatheter super-selective renal arterial embolization(SRAE)with N-butyl cyanoacrylate(NBCA)for iatrogenic renal hemorrhage.Methods:Between January 2014 and December 2019,45 patients(including 18 patients with coagulopathy),who underwent percutaneous transcatheter SRAE with NBCA for iatrogenic renal hemorrhage at our institution,were retrospectively reviewed.The technical success rate,clinical success rate,and embolization-related complications were analyzed.The values of estimated glomerular filtration rate(eGFR),serum creatinine(sCr),and serum urea(sUr)were analyzed at the time of pre-SRAE,post-SRAE,and last follow-up to evaluate the effects of NBCA-based SRAE on renal function.Results:Diagnostic renal arteriography revealed contrast extravasation in 18 patients and pseudoaneurysms in 27 patients.NBCA mixed with iodized oil in a 1:2–1:4 ratio was the sole embolic agent.No procedure-related mortality or major complications occurred.The technical and clinical success rates were both 100%.The values of eGFR,sCr and sUr were not found to be significantly different between pre-SRAE,post-SRAE and last follow-up(eGFR:91.52±21.17 vs.90.98±22.11 vs.92.14±23.51 mL/min/1.73 m^(2),p=0.729;sCr:74.73±11.08 vs.75.27±12.43 vs.73.95±10.14μmol/L,p=0.543;sUr:5.69±0.84 vs.5.71±0.96 vs.5.70±0.79,p=0.515,respectively).Conclusions:Percutaneous transcatheter SRAE with NBCA is a safe and effective treatment modality for iatrogenic renal hemorrhage with no deterioration of renal function.

Synthesis of n-Butyl Acetate by Microwave Irradiation Under the Assistance of Solid-Liquid Phase Transfer Catalysis Without Solvent

Introduction Microwave irradiation has been very widely used in heating, cooking and brewing. Several papers which describe the use of domestic microwave ovens to perform rapid organic synthesis in solution have been published. The high heating efficiency gives rise to remarkable rate of reaction and dramatic reduction of reaction time. Nevertheless, its application seems to be limited to these procedures because

Safety of bronchial arterial embolization with n-butyl cyanoacrylate in a swine model

AIM: To compare the efficacy and safety of bronchial artery embolization (BAE) with n-butyl cyanoacrylate (NBCA) and gelatin sponge particles (GSPs). METHODS: Six healthy female swine were divided into two groups to be treated with BAE using NBCA-lipiodol (NBCA-Lp) and using GSPs. The occlusive durability, the presence of embolic materials, the response of the vessel wall, and damage to the bronchial wall and pulmonary parenchyma were compared. RESULTS: No animals experienced any major complication. Two days later, no recanalization of the bronchial artery was observed in the NBCA-Lp group, while partial recanalization was seen in the GSP group. Embolic materials were not found in the pulmonary artery or pulmonary vein. NBCA-Lp was present as a bubble-like space in bronchial branch arteries of 127-1240 μm, and GSPs as reticular amorphous substance of 107-853 μm. These arteries were in the adventitia outside the bronchial cartilage but not in the fine vessels inside the bronchial cartilage. No damage to the bronchial wall and pulmonary parenchyma was found in either group. Red cell thrombus, stripping of endothelial cells, and infiltration of inflammatory cells was observed in vessels embolized with NBCA-Lp or GSP. CONCLUSION: NBCA embolization is more potent than GSP with regard to bronchial artery occlusion, and both materials were present in bronchial branch arteries≥100 μm diameter.

High-gravity technology intensified Knoevenagel condensation-Michael addition polymerization of poly (ethylene glycol)-poly (n-butyl cyanoacrylate) for blood-brain barrier delivery

Poly(ethylene glycol)-poly(n-butyl cyanoacrylate)(PEG-PBCA)is a remarkable drug delivery carrier for permeating blood-brain barrier.In this work,a novel high-gravity procedure was reported to intensify Knoevenagel condensation-Michael addition polymerization of PEG-PBCA.A series of PEG-PBCA containing different block ratios were synthesized with narrow molecular weight distribution of polydispersity indexes less than 1.1.Furthermore,the reaction time reduced 60%compared to conventional stirred tank reactor process.Chemical structures of as-prepared polymers were characterized.In vitro drug delivery performance was evaluated.The cytotoxicity of PEG-PBCA to brain microvessel endothelial cells(BMVEC)decreases with the extension of the PEG chain and the shortening of the PBCA chain.The polymer cellular uptake to BMVECs was better after improving hydrophilicity by PEG block.Results of bloodbrain barrier permeability demonstrated that medium length of PBCA chain and short PEG chain are favorable for hydrophobic Nile red permeation,while long PEG chain and short PBCA chain are beneficial to delivery water-soluble doxorubicin hydrochloride(Dox).The average apparent permeability coeffi-cient increased 1.7 and 0.25 times than that of raw Nile red and Dox,respectively.High-gravity intensi-fied condensation polymerization should have great potential in brain drug delivery system.

壳聚糖与正丁醛缩合反应的研究

The orthogonal design was employed to study the reaction conditions of chitosan condensing with n-butyl aldehrde.Applying the L9(34) table in the method of the orthogonal experiment,proposing an optimal experiment condition of pH,time,temperature and molar ratio of reactants in three different levels,the result showed that the best condition was pH:9,temperature:70℃,time:5h,and molar ratio of reactants:1∶6.Shiff base structure was determined by IR.

SYNTHESIS OF STYRENIC TONER PARTICLES BY SPG EMULSIFICATION TECHNIQUE

This research studied the initiator efficiency for producing polymeric particles of poly(styrene-co-methylmethacrylate) copolymers by a Shirasu porous glass membrane (SPG) emulsification technique followed by suspensioncopolymerization. BPO, ADVN, and AIBN were used as initiators and we found that BPO is the most suitable initiator.Copolymers for various feed ratios of styrene/methyl methacrylate were thus synthesized by benzoyl peroxide, and theircopolymer particle size, molecular weight distribution and particle size distribution were characterized. Then n-BMA or 2-EHMA was added as the third monomer to decrease the terpolymer glass transition temperature. This article describes thepreparation technique, recipes and polymerization conditions for producing both copolymer and terpolymer panicles, particlesize changes, the corresponding particle morphologies and glass transition temperatures.

氨基甲酸正丁酯的蒸汽压、汽化焓、标准生成焓以及标准熵（英文）

The vapor pressures of n-butyl carbamate were measured in the temperature range from 372.37 K to 479.27 K and fitted with Antoine equation. The compressibility factor of the vapor was calculated with the Virial equation and the second virial coefficient was determined by the Vetere model. Then the standard enthalpy of vaporization for n-butyl carbamate was estimated. The heat capacity was measured for the solid state(299.39–324.2 K) and liquid state(336.65–453.21 K) by means of adiabatic calorimeter. The standard enthalpy of formation ΔfH[crystal(cr),298.15 K] and standard entropy S(crystal,298.15 K) of the substance were calculated on the basis of the gas-phase standard enthalpy of formation ΔfH(g,298.15 K)and gas-phase standard entropy S(g,298.15 K), which were estimated by the Benson method. The results are acceptable, validated by a thermochemical cycle.

Synthesis and Characterisation of Silver Nanoparticles in Different Medium

Silver nanoparticles were synthesized in different alcoholic medium such as ethylene glycol and n-butyl alcohol by solvothermal method. The nanoparticles have been successfully synthesized by reducing silver nitrate with the above solvents in the presence of trioctyl phosphine oxide (TOPO) as the capping agent at room temperature for 1 h. Electron microscopy, X-ray diffraction, and absorption spectra have been used to investigate the products, and the mechanism is proposed to interpret the controlled synthesis of the products. The results indicate that this approach provides a versatile route to prepare silver nanowires and nanoparticles with controllable diameters. The formation of nano products by this method is rapid, simple and stable.

醋酸正丙酯与醋酸正丁酯的选择与探讨

在PTA装置中溶剂脱水正常采用两种方法:常规精馏和共沸精馏。从能耗和物耗以及方便操作的角度,通常选用共沸精馏,而采用共沸精馏时,共沸剂的选择是一个比较关键的因素。笔者从共沸剂的性能、消耗、能耗以及塔的选择方面进行了比较与探讨,为共沸精馏塔的共沸剂选择提供了一个参考。

Mechanisms of Cup-Shaped Vesicle Formation Using Amphiphilic Diblock Copolymer

A cup shape is a dynamic morphology of cells and organelles. With the aim of elucidating the formation of the biotic cup-shaped morphology, this study investigated cup-shaped vesicles consisting of an amphiphilic diblock copolymer from the aspect of synthetic polymer chemistry. Cup-shaped vesicles were obtained by the polymerization-induced self-assembly of poly(methacrylic acid)-block-poly(n-butyl methacrylate-random-methacrylic acid), PMAA-b-P(BMA-r-MAA), in an aqueous methanol solution using the photo nitroxide-mediated controlled/living radical polymerization technique. Field emission scanning electron microscopic observations demonstrated that the cup-shaped vesicles were suddenly formed during the late stage of the polymerization due to the extension of the hydrophobic P(BMA-r-MAA) block chain. During the early stage, the polymerization produced spherical vesicles rather than a cup shape. As the hydrophobic block chain was extended by the polymerization progress, the spherical vesicles reduced the size and were accompanied by the generation of small particles that were attached to the vesicles. The vesicles continued to reduce the size due to further extension of the hydrophobic chain;however, they suddenly grew into cup-shaped vesicles. This growth was accounted for by a change in the critical packing shape of the copolymer due to the hydrophobic chain extension. These findings are helpful for a better understanding of the biotic cup-shaped vesicle formation.

Posteroinferior Cerebellar Artery (PICA) Fusiform Aneurysm Ruptured Related with a Pure Arterial Malformation: Case Report and Technical Note (NBCA Embolization under Roadmap-Fluoroscopy)

Background: The pure arterial malformation (PAM) lesion has been recently described as a vascular pathology characterized by the sole presence of coiled, sometimes ectatic, arterial loops. 2% of the fusiform aneurysms are located in the vertebral-posterior inferior cerebellar arteries. Case Presentation: A 60 years old female with subarachnoid hemorrhage was diagnosed with a fusiform aneurysm in the right PICA related with a PAM in the digital subtraction angiography (DSA). With a negative super-selective Wada test, the patient was treated with embolization of the two lesions and the PICA for being in the same arterial territory with adhesive embolic liquid under roadmap fluoroscopy technique. The patient had a satisfactory clinical evolution and no added neurological deficit, so she was discharged 3 days after the treatment. Conclusion: These two vascular lesions located in the same artery are very rare and more in the PICA territory. It is important to make the best decision to treat them because of the potential complications;that’s why the procedure was supported with super-selective Wada test and neuromonitoring of the PICA territory. The injection of the mixture of NBCA and Lipiodol® under roadmap fluoroscopy is very safe.

Cerium modified Y/SBA-15 composite molecular sieve catalyzed synthesis of n-butyl acetate

A novel Ce-Y/SBA-15 catalyst was prepared by modifying HY/SBA-15 microporous-mesoporous composite molecular sieve with cerium using the impregnation method. The characterization results from scanning electron microscopy/energy dispersive X-ray dispersive spectroscopy(SEM/EDS), transmission electron microscopy(TEM), and X-ray fluorescence(XRF) studies indicated that the Ce-modified catalyst maintained the microporous-mesoporous structure of Y/SBA-15. The Ce ions were found to be uniformly dispersed in the pores of the molecular sieve without aggregation. The results from pyrolysis coupled-Fourier transform infrared spectroscopy(Pyridine-FTIR) and temperature programmed desorption of ammonia(NH3-TPD) showed that the loading of cerium caused the hydroxyl group in the catalyst to display stronger Bronsted acidity. The efficiency of the modified Ce-Y/SBA-15 catalyst was evaluated by using it to catalyze the synthesis of n-butyl acetate. The optimal synthesis conditions were determined by orthogonal experiments. The highest esterification yield of 94.4% was obtained when the reaction time was 2.0 h, with acid/alcohol molar ratio of 1:1.2, and catalyst loading of 10 wt.%. The results in this study demonstrated that the loading of cerium and the structure of Y/SBA-15 microporous-mesoporous composite molecular sieve helped in improving the catalytic activity of this acidic catalyst.

Esterification of levulinic acid into n-butyl levulinate catalyzed by sulfonic acid-functionalized lignin-montmorillonite complex

In this study,sulfonic acid-functionalized lignin-montmorillonite complex(LMT-SO_(3)H)was pre-pared and employed as an efficient heterogeneous catalyst for the esterification of levulinic acid(LA)into n-butyl levulinate(BL).An intermediate pseudo-butyl levulinate(p-BL)was determined by distilled water treatment and nuclear magnetic resonance(NMR)analysis,and a possible mech-anism for the esterification of LA is proposed.The effects of various process parameters were studied and the results showed that the LMT-SO_(3)H catalyst had the excellent catalytic perfor-mance for esterification of the LA.Under optimum reaction conditions,the yield of BL was 99.3%and the conversion of LA was 99.8%.The LMT-SO_(3)H catalyst exhibited strong acidic sites and high stability even after seven cycles of usage.Furthermore,esterification of the LA with various alcohols over the LMT-SO_(3)H was further investigated.

Synthesis of hollow spherical nickel oxide and its gas-sensing properties

Semiconductor metal oxides have attracted wide attention in the area of gas sensor due to that they have unique advantages in the rapid and accurate detection of harmful gases.A simple strategy is to synthesize porous NiO hollow microspheres via a simple hydrothermal method with trisodium citrate as structure guide agent is presented in this paper,and the shell of the microsphere is composed of porous and lamellar assembly units.The cavity proportion can be adjusted by changing the amount of trisodium citrate.A reasonable mechanism was proposed to explain the formation of porous NiO hollow microspheres.As a gas-sensing material,porous NiO hollow microspheres show excellent gas selectivity and rapid response recovery time for n-butyl alcohol gas.When the content of trisodium citrate was 0.10 g,the synthesized hollow sphere NiO had the highest response value(25.6)to 100×10^(-6) of n-butyl alcohol at 300℃ and the response and recovery times were only 68 and 10 s.

Estimating the effect of urease inhibitor on rice yield based on NDVI at key growth stages

The effect of the urease inhibitor,N-(n-butyl)thiophosphoric triamide(NBPT)at a range of application rates on rice production was examined in a field experiment at Jinxian County,Jiangxi Province,China.The normalized difference vegetation index(NDVI)was measured at key growth stages in both early and late rice.The results showed that the grain yield increased significantly when urea was applied with NBPT,with the highest yield observed at 1.00%NBPT(wt/wt).NDVI differed with the growth stage of rice;it remained steady from the heading to the filling stage.Rice yield could be predicted from the NDVI taken at key rice growing stages,with R^(2) ranging from 0.34 to 0.69 in early rice and 0.49 to 0.70 in late rice.The validation test showed that RMSE(t·hm^(–2))values were 0.77 and 0.87 in early and late rice,respectively.Therefore,it was feasible to estimate rice yield for different amounts of urease inhibitor using NDVI.