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（SO）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（SO）, showing the yields of 39.6, 30.5, 56.6 and 50.1 mol%, respectively. In addition,the recycling and reuse of Fe（SO）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.

Esterification of levulinic acid to n-butyl levulinate over heteropolyacid supported on acid-treated clay

Levulinic acid has been identified as a promising green, biomass-derived platform chemical. n-Butyl levulinate is used as an important intermediate having diverse applications. The present work focuses on the synthesis of n-butyl levulinate by esterification of levulinic acid with n-butanol using heteropolyacid （HPA） supported on acid-treated clay montmorillonite （K10）. 20% （w/w） dodecatungestophosphoric acid （DTPA） supported on K10 was found to be the most efficient catalyst with 97% levulinic acid conversion and 100% selectivity towards n-butyl levulinate. Effects of various process parameters were studied to examine the efficacy of 20% （w/w） DTPA/K10 for optimization of the activity.

n-Butyl Pyridinium Nitrate as a Reusable Ionic Liquid Medium for Knoevenagel Condensation

The Knoevenagel condensation of carbonyl substrates with active methylene compounds proceeds smoothly with ammonium acetate as catalyst in n-butyl pyridinium nitrate to afford the desired products of good purity in moderate yields.

Di-(n-butyl)-phthalate-induced Oxidative Stress and Depression-like Behavior in Mice with or without Ovalbumin Immunization

Objective To investigate the relationship between atopic allergy and depression and the role of DBP in the development of depression. Methods BALB/c mice were randomly divided into eight groups：saline;ovalbumin （OVA）-immunized;saline＋DBP （0.45 mg/kg·183;d）; saline＋DBP （45 mg/kg·d）; DBP （0.45 mg/kg·d） OVA-immunized; DBP （45 mg/kg·d） OVA-immunized; saline＋hydrocortisone （30 mg/kg·d）; and hydrocortisone （30 mg/kg·d）-exposed OVA-immunized. Behavior （e.g. open-field, tail suspension, and forced swimming tests）, viscera coefficients （brain and spleen）, oxidative damage [e.g. reactive oxygen species （ROS）, malondialdehyde （MDA）, and glutathione （GSH）], as well as levels of IgE and IL-4, were then analyzed. Results In the saline and OVA groups, the degree of depression symptoms in mice increased with increasing DBP concentration. Additionally, the OVA-immunity groups were associated with more serious depressive behavior compared with the same exposure concentration in the saline group. Oxidative damage was associated with a dose-dependent increase in DBP in the different groups. IL-4 and IgE levels were associated with low-dose DBP stimulation, which changed to high-dose inhibition with increasing DBP exposure, possibly due to spleen injury seen at high DBP concentrations.Conclusion Development of an atopic allergy has the potential to increase the risk of depression in mice, and it seems that DBP helps OVA to exert its effect in our present model. Moreover, the results of our study implicate a certain connection between brain oxidative stress and depression, which deserves a further exploration.

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. M_1) and styrene(St, M_2) 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.

Synthesis,Characterization and Catalytic Application of H_3PW_(12)O_(40)/MCM-48 in the Esterification of Methacrylic Acid with n-butyl Alcohol

A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of n-butyl methacrylate catalyzed by H3PW12O40/MCM-48 was studied with methacrylic acid and n-butyl alcohol as reactants. H3PW12O40/MCM-48 is an excellent catalyst for synthesizing n-butyl methacrylate and Keggin structure of H3PW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n（methacrylic acid）：n（n-butyl alcohol）, catalyst dosage, cyclohexane（water-stripped reagent） and reaction time on yields of the product were investigated. The optimum conditions have been found, that is, molar ratio of acid to alcohol is 1：1.6, mass ratio of catalyst used to the reactants is 0.5% and reaction time is 2.0 h. Under these conditions, the yield of n-butyl methacrylate can reach 93.7%.

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.

Controlled Radical Photopolymerization of n-Butyl Methacrylate in Bluk Mediated by HTEMPO

Controlled radical photopolymerization of n-butyl methacrylate（n-BMA） mediated by 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy（HTEMPO） was carried out in bulk at ambient temperature. It was found that obtained n-BMA homopolymers exhibited narrow polydispersities of around 1.4, which was characterized by GPC. Plots of number-average molecular weight vs. conversion and Ln（[Mo]/[M]） vs. time were liner respectively, indicating that was a controlled photopolymerization.

Effect of Oxygen on Surface Properties and Drug Release Behavior of Plasma Polymer of n-Butyl Methacrylate

The effects of oxygen on the chemical structure, morphology, hydrophilicity and drug release behavior of radio-frequency plasma poly n- butyl methacrylate （PPBMA） thin film were carded out for the first time. ATR-FTIR and XPS showed that oxygen had little influence on the chemical structure and composition of PPBMAs, which did not agree with the thought that the presence of oxygen gas would increase the oxidized carbon functionalities in the plasma polymer. SEM and static contact angle measurement indicated that in case of deposition with oxygen, the smoothness and hydrophilicity of PPBMA were dramatically improved. The drug release behavior showed that drug release from the PPBMA coating without oxygen was biphasic patterns, while from PPBMA coating with oxygen was Higuchi release. These results were helpful for the design and tailoring of the PPBMA polymer film and other of plasma polymers film, but could provide a new idea for the drug release controlled form.

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 of

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.

Surlyn/PMMA/PVDF共混物微观结构及性能的研究

采用聚甲基丙烯酸甲酯(PMMA)和乙烯-甲基丙烯酸共聚盐树脂(Surlyn)与聚偏二氟乙烯(PVDF)进行熔融共混,制备了Surlyn/PMMA/PVDF三元共混物。利用示差扫描量热法(DSC)、热重分析法(DTG)、X射线衍射(XRD)以及扫描电子显微镜(SEM)等测试方法分析共混物的微观结构和性能。结果表明,PMMA与PVDF有很好的相容性,且在一定程度上降低了共混物的结晶度与熔融温度,有利于PVDF进行塑化加工,同时导致PVDF的β相的形成。Surlyn的加入使得共混物分解温度比PVDF/PMMA提高,改善了共混物的热稳定性,提高了耐候性,但共混体系的结晶度并没有明显的改变。

丙烯酸酯类聚氨酯/蛭石纳米复合材料的制备与性能研究

分别采用十六烷基三甲基溴化铵(CTAB)、CTAB与聚乙二醇400(PEG400)的复合体系对蛭石进行有机化处理,然后用有机改性的蛭石、甲基丙烯酸-β-羟乙酯、异佛尔酮二异氰酸酯、PEG400进行复合插层反应,制得丙烯酸酯类聚氨酯/蛭石纳米复合材料,并对有机处理前后的蛭石结构和复合材料的性能进行了表征。结果表明,经有机处理后,蛭石层间距明显增大,用CTAB/PEG400复合体系做插层剂时,蛭石的层间距较大;当有机蛭石质量分数为1.00%时,复合材料的综合性能较佳,拉伸强度为25.09MPa,拉伸断裂伸长率为30.02%,冲击强度为40.48kJ/m2,玻璃化转变温度为85.51℃,分别较纯丙烯酸酯类聚氨酯提高了12.5%、36.9%、446.3%、6.86℃。

甲基丙烯酸甲酯的生产与市场

作者综述了2012年国内外甲基丙烯酸甲酯(MMA)的生产能力和实际产量,介绍了国内外甲基丙烯酸甲酯消费结构、市场需求、市场价格和进出口情况,对国内甲基丙烯酸甲酯及其市场发展趋势进行了分析和预测,并提出发展建议。今后几年,将是我国甲基丙烯酸甲酯的快速发展时期,预计到2013年末,国内甲基丙烯酸甲酯产能将超过70万t/a。

骨水泥椎体强化在骨质疏松患者行椎弓根钉内固定中的应用

目的探讨应用骨水泥行椎体强化后椎弓根钉固定的临床效果。方法回顾分析23例骨质疏松患者用聚甲基丙烯酸甲酯(PMMA)骨水泥行椎体强化加椎弓根钉固定后的临床结果,比较术后1周内的与复查时的X线片,观察内固定物有无松动、椎弓根钉周围有无透亮线出现。结果本组所有病例术后均获得随访,随访时间为6～33个月,平均为17个月。所有患者腰痛及下肢神经压迫症状均明显缓解,脊柱活动度改善21例(91.3%),无改善2例。脊柱侧凸均获不同程度改善,后凸畸形均明显改善。所有患者复查X线片均未发现椎弓根螺钉的松动及脱出,椎弓根螺钉周围均未发现有透亮线出现。结论对骨质疏松患者用PMMA行椎体强化椎弓根钉固定,可防止椎弓根钉的松动及脱落,有较好的临床效果。术中应注意操作技巧,确保无骨水泥渗漏。

纳米二氧化硅辐射接枝制备离子交换吸附材料及其吸附性能

利用偶联剂对纳米二氧化硅进行表面化学改性,制备了乙烯基活化的纳米二氧化硅。运用γ射线引发共辐射接枝的方法在改性纳米二氧化硅上接枝甲基丙烯酸缩水甘油酯(GMA)单体,得到SiO2-g-GMA接枝共聚物,然后在共聚物表面进行氨化反应得到吸附材料。研究了单体浓度、吸收剂量等因素对GMA接枝率的影响规律,明确了反应条件与接枝率的对应关系。采用傅立叶变换红外光谱(FT-IR)表征接枝物的结构,研究了pH值、GMA接枝率、最大试样体积等影响因子对吸附的影响。

PAN/PBMA共混纤维的研究

采用溶液共混法制备聚丙烯腈/聚甲基丙烯酸正丁酯（PAN/PBMA）共混纤维。分别从溶解度参数、红外光谱（FTIR）、动态力学分析（DMA）3个方面对共混组分的相容性进行研究,结果表明PAN与PBMA具有部分相容性。通过扫描电子显微镜（SEM）、热失重分析（TG）研究共混纤维形态结构和热稳定性,发现低含量组分PBMA以微区形式均匀分散于PAN基体中,使其耐热稳定性得到明显改善。吸附实验表明,PAN/PBMA（70/30）共混纤维对甲苯、氯仿、煤油的吸附能力较纯PAN纤维提高了2~3倍。

水性引发剂浓度对MMA/n-BA/H-PDMS微乳液聚合的影响

以辛基酚聚氧乙烯醚(OP-10)和OP-4、十六烷基三甲基溴化铵(CTAB)为复合乳化剂,正戊醇为助乳化剂,含氢聚二甲基硅氧烷(H-PDMS)、甲基丙烯酸甲酯(MMA)、丙烯酸正丁酯为聚合单体,以水溶性过硫酸铵(APS)-亚硫酸氢钠(NaHSO3)为氧化还原引发剂,采用微乳液聚合方法,制备了4种引发剂浓度不同的聚合物微乳液,研究了引发剂浓度对MMA/n-BA/H-PDMS的微乳液共聚合的影响。通过FT-IR和1 H-NMR分析证明,微乳液体系中的聚合物含有氢聚硅氧烷/丙烯酸酯共聚物;实验表明,当引发剂浓度太低时,聚合体系存在引发诱导效应;而当引发剂浓度适当提高时,聚合过程存在明显的恒速期;但当引发剂浓度较高时,聚合过程无明显恒速期,继续提高引发剂浓度,聚合速率明显变大,其聚合速率的最大值也更高。通过动力学研究,分别得到了聚合速率与产物特性黏度的动力学关系式:Rp∝[APS]0.75,[η]∝[APS]-0.07。另外,实验结果表明,随着聚合转化率的提高,乳胶粒径增大。在这些研究基础上初步探讨了微乳液聚合机理。