油酰柠檬酸三丁酯合成工艺的研究

采用柠檬酸与正丁醇在催化剂作用下酯化生成柠檬酸三丁酯,油酸与三氯化磷合成油酰氯,柠檬酸三丁酯与油酰氯通过酰基化反应合成油酰柠檬酸三丁酯(OTBC),研究了油酰柠檬酸三丁酯的合成工艺条件。研究表明:n(柠檬酸三丁酯):n(油酰氯)为1:2时酰化率可达到99.4%,合成的油酰柠檬酸三丁酯分子量为625、脂肪碳与极性基团的比值为8(与DOP相同)、质量浓度为0.898g/mL、沸点为194℃、折光率1.4548。     

New sorbent hydrogels for removal of acidic dyes and metal ions from aqueous solutions

Summary Poly(N-hydroxymethylacrylamide), PHMA, hydrogels were prepared by using N-hydroxymethylacrylamide, HMA, monomer and polyethyleneglycol(400)diacrylate as a crosslinking agent in aqueous medium and then amine groups were incorporated onto PHMA hydrogels by amination reaction with different diamines. The obtained hydrogels were characterized by determination of amine value, hydroxymethyl group content and FTIR spectra. The amine value of hydrogels changed from 2.23 to 4.64 mmol/g by depending on the amine compounds used in amination reaction. Their swelling degree increased at acidic pH values and they showed pH dependent swelling behaviour. They were used as sorbent for removal of indigo carmine and Cu(II) ion, as a model dye molecule and metal ion, respectively, from aqueous solutions. The adsorption properties of the hydrogels were investigated by depending on pH, time and initial indigo carmine or Cu(II) ion concentration. It was seen that the amine group incorporated hydrogels have quite high adsorption rate and adsorption capacity, and their adsorption capacities changed with pH of the solution. Langmuir isotherm model was the best fit for adsorption of both indigo carmine and Cu (II) ion.     

Crosslinked poly(glycidyl methacrylate)‐based resin for removal of mercury from aqueous solutions

Glycidyl methacrylate–based resin crosslinked beads with acetamide functions were demonstrated to be efficient in the removal of mercury. Beaded polymer supports were prepared by suspension polymerization of glycidyl methacrylate (0.9 mol) and ethylene glycol dimethacrylate (0.1 mol). The resulting copolymer beads were modified through epoxy functions in two steps: (1) by treatment with excess dibutyl amine and (2) by subsequent reaction with chloroacetamide. The resulting polymer resin, which had a chloroacetamide content of 2.5 mmol/g, was effective in extracting mercury from aqueous solutions. The mercury sorption capacity was around 2.2 mmol/g in nonbuffered conditions. Experiments performed in identical conditions with several metal ions revealed that Cd(II), Pb(II), Zn(II), and Fe(III) ions also were extractable in low quantities (0.2–0.8 mmol/g). The sorbed mercury could be eluted by repeated treatment with hot acetic acid without hydrolysis of the amide groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 348–352, 2006     

Synthesis and CO2 adsorption behavior of amine‐functionalized porous polystyrene adsorbent

A solid amine adsorbent was prepared by modifying a porous polystyrene resin (XAD‐4) with chloroacetyl chloride through a Friedel–Crafts acylation reaction, followed by aminating with tetraethylenepentamine (TEPA). The adsorption behavior of CO₂ from a simulated flue gas on the solid amine adsorbent was evaluated. Factors that could determine the CO₂ adsorption performance of the adsorbents such as amine species, adsorption temperature, and moisture were investigated. The experimental results showed that the solid amine adsorbent modified with TEPA (XAD‐4‐TEPA), which had a longer chain, showed an amine efficiency superior to the other two amine species with shorter chains. The CO₂ adsorption capacity decreased obviously as the temperature increased because the reaction between CO₂ and amine groups was an exothermic reaction, and its adsorption amount reached 1.7 mmol/g at 10 °C in dry conditions. The existence of water could significantly increase the CO₂ adsorption amount of the adsorbent by promoting the chemical adsorption of CO₂ on XAD‐4‐TEPA. The adsorbent kept almost the same adsorption amount after 10 cycles of adsorption–desorption. All of these results indicated that amine‐functionalized XAD‐4 resin was a promising CO₂ adsorbent. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45046.     

Adsorption of urokinase by polypropylene films with various amine groups

Polypropylene films with various amine groups were prepared by radiation‐induced grafting of glycidyl methacrylate (GMA) onto polypropylene (PP) films and the subsequent amination of poly‐GMA graft chains were examined. The physical and chemical properties of the GMA‐grafted PP film and the aminated PP film were investigated by IR, SEM, XPS, and TGA. The adsorption of urokinase for the PP films modified with various amine groups was examined under various conditions of different amine group contents and pH values. The adsorption of urokinase increased by increasing the amine group content. In the range of amine group content from 1.0 to 2.7 mmol/g, the adsorption of urokinase by the PP films modified with six kinds of amines was in the following order: trimethylamine > diethylenetriamine > triethylenetetraamine > ethylenediamine > dimethylamine > diethyleneamine. The adsorption amounts of urokinase by the PP film with the trimethylamine and triethylenetetraamine groups at pH 7.4 were higher than those at pH 9. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2851–2858, 2001     

Ion exchange resins for gold cyanide extraction containing a piperazine functionality, 1. Synthesis and physico‐chemical properties

The synthesis of two types of metal‐chelating resins incorporating gold‐specific piperazine groups is described. PS‐PIP is a styrene‐divinylbenzene macroporous network. MC‐PIP is a (glycidyl methacrylate)‐co‐(ethylene dimethacrylate) network. The nominal functional group concentrations are 1.84 mmol/g for PS‐PIP and 1.14 mmol/g for MC‐PIP. The proton exchange capacity is 1.95 mmol/g for PS‐PIP and 0.91 mmol/g for MC‐PIP. Accurate titration curves were used to determine pK_a values (pK_H = 7.05 ± 0.12). XPS analyses of PS‐PIP resin were followed as a function of pH (cf. Fig. 8) demonstrating that the protonation of the amine is observable by a shift in binding energy of the N (1s) peak (±1.6 eV) moving from tertiary amine form (N (1s) 399.7 eV) to the protonated tertiary amine form (N (1s) 401.3 eV). Additionally, the presence of quaternary ammonium groups was detected at a N (1s) peak at 402.3 eV (cf. Fig. 9). Metal extraction from cyanide solutions, including Brazilian mine leach solution, showed considerable preference for gold (cf. Fig. 11–12). The piperazine resins extract gold via two mechanisms: (a) ligand substitution reactions at pH > 7.05 (pK_H(a)) or (b) anion exchange reactions via the quaternary ammonium groups at high pH values. Extraction profiles were S‐shaped (cf. Fig. 10) with 50% extraction ability at pH 8.0. Cyclic experiments involving extraction, elution, regeneration and recomplexation (cf. Tab. 6 and 7) showed the ability of MC‐PIP to perform consistently at high extraction efficiencies from pH 8.6.     

水相合成S-正辛基-5,5-二苯基-2-硫代海因的绿色工艺

以5,5-二苯基-2-硫代海因和溴代正辛烷为原料，在碱水溶液中相转移催化合成S-正辛基-5,5-二苯基-2-硫代海因，考察溴代正辛烷用量、氢氧化钾用量、相转移剂种类和用量以及反应时间对产率的影响。确定较佳工艺条件为：5,5-二苯基-2-硫代海因50 mmol，溴代正辛烷55 mmol，氢氧化钾50 mmol，十八叔胺0.2 g，水50 mL，回流反应4 h，可得到高纯度S-正辛基- 5,5- 二苯 基-2 -硫代海因，产率达85%。产品结构经IR、¹H NMR、13C NMR及MS进行了表征。     

络合萃取法在2-萘酚废水处理中的应用研究

采用络合萃取法,以三烷基胺和磷酸三丁酯为萃取剂、煤油为稀释剂处理2-萘酚β-盐母液废水。试验结果表明：采用20％三烷基胺-20％磷酸三丁酯-60％煤油的混合型络合萃取剂对2．萘酚废水进行萃取具有较高的COD脱除率。     

HYDROFLUORIC ACID EXTRACTION BY TBP AND BY AMINES: I. A CRITICAL REVIEW OF THE HF-H2O-EXTRACTANT SYSTEM

Literature on HF extraction by amines and by tributyl phosphate is critically reviewed. The system amine-HF-H₂O shows an interesting feature concerning properties such as distribution curves compared to those for extraction of other acids, similarity to extraction by TBP, water extraction, selectivity, effect of amine type and dilution and diluent effect These properties sharply change (or even invert) when HF/amine molar ratio exceeds 2.     

磷钨酸铵铝复合盐催化合成柠檬酸三丁酯

以磷钨酸、碳酸铵和金属盐溶液为原料,制备了系列金属离子与NH_4~+复合掺杂磷钨酸盐的催化剂,并将其应用于酯化合成柠檬酸三丁酯的反应。其中,(NH_4)_(1/2)Al_(2/3)H_(1/2)PW_(12)O_(40)(Ⅰ)的催化活性较高,且成本相对较低。在正丁醇与柠檬酸的物质的量比为4∶1、催化剂Ⅰ用量为1.5%(以柠檬酸的质量为基准,下同)、温度150℃、时间3 h的条件下,柠檬酸三丁酯的收率达到97.1%。采用红外光谱、元素分析仪和Hammett指示剂法对催化剂Ⅰ的元素组成、结构、表面酸强度与酸密度进行了表征。结果表明,Ⅰ的表面酸强度(H_0)为-14.52～-13.75,表面酸密度为2.57 mmol/g,高于传统的单一掺杂磷钨酸盐。催化剂Ⅰ重复使用2次,催化活性没有明显下降。     

Removal of Cr(VI) from alkaline aqueous solutions using chemically modified magnetic chitosan resins

Chitosan was cross-linked using glutaraldehyde in the presence of magnetite. The resin obtained was chemically modified through the reaction with tetraethylenepentamine followed by glycidyl trimethylammonium chlorid to produce chitosan bearing amine (R1) and chitosan bearing both amine and quaternary ammonium chloride moieties (R2), respectively. The quaternary amine resin (R2) showed a higher affinity towards the uptake of Cr(VI) from alkaline medium, where an uptake value of 2.8 mmol/g was reported at pH 8 and 25 °C. The nature of interaction of R2 with chromate in alkaline medium was clarified. The resin Kinetics at different temperatures and thermodynamic parameters of the uptake process in alkaline medium were obtained. The uptake of Cr(VI) from different electrolyte solutions was studied. Regeneration curves for the desorption of Cr(VI) from R2 were studied. The adsorbed chromate anions was regenerated effectively (desorption ratio ~ 98%) using a mixture of 2 M NaCl and 0.5 M NaOH.     

URANIUM EXTRACTION SELECTIVITIES OF DIBUTYL CARBITOL AND TRIBUTYL PHOSPHATE IN THE SYSTEM UO2(NO3)2-HNO3H2O-Al(NO3)3-SOLVENT

ABSTRACT

Historically, both the BUTEX (dibutyl carbitol-based) and PUREX (tributyl phosphate-based) processes have been used for uranium recovery and purification. Currently, BUTEX- and PUREX-type extraction processes are being used in series for recovery of isotopically enriched uranium at the Oak Ridge Y-12 Plant. The use of two solvents is predicated on the differing selectivities of each with regard to the contaminant elements present in the uranium source stream. As part of efforts to streamline plant operations in response to decreasing throughput requirements, the Y-12 Development Division is evaluating options for converting the existing two-solvent operation to a single-solvent process.

At the request of the Y-12 Development Division, the Robotics and Process Division at the Oak Ridge National Laboratory has undertaken evaluation of solvents for use in a single-solvent recovery process. Initial efforts have been directed toward development of a single-solvent, dibutyl carbitol-or tributyl phosphate-based process that produces a product with purity equal to or exceeding what is currently obtained in the two-cycle, two-solvent operation. The test effort has involved both laboratory equilibrium determinations and engineering-scale process demonstrations in multistage flowsheets using centrifugal solvent extraction contactors. Excellent uranium recovery results have been obtained from both dibutyl carbitol- and tributyl phosphate-based solvent extraction flowsheets. Contaminant rejection performance by the two solvents is similar for many of the elements considered. Extraction of some contaminant elements by tributyl phosphate is significant enough to conclude that the solvent is not as selective for uranium as is dibutyl carbitol. This determination does not necessarily eliminate tributyl phosphate from consideration for use in a single-solvent process but does indicate a need for effective scrubbing of contaminants from uranium-loaded tributyl phosphate, possibly by partial reflux of the purified, aqueous uranyl nitrate product solution.

     

Antioxidative degradation mechanism of 2-mercaptobenzimidazole modified TEPA-MCM-41 adsorbents for carbon capture from flue gas

Solid amine adsorbents can efficiently adsorb CO₂, but a significant problem is that amine groups are oxidized. In this research, tetraethylenepentamine-impregnated MCM-41 adsorbents (TEPA-MCM-41) were functionally modified with sulphur-containing antioxidant 2-mercaptobenzimidazole (described as antioxidant MB) and tns-(2.4-di-tert-butyl)-phosphite (defined as antioxidant 168), respectively. The antioxidative degradation mechanism of 8% MB–50% TEPA-MCM-41 was analyzed by in situ diffuse reflectance infrared Fourier transform (in situ DRIFT) spectrum and high-performance liquid chromatography/mass spectrometry (HPLC/mass). The CO₂ adsorption capacity of 50% TEPA-MCM-41 was 4.30 mmol/g under 15% CO₂/85% N₂, but decreased to 1.38 mmol/g after oxidation at 100°C for 42 h under 95% N₂/5% O₂ certain condition. The CO₂ capacity of 8% MB–50% TEPA-MCM-41 reduced from 3.90 to 2.86 mmol/g. After 30 adsorption cycles under 5% O₂/15% CO₂/80% N₂, the capacity of 8% MB–50% TEPA-MCM-41 also only decreased by 16.8%, while 50% TEPA-MCM-41 decreased by 63.2%. The reason for the excellent antioxidant stability of 8% MB–50% TEPA-MCM-41 is that MB scavenged free radicals from amine oxidation and decomposed the hydroperoxides produced by free radical reactions. The hydroperoxides were decomposed into alcohols (non-radical products), which were eventually oxidized to sulphonic compounds. The MB modification inhibited the oxidative degradation of solid amine adsorbents guided for the production of antioxidant-efficient adsorbents.     

DGEBF/DDS体系固化动力学机理的研究

以4,4′-二氨基二苯砜(DDS)胺类固化剂固化9,9-二[4-(2,3环氧丙氧基)苯基]芴(DGEBF),采用非等温DSC法推导了固化反应参数和固化机理,并用原位红外和移动窗口二维相关红外分析对固化机理和固化模式进行了验证。结果表明:DGEBF/DDS体系固化反应的表观活化能为64.08 kJ/mol,扩散因子为4.05×104s-1,反应级数为1.55;固化工艺为150℃/1.5 h+190℃/2 h+220℃/1.5 h;固化模式为枝状成核的自催化反应;固化机理为伯胺先与环氧基反应生成仲胺,肿胺继续与环氧基反应生成叔胺,2个反应同时进行,以及在高温下的羟基与环氧基的自催化反应,交联的固化网络逐渐形成。     

TEPA/Q-10固态胺的脱碳性能

引言近年来随着全球变暖和气候变化,温室气体CO2的排放和控制日益受到人们的关注,CO2的捕集和封存(carbon capture and storage,CCS)技术是减排CO2的一种有效手段,其中CO2的捕集成本约占CCS总成本的75%[1-2]。来自化石燃料燃烧发电排放的CO2约占世界CO2总排放量的     

Ring-opening reactions of backbone epoxidized polyoxanorbornene

In this article, we report the synthesis of poly(oxanorbornene imide) (PONB) with internal epoxy groups (epoxidized-PONB₃₀) and its ring-opening reactions with various nucleophiles, such as amine, azide, and thiols. The ring-opening reactions with amines yielded the amine–hydroxyl PONBs in the range of 36–95% of functionalization depending upon the amine content per epoxy. An allylamine–hydroxyl functionalized PONB was further functionalized efficiently with 1-octanethiol by radical thiol-ene reaction. The ring-opening reaction of the main chain epoxy using thiols resulted in a lower functionalization than amines with a similar functional group (e.g., allyl). In addition, sodium azide together with NH₄Cl, was employed efficiently in the ring-opening reaction of the main chain epoxy, resulting in an azide/hydroxyl-functional PONB₃₀ with 53% efficiency, which was determined after a model copper-catalyzed azide–alkyne cycloaddition (CuAAC) experiment was carried out.     

磷酸三丁酯络合萃取含酚废水的应用研究

利用磷酸三丁酯、三烷基胺为络合剂,分别采用苯、甲苯、正辛醇、煤油作为稀释剂对含酚废水进行络合萃取.实验结果表明,采用磷酸三丁酯一甲苯混合溶剂对含酚废水进行萃取具有相当高的分配系数;同时探讨了络合萃取技术处理含酚废水工业化的可行性,实验结果表明具有工业化应用前景.     

Development of biocompatible NaGdF4: Er3+, Yb3+ upconversion nanoparticles used as contrast agents for bio‐imaging

Upconversion nanoparticles with special fluorescence and magnetic properties have been considered an alternative contrast agent for multiple bio‐imaging techniques. It is important to understand the effects of the surface properties and dosage of upconversion nanoparticles on both the magnetic resonance (MRI) image and the photoluminescence spectrum. Here, NaGdF₄: Er³⁺, Yb³⁺ upconversion nanoparticles (UCNPs) modified with amine functional group were produced through a one‐pot thermal decomposition. The average length of the cubic UCNPs is estimated at 53 ±13 nm. The effect of the dosage of amine modified UCNPs on the MRI image is investigated. The T₁ and T₂ relaxivities of the amine modified UCNPs in agarose gel at 3 T are r₁ = 6.79 ±0.14 and r₂ = 17.0 ±0.18 (mmol/L)^?1 s^?1, which are comparable to the relaxivities of commercially available MRI contrast agents. In addition, the photoluminescence of the amine modified UCNPs at low concentrations < 150 µg/mL are further investigated with the excitation wavelength (λ_ex) at 980 nm. The internalization of the amine modified UCNPs cultured with human umbilical vascular endothelial cells (HUVEC) is observed by the fluorescence imaging. Meanwhile, T₁‐weighted MRI imaging of HUVEC cells treated with amine modified UCNPs at 10 µg/mL can be obtained. No significant toxic effect on cells is found when the concentration of the amine modified UCNPs is < 300 µg/mL. This study indicates that a low concentration of amine‐modified NaGdF₄: Er³⁺, Yb³⁺ UCNPs can be used as the contrast agent for both fluorescence imaging and magnetic resonance imaging.     

无毒增塑剂乙酰柠檬酸三丁酯的合成

用氨基磺酸两步法催化合成乙酰柠檬酸三丁酯。实验确定了最佳工艺条件 :(1 )酯化反应 :以 0 2mol柠檬酸为基准 ,n (柠檬酸 )∶n (正丁醇 ) =1 0∶4 0 ,m(催化剂 ) =1 5g ,t =1 1 0～1 6 0℃ ,t=2 5h ,转化率为 98 2 % ;(2 )乙酰化反应 :以 0 2mol柠檬酸三丁酯为基准 ,n (柠檬酸三丁酯 )∶n (乙酸酐 ) =1 0∶1 5 ,m(催化剂 ) =2 0g ,t =85℃ ,t=1 5h ,乙酰化收率为 91 3%。催化剂易回收 ,可循环使用 ,不污染环境。     

Efficient Allylation of Nucleophiles Catalyzed by a Bifunctional Heterogeneous Palladium Complex‐Tertiary Amine System

We demonstrate the synergistic catalysis of a silica‐supported diaminopalladium complex and a tertiary amine (SiO₂/diamine/Pd/NEt₂) as well as synthetic scope of the Tsuji–Trost reaction of 1,3‐dicarbonyls, phenols, and carboxylic acids with allyl carbonate and acetates. The synergistic catalysis of SiO₂/diamine/Pd/NEt₂ exhibited wide applicability and high activity for the Tsuji–Trost reaction. For example, the reaction of ethyl 3‐oxobutanate with allyl methyl carbonate afforded the allylated product in >99% yield at 70 °C for 5 h. The yield of allylated products was 26% for SiO₂/diamine/Pd, without immobilization of the tertiary amine group. In the reaction of 1.0 mmol of ethyl 3‐oxobutanate using 0.60 μmol of Pd in SiO₂/diamine/Pd/NEt₂, the turnover number (TON) of Pd reached up to 1070 within 24 h. Phenols with electron‐withdrawing groups, such as nitro and chloro groups, on the para position resulted in high product yields. The SiO₂/diamine/Pd/NEt₂ catalyst was reusable at least 4 times without appreciable loss of its activity and selectivity in the reaction of p‐chlorophenol.