TiSiW_(12)O_(40)/TiO_2催化合成丁酸正丙酯

首次以固载杂多酸盐 Ti Si W12 O4 0 / Ti O2 为多相催化剂 ,通过正丁酸和正丙醇反应合成了丁酸正丙酯 ,并探讨了诸因素对酯化率的影响。实验表明 :Ti Si W12 O4 0 / Ti O2 具有良好的催化活性 ,醇酸物质量之比为 1 .4∶ 1 ,催化剂用量为反应物料总量的 2 .0 % ,反应时间 2 .0 h,反应温度 1 0 6～ 1 1 2℃ ,酯化率可达 98.3 %。

丁酸环氧丙酯的化学合成与酶法拆分

利用化学方法 ,由外消旋环氧氯丙烷出发 ,合成丁酸环氧丙酯 ,精制后可获得纯度96%以上的丁酸环氧丙酯 ,收率为 47% .利用猪胰脂肪酶进行不对称酯水解反应 ,可获得光学纯度为 93 .3 % ( ee值 )以上的

超声波辅助脂肪酶催化拆分丁酸环氧丙酯

利用超声波辅助脂肪酶催化拆分丁酸环氧丙酯,考察了超声发生装置、超声处理方法、超声功率及超声温度等反应条件对酶促拆分反应的影响,筛选得到最适反应条件.结果表明,在最适反应条件下,超声作用可以使酶活提高近4.3倍,立体选择性提高5倍.

酶促拆分丁酸环氧丙酯反应体系的筛选

利用脂肪酶对外消旋丁酸环氧丙酯进行了立体选择性的酯水解反应 ,考察了水解反应体系对拆分反应的影响。实验结果表明 :在该水解反应中添加适量正己烷有利于拆分反应的进行 ;反应体系中正己烷与缓冲液的最适体积比为 1∶1;磷酸盐缓冲液 (pH 7 6 )的最适离子强度为 0 0 3mmol/L。在最适反应条件下 ,当该酶促拆分反应的转化率为 6 0 6 % ,(R) 丁酸环氧丙酯的光学纯度可以达到 93 3%。

新型羟基磺酸盐亲水单体—2,2-二羟甲基丁酸-3'-磺酸钠-丙酯的合成、表征与应用

以2,2-二羟甲基丁酸钠、1,3-丙烷磺内酯为原料,采用磺烷基化反应合成了新型的磺酸盐亲水单体2,2-二羟甲基丁酸-3＇-磺酸钠-丙酯（DMBPS-Na）。采用FT-IR、1H-NMR、13C-NMR、EIS-MS和元素分析等对DMBPS-Na进行了表征。DMBPS-Na的熔点为85-90℃,易溶于水、乙醇、N,N-二甲基乙酰胺,微溶于丙酮、乙酸乙酯。以DMBPS-Na为亲水单体,聚四氢呋喃二醇、异佛尔酮二异氰酸酯和乙二胺为原料,采用丙酮法合成了固含量达50%以上的磺酸型聚氨酯分散体（PUD）。性能测试结果显示,DMBPS-Na用量为8 mmol？（100 g）？1树脂时,PUD的平均粒径为122.3 nm,黏度为475 m Pa·s,ζ电位为？66.39 m V,具有良好的稳定性;透射电镜（TEM）显示PUD胶粒呈二元分布的球状结构;PUD胶膜的拉伸强度为10.66 MPa,断裂伸长率为1160%;PUD胶膜的起始分解温度约为270℃,至490℃时基本分解完全。

强酸性树脂催化合成正丁酸烯丙酯的工艺研究

利用强酸性阳离子交换树脂催化合成了正丁酸烯丙酯,由实验可知:反应的酸醇量比为3:2,树脂催化剂用量为1.0g时,反应效果最佳,产品收率可达67%.同时,对树脂的重复使用性能进行了测试,结果表明:树脂在使用7次后,其催化性能保持不变.通过与其他催化剂的催化效果进行比较,说明了强酸性树脂在合成正丁酸烯丙酯的独特优越性。

新型羟基磺酸盐型聚氨酯分散体的制备与性能研究

以自制DMBPS—Na（2，2-二羟甲基丁酸-3＇磺酸钠-丙酯）为亲水单体，以PTMG-2000（聚四氢呋喃二醇）、IPDI（异佛尔酮二异氰酸酯）、EDA（乙二胺）和BDO（1，4-丁二醇）为主要原料，合成了固含量超过50％的磺酸盐型PUD（聚氨酯分散体）。研究结果表明：该PUD的平均粒径为60～490nm、黏度低于800mPa·s且稳定性良好；硬段含量越多，PUD胶膜的拉伸强度和硬度越大、断裂伸长率越低、PUD胶膜中软段和硬段的相分离程度越大；PUD胶膜在270℃时开始分解，470℃时基本分解完全，在其他条件保持不变的前提下，耐热性随硬段含量增加而变差；PUD胶膜的吸水率为2％～8％，说明其耐水性良好。

Synthesis and characterization of hybrid organic-inorganic materials based on EA-MAn-APTES and silica

Poly (EA-MAn-APTES)/silica hybrid materials were successfully prepared fromEthyl acrylate (EA), maleic anhydride (MAn) and tetraethoxysilane (TEOS) in the presence of acoupling agent 3-aminopropyltriethoxysilane (APTES),by free-radical solution polymerization and insitu sol-gel process. The mass fraction of TEOS varied from 0 to 25%. The hybrid materials werecharacterized by the methods of FT-IR spectra, solvent extraction, scanning electron microscope (SEM), transmission electron microscope (TEM), differential scanning calorimetry (DSC) andthermogravimetric analysis (TGA) measuring apparatus to get their structures, gel contents,morphologies, particle sizes and thermal performances. The results show that the covalent bonds arebetween organic and inorganic phases, gel contents in the hybrid materials are much higher, theSiO_2 phase is well dispersed in the polymer matrix, silicon dioxide exist at nanoscale in thecomposites and have excellent thermal stability.

基于正交实验的甲醇-苯共沸物萃取精馏工艺优化

本文基于化工模拟软件Aspen Plus V7.3,选用丁酸丙酯为萃取剂,对甲醇—苯共沸体系的连续萃取精馏过程进行模拟与条件优化。利用正交实验对工艺参数进行优化,结果表明,在全塔理论板数为37,原料和萃取剂分别在第20块和第9块理论板进料,回流比为0.8,溶剂比为2的条件下,可得到纯度分别为99.92%和99.85%的甲醇和苯,萃取剂丁酸丙酯的循环补充量为0.0032kmol/h。模拟与优化结果为甲醇—苯共沸物连续萃取精馏分离过程的工业化设计和操作提供了理论依据和设计参考。

Measurement and modelization of VLE of binary mixtures of propyl acetate,butyl acetate or isobutyl acetate with methanol at pressure of 0.6 MPa

The vapor-liquid equilibrium of binary mixtures of propyl acetate, butyl acetate and isobutyl acetate with meth- anol has been determined at a constant pressure of 0.6 MPa. Results have been modeled with the Peng-Robinson equation, a traditional cubic equation of state widely employed in chemical industries, as well as with the perturbed-chain statistical associating fluid PC-SAFT theory of Gross-Sadowski. By correlation of the binary inter- action parameters of these equations, the measured vapor-liquid equilibrium data can be accurately predicted. Thus, this work shows that these models are able to represent the experimental data for systems with associating comoounds via hydrogen bonding.

二茚基稀土氢化物在Claisen重排反应中的应用

在温和的条件下,二茚基稀土氢化物分别与苯乙酸烯丙酯和正丁酸烯丙酯反应,得到了发生Claisen重排反应后的相应产物2-烯丙基苯乙醛和2-乙基-4-戊烯醛。

Resolution of Ibuprofen Ester by Catalytic Antibodies in Water-miscible Organic-solvents

The asymmetric hydrolysis of racemic ibuprofen ester is one of the most important methods for chiral separation of ibuprofen. In this work, a catalytic antibody that accelerates the rate of enantioselective hydrolysis of ibuprofen methyl ester was obtained against an immunogen consisting of tetrahedral phosphonate hapten attached to bovine serum albumin (BSA). The catalytic activity of the catalytic antibody in the water-miscible organic-solvent system composed of a buffer solution and N, N-dimethylformamide (DMF) was studied. With 6% DMF in the buffer solution (containing catalytic antibody 0.25 μmol, 0.2 mol·L-1 phosphate buffer, pH 8) at 37°C for 10 h, a good conversion (48.7%) and high enantiomeric excess (>99%) could be reached. The kinetic analysis of the cata-lytic antibody-catalyzed reaction showed that the hydrolysis in the water-miscible organic-solvent system with DMF in buffer solution followed the Michaelis-Menten kinetics. The catalytic efficiency (Kcat/Km) was enhanced to 151.91 L·mmol-1·min-1, twice as large as that for the buffer solution only.

Synthesis and Characterization of Poly(St-co-BA) Latex with an Organic-Inorganic Hybrid Compound as Emulsifier

A poly (St-co-BA) latex was successfully synthesized by using an organic-inorganic hybrid compound (OIHC), an aliphatic carboxylate sodium/nano-silica composite, as the emulsifier, and investigated by particle size analyzer, transmission electron microscope (TEM), optical contact angle measurement (OCA) and dynamic mechanical analyzer (DMA). It was found that the protective agent, sodium polyacrylate (PA),could obviously improve the polymerization stability and the functional monomer, glycidyl methacrylate (GMA), could enhance the store stability of the latex. The particle size of poly(St-co-BA) latex decreased and then leveled off as OIHC content increased. TEM shows that the prepared polymers were actually organic-inorganic nanocomposites, and these films have better waterproof property than those prepared by traditional poly(St-co-BA) latex or organic silicone modified poly(St-co-BA) latex. The nanocomposite polymer has much higher glass transition temperature than organic silicone modified poly(St-co-BA) polymer containing the same organic silicone content.

Optimization of Propionic Acid Feeding for Production of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in Fed-Batch Culture of Ralstonia eutropha

The feeding method of propionic acid for production ofpoly(3-hydroxybutyrate-co-3-hydro xyvalerate) [P(3HB-co-3HV)] by fed-batch culture of Ralstoniaeutropha was optimized to achieve high cell density and high 3HV yield. Effects of different feedingstrategies of propionic acid on the production of P(3HB-co-3HV) were investigated. A decline ofspecific synthesis rate of copolymer and the yield of 3HV unit from propionic acid were observed dueto the propionic acid accumulation in culture broth when the feeding solution with highP/G(propionic acid to glucose) ratio was employed. It was further confirmed by controlling propionicacid concentration at a low level in the separate feeding of propionic acid. An optimal feedingstrategy was demonstrated to reduce the propionic acid accumulation. The cell concentration,P(3HB-co-3HV) productivity and 3HV unit fraction reached to 163.9kg·m^(-3), 1.8kg·m^(-3)·h^(-1),and 10.6%(by mass), respectively, resulting in a yield of 0.33g HV per g propionic acid.

Modified graphite filled natural rubber composites with good thermal conductivity

The rubber composites with good thermal conductivity contribute to heat dissipation of tires. Graphite filled natural rubber composites were developed in this study to provide good thermal conductivity. Graphite was coated with polyacrylate polymerized by monomers including methyl methacrylate, n-butyl acrylate and acrylic acid. The ratios between a filler and acrylate polymerization emulsion and those between monomers were varied. Eight types of surface modification formulas were experimentally investigated. Modification formula can affect coating results and composite properties greatly. The best coating type was achieved by a ratio of1:1 between methyl methacrylate and n-butyl acrylate. The coating of graphite was thermally stable in a running tire. Filled with modified graphite, the tire thermal conductivity reached up to 0.517–0.569 W·m-1·K-1. In addition, the mechanical performance was improved with increased crosslink density, extended scorch time and short vulcanization time.

Long-term result of endoscopic Histoacryl （N-butyl-2-cyanoacrylate）injection for treatment of gastric varices

AIM:To evaluate the long-term efficacy and safety of endoscopic obliteration with Histoacryl for treatment of gastric variceal bleeding and prophylaxis.METHODS:Between January 1994 and March 2010 at SoonChunHyang University Hospital,a total of 127 patients with gastric varices received Histoacryl injections endoscopically.One hundred patients underwent endoscopic Histoacryl injections because of variceal bleeding,the other 27 patients received such injections as a prophylactic procedure.RESULTS:According to Sarin classification,56 patients were GOV1,61 patients were GOV2 and 10 patients were IGV.Most of the varices were large(F2 or F3,111 patients).The average volume of Histoacryl per each session was 1.7±1.3 cc and mean number of sessions was 1.3±0.6.(1 session-98 patients,2 sessions-25 patients,≥3 sessions-4 patients).Twenty-seven patients with high risk of bleeding(large or fundal or RCS+or Child C) received Histoacryl injection as a primary prophylactic procedure.In these patients,hepatitis B virus was the major etiology of cirrhosis,25 patients showed GOV1 or 2(92.6%)and F2 or F3 accounted for 88.9%(n=24).The rate of initial hemostasis was 98.4%and recurrent bleeding within one year occurred in 18.1%of patients.Successful hemostasis during episodes of rebleeding was achieved in 73.9%of cases.Median survival was 50 mo (95%CI 30.5-69.5).Major complications occurred in 4 patients(3.1%).The rebleeding rate in patients with hepatocellular carcinoma or GOV2 was higher than in those with other conditions.None of the 27 subjects who were treated prophylactically experienced treatment-related complications.Cumulative survival rates of the 127 patients at 6 mo,1,3,and 5 years were 92.1%,84.2%,64.2%,and 45.3%,respectively.The 6 mo cumulative survival rate of the 27 patients treated prophylactically was 75%.CONCLUSION:Histoacryl injection therapy is an effective treatment for gastric varices and also an effective prophylactic treatment of gastric varices which carry high risk of bleeding.

Measurement of Infinite Diluted Activity Coefficient of Solvents in Polymer by Inverse Gas Chromatography Method

The infinite diluted activity coefficients of solvents in polyisopropyl methylacrylate was measured using inverse gas chromatography. The solvents used were benzene, toluene, ethyl benzene, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methanol, ethanol isopropyl alcohol, butyl alcohol, 1,2-dichloroethane, and chloroform. It was observed that the infinite diluted activity coefficient of alcohols are well above those of the other solvents investigated.

Porous alumina ceramic via gelcasting based on2-hydroxyethyl methacrylate dissolved in tert-butyl alcohol

To obtain porous alumina ceramic with high strength,a novel gelcasting system based on 2-hydroxyethyl methacrylate(HEMA)dissolved in tert-butyl alcohol(TBA)was developed.The polymerization of the HEMA-TBA gelcasting system,the thermal behavior of obtained green body,and the microstructures and mechanical properties of the sintered bodies were investigated by rheometer,TG-DSC,SEM and bending strength testing,respectively.The results show that,(1)10 mg/mL of the initiator(benzoyl peroxide)is the optimal amount for polymerization of this gelscasting system at 25 ℃;(2)The alumina suspension of the HEMA-TBA gelcasting system showing shear-thinning behavior is sufficiently low for gelcasting process;(3)The bending strength of porous alumina ceramic samples,whose porosities range from 42% to 56%,is from(8±0.5)to(91±4.5)MPa.

Synthesis, characterization and catalytic application of H4SiW12O40/MCM-48 in the esterification of methacrylic acid with n-butyl alcohol

A novel environmental friendly catalyst, H4SiW12O40/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 H4SiW12O40/MCM-48 was studied with methacrylic acid and n-butyl alcohol as reactants. H4SiW12O40/MCM-48 was an excellent catalyst for the synthesis of n-butyl methacrylate and Keggin structure ofH4SiW12O40 kept unchanged after 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 the yields of the product were investigated. The optimum conditions have been found, that is, molar ratio of acid to alcohol is 1：1.5, mass ratio of catalyst used to the reactant is 1.5%, cyclohexane is 10 mL and reaction time is 1.5h. Under these conditions, the yield of n-butyl methacrylate can reach 73.2%.

The structure and properties of Fe_3O_4/P (NaUA-St-BA) magnetic composite nano particles

Fe3O4/P （NaUA-St-BA） core-shell composite micro spheres were in situ prepared by soapless polymerization of styrene and butyl acrylate, with Fe3O4magnetic colloidal particles coated with NaUA. The results of IR and XRD analysis demonstrated that the desired polymer chains have been covalently bonded to the surface of Fe3O4 nano particles. The morphology analysis by TEM confirmed that the composite particles have the core-shell structure and a relatively uniform diameter of about 100nm. The magnetic properties of the obtained composite latex particles were measured by VSM and found that they exhibited super paramagnetic properties. Finally, the prepared magnetic composite particles latex is stable for several months.