Epoxidation of Unsaturated Fatty Acid Methyl Esters in the Presence of SO_3H-functional Brφnsted Acidic Ionic Liquid as Catalyst

The epoxidation of unsaturated fatty acid methyl esters(FAMEs)by peroxyacetic acid generated in situ from hydrogen peroxide and acetic acid was studied in the presence of SO3H-functional Brnsted acidic ionic liquid (IL)[C3SO3HMIM][HSO4]as catalyst.The effects of hydrogen peroxide/ethylenic unsaturation ratio,acetic acid concentration,IL concentration,recycling of the IL catalyst,and temperature on the conversion to oxirane were studied.The kinetics and thermodynamics of unsaturated FAMEs epoxidation and the kinetics of oxirane cleavage of the epoxidized FAMEs by acetic acid were also studied.The conversion of ethylenic unsaturation group to oxirane, the reaction rate of the conversion to oxirane,and the rate of hydrolysis(oxirane cleavage)were higher by using the IL catalyst.

Nickel (Ⅱ) Complex Catalyzed Conjugate Addition Reaction of Functionalised Organozinc Reagents to α,β -Unsaturated Esters

Functionalized organozinc reagents can easily under 1, 4-addition reaction withunsaturated esters in the presence of catalytic amount of Ni (acac)_2 and tertiary ammes under verymild conditions to give the products in excellent yields.

Synthesis and Characterization of Novel Fluoroalkyl Unsaturated Multi-carboxylic Acid Esters

A series of fluorinated unsaturated esters which can be used as fluorine-containing monomers have been synthesized. The esterification of maleic acid,itaconic acid,and trans-aconitic acid with 1, 1, 2, 2-tetrahydroperfluorooctanol and 1, 1, 5- octafluoropentanol was carried out, respectively. The objective monomers were obtained by using p-toluene sulfonic acid as catalyst, hydroquinone as the anti-polymerizing agent,toluene as solvent and water carrying agent. The objective products were isolated by column chromatography and characterized by Fourier transform infrared spectroscopy ( FT-IR ) , hydrogen-1 nuclear magnetic resonance ( 1 H NMR) ,fluorine-19 nuclear magnetic resonance ( 19 F NMR) ,and high resolution mass spectrometry ( HRMS) . The yield of the objective products was various from 30% to 85%. The reaction result shows that the esterification of 1, 1, 5 - octafluoropentanol with certain carboxylic acid is more difficult than that of 1,1,2,2-tetrahydroperfluorooctanol.

Low-valent Titanium Induced Reductive Coupling Reaction of Aryl Sulfonyl Chlorides with α,β-Unsaturated Esters

The reductive coupling reactions of aryl sulfonyl chloride induced by (TiCl4-Zn) reagent affords diaryl disulfide. However, reaction of aryl sulfonyl chloride with α,β-unsaturated ester under the same condition affords β-arylsulfo ester.

Chemoselective Catalytic Hydrogenation of α,β-Unsaturated Ketones and α,β-Unsaturated Carboxylic Esters

The effect of catalysts P-2 00-Ni(Nickel boride) and P-2 00-Ni-M(M: Co, Fe, Cu, Sn), prepared by adopting a modified recipe, on the chemoselective hydrogenation of carbon carbon double bonds in α,β- unsaturated ketones, and the activity of catalysts P-1.80-Ni, P-2 00-Ni or P-1.80(2 00) -Ni-M(M: Pd, Co, Cu) in the selective hydrogenation of carbon carbon double bonds in α,β-unsaturated carboxylic esters, were investigated systematically. According to the experimental results, the selectivities of these catalysts toward the hydrogenation of the carbon carbon double bonds of α,β-unsaturated keones or α,β-unsaturated carboxylic esters are 96%—100% or 100%, respectively.

Addition of Organosamarium Reagents toα, β-Unsaturated Esters

Allylsamarium bromide reacts with Q, 6 -unsaturated esters and a -alkyloxy carbonyl α, β-unsaturated esters to give l,2-addition and 1 .4-addition products respectively.

Michael Additions of Activated Methylene Compounds to α,β-Unsaturated Esters Promoted by Samarium (Ⅲ) Iodide

Promoted by SmI3 β -diketones， β-ketoesters and α -cyano esters were added to α,β -unsaturated esters to form δ-carbonyl esters in mild conditions in moderate to good yields.

Conjugate Addition Reactions of Functionalized Organozinc-copper Reagents to α,β-Unsaturated Esters

Functionalized organozinc reagents can easily conduct 1,4-addition reaction with unsaturated esters in the presence of Cu(OAc)2 and LiCl under very Anld conditions to give the products in excellent yields.

Novel Stereoselective Synthesis of (E)-a,b-Unsaturated Esters by the Tandem Reaction of Deprotonation-Oxidation-Wittig Reaction from Phosphonium and Arsonium Salt

Phosphonium or arsonium salt 1 can undergo the tandem reaction of deprotonation -oxidation-Wittig reaction with alcohol 2 in the presence of sodium hydroxide and manganese dioxide, which affords a general simplified method for the stereoselective synthesis of (E)- a, b-unsaturated esters 3.

One-pot Approach to the Conversion of Alcohols into α-Halo-α, β-unsaturated Esters

The sequential oxidation-Horner-Wadsworth-Emmons reaction of alcohols to prepare α-Halo-α,β-unsaturated esters （halo =F, Cl） with middle to excellent （Z）-selectivity was developed.

Impacts of the unsaturation degree of long-chain fatty acids on the volatile fatty acid profiles of rumen microbial fermentation in goats in vitro

This study investigated the impacts of the degree of unsaturation （unsaturity） of long-chain fatty acids on volatile fatty acid （VFA） profiles of rumen fermentation in vitro. Six types of long-chain fatty acids, including stearic acid （C18：0, control group）, oleic acid （C18：1, n-9）, linoleic acid （C18：2, n-6）, a-linolenic acid （C18：3, n-3）, arachidonic acid （C20：4, n-6） and eicosapentaenoic acid （C20：5, n-3）, were tested. Rumen fluid from three goats fitted with ruminal fistulae was used as inoculum and the inclusion rate of long-chain fatty acid was at 3% （w/w） of substrate. Samples were taken for VFA analysis at 0, 3, 6, 9, 12, 18 and 24 h of incubation, respectively. The analysis showed that there were significant differences in the total VFA among treatments, sampling time points, and treatment×time point interactions （P〈0.01）. a-Linolenic acid had the highest total VFA （P〈0.01） among different long-chain fatty acids tested. The molar proportion of acetate in total VFA significantly differed among treatments （P〈0.01） and sampling time points （P〈0.01）, but not treatment×time point interactions （P〉0.05）. In contrast, the molar proportion of propionate did not differ among treatments during the whole incubation （P〉0.05）. However, for butyrate molar proportions, significant differences were found not only among sampling time points but also among treatments and treatment×time point interactions （P〈0.01）, with eicosapentaenoic acid having the highest value （P〈0.01）. Additionally, no statistically significant differences were found in the acetate to propionate ratios among treatments groups （P〉0.05）, even the treatments stearic acid and a-linolenic acid were numerically higher than the others. The inclusion of 3% long-chain unsaturated fatty acids differing in the degree of unsaturation brought out a significant quadratic regression relation between the total VFA concentration and the double bond number of fatty acid. In conclusion, the a-linolenic acid with 3 double bonds appeared better for improving rumen microbial fermentation and the total VFA concentration.

Synthesis and Properties of Dendritic Long-Chain Esters as Crude Oil Flow Improver Additives

The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl longchain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efficiencies of dendritic long-chain esters were not only influenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efficiencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efficiencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil.

薯条煎炸工艺参数对高油酸葵花籽油中不饱和型甘油酯核心醛生成的影响

为调控煎炸过程中非挥发性甘油酯核心醛(GCAs)的生成,更合理地进行煎炸,通过高油酸葵花籽油煎炸薯条实验,探究煎炸方式、煎炸批次、煎炸温度以及油料比对10-氧代-8-癸烯醛酸酰基甘油三酯(10-oxo-8)和11-氧代-9-十一碳烯醛酸酰基甘油三酯(11-oxo-9)两种不饱和型GCAs生成的影响。结果表明:与间歇煎炸相比,连续煎炸产生更少的11-oxo-9,两种煎炸方式下10-oxo-8的含量总体上差异不大;每小时煎炸1批次薯条较煎炸多批次薯条生成的不饱和型GCAs更少,且煎炸油中的10-oxo-8和11-oxo-9含量与煎炸批次整体呈正相关;煎炸温度为160℃时较140℃和180℃生成的不饱和型GCAs更少;油料比为30∶1时,不饱和型GCAs总体含量较低。综上,为降低高油酸煎炸油中GCAs的含量,可采用连续煎炸方式并尽量控制煎炸批次,保持煎炸温度在160℃,控制油料比为30∶1。

β,γ-不饱和-α-酮酸酯参与的[3+3]环加成反应:多取代四氢吡啶类化合物的多样化合成

多取代四氢吡啶类化合物是一类重要的含氮杂环骨架,广泛存在于天然产物中,还可以通过简单反应转化为其他含氮杂环化合物,因此其多样化合成方法始终是化学家研究热点。通过β,γ-不饱和-α-酮酸酯与烯胺类化合物的[3+3]环加成反应,对一系列含多个手性中心的多取代1,2,3,4-四氢吡啶类化合物进行了多样化合成,产率最高可达92%,非对映选择性最高可达>20∶1。

溶剂分离法提取生物柴油中的不饱和脂肪酸甲酯

为了降低生物柴油的冷凝点,采用溶剂分离法提取生物柴油中的不饱和脂肪酸甲酯,重点考察了醇的种类、溶剂的用量、冷冻温度和过滤方式对分离效果的影响。结果表明:乙醇的用量为原料质量的2~3倍,冷冻温度-15℃,压滤法过滤,最高可得到96.9575%的不饱和脂肪酸甲酯含量和86.92%的得率。

In-situ generated ionic liquid catalyzed aldol condensation of trioxane with ester in mild homogeneous system

α, β-unsaturated esters were often synthesized from aldehydes and esters in the presence of strong organic base that was very sensitive to air and moisture via aldol reaction. Trioxane was very useful C1 resource, however, the decomposition of it was always the challenging problem that facing researchers. Herein, a novel synthetic methodology for α, β-unsaturated ester preparation from trioxane and ester with mild catalysis of generated ammonium trifluoromethanesulfonate ionic liquid. The enolization of ester as well as the decomposition of trioxane could proceed easily in the presence of boryl trifluoromethanesulfonate and amine at 20–25℃. Then the enolate and decomposed formaldehyde occurs aldol reaction to form α, β-unsaturated ester. With this strategy, the yield and selectivity of product from various substrates including aliphatic esters,lactones and thioester could reach up to 85.2% and 90.1%.

A Facile Synthesis of α-Phenylthio-α, β-Unsatuated Esters

a-Phenylthio-a, b-unsaturated esters 6 were synthesized by Witting reaction of 3, which were prepared by a phenylsulfenyllation-trans-ylidation reaction.

Studies on interacting Blends of Acrylated Epoxy resin based Poly(Ester-Amide)s and Vinyl EsterResin

Epoxy resin based Unsaturated poly(ester-amide) resins (UPEAs) can be prepared by many methods but here these were prepared by reported method [1]. These UPEAs were then treated with acrylotl chloride to afford acrylated UPEAs resin (i.e. AUPEAs). Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE) resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapour pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC). Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA).

双笼状磷酰胺阻燃剂的合成及其应用

基于提高不饱和聚酯树脂(UPR)的阻燃性,设计合成了苯基膦酰二(N,N-甲基硅酸三羟甲基笼状酯)胺(PPTMA),通过实验优化得到最佳反应条件为氮气保护下,以二苯醚为溶剂,原料摩尔比r=2.0,温度控制在180℃,反应4 h。利用核磁共振谱和红外光谱、热重-差热分析验证了化合物的分子结构和性能,该化合物分解温度为254℃,具有较好的耐高温性能。通过热重-差热、极限氧指数、垂直燃烧等测试方法表征了PPTMA的阻燃性能,结果表明,将PPTMA应用于UPR中,表现出较好的成炭抗熔滴效果和阻燃性能。燃烧后的复合材料表面形成了一层密集的簇状颗粒物,是通过凝聚相阻燃机理实现的。力学性能结果表明,PPTMA能有效地提高材料的拉伸强度,同时维持原料的断裂伸长率,能满足UPR在工业领域的应用要求。

树脂基复合材料模拟海洋环境长期老化及失效行为

目的实现高性能树脂基复合材料的环境适应性评价和使用寿命预测。方法选取玻璃纤维增强不饱和聚酯(GF/197S)与玻璃纤维增强乙烯基脂(GF/905-2)2种树脂基轻质复合材料,开展模拟海洋环境实验室盐雾、湿热和盐水浸泡环境9600 h的加速老化试验。基于4种力学性能(拉伸强度、弯曲强度、压缩强度及层间剪切强度)开展材料老化行为规律研究,利用傅里叶变换衰减全反射红外光谱(ATR-FTIR)对树脂基体在3种加速老化环境中的分子链段与官能团变化情况进行分析,得到基体树脂的老化机理。利用外观、超声扫描成像、SEM分析树脂纤维界面的变化情况,明确树脂/纤维界面的失效模式。利用差示扫描量热分析(DSC)与热重分析(TG)分析3种加速老化方式对玻璃纤维增强树脂复合材料(GFRPC)的玻璃化转变温度(t_(g))与热质量损失的影响。结果3种老化方式对树脂基体的老化影响顺序依次为70℃/95%RH湿热、35℃盐雾、常温盐水浸泡。结论得到了先进轻质树脂基复合材料的模拟海洋环境老化行为、失效模式以及树脂基体的老化机理,为实现高性能树脂基复合材料的环境适应性评价和使用寿命预测奠定了基础。