Synthesis of poly(vinyl propionate) from poly(vinyl alcohol) in nonaqueous medium using ethyl nitrate dimethyl sulfoxide as a catalyst

Poly(vinyl alcohol) (PVA) can be dissolved in a nonaqueous medium in the presence of catalytic concentration of ethyl nitrate dimethyl sulfoxide, C₂H₅ONO₂·DMSO. From the PVA solution, poly(vinyl propionate), PVPR was prepared by the homogeneous esterification of PVA with propionic acid. The ester thus formed contained some unconverted hydroxyl group. The formation of the ester was confirmed by the IR and ¹H‐NMR spectra. The molecular weight of the ester was determined by GPC and intrinsic viscosity (η) was determined by viscometric method. Glass transition temperature, T_g, was obtained from differential scanning calorimetric (DSC) analysis. Thermal stabilities of the ester were checked by thermogravimetric analysis (TGA) and differential thermogravimetric (DTG) analysis. The efficiency of the ester as a flow improver of crude oil was also examined. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5675–5679, 2006     

脱水法合成3-羟基丁酸乙酯

以3-羟基丁酸和乙醇为原料，在对甲苯磺酸的催化下分别以氧化钙、3A分子筛、无水硫酸镁为脱水剂，采用索氏提取器进行回流脱水合成3-羟基丁酸乙酯。对影响3-羟基丁酸乙酯收率的诸因素进行了考察。试验结果表明：加入脱水剂和带水剂可以显著提高3-羟基丁酸乙酯的收率。当原料配比为：0．1mol 3-羟基丁酸、0．12mol乙醇，0．7175g对甲苯磺酸，带水剂环己烷50mL，脱水剂18．7g氧化钙，反应时间3h时，产品3-羟基丁酸乙酯的收率可达96．6％(质量分数，下同)。     

对叔丁基苄胺的合成研究

摘要选择Delepine反应法的路线合成对叔丁基苄胺，并对反应投料比、反应温度及酸化后的反应时间进行了优化试验，得到了较好的反应条件：反应温度为40℃，对叔丁基苄氯与乌洛托品投料比为1：1；加入酸和醇后的保温时间为2h，从而使反应收率稳定在90％以上，含量达到95％。     

Preparation and modification of macroporous epoxy‐triethylenetetramine resin for preconcentration and removal of Hg(II) in aqueous solution

A novel macroporous resin was prepared from epoxy resin and triethylenetetramine through a polymerization with phase separation. In this experiment, the polyethylene glycol (PEG‐1000) plays a very important part. It was used as solvent, as phase‐separation reagent in the preparation processes, and as the pore‐forming reagent through removing PEG‐1000 from polymer by water‐cleaning process after completing polymerization. The prepared resin was modified by carbon bisulfide and soaked in 1 mol L^?1 NaOH. Its structure was characterized by Fourier transform‐infrared spectra, scanning electron microscopy, and elemental analysis. The adsorption characteristic of the chelating resin was studied by series of experiments. The results show that the chelating resin possesses excellent adsorption characteristic toward trace Hg(II). The recovery can come to 100% when the concentration of Hg(II) is only 0.05 ppm, and the average maximum adsorption capacity of the chelating resin for Hg(II) is 122 mg g^?1. The precision (relative standard deviation) for six replicate adsorbent extraction of 0.01 μg mL^?1 Hg(II) was 1.1%. The accuracy of the proposed procedure was verified by analyzing a standard reference material. Moreover, the chelating resin was applied to two natural samples and also got satisfactory results. That is to say, the chelating resin modified by carbon bisulfide exhibits a high chelating ability toward Hg(II) and can be used as adsorbent for preconcentration and removal of trace Hg(II) in aqueous solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2372–2378, 2006     

Addition of ferulic acid,ethyl ferulate,and feruloylated monoacyl- and diacylglycerols to salad oils and frying oils

To determine antioxidative effects of ferulic acid and esterified ferulic acids, these compounds were added to soybean oils (SBO), which were evaluated for oxidative stability and frying stability. Additives included feruloylated MAG and DAG (FMG/FDG), ferulic acid, ethyl ferulate, and TBHQ. After frying tests with potato chips, oils were analyzed for retention of additives and polar compounds. Chips were evaluated for hexanal and rancid odor. After 15 h frying, 71% of FMG/FDG was retained, whereas 55% of ethyl ferulate was retained. TBHQ and ferulic acid levels were 6% and <1%, respectively. Frying oils with ethyl ferulate or TBHQ produced significantly less polar compounds than SBO with no additives. Chips fried in SBO with TBHQ or ferulic acid had significantly lower amounts of hexanal and significantly less rancid odor after 8 d at 60°C than other samples. Oils were also aged at 60°C, and stability was analyzed by PV, hexanal, and rancid odor. Oils with TBHQ or FMG/FDG had significantly less peroxides and hexanal, and a lower rancid odor intensity than the control. FMG/FDG inhibited deterioration at 60°C, whereas ethyl ferulate inhibited the formation of polar compounds in frying oil. Ferulic acid acted as an antioxidant in aged fried food. TBHQ inhibited oil degradation at both temperatures. Presented at the 94th AOCS Meeting & Expo, Kansas City, MO, May 4–7, 2003.     

锝萃取型发生器萃取锝初探

锝萃取型发生器技术是采用溶剂萃取的方法生产^99Tc^m。对锝萃取工艺条件进行了初步研究。由于锝与铼有相似的化学性质,实验中研究了在碱性体系中甲乙酮对铼的萃取行为,考察了萃取剂用量、碱液浓度、铼的浓度及水相中铝浓度对萃取铼的影响,在此基础上进行了^99Tc^m的示踪实验,实验结果表明：甲乙酮对^99Tc^m萃取率达99％。     

新型燃煤烟气汞吸附剂的评价研究

利用汞蒸气发生器产生的单质汞,与压缩空气组成模拟烟气,在吸附剂评价实验台上进行吸附剂脱汞实验,研究不同吸附剂对单质汞的脱除效率．实验结果表明,活性炭对汞的吸附效率在60％左右,未改性的燃煤飞灰吸附效率在10％～20％,改性后的燃煤飞灰比表面积有很大程度的提高,吸附效率可以达到25％,与活性炭吸附效率相比仍有不小的差距．     

Study on volume ratio and plasticizer screening of free coating membranes composed of ethyl cellulose and chitosan

The aim of this study was to optimize the formula of free blended coating membrane of ethyl cellulose (EC) and chitosan (CS), including their suitable ratio range and the best plasticizer used. The dry films were produced by a casting/solvent evaporation method, with different volume ratio of EC and CS solution plasticized by various plasticizers, respectively. The wet films were prepared by immersing dry films in pH 6.8 phosphate buffer saline (PBS) for 24 h. The promising ratio range of EC/CS was below 20/5 or 20/6 with various plasticizer, which was determined by comparing the viscosity of the blended solutions and the morphology of the blended films. The efficiency of plasticization was evaluated by measuring glass transition temperature (T_g). All the testing plasticizers have good compatibility with EC or CS and dibutyl phthalate (DBP) have the strongest efficiency inducing the lowest T_g (39.9°C) of the film. Mechanical properties were evaluated by the ratio of tensile strength (T) to elastic modulus (E). In the wet state, the films with DBP had the highest T/E value (1.2). The results of leaching of plasticizers also verified that DBP was the most stable plasticizer in the films. The release rates of tetramethylpyrazine phosphate (TMPP) through the pellets coated with the blended films of EC/CS (20 : 6 v/v) plasticized by various plasticizers showed that the more water‐soluble the plasticizer was, the more quickly TMPP dissolved from the coated pellets, which further indicated that the water‐insoluble plasticizers (such as DBP) could be more applicable to keep the sustained or controlled release property of the blended films in wet state. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1932–1939, 2006     

丙烯酸乙酯合成反应产物的GC／MS分析

本文叙述了丙烯酸乙酯合成产物的ＧＣ／ＭＳ分析．从分析结果看出，本应在酯化反应前除去的ＣＨ３Ｃｌ３仍有较大的含量，这也许是导致丙烯酸乙酯被氯代的原因。     

In situ esterification of rice bran oil with methanol and ethanol

In situ esterifications of high-acidity rice bran oil with methanol and ethanol and with sulfuric acid as catalyst were investigated. In the esterification with methanol, all free fatty acids (FFA) dissolved in methanol were interesterified within 15 min, and it was possible to obtain nearly pure methyl esters. The amount of methyl esters obtained from a given rice bran was dependent on the FFA content of the rice bran oil. In the esterification with ethanol, it was not possible to obtain pure esters as in methanol esterification, because the solubilities of oil components in ethanol were much higher than those in methanol.