The effect of branching and unsaturation upon some properties of polyoxyethylene glycol diesters

Fatty acid diesters based upon polyoxyethylene glycol (PEG diesters) find applications in many diverse segments of thechemical industry. PEG diesters contain both a water-soluble and an oil-soluble portion, resulting in a surface-active product. These surfactants exhibit emulsification properties. A study of PEG diesters was undertaken to determine the effect of the following variables in the fatty portion of the molecule: (i) number of carbon atoms present, (ii) branching or lack of branching, and (iii) presence of unsaturation. The objective was to compare titer point, solubilities and emulsification properties of various PEG-600 based diesters that were synthesized using high-purity linear saturated, Guerbet-branched, and unsaturated acids. Included in the test was a series of esters based upon meadowfoam oil, a high-molecular-weight unsaturated oil.     

硫酸铁水合物催化合成乙酸酯

报道了以硫酸铁水合物作催化剂合成乙酸酯的研究结果，并讨论了该酯化反应的最佳条件。     

BMI和BCE为基础的多元共聚热固性高性能基体树脂研究

用熔融预聚法对二苯甲烷双马来酰亚胺（BDM,即BMI）/二烯丙基双酚A（DABPA）和双酚A二氰酸酯（BCE）/溴化环氧树脂（BCE）各二元体系分别预聚再热混,制成溶解性、稳定性和反应性、粘接性好的多元共聚树脂。经阶梯式固化,并通过FTIR、DSC、DMA、TGA和SEM等手段测试了固化树脂的性能。结果表明,该树脂的玻璃化温度（Tg）为230.7℃,耐热指数（Z）为197℃,热膨胀系数（CTE）为7.0104×10-5/℃,介电常数ε为3.61,介电损耗tanδ（1MHz）为0.007,弯曲强度为131.83MPa,冲击强度25.0kJ/m2,氧指数为31,吸水率为0.44%。此耐热性、介电性能和力学性能等综合性能优异的阻燃型树脂适合做刚性覆铜板（CCL）和先进复合材料的高性能基体树脂。     

Study on synthesis and electrochemical properties of novel ferrocene-based compounds and their applications in anion recognition

Two novel ferrocene-based compounds glycidyl ester of ferrocene carboxylate (GEFC) and 1,3-diferrocenecarboxylic acid diacylglycerol (DFCDG) were synthesized and characterized by ¹H NMR and mass spectrum. The influence of some factors, namely, solvent type, potential scan rate, electrolyte concentration and [Fe] unit concentration, on the electrochemical behaviors of two novel ferrocene-based compounds was investigated, and the mechanism of the electrode processes was studied. Finally, two compounds were applied to sense the H₂PO₄⁻ by cyclic voltammetry (CV) method and it was found that the DFCDG with a symmetric structure which was synthesized through ring opening reaction of ferrocene carboxylate and GEFC showed stronger interaction with the H₂PO₄⁻ than GEFC.     

Fractionation of liquid lubricants at solid surfaces

The film-forming properties of lubricant base fluid mixtures in elastohydrodynamic contacts have been studied using ultrathin film interferometry. It has been shown that in binary mixtures where one of the components is more polar than the other, the EHD film thickness formed in the very thin film (< 10 nm region) is controlled by the viscosity of the polar component rather than the viscosity of the blend. This means that a mixture of a highly viscous ester in less viscous hydrocarbon gives thicker than predicted lubricant films in the sub 20 nm region and vice versa. This phenomenon can be ascribed to the fractionation of the lubricant mixtures close to the surface caused by lubricant molecule/surface van der Waals forces.     

高纯度乌桕脂棕榈酰胺,油酰胺制取工艺研究

为充分利用中国乌桕脂的资源优势和化学组成特点,研究并提出“两段醇解－膜式精馏－甲酯氨解”法,制得高纯度乌桕脂棕榈酸甲酯及酰胺,油酸甲酯及酰胺。     

DCC法合成胆甾醇酯

研究以二环己基碳二亚胺(DCC)作脱水剂,分别用4-二甲胺基吡啶(DMAP)和N,N-二甲基苯胺作除水促进剂,胆甾醇与丙酸、苯甲酸在室温下反应合成液晶材料胆甾醇丙酸酯和胆甾醇苯甲酸酯的方法.该方法反应条件比较温和,用DMAP作除水促进剂时,胆甾醇酯产率比较高.发现用N,N-二甲基苯胺作除水促进剂也可以合成胆甾醇丙酸酯,这有利于降低胆甾醇丙酸酯合成成本,但合成胆甾醇苯甲酸酯时没有成功.     

Formation of Triterpenoids throughout <Emphasis Type="Italic">Olea europaea</Emphasis> Fruit Ontogeny

Drupes were handpicked from olive (Olea europaea L.) trees, cv chemlali, at 13 distinct stages of fruit development, referred to as weeks after flowering (WAF), and analyzed for their free and esterified sterols and triterpenoids content. These two classes of compounds are synthesized via the acetate/mevalonate pathway and share common precursors up to oxidosqualene (OS). Cyclization of OS in either cycloartenol or beta-amyrin constitutes a branch point between primary (sterol pathway) and secondary (triterpenoid pathway) metabolisms. At the onset of fruit development, i.e., between 12 and 18 WAF, drupes were found to contain high amounts of alpha- and beta-amyrins as well as more-oxygenated compounds such as triterpenic diols (erythrodiol and uvaol) and acids (oleanolic, ursolic and maslinic acids). Concomitantly, sterol precursors were barely detectable. From 21 WAF, when the olive fruit reached its final size and began to turn from green to purple, alpha- and beta-amyrins were no longer present, while 4,4-dimethyl- and 4alpha-methylsterols started to be formed, indicating a redirection of the carbon flux from the triterpenoid pathway towards the sterol pathway. Between 21 and 30 WAF, sterol end products, mainly represented by sitosterol, progressively accumulated and triterpenic diols were replaced by triterpenic acids, essentially maslinic acid. Interestingly, the developing olive fruit was found to accumulate significant amounts of parkeol as an ester conjugate. Whatever the stage of development, triterpenoids represent the major triterpenic compounds of the olive fruit.     

Flow properties of haloarchaeal polysaccharides in aqueous solutions

The flow properties of the polysaccharides produced by Haloferax mediterranei^T ATCC 33500 and its super mutant Haloferax mediterranei EPS⁺⁺, R4 and EPS⁺⁺ respectively, were investigated. The R4 repeating unit is a trisaccharide containing mannose and 2-acetamido-2-deoxyglucuronic acid, ester sulphate groups are also present. In order to compare the properties of both polymers viscosimetric measurements were carried out at different integration times and using different concentrations of polymer. Under the assayed experimental conditions no effect of the time applying stress is detected for either polymer. A strong pseudoplastic behaviour is observed which is increased as the polymer concentration rises. Differences in viscosity between both polymers are due to the different molecular weights. The correlation of the experimental data using a modification of the Cross model has given very good results.     

三（2,2—二溴甲基—3—溴丙基）磷酸酯的热性能及其阻燃聚丙烯的研究

对三（２,２－二溴甲基－３－溴丙基）磷酸酯（ＴＰＢ－３０７０）的热性能及其阻燃聚丙烯进行了研究。热性能研究结果表明,ＴＰＢ－３０７０的热稳定性能优于传统的ＨＢＣＤ和ＴＢＣ,起始分解温度分别高６０℃和８０℃。对其用于聚丙烯的阻燃研究中发现,在用量较低的情形下ＴＰＢ－３０７０与Ｓｂ２Ｏ３有良好的协同效应,随着用量的增加这种协同效应逐渐减弱。研究结果表明ＴＰＢ－３０７０具有优异的热稳定性和对聚丙烯优良的阻燃和加工性能。