Friction and adsorption properties of normal and high-oleic soybean oils

The steel/steel boundary friction properties of soybean oil (SBO) and high-oleic soybean oil (HOSBO) are compared. HOSBO is significantly more saturated than SBO and more oxidatively stable. Changes in degree of unsaturation affect lateral interactions of adsorbate molecules, which in turn affects their adsorption and, hence, their boundary lubrication properties. To investigate this possibility, the free energies of adsorption (ΔG _ads) of SBO, HOSBO, and methyl laurate (ML) were determined from the analysis of friction-derived adsorption isotherms using the Langmuir and Temkin adsorption models. The results showed a stronger adsorption for the vegetable oils than for ML, an indication of multiple interactions between the ester groups of the triglycerides and the steel surface. The result also showed no difference in the ΔG _ads values of SBO and HOSBO obtained using either the Langmuir or Temkin models. This was interpreted as an indication of the lack of appreciable net lateral interaction between triglyceride adsorbates.     

季戊四醇锌与月桂酸锌并用对天然橡胶硫化特性的影响

采用季戊四醇锌与月桂酸锌并用作为硫化活性剂,考察其对天然橡胶硫化特性及物理机械性能的影响。结果表明,季戊四醇锌具有较高的硫化活性,可使胶料的硫化速率加快,硫化活化能下降,硫化活性高于月桂酸锌,但抗硫化返原性能较差,胶料的物理机械性能较低,耐磨性较差。将季戊四醇锌与月桂酸锌并用可产生硫化协同效应,明显提高胶料的表观交联密度,改善抗硫化返原性能,同时还能降低门尼黏度、提高填料分散性并降低生热和滚动阻力。加入6.70份季戊四醇锌并用5.56份月桂酸锌的天然橡胶硫化胶,其综合性能优于添加5.00份氧化锌的硫化胶,并且含锌质量分数减少48%。     

α-烯烃磺酸盐(AOS)的性质及生产现状分析

详细介绍α-烯烃磺酸盐(AOS)的溶解性、表面活性以及对人体的安全性等性质,并概述了α-烯烃磺酸盐的生产工艺及其典型生产参数。最后对国内α-烯烃磺酸盐的生产现状进行了分析,对国内的主要生产企业的生产装置进行了总结。目前我国的AOS统计生产能力将达到23万t/a。     

月桂酸铋的合成及其在聚氨酯中的催化特性

以氢氧化钠、月桂酸、硝酸铋为原料,采用沉淀法合成新型、无毒、绿色催化剂月桂酸铋.研究月桂酸铋的合成工艺、结构特性及其在聚氨酯中的催化特性.结果表明,月桂酸铋的产率可达97.1%,属低结晶性化合物,对聚氨酯反应具有明显的催化活性.     

Growth of microalgae using CO2 enriched air for biodiesel production in supercritical CO2

The optimum conditions for lipids productivity and CO₂ fixation of two freshwater strains, namely Chlorella sp. and Pseudochlorococcum sp. and a marine strain; namely Nannochlorpsis sp. have been determined in this work. The species were grown autotrophically under aeration with different CO₂ concentrations, ranging from 0.04 to 2% (v/v). The growth was tested in nitrogen sufficient and deficient media at different salinities (0.49–680 mM) and temperatures of 27 and 31 °C. The optimum CO₂ enrichment was found to be 1% (v/v) in both media. Nitrogen starvation resulted in an increase in lipid contents, but at lower growth rate, which resulted in a lower overall lipid productivity. The experimental data were used to determine the kinetic parameters of Haldane model. The Chlorella sp. grew well at salinity levels of up to 460 mM. The highest CO₂ biofixation rate was observed when Chlorella sp. was grown at 27 °C in seawater (230 mM NaCl).Lipids were extracted from harvested marine strain, Nannochlorpsis sp., and enzymatically transesterified to produce biodiesel in supercritical CO₂ (SC–CO₂) medium. It was found that the conversion of biodiesel produced from microalgae lipids was 35% higher than that achieved using lamb fat in a similar system.     

月桂酸甲酯的合成研究

采用自制的磺化DNW 1树脂作为合成月桂酸甲酯的催化剂。考察了酯化反应中各种因素对酯化率的影响。在醇酸摩尔比20∶1,催化剂用量为月桂酸质量的15%,回流反应12h的反应条件下,酯化率可达94.6%。该方法反应条件温和,不需要加带水剂,不需要分水;催化剂可以直接过滤分离出来重复使用,大大简化了分离操作;催化剂重复使用12次以上,酯化率仍保持在94%左右,表现出良好的活性和选择性。磺化DNW 1树脂作为液固酯化反应催化剂具有显著的应用价值。     

用钙系催化剂合成月桂醇聚氧乙烯醚

研究了以不同的羧酸钙和月桂醇钙为催化剂的月桂醇聚氯乙烯醚(A_(12)POE)的合成,并研究了以上述钙化合物为主催化剂的复合催化剂中一些酸性助催化剂对反应的影响。结果表明几种羧酸钙的活性顺序为丙酸钙>乙酸钙>硬脂酸钙。月桂醇钙的活性与丙酸钙相似,而乙氧基化产物质量优于后者。对催化活性和反应产物质量综合比较,表明月桂醇钙明显优刊专统的氢氧化钠催化剂。在乙酸钙或月桂醇钙中加入酸助催化剂使催化活性提高,反应诱导期缩短。     

镁铝复合介孔氧化物催化月桂酸甲酯乙氧基化反应

以十二烷基硫酸钠为模板剂、乙二胺为碱性介质,采用水热法合成了镁铝复合介孔氧化物(MMAO),采用氮吸附-脱附、X射线衍射、程序升温脱附和热重-差热分析等方法对MMAO进行了表征,并考察了MMAO在月桂酸甲酯乙氧基化反应中的催化性能。表征结果显示,合成的MMAO具有介孔结构特征,平均孔径为3.2nm,比表面积为280m2/g,孔体积为0.18cm3/g。实验结果表明,MMAO催化剂在月桂酸甲酯乙氧基化反应中具有较高的催化活性,适宜的合成条件为:反应温度180℃、初始压力0.6～0.7MPa、MMAO催化剂用量为月桂酸甲酯质量的3%。在此条件下得到的月桂酸甲酯聚氧乙烯醚的相对分子质量分布较窄,当环氧乙烷平均聚合度为5时,月桂酸甲酯聚氧乙烯醚的相对分子质量分布选择性系数为18.50。     

Synthesis of Higher Fatty Acid Starch Esters using Vinyl Laurate and Stearate as Reactants

This paper describes the synthesis of long‐chain fatty esters of corn starch (starch laurate and starch stearate) with a broad range in degree of substitution (DS = 0.24−2.96). The fatty esters were prepared by reacting the starch with vinyl laurate or vinyl stearate in the presence of basic catalysts (Na₂HPO₄, K₂CO₃, and Na acetate) in DMSO at 110°C. The yellowish products were characterized by ¹H‐, ¹³C‐NMR and FT‐IR. The DS of the products is a function of the carbon number of the fatty acid chain, vinyl ester to starch ratio and the type of catalyst. When performing the reactions using Na₂HPO₄ as the catalyst, the DS for the starch laurate compounds is higher than for the corresponding starch stearates. For low vinyl ester to starch ratios, an increase in the vinyl ester concentration leads to higher product DS values. At higher ratios, the DS decreases, presumably due to a reduction of the polarity of the reaction medium. K₂CO₃ and Na acetate are superior catalysts with respect to activity compared to Na₂HPO₄ and products with DS values close to 3 were obtained.     

二价芳基杂环磷酸盐/月桂酸钠对聚丙烯性能的协同效应

以芳基杂环磷酸盐(AHPS)作为成核剂主体,月桂酸钠(NaL)为配体,研究该类复配体诱导等规聚丙烯(iPP)成核的协效作用,通过偏光显微观察、差示扫描量热分析、力学性能测试、光学性能测试以及耐热性能表征等手段,研究成核剂复配前后对复合材料球晶结构、结晶行为以及力学性能、光学性能、耐热性的影响。结果表明,NaL对iPP的成核作用较差,对球晶尺寸的细化不明显,平均尺寸为246μm,与纯iPP在球晶尺度在同一数量级,结晶温度提高仅为2.61℃,成核有效性低于10%,对复合材料力学性能、光学性能及耐热性的改善非常有限;AHPS对iPP的成核作用达到中等水平,晶体尺寸比纯iPP减小了1个数量级,平均尺寸为40μm,结晶温度平均提高7.26℃,成核有效性提高23.0%,力学性能、光学性能及耐热性同样达到中等水平;NaL与AHPS复配后使iPP的球晶尺度迅速减小,结晶峰值温度可提高20℃以上,成核有效性高达60%以上,拉伸强度、弯曲强度、弯曲模量平均分别提高14.8%、33.8%、38.7%,雾度值平均下降50.4%,透光率平均增加6.94%,热变形温度平均升高40.7%。NaL和AHPS之间表现出极强的协效成核作用。