Hepatoprotection by palm tocotrienol‐rich fraction

Tocotrienols, a group of important phytonutrients of palm oil, have been shown to possess antioxidant, anticancer, neuroprotectory, and anti‐inflammatory activities. In this study, our objective was to examine the protective effects of tocotrienol‐rich fraction (TRF) from palm oil on chronic carbon tetrachloride (CCl₄)‐induced hepatotoxicity in rats. Animals were subjected to vehicle only (control), CCl₄ only, CCl₄ + 100 mg/kg silymarin (silymarin), CCl₄ + 25 mg/kg TRF (TRF‐25) and CCl₄ + 50 mg/kg TRF (TRF‐50) treatments for a period of 8 wks. Results showed that daily oral administration of TRF‐25, TRF‐50, and silymarin prevented the elevation of serum glutamate oxalate transaminase (sGOT) and glutamate pyruvate transaminase (sGPT), liver thiobarbituric acid reactive substances (TBARS), triglycerides and total cholesterol levels, as well as enhancing the liver catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels in rats with hepatotoxicity. At 50 mg/kg, the hepatoprotection of TRF was as good as or better than silymarin (100 mg/kg) in normalization of oxidative stress parameters in liver injury rats. These results suggest that TRF exerts effective protection against chronic CCl₄‐induced hepatic injury in rats, and its mechanism of action could be related to reducing oxidative stress in the liver tissue.     

The physical and mechanical properties of polyurethanes from oleic acid polyols

Three different polyester polyols, with various oleic acid content, were used in the preparation of polyurethane (PUR) coatings. The polyols were designated as Alk28, Alk40, and Alk65, in which 28, 40, and 65 represent the percentage of oleic acid of the polyol formulations. These polyester polyols were reacted with aromatic diisocyanate [toluene diisocyanate (TDI)] to form PUR coatings. The acid value, hydroxyl value, molecular weight, and viscosity of the polyols have been determined. The reaction between the polyols and TDI was studied by Fourier Transform Infrared spectroscopy and X‐ray diffraction (XRD). The effects of varying NCO/OH ratio and oleic acid content of polyols on physical and mechanical properties of PUR films were studied. XRD results indicate that the samples are amorphous. PURs, made with Alk28, have the best mechanical properties followed by Alk40 and Alk65. The mechanical properties of the samples have increased as the NCO/OH ratio was increased from 1.2 to 1.6. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

分步加料法合成聚酯多元醇

以二元醇分步加料法合成了聚酯二醇。研究结果表明，该法与一步法相比具有某些优点，例如：实际分子量与理论计算值相近，合成过程中副产物及二元醇损失为较少。研究还表明，保持最后一次加二元醇时反应体系ｎＯＨ／ｎＣＯＯＨ＝２是必要的。     

Palm kernel shell as fuel for burning bricks

The use of an agricultural waste product, palm kernel shell, as a fuel for firing bricks is explored as a means of reducing environmental degradation and depletion of scarce firewood in Ghana. A simple but efficient methodology of clamp firing bricks using the new fuel is developed and tested. The resulting bricks are analysed for physical properties and suitability for construction use. The viability of palm kernel shell as a fuel for small-scale brick industries is considered. On etudie actuellement au Ghana les possibilites d'utilisation d'un dechet agricole, en l'occurrence, les coquilles de noix de palme, comme combustible dans les briqueteries; une telle solution permettrait de reduire la degradation de l'environnement et de diminuer l'appauvrissement des maigres reserves en bois de chauffage du pays. A cet effet, on met au point une methodologie simple mais efficace de cuisson des briques en brulant des dechets de coquilles de noix de palme. On analyse les proprietes physiques de ces briques et on verifie qu'elles conviennent a la construction. On etudie la viabilite de la coquille de noix de palme pour l'alimentation en combustible des petites briqueteries.     

磁性固体碱催化剂在棕榈油制备生物柴油中的应用研究

采用煅烧法制得磁性固体碱催化剂CaO/Fe3O4，考察了该催化剂催化24℃分提棕榈油与甲醇酯交换反应制备生物柴油的最佳反应条件及催化剂使用寿命。结果表明，最佳反应条件为醇油摩尔比8、催化剂用量4％、反应温度65℃、反应时间2.0 h。在该条件下制得的生物柴油中脂肪酸甲酯含量为98.2%，其性能指标均达到国家标准GB/T-20828-2007的要求。在棕榈油制备生物柴油过程中重复利用催化剂CaO/Fe3O4进行酯交换反应8次，产物中脂肪酸甲酯含量均在96.5％以上。     

Binary Phase Behavior of 1,3-Dipalmitoyl-2-oleoyl-<Emphasis Type="Italic">sn</Emphasis>-glycerol and 1,2-Dioleoyl-3-palmitoyl-<Emphasis Type="Italic">rac</Emphasis>-glycerol

1,3-Dipalmitoyl-2-oleoyl-sn-glycerol (POP) and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP) are two major molecular species that account for roughly half of the total triacylglycerols in palm oil. The binary phase behavior of a POP/OOP mixture plays an important role in the crystallization of palm oil. We conducted thermodynamic and kinetic studies of OOP and its mixtures with POP using differential scanning calorimetry and X-ray diffraction with a conventional generator and synchrotron radiation. We found that OOP has two polymorphs, α as a metastable form and β′ as the most stable form, and that the two forms are stacked in a triple-chain-length structure. The POP/OOP mixtures exhibited immiscible eutectic natures in both their metastable and their most stable states, in contrast to POP/1,2-dipalmitoyl-3-oleoyl-rac-glycerol and POP/1,3-dioleoyl-2-palmitoyl-sn-glycerol mixtures, in which molecular compounds of a double-chain-length structure were formed. A time-resolved synchrotron radiation X-ray diffraction study undertaken during the cooling and heating processes indicated that the α and β′ forms of the POP and OOP fractions crystallized and melted in separate manners, and that crystallization of the β′ form and the polymorphic transformation from α to β′ of POP and OOP are promoted in the presence of another component. The absence of molecular compound crystals in the binary mixtures of POP/OOP is explained by taking into account the molecular interactions of acyl chain packing, glycerol conformation, and methyl end stacking, among which glycerol conformation appeared to be most influential.     

多元醇法制备银纳米棒的放大试验影响因素研究

采用银晶种为引导剂,以高浓度硝酸银溶液为银源,乙二醇为还原剂,聚乙烯吡咯烷酮为盖帽剂,大规模制备银纳米棒。用扫描电镜,元素分析和X射线衍射对银纳米棒进行表征。结果表明,通过预加银晶种的方式替代添加金属盐类,最佳的反应条件为:搅拌速度为350 r/min,反应温度为160℃,硝酸银浓度不高于0.50 mol/L,采取体积放大6倍高浓度硝酸银制备银纳米棒时,需要提高银晶种的浓度为9.81 mmol/L,PVP/AgNO3摩尔比为1.3,该方法利用银晶种的引导作用,调控硝酸银的还原速度使之与银纳米棒的生长速度相匹配。     

棕榈酸化油制备生物柴油的工艺优化研究

试验研究了以棕榈酸化油与甲醇为原料,在催化剂(浓硫酸)的作用下,通过酯化反应制备生物柴油。采用单因素试验和正交优化试验,考察反应温度、搅拌速率、醇油摩尔比和催化剂用量(与原料油质量比)对酯化反应收率的影响。确定最佳反应条件为反应温度为55℃,搅拌速率为200 r/min,醇油摩尔比为7:1,催化剂用量为2.0%,且在该条件下酯化效率为93.9%。     

气相色谱法测定化妆品中的多元醇保湿剂

建立了气相色谱(GC)同时测定化妆品中5种多元醇(1,2-丙二醇、乙二醇、1,3-丁二醇、二甘醇和甘油)保湿剂的方法.试样用甲醇提取过滤后,采用GC对样品进行定量分析.结果显示,5种多元醇保湿剂的质量浓度与其相应的峰面积呈线性关系,线性范围分别为10 μg/mL～1 200 μg/mL(1,2-丙二醇和1,3-丁二醇),10 μg/mL～1 100 μg/mL(乙二醇),10 μg/mL～1 000 μg/mL(二甘醇),10 μg/mL～1 300 μg/mL(甘油),相关系数r＞0.99.应用此法测定化妆品中5种多元醇保湿剂的质量分数,回收率在93.6%～102.4%,相对标准偏差为0.84%～1.75%.该方法简便快速,结果稳定准确,可用于化妆品中多元醇保湿剂含量的质量控制.     

水性聚氨酯的制备

要制得性能优良的木器用水性聚氨酯乳液,要从制备水性聚氨酯用的原料聚酯二元醇入手,文章设计分子量为1000的聚酯二元醇,它使用邻苯二甲酸酐和己二酸以摩尔比40∶60混合后再与乙二醇反应,制得的水性聚氨酯乳液,其化学稳定性、涂膜硬度,相对于单独用脂肪族聚酯二元醇制备的水性聚氨酯的性能要优。