棕榈油甲酯制备生物润滑油三羟甲基丙烷脂肪酸三酯的工艺研究

以棕榈油脂肪酸甲酯(fatty acid methyl ester,FAME)和三羟甲基丙烷(trimethylolpropane,TMP)为原料,经酯交换反应制备可用作生物润滑油基础油的三羟甲基丙烷脂肪酸三酯(trimethylolpropane fatty acidtiester,TFATE)。通过比较FAME的转化率和TFATE在反应混合物中的含量,探讨了催化剂种类、催化剂用量、反应时间、反应温度、反应物物质的量比及真空度对反应的影响。最佳合成条件为:催化剂为三羟甲基丙烷钾(Trimethylolpropane mono potassium salt,TMP-K),催化剂添加量为TMP-K与TMP物质的量比0.02∶1,反应时间1 h,反应温度128℃,FAME与TMP物质的量比4∶1,反应压力为300 Pa,在此条件下,脂肪酸甲酯的转化率为91.78%,反应混合物中TFATE质量分数为90.11%。经分子蒸馏分离纯化后终产品TFATE质量分数为97.02%。     

气相色谱法分析生物润滑油三羟甲基丙烷脂肪酸三酯的研究

建立了高温气相色谱快速分析棕榈油脂肪酸甲酯(fatty acid methyl ester,FAME)酯交换反应样品中三羟甲基丙烷脂肪酸三酯(trimethylolpropane fatty acid trimester,TFATE)的方法。采用DB-1ht型毛细管柱(15 m×250μm×0.1μm),柱温条件为:起始温度50℃,以50℃/min升至220℃,以30℃/min升至290℃,以40℃/min升至330℃保留2 min,以30℃/min升至370℃保留3 min;载气为高纯氮气,进样口380℃,FID检测器400℃,分流比20∶1,进样量为1μL。制备了TFATE的标准样品,并验证了标准样品的纯度,建立了TFATE的标准曲线,在质量浓度范围0.5～20.0 mg/mL内峰面积与被测物质量浓度线性关系良好。加样回收试验表明,平均加样回收率在96.64%～98.06%之间,RSD在0.20%～0.45%之间,该方法有较好的精密度和重复性。     

Rheological and mechanical properties of polycarbonate–liquid-crystalline polymer blends with controlled chemical reactions

Chemical reactions can occur during the melt blending of polymers containing an ester group because ester groups are usually unstable at high temperatures; this instability generally deteriorates the mechanical properties of blends. Here, effects of chemical reactions on the rheological and mechanical properties of polycarbonate (PC)/liquid-crystalline polymer (LCP) blends are carefully investigated to determine a method for minimizing such undesirable impacts. For comparison, a physical blend, in which chemical reactions were minimized, was prepared at 300 °C in a twin-screw extruder. Both shear viscosity and complex viscosities of reactive blends were lower than those of physical blends, being almost proportional to [M_w ]^3.4 as a result of depolymerization and transesterification. Because of the enhanced miscibility, the tensile modulus of reactive blends increased compared with that of physical blend, according to the increase in the degree of incorporation (DI). It was also possible to increase tensile modulus if triester was added to the reactive blends. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2799–2807, 2001     

碱催化合成三羟甲基丙烷二脂肪酸一乙酸酯的研究

研究以玉米油脱臭馏出物为原料制备三羟甲基丙烷脂肪酸三酯(TFATE),通过TFATE与三乙酸甘油酯(GTA)酯交换制备可再生的生物润滑油基础油三羟甲基丙烷二脂肪酸一乙酸酯。使用三羟甲基丙烷钾(TMP-K)为催化剂,通过测定三羟甲基丙烷二脂肪酸一乙酸酯(TMP-DEMA)在反应产物中的含量,探讨了反应时间、反应温度、反应物摩尔比、催化剂添加量对反应的影响。最佳合成条件为:真空度800 Pa,反应时间3 h,反应温度190℃,TFATE与GTA摩尔比1∶1.25,催化剂TMP-K与GTA摩尔比0.075∶1。在最佳合成条件下,反应产物中TMP-DE-MA的含量为52.56%。经电喷雾离子化质谱(ESI-MS)分析,TFATE的平均相对分子质量为905.9,TMP-DE-MA的平均相对分子质量为690.8,三羟甲基丙烷一脂肪酸二乙酸酯(TMP-ME-DA)的平均相对分子质量为435.4。