【作者】 苏娜；

【导师】 李坤兰；

【作者基本信息】 大连工业大学 ， 化学工艺， 2009， 硕士

【摘要】 季戊四醇四脂肪酸酯具有良好的生物降解性、热稳定性和抗磨减磨性,不仅可作为防尘油、胶粘剂、高温增塑剂工业用途中,而且它是一种性能优良的绿色润滑油基础油,已在航空领域得到广泛的应用。而季戊四醇奇数碳原子支链酸酯的低温性能更为优异,与直链酸酯混合使用后,可以显著提高润滑油基础油的低温性能,因此合成季戊四醇支链酸酯成为该领域的研究热点。但是由于支链脂肪酸存在空间位阻,使得支链脂肪酸与季戊四醇的酯化反应较难进行完全,因此选择合适的催化体系成为研究的难点。关于季戊四醇四脂肪酸酯的合成,国内外学者主要致力于催化剂的选择上,但在实验方法上,大多是在溶剂中进行的。有机溶剂的易挥发性和毒性使之成为对人体和环境有害的因素。为适应现代化工环保、安全、绿色的技术要求,实验研究了在无溶剂的条件下,以季戊四醇和异辛酸为原料合成季戊四醇四异辛酸酯的工艺过程。主要通过催化剂的筛选,比较不同的原料配比、反应温度、反应时间等影响因素,得到了最佳的工艺条件。结果表明,对甲苯磺酸为催化剂催化反应的效果最佳。反应条件是：季戊四醇、异辛酸的摩尔比为1：5,催化剂用量为反应物总质量的2%,反应温度为160℃,反应时间为5h,酯化率可达97%以上。实验通过使用红外谱图分析手段确认了产品的结构组成。所得产品纯度高、色泽淡、酸值低,其性能指标符合润滑剂基础油的性能要求。且该工艺简单,成本低,不污染环境,是合成季戊四醇四异辛酸酯的理想工艺。另外,实验研究了固体酸催化剂在该合成反应中的催化效果。考察浸渍液种类及浓度、焙烧温度等对固体超强酸催化性能的影响。采用流动指示剂法测定催化剂的酸强度,并用原位吡啶吸附的IR谱图对催化剂进行表征。结果表明,在H2SO4浸渍液浓度为1mol/L、500℃下焙烧3h,制备的SO42-/TiO2固体超强酸催化剂活性最好,酯化反应的酯化率可达到85%。更多还原

【Abstract】 Pentaerythritol fatty acid ester is not only used in industy, such as a dust-proof oil, adhesives, plasticizers, etc, but also widely used in aviation fields as an excellent green lubricant base oil, for its good biodegradability, thermal stability and anti-wear and friction. The branched-chain pentaerythritol ester has more excellent low temperature performance. The low-temperature properties of lubricant base oil can be significantly improved when it mixed with straight-chain esters. Therefore, it become a research hotspot in the synthesis of branched-chain pentaerythritol ester. The difficulties is to choose a suitable catalyst system, because the branched-chain fatty acids is difficult to be carried out fully because of its steric.In the synthesis process of pentaerythritol fatty acid ester, the scholars committed to the choice of catalyst by solvent. Because of the effumability and toxicity of organic solvent it will become harmful to human and environmental factors. In order to meet the requirements of environmental protection, safety, green in modern chemical industry, the pentaerythritol and Isocaprylic acid are taken as raw material to synthesize2-ethyl-,1,1’-[2,2-bis[[(2-ethyl-l-oxohexyl)oxy]methyl]-1,3-propanediyl] ester under solvent-free condition. The optimal operating conditions can be get by the choice of catalysts and the comparing of the the raw materials’s ratio, reaction temperature, reaction time, etc. The optimal esterification conditions were as follows:para-toluenesulfonic acid is the best catalyst with usage amount of2%(w/w) based on the total weight of the raw materials, n(pentaerythritol):n(Isocaprylic acid)=1:5, the reaction was carried out at160"C for5h while the esterification rate of97%was obtained. The structure of the product was determined by FT-IR spectrum. The products have high purity, low color, low acid value. It is an ideal process with simple, low cost, without environment.In addition, the experiment study on the catalytic effect of solid acid catalyst in the synthesis process. The influence of preparation conditions of the catalyst such as, calcination temperature, catalytic property were studied. The flowing Hammett indicator method was used to test the acidity of the catalyst and the catalyst SO42-/TiO2was characterized by means of IR spectra of pyridine adsorbed on the surface. The optimal prepared conditions were as follows:the concentration of H2SO4was1mol/L, the catalyst SO42-/TiO2was calcinated at500℃for3h, while the esterification rate of85%was obtained.更多还原