【作者】 郭艳；

【导师】 李惠萍；

【作者基本信息】 郑州大学 ， 化学工艺， 2008， 硕士

【摘要】 有机硼酸酯具有无毒无臭、环境适应性好以及极佳的抗磨减摩特性等特点,近年来备受关注。本研究开发出以2-甲基-1,3-丙二醇（MPO）和硼酸为主要原料,非酸催化酯化合成了新型环状功能有机硼酸酯:环状2-甲基三亚甲基-3-羟基-2-甲基丙基硼酸酯（简称MPO硼酸酯）的新工艺。该工艺采用干法中和,克服了传统酯化工艺采用酸催化、洗涤废水污染环境的弊端,整个工艺过程简单、绿色环保。并对合成的相关工艺条件及其酯化动力学进行了研究,该研究具有重要的学术意义和工业应用前景。首先,采用MPO和硼酸为主要原料,自制的非酸催化剂和自行设计加工的油水分离器,筛选出甲苯为带水剂,非酸催化合成了MPO硼酸酯,并对合成的产物进行了MS、IR和H-NMR结构鉴定。通过正交试验及单因素实验优化筛选出最佳酯化工艺条件:醇酸比=2.1:1（mol）;催化剂/总物料（wt%）=0.1%;带水剂甲苯用量为12.5mL（即带水剂与醇的体积比=25%）;反应时间2.5h;温度控制在180℃以内;此时酯化率可以达到99.16%。在此基础上,对MPO非等温酯化反应进行了动力学研究,利用温度、时间和反应进程之间的相互关系,确定其动力学有关参数。结果表明,在酯化过程中,固体硼酸溶解前后,其动力学规律有所不同。动力学曲线在反应进程为14%左右时出现折点。固体硼酸未溶解完全时,酯化为速控步骤,此时反应可视为准一级反应。固体硼酸完全溶解后,酯化反应为二级,且对液相硼酸和MPO分别表现为一级,反应表观活化能为101.3±3.0kJ·mol^-1,频率因子为0.656×10⁶dm³·mol^-1·s^-1。此外,常压下对纯液态MPO、MPO-H₂O及MPO-BDO二元体系汽液平衡进行了研究。采用静态法实验测定了MPO的饱和蒸汽压,在298.15K-484.95K温度范围,MPO蒸汽压与温度的关系符合Clapeyron-Clausis方程,该温度范围MPO的平均摩尔汽化焓为37.68kJ·mol^-1。用改进的ROSE平衡釜测定了MPO-H₂O及MPO-BDO二元体系的汽液平衡数据。结果表明,MPO-H₂O二元体系没有恒沸点,而MPO-BDO二元体系在215℃左右出现恒沸点,并进行了一致性检验,表明所得数据符合热力学一致性。更多还原

【Abstract】 Organic boric acid ester has attracted more attention recent years because of its non-toxicity, odorless, environmental compatibility, excellent antiwear and antifriction characteristics. This research developed a new process for synthesizing a new cyclic functional organic boric acid ester—cyclic 2-methyltrimethylene 3-hydroxy-2-methyl-propyl boric acid ester, which 2-methyl-l,3 -propanediol（MPO） and boric acid were used as the main materials in the presence of non-acid catalyst. It is important not only to science research but also to industrial application, for the new process eliminated a large amount of waste water disposal. The synthesis conditions and kinetics were also studied.At first, cyclic 2-methyltrimethylene 3-hydroxy-2-methylpropyl boric acid ester was synthesized by using 2-methyl-1,3-propanediol（MPO） and boric acid as the main materials, improved non-acid catalyst, toluene as water-carrier and organic-water separator. The structure of synthesized product was characterized by MS, IR and H-NMR. The optimum esterifying conditions were obtained through Orthogonal Test Design and single factor experiments: n（MPO）/n（acid）=2.1:1, w（cata.）/w（total）=0.1%, 2.5h and within 180℃, v（water-carrier）/v（MPO）=25%. The esterification ratio was 99.16%.Nonisothermal esterification kinetics was studied by means of the relationship between temperature, reaction time and reaction processing to determine the kinetic parameters. The results showed that the MPO esterification follows different kinetics rules during different reaction stages. There is a turning-point before and after the boric acid dissolved completely, appeared at about 14%of the reaction progress degree. Before the boric acid dissolved completely, the esterification is the rate-controlling step, and the reaction can be seen as quasi-one-order. After the boric acid dissolved completely, the esterification is two-order, one-order for liquid boric and one-order for MPO respectively. The apparent activation energy was 100±3.0kJ·mol^-1 and the frequency factor was 0.656×10⁶ L·mol^-1·s^-1.Moreover, vapor-liquid equilibrium of pure liquid MPO, MPO-H₂O and MPO-BDO （1,4-butanediol） binary systems were studied under atmospheric pressure. Vapor pressure of MPO from 298.15K to 484.95K was measured by using static-method, the changing of vapor pressure of MPO with temperatures follows Clapeyron-Clausis equation. The average enthalpy of vaporization of MPO was 37.68kJ·mol^-1. Vapor-liquid equilibrium data for MPO-H₂O and MPO-BDO binary systems were measured by improved ROSE kettle under atmospheric pressure. The results showed that there was an azeotropic point （215℃, x（BDO）=0.121） for MPO-BDO system, while no azeotropic point for MPO-H₂O. The consistency of thermodynamics was also verified for experimental equilibrium data.更多还原