以地沟油为原料制备混合脂肪基苯并咪唑啉及其缓蚀性能的研究

发布时间：2018-02-28 06:41

  本文关键词： 地沟油 缓蚀剂 苯并咪唑啉 合成 缓蚀性能　出处：《广东工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：在我国,每年至少产生300~500万吨地沟油,如果直接排放,不仅对环境造成严重污染,而且造成资源的浪费。目前,一般处理是先将地沟油催化分解为高级脂肪酸和甘油,再经过初加工成洗衣粉、生物柴油等初级产品,但产品的附加值都不高,因此,研究利用地沟油生产高附加值精细化工产品具有重要的经济效益和社会意义。本论文以地沟油为原料,利用酯氨解-环化脱水反应,使其与邻苯二胺及其衍生物反应,合成了3种混合脂肪基苯并咪唑啉类缓蚀剂:即2-混合脂肪基苯并咪唑啉(MFBI)、1-甲基-2-混合脂肪基苯并咪唑啉(MMFBI)及5-硝基-2-混合脂肪基苯并咪唑啉(NMFBI)。通过IR谱图对三种产物的官能团结构进行了表征;采用挂片失重法和电化学极化曲线法,研究了三种产物在盐酸体系中对Q235和N80钢的缓蚀性能,并与市售咪唑啉缓蚀剂进行了对比试验。利用扫描电子显微镜(SEM)对N80钢腐蚀表面的微观形貌进行观测和对比;并进行了缓蚀剂在金属表面上吸附动力学和热力学研究,实验得出了如下结果:以地沟油为原料,与邻苯二胺直接地进行酰化-环化反应,合成了MFBI,以缓蚀率作为评价指标,采用正交设计实验法,优化了MFBI合成工艺,实验得到的最佳合成工艺条件为:地沟油和邻苯二胺的原料摩尔比为1:3.3,酰化温度为160℃,酰化时间为6h,环化时间为15h。按此改进的合成工艺,使地沟油分别与N-甲基邻苯二胺盐酸盐及4-硝基邻苯二胺进行了反应,分别制得MMFBI及NMFBI。通过IR光谱图的解析,验证了三种化合物已成功被合成。静态失重法研究结果表明,三种新型缓蚀剂在5%HCl介质中对Q235和N80钢均有良好的缓蚀作用,缓蚀率随着缓蚀剂投加浓度增大而升高,随温度升高而下降;在30-70℃实验范围内,MMFBI对N80钢的缓蚀率维持在95%以上左右,且显示出优异的耐高温性能。同样的条件下,三种缓蚀剂对N80钢的缓蚀能力顺序依次为:MMFBIMFBINMFBI。对比试验结果表明,MMFBI缓蚀性能与市售咪唑啉缓蚀剂的相当。电化学极化曲线实验结果表明,三种缓蚀剂在不同程度上抑制了阴阳两级反应,且MMFBI和MFBI属于以抑制阴极为主的混合型缓蚀剂,而NMFBI是以抑制阳极为主的混合型缓蚀剂。扫描电子显微镜(SEM)的图像分析表明:三种缓蚀剂均可在N80钢表面形成一层吸附保护膜,但NMFBI的成膜能力较差。缓蚀剂在金属表面上吸附动力学和热力学研究表明,三种缓蚀剂在N80钢表面的吸附规律均符合Langmuir吸附等温式,且吸附过程是自发进行的,包含物理和化学两种吸附。吸附膜形成过程属于放热反应。
[Abstract]:In China, at least 300 to 5 million tons of gutter oil is produced every year. If it is discharged directly, it will not only cause serious pollution to the environment, but also cause a waste of resources. At present, the general treatment is to decompose the gutter oil into high fatty acids and glycerol first. After initial processing into primary products such as laundry powder, biodiesel and so on, but the added value of the products is not high, therefore, It is of great economic and social significance to study the production of high value-added fine chemical products from gutter oil. In this paper, using gutter oil as raw material, esterification and cyclization dehydration reaction are used to make it react with o-phenylenediamine and its derivatives. Three kinds of mixed aliphatic benzimidazoline corrosion inhibitors, I. e., 2-mixed aliphatic benzimidazoline (MFBI) 1-methyl-2-aliphatic benzimidazoline (MMFBI) and 5-nitro-2-aliphatic benzimidazoline (NMFBII) were synthesized. The functional group structure of seed product was characterized. The corrosion inhibition properties of three products on Q235 and N80 steels in hydrochloric acid system were studied by means of plate weight loss and electrochemical polarization curves. The micromorphology of corrosion surface of N80 steel was observed and compared by scanning electron microscope (SEM), and the adsorption kinetics and thermodynamics of corrosion inhibitor on metal surface were studied. The experimental results are as follows: using gutter oil as raw material, direct acylation cyclization reaction with o-phenylenediamine was carried out to synthesize MFBI. The corrosion inhibition rate was used as the evaluation index and the orthogonal design experiment method was used to optimize the synthesis process of MFBI. The optimum synthetic conditions are as follows: molar ratio of waste oil to o-phenylenediamine is 1: 3.3, acylation temperature is 160 鈩，

本文编号：1546188