二硫化二苯并噻唑（MBTS）是重要的橡胶硫化促进剂，用于加速橡胶硫化过程；高纯度的MBTS是生产头孢类消炎药的中间体，一般由粗品通过重结晶制备得到，严重依赖进口。目前工业上以双氧水氧化2-巯基苯并噻唑（MBT）的合成方法存在着高含盐有机废水大量排放与产品纯度难以控制的问题，开发高品质MBTS的合成方法充满挑战。此外，合成MBTS采用间歇的生产模式，效率低下、反应器体积庞大。因此，围绕MBTS的清洁合成与产品升级展开研究，揭示MBTS合成过程反应的基本规律，开发高品质MBTS绿色、经济、高效的合成工艺并发展连续过程技术具有重要的理论意义和应用价值。针对双氧水混酸氧化MBTS的合成过程，建立了主要反应网络与氧化反应动力学模型，提出在酸性或有机溶剂环境下的氧化是高质高效合成MBTS的发展方向。面向硫化促进剂产品，结合工业上以粗品MBT为原料的产业链背景，对于在碱性水溶液中的合成工艺发展了母液循环新过程。以二氧化碳代替硫酸作为酸化剂，以碳酸钠代替氢氧化钠作为碱液溶解MBT，通过碳酸盐与碳酸氢盐的转化实现了母液的循环利用，避免了高含盐有机废水的排放，反应转化率达到98 %以上。面向医药中间体产品，开发了在叔丁醇中利用磷钨酸均相催化氧化的新工艺，制备得到的产品纯度与医药级商品相当，反应选择性高达99 %以上。通过模拟晶体生长习性，结合样品结构的表征信息，解释了MBTS晶体形貌差异的原因，发展了MBTS晶体结构和纯度可控的制备新技术。针对两种合成方法分别构建了以微型泰勒库特流反应器（TCR）为核心的微反应系统。对于以叔丁醇为溶剂的合成方法，微反应系统可有效提高时空收率至160 g·L-1·h-1。对于碳酸钠溶液中的合成方法，通过将双氧水分段进料实现了间歇滴加工艺的连续化过程，提出了微型TCR的径向多级放大策略，有望满足工业上的规模化生产需求。本论文将所开发的绿色合成工艺与连续流技术结合，最终实现了高品质MBTS的可控绿色合成。本论文在基本反应规律、反应工艺以及反应装备上的创新对于二硫化物的高选择性连续合成有重要的参考意义。
2,2‘-Dibenzothiazole disulfide (MBTS) is an important vulcanization accelerator used to accelerate the rubber vulcanization process. High-purity MBTS is an intermediate for the production of cephalosporin anti-inflammatory drugs. It is generally prepared by the recrystallization of crude products, which is heavily dependent on imports. At present, there are two problems in the synthesis method of 2-mercaptobenzothiazole (MBT) oxidized by hydrogen peroxide in industry, which are the large amount of high-salt organic wastewater discharge and the difficulty in controlling the purity of the product. The development of high quality MBTS synthesis methods is full of challenges. In addition, MBTS is produced in batch reactors with huge volume, which is inefficient. Therefore, it is of great theoretical significance and application value to carry out research around the clean synthesis and product upgrading of MBTS, to reveal the basic laws of reactions in the synthesis process, to develop green, economic and efficient synthesis process of high-quality MBTS and develop continuous process technology.Aimed at the synthesis process of MBTS oxidized by hydrogen peroxide with mixed acid, the main reaction network and oxidation reaction kinetic models were established. It is pointed out that oxidation in acidic or organic solvent environment is the development direction of efficient synthesis of MBTS with high quality. For vulcanization accelerator products, combined with the industrial chain background of crude MBT as the raw material, a new process of mother liquor circulation has been developed for the synthesis process in alkaline aqueous solution. Carbon dioxide is used as the acidifier instead of sulfuric acid used in industry, and sodium carbonate is used as the alkaline solution to dissolve MBT instead of sodium hydroxide. The recycling of mother liquor is realized through the conversion of carbonate and bicarbonate, thus, the discharge of high-salinity organic wastewater can be avoided. The reaction conversion reached 98 %. For pharmaceutical intermediate products, a new process of homogeneous catalytic oxidation with phosphotungstic acid in tert-butyl alcohol has been developed. The purity of the prepared product was equivalent to that of pharmaceutical products, and the reaction selectivity was up to 99 %. By simulating the crystal growth habit and combining the characterization information of the sample structure, the reason for the difference of MBTS crystal morphology was explained, and a new preparation technology with controllable crystal structure and purity of MBTS has been developed.For the two synthesis methods, the microreaction systems based on the micro Taylor-Couette flow reactor (TCR) were constructed. For the synthesis method using tert-butyl alcohol as solvent, the microreaction system can effectively improve the space-time yield to 160 g·L-1·h-1. For the synthesis method in sodium carbonate solution, the continuous process of drip feeding was realized by staged feeding of hydrogen peroxide. The radial multistage amplification strategy of micro TCR is proposed, which shows the potential of large-scale production.
