摘要
目前橡胶促进剂CBS(N-环己基-2-苯并噻唑次磺酰胺)的工业生产主要采用次氯酸钠氧化法。为了解决该工艺废水含盐量高、排放量大、对设备腐蚀性强等问题,采用双氧水作氧化剂,首先探索了以促进剂DM(2,2′-二硫代二苯并噻唑)为原料,与环己胺一步氧化制得促进剂CBS,研究了pH、氧化反应温度、环己胺用量以及催化剂种类等因素对收率的影响。优选催化剂为醋酸铜、环己胺用量(摩尔比)为n(DM)∶n(环己胺)=1∶4.9、氧化温度35℃、pH为12时,促进剂CBS收率可达94.6%,纯度为94.3%。进而以促进剂M(2-巯基苯并噻唑)为原料,先在双氧水作用下氧化原位高效生成促进剂DM,不经分离再与环己胺氧化得到促进剂CBS,从而建立了由M为起始原料并以DM为中间产物的双氧水分步氧化“一锅法”新工艺。此外,探索了第一阶段氧化反应温度、第一阶段双氧水浓度等关键因素的影响规律。结果表明,环己胺用量(摩尔比)n(M)∶n(环己胺)=1∶2.45、第一阶段氧化温度50℃、双氧水浓度30%,第二阶段反应条件同前时,促进剂CBS总收率为91.0%,纯度为94.8%。
At present,the industrial production of rubber accelerator CBS(N-cyclohexylbenzothiazole-2-sulphenamide)mainly adopts the sodium hypochlorite oxidation method.To solve the problem of high salt content,large discharge of wastewater and strong equipment corrosion in this process,using hydrogen peroxide as oxidant,the accelerator DM(2,2′-dibenzothiazoledisulfde)was used as the raw material and oxidized together with cyclohexylamine to obtain the accelerator CBS.The effects of pH,oxidation reaction temperature,cyclohexylamine dosage,and catalyst type on the yield were studied.The optimal conditions are copper acetate as catalyst,n(DM)∶n(cyclohexylamine)=1∶4.9,the oxidation reaction temperature of 35℃,and pH 12.The yield of accelerator CBS reaches 94.6%,and the purity is 94.3%.Further,using accelerator M(2-mercaptobenzothiazole)as the raw material,oxidized by hydrogen peroxide to form accelerator DM,and then oxidized with cyclohexylamine to obtain accelerator CBS,established a new one-pot process for step-by-step oxidation of hydrogen peroxide with M as start material and DM as intermediate.In addition,the influence laws of key factors such as the oxidation reaction temperature in the first stage and the concentration of hydrogen peroxide in the first stage were explored.The results show that the total yield of accelerator CBS reaches 91.0%,and the purity is 94.8%.The optimal reaction conditions are as follows:the dosage of cyclohexylamine is n(M)∶n(cyclohexylamine)=1∶2.45,the first stage oxidation reaction temperature is 50℃and the concentration of hydrogen peroxide is 30%,the second stage reaction conditions are the same as before.
作者
李彬
徐正虎
姜爽
张天永
LI Bin;XU Zhenghu;JIANG Shuang;ZHANG Tianyong(Tianjin Key Laboratory of Applied Catalysis Science and Technology,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300354,China;Tianjin Engineering Research Center of Functional Fine Chemicals,Tianjin 300354,China;Collaborative Innovation Center of Chemical Science and Engineering(Tianjin),Tianjin 300072,China)
出处
《化工学报》
EI
CSCD
北大核心
2023年第7期2919-2925,共7页
CIESC Journal
基金
国家重点研发计划项目(2022YFB3603101)
国家自然科学基金项目(22278315)。
关键词
促进剂
双氧水
氧化
分子合成
accelerator
hydrogen peroxide
oxidation
molecular synthesis