哌嗪胺型曼尼希碱汽油清净剂的绿色合成及清净性能研究

Study on green synthesis and detergent performance ofpiperazinamide type Mannich base gasoline detergent

以高活性聚异丁烯(HRPIB)和邻甲酚(o-cresol)为原料,采用Amberlyst-15催化烷基化反应合成了对聚异丁烯邻甲酚,并通过曼尼希反应制备了哌嗪胺型曼尼希碱汽油清净剂。设计正交实验考察了不同因素对烷基化反应的影响,通过FTICR-MS、NMR和FTIR等分析手段表征了产物组成及分子结构,并进行了清净性能评价。结果表明,烷基化最佳反应条件为:反应温度60℃,反应时间8 h,催化剂用量为5%,o-cresol和HRPIB摩尔比为2∶1;高温烷基化反应会导致裂解和聚合副反应增加,生成分子量100~500的裂解产物和1 200~2 000的聚合产物;Amberlyst-15与BF3两种催化剂制备的哌嗪胺型曼尼希碱清净性能相当,具有良好的清净性和分散性,沉积物下降率接近90%。

p-Polyisobutylene o-cresol was synthesized from high reactivity polyisobutene(HRPIB)and o-cresol by Amberlyst-15-catalyzed alkylation reaction,and piperazinamide-type Mannich base gasoline detergent was synthesized via Mannich reaction.Orthogonal experiments were designed to investigate the effects of different factors on the alkylation reaction.The composition and molecular structure of the product were characterized by FTICR-MS,NMR and FTIR and the detergency performance was evaluated.The results show that the optimum reaction conditions of alkylation are as follows:the reaction temperature is 60℃,the reaction time is 8 h,the amount of catalyst is 5%,the molar ratio of HRPIB to o-cresol is 2∶1.Alkylation reaction under high temperature will lead to the increase of cracking and polymerization side reactions,resulting in pyrolysis products with molecular weight of 100~500 and polymerization products of 1200~2000.The detergent performance of piperazinamide type Mannich base prepared by Amberlyst-15 and BF 3 catalysts is similar,and has good detergency and dispersibility,and the carborn doposit decline rate is close to 90%.