新型双曼尼希碱缓蚀剂的合成及性能评价

SYNTHESIS AND PERFORMANCE EVALUATION OF A NEW DOUBLE MANNICH BASE CORROSION INHIBITOR

以硫脲、苯甲醛、苯乙酮为原料,采用两步反应合成出一种双曼尼希碱。以静态腐蚀速率为评价指标,用正交试验法对主剂的第二步合成工艺条件进行优化,最佳合成工艺条件为:n(中间体):n(苯甲醛):n(苯乙酮)=1:1:1,反应温度110℃,反应时间4 h。实验表明:这种双曼尼希碱是以抑制阴极腐蚀过程为主的混合型缓蚀剂,在N80钢表面的吸附行为符合Langmuir吸附等温式,吸附为吸热、自发、熵增的过程。在15%HCl中加入1%该缓蚀剂,在60℃N80钢片的腐蚀速率降至0.986 g/(m^2·h),远优于一级缓蚀剂标准。

With thiourea, benzaldehyde and acetophenone as raw materials, the double Mannich base was synthesized in two-step reaction. Static corrosion rate was used as the experimental evaluation in-dexes, the synthetic conditions of the second reaction were optimized in terms of orthogonal test method. The optimal synthetic conditions under experimental condition were as follows： the molar ra-tio of intermediate, benzaldehyde and acetophenone was 1 ： 1 ： 1, reaction temperature was 110 ℃ and reaction time was 4 h. The electrochemical polarization curves showed that it was a mixed-type in-hibitor which mainly retarded the cathodic process of corrosion. The absorption of it on N80 steel was endothermic, spontaneous, entropy increasing process and adsorption behaviors followed Langmuir i-sotherm. The increase of entropy was the main driving force of absorption. When 1 % of this corro-sion inhibitor was added into 15% HC1, the corrosion rate of NS0 steel could be reduced to 0. 986 g/ （m^2· h） at 60 ℃. It is much superior to the national standard of the first-grade corrosion inhibitor. A good industrial application prospect is showed.