曼尼希碱缓蚀剂的合成及其缓蚀效果

Synthesis of Mannich Base Corrosion Inhibitor and Its Corrosion Inhibition Effect

以甲醛、苄叉丙酮、对甲基苯胺为原料,通过曼尼希反应,制备了一种新型的曼尼希碱缓蚀剂(MHX),并采用正交试验优化了制备条件。采用静态失重法、电化学测试及分子动力学模拟的方法,研究了MHX添加量对N80钢片在HCl溶液中缓蚀效果的影响。结果表明:在90℃、添加1%MHX的20%HCl溶液中,N80钢片的腐蚀速率为2.6 g·m^(-2)·h^(-1),缓蚀率为99.63%;该缓蚀剂是一种以抑制阳极为主的混合型缓蚀剂,可以大幅降低腐蚀电流密度,提高电极阻抗;MHX能够在N80钢表面吸附成膜,降低钢表面Fe的损耗,使其表面粗糙度降至93.81 nm;MHX分子在N80钢表面的吸附能为-7.59 eV,能有效取代H_(2)O分子吸附在金属表面,从而起到缓蚀作用。

A new Mannich base corrosion inhibitor(MHX)was prepared by Mannich reaction with formaldehyde,benzylideneacetone and p-methylaniline as raw materials.The preparation conditions were optimized by orthogonal test.The effects of MHX addition on the corrosion inhibition of N80 steel in HCl solution were studied by static weight loss method,electrochemical test and molecular dynamics simulation.The results showed that the corrosion rate of N80 steel sheet was 2.6 g·m^(-2)·h^(-1 )and the corrosion inhibition rate was 99.63%in 20%HCl solution with 1%MHX at 90℃.The corrosion inhibitor was a mixed type corrosion inhibitor which mainly inhibited the anode,it could greatly reduce the corrosion current density and improve the electrode impedance.MHX could adsorb and form film on the surface of N80 steel,reduce the loss of Fe on the surface of steel,and reduce the surface roughness to 93.81 nm.The adsorption energy of MHX molecule on N80 steel surface was-7.59 eV,which could effectively replace H_(2)O molecule and adsorb on the metal surface,thus playing a role in corrosion inhibition.