Mannich碱及其复配体系在磷酸介质中的缓蚀性

Corrosion inhibition property study of mannich alkali and its combinational system in phosphoric acid medium.

为解决磷酸酸化过程中的腐蚀问题,通过胺甲基化反应合成一种曼尼希(M ann ich)碱DS-3,采用静态挂片失重法测定了DS-3及其复配体系在磷酸介质中的缓蚀作用,用电化学方法和扫描电镜(SME)分别对M an-n ich碱体系在磷酸介质中的缓蚀机理以及N80试片腐蚀前后表面状态的变化进行了分析。结果表明,在磷酸介质中,DS-3和少量硫脲衍生物A复配可产生良好的缓蚀协同作用。90℃时,在15%磷酸中加入质量分数为0.25%的复配体系,腐蚀速率为0.82 g/(m2.h),缓蚀率大于99%;电化学分析认为,M ann ich碱DS-3及其复配体系都是以抑制阳极腐蚀过程为主的混合型缓蚀剂;SME观察,磷酸中加入DS-3复配体系后,腐蚀试片表面形成了致密、均匀的吸附膜。

To solve the corrosion in phosphoric acidizing,a kind of mannich alkali,DS-3,was developed by aminomethylation reaction.The corrosion inhibition effect of this alkali and its combinational system in phosphoric acid medium was measured by static weight loss measurement.Its corrosion inhibition mechanism was investigated by electrochemistry and SEM.The surface state change of N80 testing material before and after corrosion was analyzed.The study indicates that the combinational system of DS-3 and a kind of thiourea derivative show good conspiracy in corrosion inhibition in the environment of phosphoric acid medium.0.25% combinational system was added in 15% phosphoric acid at 90 ℃,and the corrosive rate was 0.82 g/(m^2·h),anticorrosion efficiency of this combinational system was over 99%.Electrochemistry study manifests DS3 and its combinational system reacted by restraining anode corrosion process.Observation from SEM shows a tight and even layer of absorption film is formed on the surface of the testing material when DS-3 combinational system is added into phosphoric acid.